Enteric and indicator virus removal by surface flow wetlands.

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Rachmadi, Andri T; Kitajima, Masaaki; Pepper, Ian L; Gerba, Charles P

2016-01-15

We investigated the occurrence and attenuation of several human enteric viruses (i.e., norovirus, adenovirus, Aichi virus 1, polyomaviruses, and enterovirus) as well as a plant virus, pepper mild mottle virus (PMMoV), at two surface flow wetlands in Arizona. The retention time in one of the wetlands was seven days, whereas in the other wetland it could not be defined. Water samples were collected at the inlet and outlet from the wetlands over nine months, and concentration of viral genomes was determined by quantitative polymerase chain reaction (qPCR). Of the human enteric viruses tested, adenovirus and Aichi virus 1 were found in the greatest prevalence in treated wastewater (i.e., inlet of the wetlands). Reduction efficiencies of enteric viruses by the wetlands ranged from 1 to 3 log10. Polyomaviruses were generally removed to below detection limit, indicating at least 2 to 4 log10 removal. PMMoV was detected in a greater concentration in the inlet of both wetlands for all the viruses tested (10(4) to 10(7) genome copies/L), but exhibited little or no removal (1 log10 or less). To determine the factors associated with virus genome attenuation (as determined by qPCR), the persistence of PMMoV and poliovirus type 1 (an enterovirus) was studied in autoclaved and natural wetland water, and deionized water incubated under three different temperatures for 21 days. A combination of elevated water temperature and biological activities reduced poliovirus by 1 to 4 log10, while PMMoV was not significantly reduced during this time period. Overall, PMMoV showed much greater persistence than human viruses in the wetland treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Infection and Replication of Influenza Virus at the Ocular Surface.

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Creager, Hannah M; Kumar, Amrita; Zeng, Hui; Maines, Taronna R; Tumpey, Terrence M; Belser, Jessica A

2018-04-01

Although influenza viruses typically cause respiratory tract disease, some viruses, particularly those with an H7 hemagglutinin, have been isolated from the eyes of conjunctivitis cases. Previous work has shown that isolates of multiple subtypes from both ocular and respiratory infections are capable of replication in human ex vivo ocular tissues and corneal or conjunctival cell monolayers, leaving the determinants of ocular tropism unclear. Here, we evaluated the effect of several variables on tropism for ocular cells cultured in vitro and examined the potential effect of the tear film on viral infectivity. All viruses tested were able to replicate in primary human corneal epithelial cell monolayers subjected to aerosol inoculation. The temperature at which cells were cultured postinoculation minimally affected infectivity. Replication efficiency, in contrast, was reduced at 33°C relative to that at 37°C, and this effect was slightly greater for the conjunctivitis isolates than for the respiratory ones. With the exception of a seasonal H3N2 virus, the subset of viruses studied in multilayer corneal tissue constructs also replicated productively after either aerosol or liquid inoculation. Human tears significantly inhibited the hemagglutination of both ocular and nonocular isolates, but the effect on viral infectivity was more variable, with tears reducing the infectivity of nonocular isolates more than ocular isolates. These data suggest that most influenza viruses may be capable of establishing infection if they reach the surface of ocular cells but that this is more likely for ocular-tropic viruses, as they are better able to maintain their infectivity during passage through the tear film. IMPORTANCE The potential spread of zoonotic influenza viruses to humans represents an important threat to public health. Unfortunately, despite the importance of cellular and tissue tropism to pathogenesis, determinants of influenza virus tropism have yet to be fully

Circulating avian influenza viruses closely related to the 1918 virus have pandemic potential

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Watanabe, Tokiko; Zhong, Gongxun; Russell, Colin A.; Nakajima, Noriko; Hatta, Masato; Hanson, Anthony; McBride, Ryan; Burke, David F.; Takahashi, Kenta; Fukuyama, Satoshi; Tomita, Yuriko; Maher, Eileen A.; Watanabe, Shinji; Imai, Masaki; Neumann, Gabriele; Hasegawa, Hideki; Paulson, James C.; Smith, Derek J.; Kawaoka, Yoshihiro

2014-01-01

Summary Wild birds harbor a large gene pool of influenza A viruses that have the potential to cause influenza pandemics. Foreseeing and understanding this potential is important for effective surveillance. Our phylogenetic and geographic analyses revealed the global prevalence of avian influenza virus genes whose proteins differ only a few amino acids from the 1918 pandemic influenza virus, suggesting that 1918-like pandemic viruses may emerge in the future. To assess this risk, we generated and characterized a virus composed of avian influenza viral segments with high homology to the 1918 virus. This virus exhibited higher pathogenicity in mice and ferrets than an authentic avian influenza virus. Further, acquisition of seven amino acid substitutions in the viral polymerases and the hemagglutinin surface glycoprotein conferred respiratory droplet transmission to the 1918-like avian virus in ferrets, demonstrating that contemporary avian influenza viruses with 1918 virus-like proteins may have pandemic potential. PMID:24922572

Large-scale FMO-MP3 calculations on the surface proteins of influenza virus, hemagglutinin (HA) and neuraminidase (NA)

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Mochizuki, Yuji; Yamashita, Katsumi; Fukuzawa, Kaori; Takematsu, Kazutomo; Watanabe, Hirofumi; Taguchi, Naoki; Okiyama, Yoshio; Tsuboi, Misako; Nakano, Tatsuya; Tanaka, Shigenori

2010-06-01

Two proteins on the influenza virus surface have been well known. One is hemagglutinin (HA) associated with the infection to cells. The fragment molecular orbital (FMO) calculations were performed on a complex consisting of HA trimer and two Fab-fragments at the third-order Møller-Plesset perturbation (MP3) level. The numbers of residues and 6-31G basis functions were 2351 and 201276, and thus a massively parallel-vector computer was utilized to accelerate the processing. This FMO-MP3 job was completed in 5.8 h with 1024 processors. Another protein is neuraminidase (NA) involved in the escape from infected cells. The FMO-MP3 calculation was also applied to analyze the interactions between oseltamivir and surrounding residues in pharmacophore.

Phylogenetic and evolutionary history of influenza B viruses, which caused a large epidemic in 2011-2012, Taiwan.

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Ji-Rong Yang

Full Text Available The annual recurrence of the influenza epidemic is considered to be primarily associated with immune escape due to changes to the virus. In 2011-2012, the influenza B epidemic in Taiwan was unusually large, and influenza B was predominant for a long time. To investigate the genetic dynamics of influenza B viruses during the 2011-2012 epidemic, we analyzed the sequences of 4,386 influenza B viruses collected in Taiwan from 2004 to 2012. The data provided detailed insight into the flux patterns of multiple genotypes. We found that a re-emergent TW08-I virus, which was the major genotype and had co-circulated with the two others, TW08-II and TW08-III, from 2007 to 2009 in Taiwan, successively overtook TW08-II in March and then underwent a lineage switch in July 2011. This lineage switch was followed by the large epidemic in Taiwan. The whole-genome compositions and phylogenetic relationships of the representative viruses of various genotypes were compared to determine the viral evolutionary histories. We demonstrated that the large influenza B epidemic of 2011-2012 was caused by Yamagata lineage TW08-I viruses that were derived from TW04-II viruses in 2004-2005 through genetic drifts without detectable reassortments. The TW08-I viruses isolated in both 2011-2012 and 2007-2009 were antigenically similar, indicating that an influenza B virus have persisted for 5 years in antigenic stasis before causing a large epidemic. The results suggest that in addition to the emergence of new variants with mutations or reassortments, other factors, including the interference of multi-types or lineages of influenza viruses and the accumulation of susceptible hosts, can also affect the scale and time of an influenza B epidemic.

Exploring nucleo-cytoplasmic large DNA viruses in Tara Oceans microbial metagenomes.

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Hingamp, Pascal; Grimsley, Nigel; Acinas, Silvia G; Clerissi, Camille; Subirana, Lucie; Poulain, Julie; Ferrera, Isabel; Sarmento, Hugo; Villar, Emilie; Lima-Mendez, Gipsi; Faust, Karoline; Sunagawa, Shinichi; Claverie, Jean-Michel; Moreau, Hervé; Desdevises, Yves; Bork, Peer; Raes, Jeroen; de Vargas, Colomban; Karsenti, Eric; Kandels-Lewis, Stefanie; Jaillon, Olivier; Not, Fabrice; Pesant, Stéphane; Wincker, Patrick; Ogata, Hiroyuki

2013-09-01

Nucleo-cytoplasmic large DNA viruses (NCLDVs) constitute a group of eukaryotic viruses that can have crucial ecological roles in the sea by accelerating the turnover of their unicellular hosts or by causing diseases in animals. To better characterize the diversity, abundance and biogeography of marine NCLDVs, we analyzed 17 metagenomes derived from microbial samples (0.2-1.6 μm size range) collected during the Tara Oceans Expedition. The sample set includes ecosystems under-represented in previous studies, such as the Arabian Sea oxygen minimum zone (OMZ) and Indian Ocean lagoons. By combining computationally derived relative abundance and direct prokaryote cell counts, the abundance of NCLDVs was found to be in the order of 10(4)-10(5) genomes ml(-1) for the samples from the photic zone and 10(2)-10(3) genomes ml(-1) for the OMZ. The Megaviridae and Phycodnaviridae dominated the NCLDV populations in the metagenomes, although most of the reads classified in these families showed large divergence from known viral genomes. Our taxon co-occurrence analysis revealed a potential association between viruses of the Megaviridae family and eukaryotes related to oomycetes. In support of this predicted association, we identified six cases of lateral gene transfer between Megaviridae and oomycetes. Our results suggest that marine NCLDVs probably outnumber eukaryotic organisms in the photic layer (per given water mass) and that metagenomic sequence analyses promise to shed new light on the biodiversity of marine viruses and their interactions with potential hosts.

Systematic CpT (ApG) Depletion and CpG Excess Are Unique Genomic Signatures of Large DNA Viruses Infecting Invertebrates

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Upadhyay, Mohita; Sharma, Neha; Vivekanandan, Perumal

2014-01-01

Differences in the relative abundance of dinucleotides, if any may provide important clues on host-driven evolution of viruses. We studied dinucleotide frequencies of large DNA viruses infecting vertebrates (n = 105; viruses infecting mammals = 99; viruses infecting aves = 6; viruses infecting reptiles = 1) and invertebrates (n = 88; viruses infecting insects = 84; viruses infecting crustaceans = 4). We have identified systematic depletion of CpT(ApG) dinucleotides and over-representation of CpG dinucleotides as the unique genomic signature of large DNA viruses infecting invertebrates. Detailed investigation of this unique genomic signature suggests the existence of invertebrate host-induced pressures specifically targeting CpT(ApG) and CpG dinucleotides. The depletion of CpT dinucleotides among large DNA viruses infecting invertebrates is at least in part, explained by non-canonical DNA methylation by the infected host. Our findings highlight the role of invertebrate host-related factors in shaping virus evolution and they also provide the necessary framework for future studies on evolution, epigenetics and molecular biology of viruses infecting this group of hosts. PMID:25369195

Endothelial Targeting of Cowpea Mosaic Virus (CPMV) via Surface Vimentin

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Koudelka, Kristopher J.; Destito, Giuseppe; Plummer, Emily M.; Trauger, Sunia A.; Siuzdak, Gary; Manchester, Marianne

2009-01-01

Cowpea mosaic virus (CPMV) is a plant comovirus in the picornavirus superfamily, and is used for a wide variety of biomedical and material science applications. Although its replication is restricted to plants, CPMV binds to and enters mammalian cells, including endothelial cells and particularly tumor neovascular endothelium in vivo. This natural capacity has lead to the use of CPMV as a sensor for intravital imaging of vascular development. Binding of CPMV to endothelial cells occurs via interaction with a 54 kD cell-surface protein, but this protein has not previously been identified. Here we identify the CPMV binding protein as a cell-surface form of the intermediate filament vimentin. The CPMV-vimentin interaction was established using proteomic screens and confirmed by direct interaction of CPMV with purified vimentin, as well as inhibition in a vimentin-knockout cell line. Vimentin and CPMV were also co-localized in vascular endothelium of mouse and rat in vivo. Together these studies indicate that surface vimentin mediates binding and may lead to internalization of CPMV in vivo, establishing surface vimentin as an important vascular endothelial ligand for nanoparticle targeting to tumors. These results also establish vimentin as a ligand for picornaviruses in both the plant and animal kingdoms of life. Since bacterial pathogens and several other classes of viruses also bind to surface vimentin, these studies suggest a common role for surface vimentin in pathogen transmission. PMID:19412526

Endothelial targeting of cowpea mosaic virus (CPMV via surface vimentin.

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Kristopher J Koudelka

2009-05-01

Full Text Available Cowpea mosaic virus (CPMV is a plant comovirus in the picornavirus superfamily, and is used for a wide variety of biomedical and material science applications. Although its replication is restricted to plants, CPMV binds to and enters mammalian cells, including endothelial cells and particularly tumor neovascular endothelium in vivo. This natural capacity has lead to the use of CPMV as a sensor for intravital imaging of vascular development. Binding of CPMV to endothelial cells occurs via interaction with a 54 kD cell-surface protein, but this protein has not previously been identified. Here we identify the CPMV binding protein as a cell-surface form of the intermediate filament vimentin. The CPMV-vimentin interaction was established using proteomic screens and confirmed by direct interaction of CPMV with purified vimentin, as well as inhibition in a vimentin-knockout cell line. Vimentin and CPMV were also co-localized in vascular endothelium of mouse and rat in vivo. Together these studies indicate that surface vimentin mediates binding and may lead to internalization of CPMV in vivo, establishing surface vimentin as an important vascular endothelial ligand for nanoparticle targeting to tumors. These results also establish vimentin as a ligand for picornaviruses in both the plant and animal kingdoms of life. Since bacterial pathogens and several other classes of viruses also bind to surface vimentin, these studies suggest a common role for surface vimentin in pathogen transmission.

Ebola virus host cell entry.

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Sakurai, Yasuteru

2015-01-01

Ebola virus is an enveloped virus with filamentous structure and causes a severe hemorrhagic fever in human and nonhuman primates. Host cell entry is the first essential step in the viral life cycle, which has been extensively studied as one of the therapeutic targets. A virus factor of cell entry is a surface glycoprotein (GP), which is an only essential viral protein in the step, as well as the unique particle structure. The virus also interacts with a lot of host factors to successfully enter host cells. Ebola virus at first binds to cell surface proteins and internalizes into cells, followed by trafficking through endosomal vesicles to intracellular acidic compartments. There, host proteases process GPs, which can interact with an intracellular receptor. Then, under an appropriate circumstance, viral and endosomal membranes are fused, which is enhanced by major structural changes of GPs, to complete host cell entry. Recently the basic research of Ebola virus infection mechanism has markedly progressed, largely contributed by identification of host factors and detailed structural analyses of GPs. This article highlights the mechanism of Ebola virus host cell entry, including recent findings.

Astrovirology: Viruses at Large in the Universe.

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Berliner, Aaron J; Mochizuki, Tomohiro; Stedman, Kenneth M

2018-02-01

Viruses are the most abundant biological entities on modern Earth. They are highly diverse both in structure and genomic sequence, play critical roles in evolution, strongly influence terran biogeochemistry, and are believed to have played important roles in the origin and evolution of life. However, there is yet very little focus on viruses in astrobiology. Viruses arguably have coexisted with cellular life-forms since the earliest stages of life, may have been directly involved therein, and have profoundly influenced cellular evolution. Viruses are the only entities on modern Earth to use either RNA or DNA in both single- and double-stranded forms for their genetic material and thus may provide a model for the putative RNA-protein world. With this review, we hope to inspire integration of virus research into astrobiology and also point out pressing unanswered questions in astrovirology, particularly regarding the detection of virus biosignatures and whether viruses could be spread extraterrestrially. We present basic virology principles, an inclusive definition of viruses, review current virology research pertinent to astrobiology, and propose ideas for future astrovirology research foci. Key Words: Astrobiology-Virology-Biosignatures-Origin of life-Roadmap. Astrobiology 18, 207-223.

Dengue virus-like particles mimic the antigenic properties of the infectious dengue virus envelope.

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Metz, Stefan W; Thomas, Ashlie; White, Laura; Stoops, Mark; Corten, Markus; Hannemann, Holger; de Silva, Aravinda M

2018-04-02

The 4 dengue serotypes (DENV) are mosquito-borne pathogens that are associated with severe hemorrhagic disease. DENV particles have a lipid bilayer envelope that anchors two membrane glycoproteins prM and E. Two E-protein monomers form head-to-tail homodimers and three E-dimers align to form "rafts" that cover the viral surface. Some human antibodies that strongly neutralize DENV bind to quaternary structure epitopes displayed on E protein dimers or higher order structures forming the infectious virus. Expression of prM and E in cell culture leads to the formation of DENV virus-like particles (VLPs) which are smaller than wildtype virus particles and replication defective due to the absence of a viral genome. There is no data available that describes the antigenic landscape on the surface of flavivirus VLPs in comparison to the better studied infectious virion. A large panel of well characterized antibodies that recognize epitope of ranging complexity were used in biochemical analytics to obtain a comparative antigenic surface view of VLPs in respect to virus particles. DENV patient serum depletions were performed the show the potential of VLPs in serological diagnostics. VLPs were confirmed to be heterogeneous in size morphology and maturation state. Yet, we show that many highly conformational and quaternary structure-dependent antibody epitopes found on virus particles are efficiently displayed on DENV1-4 VLP surfaces as well. Additionally, DENV VLPs can efficiently be used as antigens to deplete DENV patient sera from serotype specific antibody populations. This study aids in further understanding epitopic landscape of DENV VLPs and presents a comparative antigenic surface view of VLPs in respect to virus particles. We propose the use VLPs as a safe and practical alternative to infectious virus as a vaccine and diagnostic antigen.

Two separable functional domains of simian virus 40 large T antigen: carboxyl-terminal region of simian virus 40 large T antigen is required for efficient capsid protein synthesis.

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Tornow, J; Polvino-Bodnar, M; Santangelo, G; Cole, C N

1985-01-01

The carboxyl-terminal portion of simian virus 40 large T antigen is essential for productive infection of CV-1 and CV-1p green monkey kidney cells. Mutant dlA2459, lacking 14 base pairs at 0.193 map units, was positive for viral DNA replication, but unable to form plaques in CV-1p cells (J. Tornow and C.N. Cole, J. Virol. 47:487-494, 1983). In this report, the defect of dlA2459 is further defined. Simian virus 40 late mRNAs were transcribed, polyadenylated, spliced, and transported in dlA2459-infected cells, but the level of capsid proteins produced in infected CV-1 green monkey kidney cells was extremely low. dlA2459 large T antigen lacks those residues known to be required for adenovirus helper function, and the block to productive infection by dlA2459 occurs at the same stage of infection as the block to productive adenovirus infection of CV-1 cells. These results suggest that the adenovirus helper function is required for productive infection by simian virus 40. Mutant dlA2459 was able to grow on the Vero and BSC-1 lines of African green monkey kidney cells. Additional mutants affecting the carboxyl-terminal portion of large T were prepared. Mutant inv2408 contains an inversion of the DNA between the BamHI and BclI sites (0.144 to 0.189 map units). This inversion causes transposition of the carboxyl-terminal 26 amino acids of large T antigen and the carboxyl-terminal 18 amino acids of VP1. This mutant was viable, even though the essential information absent from dlA2459 large T antigen has been transferred to the carboxyl terminus of VP1 of inv2408. The VP1 polypeptide carrying this carboxyl-terminal portion of large T could overcome the defect of dlA2459. This indicates that the carboxyl terminus of large T antigen is a separate and separable functional domain. Images PMID:2982029

Inactivation of Avian Influenza Viruses on Porous and Non-porous Surfaces is Enhanced by Elevating Absolute Humidity.

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Guan, J; Chan, M; VanderZaag, A

2017-08-01

This study was to evaluate the effect of absolute humidity (AH), a combined factor of temperature and relative humidity (RH), on inactivation of avian influenza viruses (AIVs) on surfaces. Suspensions of the H9N2 or H6N2 AIV were deposited onto carrier surfaces that were either porous (pine wood) or non-porous (stainless steel, synthetic rubber and glass). The inoculated carriers were incubated at 23, 35 or 45°C with 25% or 55% RH for up to 28 days. After incubation, virus was recovered and quantified by chicken embryo assays. The time required to obtain a log 10 reduction in virus infectivity (D-value) was estimated using a linear regression model. At AH of 5.2 g/m 3 (23°C & 25% RH), both viruses survived up to 14 days on the porous surface and for at least 28 days on the non-porous surfaces. The corresponding D-values for H9N2 and H6N2 were 1.49 and 6.90 days on the porous surface and 7.81 and 12.5 days on the non-porous surfaces, respectively. In comparison, at AH of 9.9 g/m 3 (35°C & 25% RH) or 11.3 g/m 3 (23°C & 55% RH), the D-values for H9N2 and H6N2 dropped to ≤0.76 day on the porous surface and to ≤1.81 days on the non-porous surfaces. As the AH continued to rise from 11.3 to 36.0 g/m 3 , the D-value for both viruses decreased further. The relationship between D-value and AH followed a form of y = ax -b for both viruses. The D-values for H9N2 virus were significantly lower (P < 0.05) than those for H6N2 virus. Exposure to ammonia gas at concentrations of 86 and 173 ppm did not significantly alter test results. The findings give evidence that increasing the AH in poultry buildings following an outbreak of disease could greatly reduce the length of time required for their decontamination. © Her Majesty the Queen in Right of Canada 2016.

Chemical disinfection of non-porous inanimate surfaces experimentally contaminated with four human pathogenic viruses.

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Sattar, S. A.; Springthorpe, V. S.; Karim, Y.; Loro, P.

1989-01-01

The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were...

Maintenance of influenza virus infectivity on the surfaces of personal protective equipment and clothing used in healthcare settings.

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Sakaguchi, Hiroko; Wada, Koji; Kajioka, Jitsuo; Watanabe, Mayumi; Nakano, Ryuichi; Hirose, Tatsuko; Ohta, Hiroshi; Aizawa, Yoshiharu

2010-11-01

The maintenance of infectivity of influenza viruses on the surfaces of personal protective equipment and clothing is an important factor in terms of controlling viral cross-infection in the environment and preventing contact infection. The aim of this study was to determine if laboratory-grown influenza A (H1N1) virus maintained infectivity on the surfaces of personal protective equipment and clothing used in healthcare settings. Influenza A virus (0.5 mL) was deposited on the surface of a rubber glove, an N95 particulate respirator, a surgical mask made of non-woven fabric, a gown made of Dupont Tyvek, a coated wooden desk, and stainless steel. Each sample was left for 1, 8, and 24 h, and hemagglutination (HA) and 50% tissue culture infective dose (TCID(50))/mL were measured. The HA titer of this influenza A virus did not decrease in any of the materials tested even after 24 h. The infectivity of influenza A virus measured by TCID(50) was maintained for 8 h on the surface of all materials, with the exception of the rubber glove for which virus infectivity was maintained for 24 h. Our results indicate that the replacement/renewal of personal protective equipment and clothing by healthcare professionals in cases of exposure to secretions and droplets containing viruses spread by patients is an appropriate procedure to prevent cross-infection.

Efficient purification and concentration of viruses from a large body of high turbidity seawater.

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Sun, Guowei; Xiao, Jinzhou; Wang, Hongming; Gong, Chaowen; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

2014-01-01

Marine viruses are the most abundant entities in the ocean and play crucial roles in the marine ecological system. However, understanding of viral diversity on large scale depends on efficient and reliable viral purification and concentration techniques. Here, we report on developing an efficient method to purify and concentrate viruses from large body of high turbidity seawater. The developed method characterizes with high viral recovery efficiency, high concentration factor, high viral particle densities and high-throughput, and is reliable for viral concentration from high turbidity seawater. Recovered viral particles were used directly for subsequent analysis by epifluorescence microscopy, transmission electron microscopy and metagenomic sequencing. Three points are essential for this method:•The sampled seawater (>150 L) was initially divided into two parts, water fraction and settled matter fraction, after natural sedimentation.•Both viruses in the water fraction concentrated by tangential flow filtration (TFF) and viruses isolated from the settled matter fraction were considered as the whole viral community in high turbidity seawater.•The viral concentrates were re-concentrated by using centrifugal filter device in order to obtain high density of viral particles.

Virus-host interactions: insights from the replication cycle of the large Paramecium bursaria chlorella virus.

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Milrot, Elad; Mutsafi, Yael; Fridmann-Sirkis, Yael; Shimoni, Eyal; Rechav, Katya; Gurnon, James R; Van Etten, James L; Minsky, Abraham

2016-01-01

The increasing interest in cytoplasmic factories generated by eukaryotic-infecting viruses stems from the realization that these highly ordered assemblies may contribute fundamental novel insights to the functional significance of order in cellular biology. Here, we report the formation process and structural features of the cytoplasmic factories of the large dsDNA virus Paramecium bursaria chlorella virus 1 (PBCV-1). By combining diverse imaging techniques, including scanning transmission electron microscopy tomography and focused ion beam technologies, we show that the architecture and mode of formation of PBCV-1 factories are significantly different from those generated by their evolutionary relatives Vaccinia and Mimivirus. Specifically, PBCV-1 factories consist of a network of single membrane bilayers acting as capsid templates in the central region, and viral genomes spread throughout the host cytoplasm but excluded from the membrane-containing sites. In sharp contrast, factories generated by Mimivirus have viral genomes in their core, with membrane biogenesis region located at their periphery. Yet, all viral factories appear to share structural features that are essential for their function. In addition, our studies support the notion that PBCV-1 infection, which was recently reported to result in significant pathological outcomes in humans and mice, proceeds through a bacteriophage-like infection pathway. © 2015 John Wiley & Sons Ltd.

Hepatitis B virus surface antigen impairs myeloid dendritic cell function: a possible immune escape mechanism of hepatitis B virus

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Op den Brouw, Marjoleine L; Binda, Rekha S; van Roosmalen, Mark H; Protzer, Ulrike; Janssen, Harry L A; van der Molen, Renate G; Woltman, Andrea M

2009-01-01

Chronic hepatitis B virus (HBV) infection is the result of an inadequate immune response towards the virus. Myeloid dendritic cells (mDC) of patients with chronic HBV are impaired in their maturation and function, resulting in more tolerogenic rather than immunogenic responses, which may contribute to viral persistence. The mechanism responsible for altered mDC function remains unclear. The HBV-infected patients display large amounts of HBV particles and viral proteins in their circulation, especially the surface antigen HBsAg, which allows multiple interactions between the virus, its viral proteins and DC. To assess whether HBV directly influences mDC function, the effects of HBV and HBsAg on human mDC maturation and function were investigated in vitro. As already described for internalization of HBV by DC, the present study shows that peripheral blood-derived mDC of healthy controls also actively take up HBsAg in a time-dependent manner. Cytokine-induced maturation in the presence of HBV or HBsAg resulted in a significantly more tolerogenic mDC phenotype as demonstrated by a diminished up-regulation of costimulatory molecules and a decreased T-cell stimulatory capacity, as assessed by T-cell proliferation and interferon-γ production. In addition, the presence of HBV significantly reduced interleukin-12 production by mDC. These results show that both HBV particles and purified HBsAg have an immune modulatory capacity and may directly contribute to the dysfunction of mDC in patients with chronic HBV. The direct immune regulatory effect of HBV and circulating HBsAg particles on the function of DC can be considered as part of the mechanism by which HBV escapes immunity. PMID:18624732

Molecular Characterizations of Surface Proteins Hemagglutinin and Neuraminidase from Recent H5Nx Avian Influenza Viruses

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Yang, Hua; Carney, Paul J.; Mishin, Vasiliy P.; Guo, Zhu; Chang, Jessie C.; Wentworth, David E.; Gubareva, Larisa V.; Stevens, James; Schultz-Cherry, S.

2016-04-06

During 2014, a subclade 2.3.4.4 highly pathogenic avian influenza (HPAI) A(H5N8) virus caused poultry outbreaks around the world. In late 2014/early 2015, the virus was detected in wild birds in Canada and the United States, and these viruses also gave rise to reassortant progeny, composed of viral RNA segments (vRNAs) from both Eurasian and North American lineages. In particular, viruses were found with N1, N2, and N8 neuraminidase vRNAs, and these are collectively referred to as H5Nx viruses. In the United States, more than 48 million domestic birds have been affected. Here we present a detailed structural and biochemical analysis of the surface antigens of H5N1, H5N2, and H5N8 viruses in addition to those of a recent human H5N6 virus. Our results with recombinant hemagglutinin reveal that these viruses have a strict avian receptor binding preference, while recombinantly expressed neuraminidases are sensitive to FDA-approved and investigational antivirals. Although H5Nx viruses currently pose a low risk to humans, it is important to maintain surveillance of these circulating viruses and to continually assess future changes that may increase their pandemic potential.

IMPORTANCEThe H5Nx viruses emerging in North America, Europe, and Asia pose a great public health concern. Here we report a molecular and structural study of the major surface proteins of several H5Nx influenza viruses. Our results improve the understanding of these new viruses and provide important information on their receptor preferences and susceptibilities to antivirals, which are central to pandemic risk assessment.

Symbiotic virus at the evolutionary intersection of three types of large DNA viruses; iridoviruses, ascoviruses, and ichnoviruses.

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Yves Bigot

Full Text Available BACKGROUND: The ascovirus, DpAV4a (family Ascoviridae, is a symbiotic virus that markedly increases the fitness of its vector, the parasitic ichneumonid wasp, Diadromus puchellus, by increasing survival of wasp eggs and larvae in their lepidopteran host, Acrolepiopsis assectella. Previous phylogenetic studies have indicated that DpAV4a is related to the pathogenic ascoviruses, such as the Spodoptera frugiperda ascovirus 1a (SfAV1a and the lepidopteran iridovirus (family Iridoviridae, Chilo iridescent virus (CIV, and is also likely related to the ancestral source of certain ichnoviruses (family Polydnaviridae. METHODOLOGY/PRINCIPAL FINDINGS: To clarify the evolutionary relationships of these large double-stranded DNA viruses, we sequenced the genome of DpAV4a and undertook phylogenetic analyses of the above viruses and others, including iridoviruses pathogenic to vertebrates. The DpAV4a genome consisted of 119,343 bp and contained at least 119 open reading frames (ORFs, the analysis of which confirmed the relatedness of this virus to iridoviruses and other ascoviruses. CONCLUSIONS: Analyses of core DpAV4a genes confirmed that ascoviruses and iridoviruses are evolutionary related. Nevertheless, our results suggested that the symbiotic DpAV4a had a separate origin in the iridoviruses from the pathogenic ascoviruses, and that these two types shared parallel evolutionary paths, which converged with respect to virion structure (icosahedral to bacilliform, genome configuration (linear to circular, and cytopathology (plasmalemma blebbing to virion-containing vesicles. Our analyses also revealed that DpAV4a shared more core genes with CIV than with other ascoviruses and iridoviruses, providing additional evidence that DpAV4a represents a separate lineage. Given the differences in the biology of the various iridoviruses and ascoviruses studied, these results provide an interesting model for how viruses of different families evolved from one another.

Genetically distant American Canine distemper virus lineages have recently caused epizootics with somewhat different characteristics in raccoons living around a large suburban zoo in the USA

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Lednicky, John A; Dubach, Jean; Kinsel, Michael J; Meehan, Thomas P; Bocchetta, Maurizio; Hungerford, Laura L; Sarich, Nicolene A; Witecki, Kelley E; Braid, Michael D; Pedrak, Casandra; Houde, Christiane M

2004-01-01

Background Mortality rates have differed during distemper outbreaks among free-ranging raccoons (Procyon lotor) living around a large Chicago-area zoo, and appeared higher in year 2001 than in 1998 and 2000. We hypothesized that a more lethal variant of the local Canine distemper virus (CDV) lineage had emerged in 2001, and sought the genetic basis that led to increased virulence. However, a more complex model surfaced during preliminary analyses of CDV genomic sequences in infected tissues and of virus isolated in vitro from the raccoons. Results Phylogenetic analyses of subgenomic CDV fusion (F) -, phosphoprotein (P) -, and complete hemagglutinin (H) – gene sequences indicated that distinct American CDV lineages caused the distemper epizootics. The 1998 outbreak was caused by viruses that are likely from an old CDV lineage that includes CDV Snyder Hill and Lederle, which are CDV strains from the early 1950's. The 2000 and 2001 viruses appear to stem from the lineage of CDV A75/17, which was isolated in the mid 1970's. Only the 2001 viruses formed large syncytia in brain and/or lung tissue, and during primary isolation in-vitro in Vero cells, demonstrating at least one phenotypic property by which they differed from the other viruses. Conclusions Two different American CDV lineages caused the raccoon distemper outbreaks. The 1998 viruses are genetically distant to the 2000/2001 viruses. Since CDV does not cause persistent infections, the cycling of different CDV lineages within the same locale suggests multiple reintroductions of the virus to area raccoons. Our findings establish a precedent for determining whether the perceived differences in mortality rates are actual and attributable in part to inherent differences between CDV strains arising from different CDV lineages. PMID:15507154

Genetically distant American Canine distemper virus lineages have recently caused epizootics with somewhat different characteristics in raccoons living around a large suburban zoo in the USA

Directory of Open Access Journals (Sweden)

Lednicky John A

2004-09-01

Full Text Available Abstract Background Mortality rates have differed during distemper outbreaks among free-ranging raccoons (Procyon lotor living around a large Chicago-area zoo, and appeared higher in year 2001 than in 1998 and 2000. We hypothesized that a more lethal variant of the local Canine distemper virus (CDV lineage had emerged in 2001, and sought the genetic basis that led to increased virulence. However, a more complex model surfaced during preliminary analyses of CDV genomic sequences in infected tissues and of virus isolated in vitro from the raccoons. Results Phylogenetic analyses of subgenomic CDV fusion (F -, phosphoprotein (P -, and complete hemagglutinin (H – gene sequences indicated that distinct American CDV lineages caused the distemper epizootics. The 1998 outbreak was caused by viruses that are likely from an old CDV lineage that includes CDV Snyder Hill and Lederle, which are CDV strains from the early 1950's. The 2000 and 2001 viruses appear to stem from the lineage of CDV A75/17, which was isolated in the mid 1970's. Only the 2001 viruses formed large syncytia in brain and/or lung tissue, and during primary isolation in-vitro in Vero cells, demonstrating at least one phenotypic property by which they differed from the other viruses. Conclusions Two different American CDV lineages caused the raccoon distemper outbreaks. The 1998 viruses are genetically distant to the 2000/2001 viruses. Since CDV does not cause persistent infections, the cycling of different CDV lineages within the same locale suggests multiple reintroductions of the virus to area raccoons. Our findings establish a precedent for determining whether the perceived differences in mortality rates are actual and attributable in part to inherent differences between CDV strains arising from different CDV lineages.

Surface antigen-negative hepatitis B virus infection in Dutch blood donors

NARCIS (Netherlands)

Lieshout-Krikke, R. W.; Molenaar-de Backer, M. W. A.; van Swieten, P.; Zaaijer, H. L.

2014-01-01

Hepatitis B virus (HBV) surface antigen (HBsAg) is a reliable marker for HBV infection, but HBsAg-negative forms of HBV infection occur. The introduction of HBV DNA screening of Dutch blood donors, which were not preselected for absence of HBV core antibodies, enabled the characterization of

Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: Significance of hepatitis B core antibodies screening

International Nuclear Information System (INIS)

Elbedewy, T.A.; Elashtokhy, H.A.; Rabee, E.S.; Kheder, G.E.

2015-01-01

Background: Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies. Aim of the work: To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy. Patients and methods: This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR). Results: Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation. Conclusion: The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

Comparative Genomics of Chrysochromulina Ericina Virus and Other Microalga-Infecting Large DNA Viruses Highlights Their Intricate Evolutionary Relationship with the Established Mimiviridae Family.

Science.gov (United States)

Gallot-Lavallée, Lucie; Blanc, Guillaume; Claverie, Jean-Michel

2017-07-15

Chrysochromulina ericina virus CeV-01B (CeV) was isolated from Norwegian coastal waters in 1998. Its icosahedral particle is 160 nm in diameter and encloses a 474-kb double-stranded DNA (dsDNA) genome. This virus, although infecting a microalga (the haptophyceae Haptolina ericina , formerly Chrysochromulina ericina ), is phylogenetically related to members of the Mimiviridae family, initially established with the acanthamoeba-infecting mimivirus and megavirus as prototypes. This family was later split into two genera ( Mimivirus and Cafeteriavirus ) following the characterization of a virus infecting the heterotrophic stramenopile Cafeteria roenbergensis (CroV). CeV, as well as two of its close relatives, which infect the unicellular photosynthetic eukaryotes Phaeocystis globosa (Phaeocystis globosa virus [PgV]) and Aureococcus anophagefferens (Aureococcus anophagefferens virus [AaV]), are currently unclassified by the International Committee on Viral Taxonomy (ICTV). The detailed comparative analysis of the CeV genome presented here confirms the phylogenetic affinity of this emerging group of microalga-infecting viruses with the Mimiviridae but argues in favor of their classification inside a distinct clade within the family. Although CeV, PgV, and AaV share more common features among them than with the larger Mimiviridae , they also exhibit a large complement of unique genes, attesting to their complex evolutionary history. We identified several gene fusion events and cases of convergent evolution involving independent lateral gene acquisitions. Finally, CeV possesses an unusual number of inteins, some of which are closely related despite being inserted in nonhomologous genes. This appears to contradict the paradigm of allele-specific inteins and suggests that the Mimiviridae are especially efficient in spreading inteins while enlarging their repertoire of homing genes. IMPORTANCE Although it infects the microalga Chrysochromulina ericina , CeV is more closely

Unveiling the role and life strategies of viruses from the surface to the dark ocean

KAUST Repository

Lara, Elena; Vaqué , Dolors; Sà , Elisabet Laia; Boras, Julia A.; Gomes, Ana; Borrull, Encarna; Dí ez-Vives, Cristina; Teira, Eva; Pernice, Massimo C.; Garcia, Francisca C.; Forn, Irene; Castillo, Yaiza M.; Peiró , Aida; Salazar, Guillem; Moran, Xose Anxelu G.; Massana, Ramon; Catalá , Teresa S.; Luna, Gian Marco; Agusti, Susana; Estrada, Marta; Gasol, Josep M M; Duarte, Carlos M.

2017-01-01

Viruses are a key component of marine ecosystems, but the assessment of their global role in regulating microbial communities and the flux of carbon is precluded by a paucity of data, particularly in the deep ocean. We assessed patterns in viral abundance and production and the role of viral lysis as a driver of prokaryote mortality, from surface to bathypelagic layers, across the tropical and subtropical oceans. Viral abundance showed significant differences between oceans in the epipelagic and mesopelagic, but not in the bathypelagic, and decreased with depth, with an average power-law scaling exponent of −1.03 km−1 from an average of 7.76 × 106 viruses ml−1 in the epipelagic to 0.62 × 106 viruses ml−1 in the bathypelagic layer with an average integrated (0 to 4000 m) viral stock of about 0.004 to 0.044 g C m−2, half of which is found below 775 m. Lysogenic viral production was higher than lytic viral production in surface waters, whereas the opposite was found in the bathypelagic, where prokaryotic mortality due to viruses was estimated to be 60 times higher than grazing. Free viruses had turnover times of 0.1 days in the bathypelagic, revealing that viruses in the bathypelagic are highly dynamic. On the basis of the rates of lysed prokaryotic cells, we estimated that viruses release 145 Gt C year−1 in the global tropical and subtropical oceans. The active viral processes reported here demonstrate the importance of viruses in the production of dissolved organic carbon in the dark ocean, a major pathway in carbon cycling.

Unveiling the role and life strategies of viruses from the surface to the dark ocean

KAUST Repository

Lara, Elena

2017-09-07

Viruses are a key component of marine ecosystems, but the assessment of their global role in regulating microbial communities and the flux of carbon is precluded by a paucity of data, particularly in the deep ocean. We assessed patterns in viral abundance and production and the role of viral lysis as a driver of prokaryote mortality, from surface to bathypelagic layers, across the tropical and subtropical oceans. Viral abundance showed significant differences between oceans in the epipelagic and mesopelagic, but not in the bathypelagic, and decreased with depth, with an average power-law scaling exponent of −1.03 km−1 from an average of 7.76 × 106 viruses ml−1 in the epipelagic to 0.62 × 106 viruses ml−1 in the bathypelagic layer with an average integrated (0 to 4000 m) viral stock of about 0.004 to 0.044 g C m−2, half of which is found below 775 m. Lysogenic viral production was higher than lytic viral production in surface waters, whereas the opposite was found in the bathypelagic, where prokaryotic mortality due to viruses was estimated to be 60 times higher than grazing. Free viruses had turnover times of 0.1 days in the bathypelagic, revealing that viruses in the bathypelagic are highly dynamic. On the basis of the rates of lysed prokaryotic cells, we estimated that viruses release 145 Gt C year−1 in the global tropical and subtropical oceans. The active viral processes reported here demonstrate the importance of viruses in the production of dissolved organic carbon in the dark ocean, a major pathway in carbon cycling.

Chemical disinfection of non-porous inanimate surfaces experimentally contaminated with four human pathogenic viruses.

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Sattar, S A; Springthorpe, V S; Karim, Y; Loro, P

1989-06-01

The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were selected for this study based on the findings of an earlier investigation with a human rotavirus. After 1 min exposure to 20 microliters of the disinfectant, the virus from the disks was immediately eluted into tryptose phosphate broth and plaque assayed. Using an efficacy criterion of a 3 log10 or greater reduction in virus infectivity titre and irrespective of the virus suspending medium, only the following five disinfectants proved to be effective against all the four viruses tested: (1) 2% glutaraldehyde normally used as an instrument soak, (2) a strongly alkaline mixture of 0.5% sodium o-benzyl-p-chlorophenate and 0.6% sodium lauryl sulphate, generally used as a domestic disinfectant cleaner for hard surfaces, (3) a 0.04% solution of a quaternary ammonium compound containing 7% hydrochloric acid, which is the basis of many toilet bowl cleaners, (4) chloramine T at a minimum free chlorine level of 3000 p.p.m. and (5) sodium hypochlorite at a minimum free chlorine concentration of 5000 p.p.m. Of those chemicals suitable for use as topical antiseptics, 70% ethanol alone or products containing at least 70% ethanol were ineffective only against coxsackievirus B3. These results emphasize the care needed in selecting chemical disinfectants for routine use in infection control.

Controlled immobilisation of active enzymes on the cowpea mosaic virus capsid

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Aljabali, Alaa A. A.; Barclay, J. Elaine; Steinmetz, Nicole F.; Lomonossoff, George P.; Evans, David J.

2012-08-01

Immobilisation of horseradish peroxidase (HRP) and glucose oxidase (GOX) via covalent attachment of modified enzyme carbohydrate to the exterior of the cowpea mosaic virus (CPMV) capsid gave high retention of enzymatic activity. The number of enzymes bound per virus was determined to be about eleven for HRP and 2-3 for GOX. This illustrates that relatively large biomacromolecules can be readily coupled to the virus surface using simple conjugation strategies. Virus-biomacromolecule hybrids have great potential for uses in catalysis, diagnostic assays or biosensors.Immobilisation of horseradish peroxidase (HRP) and glucose oxidase (GOX) via covalent attachment of modified enzyme carbohydrate to the exterior of the cowpea mosaic virus (CPMV) capsid gave high retention of enzymatic activity. The number of enzymes bound per virus was determined to be about eleven for HRP and 2-3 for GOX. This illustrates that relatively large biomacromolecules can be readily coupled to the virus surface using simple conjugation strategies. Virus-biomacromolecule hybrids have great potential for uses in catalysis, diagnostic assays or biosensors. Electronic supplementary information (ESI) available: Alternative conjugation strategies, agarose gel electrophoresis of CPMV and CPMV-HRP conjugates, UV-vis spectrum of HRP-ADHCPMV, agarose gel electrophoresis of GOX-ADHCPMV particles and corresponding TEM image, calibration curves for HRP-ADHCPMV and GOX-ADHCPMV, DLS data for GOX-ADHCPMV are made available. See DOI: 10.1039/c2nr31485a

Integration of antibody by surface functionalization of graphite-encapsulated magnetic beads using ammonia gas plasma technology for capturing influenza A virus.

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Sakudo, Akikazu; Chou, Han; Ikuta, Kazuyoshi; Nagatsu, Masaaki

2015-05-01

Antibody-integrated magnetic beads have been functionalized for influenza A virus capture. First, ammonia plasma produced by a radio frequency power source was reacted with the surface of graphite-encapsulated magnetic beads to introduce amino groups. Anti-influenza A virus hemagglutinin antibody was then anchored by its surface sulfide groups to the amino groups on the beads via N-succinimidyl 3-(2-pyridyldithio) propionate. After incubation with influenza A virus, adsorption of the virus to the beads was confirmed by immunochromatography, polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and inoculation of chicken embryonated eggs, indicating that virus infectivity is maintained and that the proposed method is useful for the enhanced detection and isolation of influenza A virus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exactly soluble models for surface partition of large clusters

International Nuclear Information System (INIS)

Bugaev, K.A.; Bugaev, K.A.; Elliott, J.B.

2007-01-01

The surface partition of large clusters is studied analytically within a framework of the 'Hills and Dales Model'. Three formulations are solved exactly by using the Laplace-Fourier transformation method. In the limit of small amplitude deformations, the 'Hills and Dales Model' gives the upper and lower bounds for the surface entropy coefficient of large clusters. The found surface entropy coefficients are compared with those of large clusters within the 2- and 3-dimensional Ising models

Nudiviruses and other large, double-stranded circular DNA viruses of invertebrates: new insights on an old topic.

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Wang, Yongjie; Jehle, Johannes A

2009-07-01

Nudiviruses (NVs) are a highly diverse group of large, circular dsDNA viruses pathogenic for invertebrates. They have rod-shaped and enveloped nucleocapsids, replicate in the nucleus of infected host cells, and possess interesting biological and molecular properties. The unassigned viral genus Nudivirus has been proposed for classification of nudiviruses. Currently, the nudiviruses comprise five different viruses: the palm rhinoceros beetle virus (Oryctes rhinoceros NV, OrNV), the Hz-1 virus (Heliothis zea NV-1, HzNV-1), the cricket virus (Gryllus bimaculatus NV, GbNV), the corn earworm moth Hz-2 virus (HzNV-2), and the occluded shrimp Monodon Baculovirus reassigned as Penaeus monodon NV (PmNV). Thus far, the genomes of OrNV, GbNV, HzNV-1 and HzNV-2 have been completely sequenced. They vary between 97 and 230kbp in size and encode between 98 and 160 open reading frames (ORFs). All sequenced nudiviruses have 33 ORFs in common. Strikingly, 20 of them are homologous to baculovirus core genes involved in RNA transcription, DNA replication, virion structural components and other functions. Another nine conserved ORFs are likely associated with DNA replication, repair and recombination, and nucleotide metabolism; one is homologous to baculovirus iap-3 gene; two are nudivirus-specific ORFs of unknown function. Interestingly, one nudivirus ORF is similar to polh/gran gene, encoding occlusion body protein matrix and being conserved in Alpha- Beta- and Gammabaculoviruses. Members of nudiviruses are closely related and form a monophyletic group consisting of two sister clades of OrNV/GbNV and HzNVs/PmNV. It is proposed that nudiviruses and baculoviruses derived from a common ancestor and are evolutionarily related to other large DNA viruses such as the insect-specific salivary gland hypertrophy virus (SGHV) and the marine white spot syndrome virus (WSSV).

Naturally occurring mutations in large surface genes related to occult infection of hepatitis B virus genotype C.

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Hong Kim

Full Text Available Molecular mechanisms related to occult hepatitis B virus (HBV infection, particularly those based on genotype C infection, have rarely been determined thus far in the ongoing efforts to determine infection mechanisms. Therefore, we aim to elucidate the mutation patterns in the surface open reading frame (S ORF underlying occult infections of HBV genotype C in the present study. Nested PCRs were applied to 624 HBV surface antigen (HBsAg negative Korean subjects. Cloning and sequencing of the S ORF gene was applied to 41 occult cases and 40 control chronic carriers. Forty-one (6.6% of the 624 Korean adults with HBsAg-negative serostatus were found to be positive for DNA according to nested PCR tests. Mutation frequencies in the three regions labeled here as preS1, preS2, and S were significantly higher in the occult subjects compared to the carriers in all cases. A total of two types of deletions, preS1 deletions in the start codon and preS2 deletions as well as nine types of point mutations were significantly implicated in the occult infection cases. Mutations within the "a" determinant region in HBsAg were found more frequently in the occult subjects than in the carriers. Mutations leading to premature termination of S ORF were found in 16 occult subjects (39.0% but only in one subject from among the carriers (2.5%. In conclusion, our data suggest that preS deletions, the premature termination of S ORF, and "a" determinant mutations are associated with occult infections of HBV genotype C among a HBsAg-negative population. The novel mutation patterns related to occult infection introduced in the present study can help to broaden our understanding of HBV occult infections.

Varicella Zoster Virus and Large Vessel Vasculitis, the Absence of an Association

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Gary W. Procop

2017-06-01

Full Text Available Objective: It is controversial whether microorganisms play a role in the pathogenesis of large and medium vessel vasculitides (eg, giant cell arteritis [GCA], Takayasu arteritis [TAK] and focal idiopathic aortitis [FIA]. Recent studies have reported the presence of Varicella Zoster Virus (VZV within formalin-fixed, paraffin-embedded temporal arteries and aortas of about three-quarters or more of patients with these conditions, and in a minority of controls. In a prospective study, we sought to confirm these findings using DNA extracted from vessels that were harvested under surgically aseptic conditions and snap frozen. Methods and Results: DNA samples extracted from 11 surgically sterile temporal arteries and 31 surgically sterile thoracic aortas were used in an attempt to identify the vessel-associated VZV genome. Two different validated PCR methods were used. Thirty-one thoracic aorta aneurysm specimens included biopsies from 8 patients with GCA, 2 from patients with TAK, 6 from patients with FIA, and 15 from patients without vasculitis, who had non-inflammatory aneurysms. Eleven temporal artery biopsies were collected from 5 patients with GCA and 6 controls. The presence of VZV was not identified in either the specimens from patients with large vessel vasculitis or from the controls. Conclusions: Using surgically sterile snap-frozen specimens, we were unable to confirm recent reports of the presence of VZV in either aortas or temporal arteries from patients with large vessel vasculitis or controls. Keywords: Aorta and temporal artery biopsies, Varicella Zoster Virus, Large Vessel Vasculitis

Multisubunit DNA-Dependent RNA Polymerases from Vaccinia Virus and Other Nucleocytoplasmic Large-DNA Viruses: Impressions from the Age of Structure.

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Mirzakhanyan, Yeva; Gershon, Paul D

2017-09-01

The past 17 years have been marked by a revolution in our understanding of cellular multisubunit DNA-dependent RNA polymerases (MSDDRPs) at the structural level. A parallel development over the past 15 years has been the emerging story of the giant viruses, which encode MSDDRPs. Here we link the two in an attempt to understand the specialization of multisubunit RNA polymerases in the domain of life encompassing the large nucleocytoplasmic DNA viruses (NCLDV), a superclade that includes the giant viruses and the biochemically well-characterized poxvirus vaccinia virus. The first half of this review surveys the recently determined structural biology of cellular RNA polymerases for a microbiology readership. The second half discusses a reannotation of MSDDRP subunits from NCLDV families and the apparent specialization of these enzymes by virus family and by subunit with regard to subunit or domain loss, subunit dissociability, endogenous control of polymerase arrest, and the elimination/customization of regulatory interactions that would confer higher-order cellular control. Some themes are apparent in linking subunit function to structure in the viral world: as with cellular RNA polymerases I and III and unlike cellular RNA polymerase II, the viral enzymes seem to opt for speed and processivity and seem to have eliminated domains associated with higher-order regulation. The adoption/loss of viral RNA polymerase proofreading functions may have played a part in matching intrinsic mutability to genome size. Copyright © 2017 American Society for Microbiology.

Interactions between protein molecules and the virus removal membrane surface: Effects of immunoglobulin G adsorption and conformational changes on filter performance.

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Hamamoto, Ryo; Ito, Hidemi; Hirohara, Makoto; Chang, Ryongsok; Hongo-Hirasaki, Tomoko; Hayashi, Tomohiro

2018-03-01

Membrane fouling commonly occurs in all filter types during virus filtration in protein-based biopharmaceutical manufacturing. Mechanisms of decline in virus filter performance due to membrane fouling were investigated using a cellulose-based virus filter as a model membrane. Filter performance was critically dependent on solution conditions; specifically, ionic strength. To understand the interaction between immunoglobulin G (IgG) and cellulose, sensors coated with cellulose were fabricated for surface plasmon resonance and quartz crystal microbalance with energy dissipation measurements. The primary cause of flux decline appeared to be irreversible IgG adsorption on the surface of the virus filter membrane. In particular, post-adsorption conformational changes in the IgG molecules promoted further irreversible IgG adsorption, a finding that could not be adequately explained by DLVO theory. Analyses of adsorption and desorption and conformational changes in IgG molecules on cellulose surfaces mimicking cellulose-based virus removal membranes provide an effective approach for identifying ways of optimizing solution conditions to maximize virus filter performance. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:379-386, 2018. © 2017 American Institute of Chemical Engineers.

The presence of Epstein-Barr virus (EBV) in diffuse large B-cell lymphomas (DLBCLs) in Turkey: special emphasis on 'EBV-positive DLBCL of the elderly'.

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Uner, Aysegul; Akyurek, Nalan; Saglam, Arzu; Abdullazade, Samir; Uzum, Nuket; Onder, Sevgen; Barista, Ibrahim; Benekli, Mustafa

2011-04-01

Accumulated evidence has shown the importance of Epstein-Barr virus in the pathogenesis of various lymphomas. This study aimed to determine the prevalence of Epstein-Barr virus expression and its effect on survival amongst diffuse large B-cell lymphoma (DLBCL) cases from two large tertiary care centres in Turkey with a particular interest in identifying cases of 'Epstein-Barr virus-positive DLBCL of the elderly'. Diffuse large B-cell lymphoma cases diagnosed between 1999 and 2009 were retrieved and 340 cases were used to construct tissue microarrays. The presence of Epstein-Barr virus small ribonucleic acids was examined by in situ hybridization using Epstein-Barr virus (EBV)-encoded small RNA (EBER) oligonucleotides. A total of 18 cases (5.3%) showed Epstein-Barr virus expression. Twelve cases were classified as Epstein-Barr virus-positive DLBCL of the elderly. Epstein-Barr virus-positive DLBCL cases showed a significantly inferior overall survival as compared with Epstein-Barr virus-negative cases (p < 0.001). In our study group Epstein-Barr virus expression is not prevalent in DLBCLs. Epstein-Barr virus-positive DLBCL of the elderly is also rare in the Turkish population. The presence of Epstein-Barr virus, however, is associated with poor prognosis. © 2011 The Authors. APMIS © 2011 APMIS.

Active Surface Compensation for Large Radio Telescope Antennas

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Congsi Wang

2018-01-01

Full Text Available With the development of radio telescope antennas with large apertures, high gain, and wide frequency bands, compensation methods, such as mechanical or electronic compensation, are obviously essential to ensure the electrical performance of antennas that work in complex environments. Since traditional compensation methods can only adjust antenna pointing but not the surface accuracy, which are limited for obtaining high surface precision and aperture efficiency, active surface adjustment has become an indispensable tool in this field. Therefore, the development process of electrical performance compensation methods for radio telescope antennas is introduced. Further, a series of analyses of the five key technologies of active surface adjustment is presented. Then, four typical large antennas that have been designed with active main reflector technology are presented and compared. Finally, future research directions and suggestions for reflector antenna compensation methods based on active surface adjustment are presented.

Optimized method for manufacturing large aspheric surfaces

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Zhou, Xusheng; Li, Shengyi; Dai, Yifan; Xie, Xuhui

2007-12-01

Aspheric optics are being used more and more widely in modern optical systems, due to their ability of correcting aberrations, enhancing image quality, enlarging the field of view and extending the range of effect, while reducing the weight and volume of the system. With optical technology development, we have more pressing requirement to large-aperture and high-precision aspheric surfaces. The original computer controlled optical surfacing (CCOS) technique cannot meet the challenge of precision and machining efficiency. This problem has been thought highly of by researchers. Aiming at the problem of original polishing process, an optimized method for manufacturing large aspheric surfaces is put forward. Subsurface damage (SSD), full aperture errors and full band of frequency errors are all in control of this method. Lesser SSD depth can be gained by using little hardness tool and small abrasive grains in grinding process. For full aperture errors control, edge effects can be controlled by using smaller tools and amendment model with material removal function. For full band of frequency errors control, low frequency errors can be corrected with the optimized material removal function, while medium-high frequency errors by using uniform removing principle. With this optimized method, the accuracy of a K9 glass paraboloid mirror can reach rms 0.055 waves (where a wave is 0.6328μm) in a short time. The results show that the optimized method can guide large aspheric surface manufacturing effectively.

Overexpression of human virus surface glycoprotein precursors induces cytosolic unfolded protein response in Saccharomyces cerevisiae

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Sasnauskas Kęstutis

2011-05-01

Full Text Available Abstract Background The expression of human virus surface proteins, as well as other mammalian glycoproteins, is much more efficient in cells of higher eukaryotes rather than yeasts. The limitations to high-level expression of active viral surface glycoproteins in yeast are not well understood. To identify possible bottlenecks we performed a detailed study on overexpression of recombinant mumps hemagglutinin-neuraminidase (MuHN and measles hemagglutinin (MeH in yeast Saccharomyces cerevisiae, combining the analysis of recombinant proteins with a proteomic approach. Results Overexpressed recombinant MuHN and MeH proteins were present in large aggregates, were inactive and totally insoluble under native conditions. Moreover, the majority of recombinant protein was found in immature form of non-glycosylated precursors. Fractionation of yeast lysates revealed that the core of viral surface protein aggregates consists of MuHN or MeH disulfide-linked multimers involving eukaryotic translation elongation factor 1A (eEF1A and is closely associated with small heat shock proteins (sHsps that can be removed only under denaturing conditions. Complexes of large Hsps seem to be bound to aggregate core peripherally as they can be easily removed at high salt concentrations. Proteomic analysis revealed that the accumulation of unglycosylated viral protein precursors results in specific cytosolic unfolded protein response (UPR-Cyto in yeast cells, characterized by different action and regulation of small Hsps versus large chaperones of Hsp70, Hsp90 and Hsp110 families. In contrast to most environmental stresses, in the response to synthesis of recombinant MuHN and MeH, only the large Hsps were upregulated whereas sHsps were not. Interestingly, the amount of eEF1A was also increased during this stress response. Conclusions Inefficient translocation of MuHN and MeH precursors through ER membrane is a bottleneck for high-level expression in yeast. Overexpression of

Virus-mimetic polyplex particles for systemic and inflammation-specific targeted delivery of large genetic contents.

Science.gov (United States)

Kang, S; Lu, K; Leelawattanachai, J; Hu, X; Park, S; Park, T; Min, I M; Jin, M M

2013-11-01

Systemic and target-specific delivery of large genetic contents has been difficult to achieve. Although viruses effortlessly deliver kilobase-long genome into cells, its clinical use has been hindered by serious safety concerns and the mismatch between native tropisms and desired targets. Nonviral vectors, in contrast, are limited by low gene transfer efficiency and inherent cytotoxicity. Here we devised virus-mimetic polyplex particles (VMPs) based on electrostatic self-assembly among polyanionic peptide (PAP), cationic polymer polyethyleneimine (PEI) and nucleic acids. We fused PAP to the engineered ligand-binding domain of integrin αLβ2 to target intercellular adhesion molecule-1 (ICAM-1), an inducible marker of inflammation. Fully assembled VMPs packaged large genetic contents, bound specifically to target molecules, elicited receptor-mediated endocytosis and escaped endosomal pathway, resembling intracellular delivery processes of viruses. Unlike conventional PEI-mediated transfection, molecular interaction-dependent gene delivery of VMPs was unaffected by the presence of serum and achieved higher efficiency without toxicity. By targeting overexpressed ICAM-1, VMPs delivered genes specifically to inflamed endothelial cells and macrophages both in vitro and in vivo. Simplicity and versatility of the platform and inflammation-specific delivery may open up opportunities for multifaceted gene therapy that can be translated into the clinic and treat a broad range of debilitating immune and inflammatory diseases.

Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

Directory of Open Access Journals (Sweden)

Anne Endmann

Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

Virus removal in ceramic depth filters based on diatomaceous earth.

Science.gov (United States)

Michen, Benjamin; Meder, Fabian; Rust, Annette; Fritsch, Johannes; Aneziris, Christos; Graule, Thomas

2012-01-17

Ceramic filter candles, based on the natural material diatomaceous earth, are widely used to purify water at the point-of-use. Although such depth filters are known to improve drinking water quality by removing human pathogenic protozoa and bacteria, their removal regarding viruses has rarely been investigated. These filters have relatively large pore diameters compared to the physical dimension of viruses. However, viruses may be retained by adsorption mechanisms due to intermolecular and surface forces. Here, we use three types of bacteriophages to investigate their removal during filtration and batch experiments conducted at different pH values and ionic strengths. Theoretical models based on DLVO-theory are applied in order to verify experimental results and assess surface forces involved in the adsorptive process. This was done by calculation of interaction energies between the filter surface and the viruses. For two small spherically shaped viruses (MS2 and PhiX174), these filters showed no significant removal. In the case of phage PhiX174, where attractive interactions were expected, due to electrostatic attraction of oppositely charged surfaces, only little adsorption was reported in the presence of divalent ions. Thus, we postulate the existence of an additional repulsive force between PhiX174 and the filter surface. It is hypothesized that such an additional energy barrier originates from either the phage's specific knobs that protrude from the viral capsid, enabling steric interactions, or hydration forces between the two hydrophilic interfaces of virus and filter. However, a larger-sized, tailed bacteriophage of the family Siphoviridae was removed by log 2 to 3, which is explained by postulating hydrophobic interactions.

Association of Paramecium bursaria Chlorella viruses with Paramecium bursaria cells: ultrastructural studies.

Science.gov (United States)

Yashchenko, Varvara V; Gavrilova, Olga V; Rautian, Maria S; Jakobsen, Kjetill S

2012-05-01

Paramecium bursaria Chlorella viruses were observed by applying transmission electron microscopy in the native symbiotic system Paramecium bursaria (Ciliophora, Oligohymenophorea) and the green algae Chlorella (Chlorellaceae, Trebouxiophyceae). Virus particles were abundant and localized in the ciliary pits of the cortex and in the buccal cavity of P. bursaria. This was shown for two types of the symbiotic systems associated with two types of Chlorella viruses - Pbi or NC64A. A novel quantitative stereological approach was applied to test whether virus particles were distributed randomly on the Paramecium surface or preferentially occupied certain zones. The ability of the virus to form an association with the ciliate was investigated experimentally; virus particles were mixed with P. bursaria or with symbiont-free species P. caudatum. Our results confirmed that in the freshwater ecosystems two types of P. bursaria -Chlorella symbiotic systems exist, those without Chlorella viruses and those associated with a large amount of the viruses. The fate of Chlorella virus particles at the Paramecium surface was determined based on obtained statistical data and taking into account ciliate feeding currents and cortical reorganization during cell division. A life cycle of the viruses in the complete symbiotic system is proposed. Copyright © 2011 Elsevier GmbH. All rights reserved.

Surface gene variants of hepatitis B Virus in Saudi Patients.

Science.gov (United States)

Al-Qudari, Ahmed Y; Amer, Haitham M; Abdo, Ayman A; Hussain, Zahid; Al-Hamoudi, Waleed; Alswat, Khalid; Almajhdi, Fahad N

2016-01-01

Hepatitis B virus (HBV) continues to be one of the most important viral pathogens in humans. Surface (S) protein is the major HBV antigen that mediates virus attachment and entry and determines the virus subtype. Mutations in S gene, particularly in the "a" determinant, can influence virus detection by ELISA and may generate escape mutants. Since no records have documented the S gene mutations in HBV strains circulating in Saudi Arabia, the current study was designed to study sequence variation of S gene in strains circulating in Saudi Arabia and its correlation with clinical and risk factors. A total of 123 HBV-infected patients were recruited for this study. Clinical and biochemical parameters, serological markers, and viral load were determined in all patients. The entire S gene sequence of samples with viral load exceeding 2000 IU/mL was retrieved and exploited in sequence and phylogenetic analysis. A total of 48 mutations (21 unique) were recorded in viral strains in Saudi Arabia, among which 24 (11 unique) changed their respective amino acids. Two amino acid changes were recorded in "a" determinant, including F130L and S135F with no evidence of the vaccine escape mutant G145R in any of the samples. No specific relationship was recognized between the mutation/amino acid change record of HBsAg in strains in Saudi Arabia and clinical or laboratory data. Phylogenetic analysis categorized HBV viral strains in Saudi Arabia as members of subgenotypes D1 and D3. The present report is the first that describes mutation analysis of HBsAg in strains in Saudi Arabia on both nucleotide and amino acid levels. Different substitutions, particularly in major hydrophilic region, may have a potential influence on disease diagnosis, vaccination strategy, and antiviral chemotherapy.

Directed Growth of Virus Nanofilaments on a Superhydrophobic Surface

KAUST Repository

Marinaro, Giovanni

2015-06-17

The evaporation of single droplets of colloidal tobacco mosaic virus (TMV) nanoparticles on a superhydrophobic surface with a hexagonal pillar-pattern results in the formation of coffee-ring type residues. We imaged surface features by optical, scanning electron, and atomic force microscopies. Bulk features were probed by raster-scan X-ray nanodiffraction. At ∼100 pg/μL nanoparticle concentration, the rim of the residue connects to neighboring pillars via fibrous extensions containing flow-aligned crystalline domains. At ∼1 pg/μL nanoparticle concentration, nanofilaments of ¥80 nm diameter and ∼20 μm length are formed, extending normal to the residue-rim across a range of pillars. X-ray scattering is dominated by the nanofilament form-factor but some evidence for crystallinity has been obtained. The observation of sheets composed of stacks of self-assembled nanoparticles deposited on pillars suggests that the nanofilaments are drawn from a structured droplet interface. © 2015 American Chemical Society.

Directed Growth of Virus Nanofilaments on a Superhydrophobic Surface

KAUST Repository

Marinaro, Giovanni; Burghammer, Manfred; Costa, Luca; Dane, Thomas; De Angelis, Francesco; Di Fabrizio, Enzo M.; Riekel, Christian

2015-01-01

The evaporation of single droplets of colloidal tobacco mosaic virus (TMV) nanoparticles on a superhydrophobic surface with a hexagonal pillar-pattern results in the formation of coffee-ring type residues. We imaged surface features by optical, scanning electron, and atomic force microscopies. Bulk features were probed by raster-scan X-ray nanodiffraction. At ∼100 pg/μL nanoparticle concentration, the rim of the residue connects to neighboring pillars via fibrous extensions containing flow-aligned crystalline domains. At ∼1 pg/μL nanoparticle concentration, nanofilaments of ¥80 nm diameter and ∼20 μm length are formed, extending normal to the residue-rim across a range of pillars. X-ray scattering is dominated by the nanofilament form-factor but some evidence for crystallinity has been obtained. The observation of sheets composed of stacks of self-assembled nanoparticles deposited on pillars suggests that the nanofilaments are drawn from a structured droplet interface. © 2015 American Chemical Society.

Acute Respiratory Distress Syndrome Caused by Influenza B Virus Infection in a Patient with Diffuse Large B-Cell Lymphoma

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Silvio A. Ñamendys-Silva

2011-01-01

Full Text Available Influenza B virus infections are less common than infections caused by influenza A virus in critically ill patients, but similar mortality rates have been observed for both influenza types. Pneumonia caused by influenza B virus is uncommon and has been reported in pediatric patients and previously healthy adults. Critically ill patients with pneumonia caused by influenza virus may develop acute respiratory distress syndrome. We describe the clinical course of a critically ill patient with diffuse large B-cell lymphoma nongerminal center B-cell phenotype who developed acute respiratory distress syndrome caused by influenza B virus infection. This paper emphasizes the need to suspect influenza B virus infection in critically ill immunocompromised patients with progressive deterioration of cardiopulmonary function despite treatment with antibiotics. Early initiation of neuraminidase inhibitor and the implementation of guidelines for management of severe sepsis and septic shock should be considered.

Enzymatic treatment of duck hepatitis B virus: Topology of the surface proteins for virions and noninfectious subviral particles

International Nuclear Information System (INIS)

Franke, Claudia; Matschl, Urte; Bruns, Michael

2007-01-01

The large surface antigen L of duck hepatitis B virus exhibits a mixed topology with the preS domains of the protein alternatively exposed to the particles' interior or exterior. After separating virions from subviral particles (SVPs), we compared their L topologies and showed that both particle types exhibit the same amount of L with the following differences: 1-preS of intact virions was enzymatically digested with chymotrypsin, whereas in SVPs only half of preS was accessible, 2-phosphorylation of L at S118 was completely removed by phosphatase treatment only in virions, 3-iodine-125 labeling disclosed a higher ratio of exposed preS to S domains in virions compared to SVPs. These data point towards different surface architectures of virions and SVPs. Because the preS domain acts in binding to a cellular receptor of hepatocytes, our findings implicate the exclusion of SVPs as competitors for the receptor binding and entry of virions

Utilisation of ISA Reverse Genetics and Large-Scale Random Codon Re-Encoding to Produce Attenuated Strains of Tick-Borne Encephalitis Virus within Days.

Science.gov (United States)

de Fabritus, Lauriane; Nougairède, Antoine; Aubry, Fabien; Gould, Ernest A; de Lamballerie, Xavier

2016-01-01

Large-scale codon re-encoding is a new method of attenuating RNA viruses. However, the use of infectious clones to generate attenuated viruses has inherent technical problems. We previously developed a bacterium-free reverse genetics protocol, designated ISA, and now combined it with large-scale random codon-re-encoding method to produce attenuated tick-borne encephalitis virus (TBEV), a pathogenic flavivirus which causes febrile illness and encephalitis in humans. We produced wild-type (WT) and two re-encoded TBEVs, containing 273 or 273+284 synonymous mutations in the NS5 and NS5+NS3 coding regions respectively. Both re-encoded viruses were attenuated when compared with WT virus using a laboratory mouse model and the relative level of attenuation increased with the degree of re-encoding. Moreover, all infected animals produced neutralizing antibodies. This novel, rapid and efficient approach to engineering attenuated viruses could potentially expedite the development of safe and effective new-generation live attenuated vaccines.

Predicting Surface Runoff from Catchment to Large Region

Directory of Open Access Journals (Sweden)

Hongxia Li

2015-01-01

Full Text Available Predicting surface runoff from catchment to large region is a fundamental and challenging task in hydrology. This paper presents a comprehensive review for various studies conducted for improving runoff predictions from catchment to large region in the last several decades. This review summarizes the well-established methods and discusses some promising approaches from the following four research fields: (1 modeling catchment, regional and global runoff using lumped conceptual rainfall-runoff models, distributed hydrological models, and land surface models, (2 parameterizing hydrological models in ungauged catchments, (3 improving hydrological model structure, and (4 using new remote sensing precipitation data.

Large optical conductivity of Dirac semimetal Fermi arc surface states

Science.gov (United States)

Shi, Li-kun; Song, Justin C. W.

2017-08-01

Fermi arc surface states, a hallmark of topological Dirac semimetals, can host carriers that exhibit unusual dynamics distinct from that of their parent bulk. Here we find that Fermi arc carriers in intrinsic Dirac semimetals possess a strong and anisotropic light-matter interaction. This is characterized by a large Fermi arc optical conductivity when light is polarized transverse to the Fermi arc; when light is polarized along the Fermi arc, Fermi arc optical conductivity is significantly muted. The large surface spectral weight is locked to the wide separation between Dirac nodes and persists as a large Drude weight of Fermi arc carriers when the system is doped. As a result, large and anisotropic Fermi arc conductivity provides a novel means of optically interrogating the topological surfaces states of Dirac semimetals.

Piston surface heat transfer during combustion in large marine diesel engines

DEFF Research Database (Denmark)

Jensen, Michael Vincent; Walther, Jens Honore

2010-01-01

In the design process of large marine diesel engines information on the maximum heat load on the piston surface experienced during the engine cycle is an important parameter. The peak heat load occurs during combustion when hot combustion products impinge on the piston surface. Although the maximum...... heat load is only present for a short time of the total engine cycle, it is a severe thermal load on the piston surface. At the same time, cooling of the piston crown is generally more complicated than cooling of the other components of the combustion chamber. This can occasionally cause problems...... with burning off piston surface material. In this work the peak heat load on the piston surface of large marine diesel engines during combustion was investigated. Measurements of the instantaneous surface temperature and surface heat flux on pistons in large marine engines are difficult due to expensive...

Multiple surface antigen mutations in five blood donors with occult hepatitis B virus infection

NARCIS (Netherlands)

Zaaijer, H. L.; Torres, P.; Ontañón, A.; Ponte, L. González; Koppelman, M. H. G. M.; Lelie, P. N.; Hemert, F. J. van; Boot, H. J.

2008-01-01

Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA while the HBV surface antigen (HBsAg) remains undetectable. The HBV genomes in five asymptomatic blood donors with occult HBV infection and low viremia ( <10 to 1,000 HBV DNA copies/mL, genotype D) were studied. An

Surface localization of the nuclear receptor CAR in influenza A virus-infected cells

International Nuclear Information System (INIS)

Takahashi, Tadanobu; Moriyama, Yusuke; Ikari, Akira; Sugatani, Junko; Suzuki, Takashi; Miwa, Masao

2008-01-01

Constitutive active/androstane receptor CAR is a member of the nuclear receptors which regulate transcription of xenobiotic metabolism enzymes. CAR is usually localized in the cytosol and nucleus. Here, we found that CAR was localized at the cell surface of influenza A virus (IAV)-infected cells. Additionally, we demonstrated that expression of a viral envelope glycoprotein, either hemagglutinin (HA) or neuraminidase (NA), but not viral nucleoprotein (NP), was responsible for this localization. This report is the first demonstration of CAR at the surface of tissue culture cells, and suggests that CAR may exert the IAV infection mechanism

Ultraviolet-C efficacy against a norovirus surrogate and hepatitis A virus on a stainless steel surface.

Science.gov (United States)

Park, Shin Young; Kim, An-Na; Lee, Ki-Hoon; Ha, Sang-Do

2015-10-15

In this study, the effects of 10-300 mWs/cm(2) of ultraviolet radiation (UV-C) at 260 nm were investigated for the inactivation of two foodborne viruses: murine norovirus-1 (MNV-1; a human norovirus [NoV] surrogate) and hepatitis A virus (HAV). We used an experimentally contaminated stainless steel surface, a common food-contact surface, to examine the effects of low doses of UV-C radiation on MNV-1 and HAV titers. The modified Gompertz equation was used to generate non-linear survival curves and calculate dR-values as the UV-C dose of 90% reduction for MNV-1 (R(2)=0.95, RMSE=0.038) and HAV (R(2)=0.97, RMSE=0.016). Total MNV-1 and HAV titers significantly decreased (pradiation than MNV-1. These data suggest that low doses of UV-C light on food contact surfaces could be effective to inactivate human NoV and HAV in restaurant, institutional, and industrial kitchens and facilities. Copyright © 2015 Elsevier B.V. All rights reserved.

Dual-band frequency selective surface with large band separation and stable performance

Science.gov (United States)

Zhou, Hang; Qu, Shao-Bo; Peng, Wei-Dong; Lin, Bao-Qin; Wang, Jia-Fu; Ma, Hua; Zhang, Jie-Qiu; Bai, Peng; Wang, Xu-Hua; Xu, Zhuo

2012-05-01

A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations.

Electrostatic potential of human immunodeficiency virus type 2 and rhesus macaque simian immunodeficiency virus capsid proteins

Directory of Open Access Journals (Sweden)

Katarzyna eBozek

2012-06-01

Full Text Available Human immunodeficiency virus type 2 (HIV-2 and simian immunodeficiency virus isolated from a macaque monkey (SIVmac are assumed to have originated from simian immunodeficiency virus isolated from sooty mangabey (SIVsm. Despite their close similarity in genome structure, HIV-2 and SIVmac show different sensitivities to TRIM5α, a host restriction factor against retroviruses. The replication of HIV-2 strains is potently restricted by rhesus (Rh monkey TRIM5α, while that of SIVmac strain 239 (SIVmac239 is not. Viral capsid protein is the determinant of this differential sensitivity to TRIM5α, as the HIV-2 mutant carrying SIVmac239 capsid protein evaded Rh TRIM5α-mediated restriction. However, the molecular determinants of this restriction mechanism are unknown. Electrostatic potential on the protein-binding site is one of the properties regulating protein-protein interactions. In this study, we investigated the electrostatic potential on the interaction surface of capsid protein of HIV-2 strain GH123 and SIVmac239. Although HIV-2 GH123 and SIVmac239 capsid proteins share more than 87% amino acid identity, we observed a large difference between the two molecules with the HIV-2 GH123 molecule having predominantly positive and SIVmac239 predominantly negative electrostatic potential on the surface of the loop between α-helices 4 and 5 (L4/5. As L4/5 is one of the major determinants of Rh TRIM5α sensitivity of these viruses, the present results suggest that the binding site of the Rh TRIM5α may show complementarity to the HIV-2 GH123 capsid surface charge distribution.

A chimeric measles virus with a lentiviral envelope replicates exclusively in CD4+/CCR5+ cells

International Nuclear Information System (INIS)

Mourez, Thomas; Mesel-Lemoine, Mariana; Combredet, Chantal; Najburg, Valerie; Cayet, Nadege; Tangy, Frederic

2011-01-01

We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimeric particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes.

Dual-band frequency selective surface with large band separation and stable performance

International Nuclear Information System (INIS)

Zhou Hang; Qu Shao-Bo; Lin Bao-Qin; Wang Jia-Fu; Ma Hua; Zhang Jie-Qiu; Peng Wei-Dong; Bai Peng; Wang Xu-Hua; Xu Zhuo

2012-01-01

A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Release of Virus from Lymphoid Tissue Affects Human Immunodeficiency Virus Type 1 and Hepatitis C Virus Kinetics in the Blood

NARCIS (Netherlands)

Müller, Viktor; Marée, Athanasius F.M.; Boer, R.J. de

2000-01-01

Kinetic parameters of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) infections have been estimated from plasma virus levels following perturbation of the chronically infected (quasi-) steady state. We extend previous models by also considering the large pool of virus

Evidences of Changes in Surface Electrostatic Charge Distribution during Stabilization of HPV16 Virus-Like Particles.

Directory of Open Access Journals (Sweden)

Juan F Vega

Full Text Available The stabilization of human papillomavirus type 16 virus-like particles has been examined by means of different techniques including dynamic and static light scattering, transmission electron microscopy and electrophoretic mobility. All these techniques provide different and often complementary perspectives about the aggregation process and generation of stabilized virus-like particles after a period of time of 48 hours at a temperature of 298 K. Interestingly, static light scattering results point towards a clear colloidal instability in the initial systems, as suggested by a negative value of the second virial coefficient. This is likely related to small repulsive electrostatic interactions among the particles, and in agreement with relatively small absolute values of the electrophoretic mobility and, hence, of the net surface charges. At this initial stage the small repulsive interactions are not able to compensate binding interactions, which tend to aggregate the particles. As time proceeds, an increase of the size of the particles is accompanied by strong increases, in absolute values, of the electrophoretic mobility and net surface charge, suggesting enhanced repulsive electrostatic interactions and, consequently, a stabilized colloidal system. These results show that electrophoretic mobility is a useful methodology that can be applied to screen the stabilization factors for virus-like particles during vaccine development.

The role of genomics in tracking the evolution of influenza A virus.

Directory of Open Access Journals (Sweden)

Alice Carolyn McHardy

2009-10-01

Full Text Available Influenza A virus causes annual epidemics and occasional pandemics of short-term respiratory infections associated with considerable morbidity and mortality. The pandemics occur when new human-transmissible viruses that have the major surface protein of influenza A viruses from other host species are introduced into the human population. Between such rare events, the evolution of influenza is shaped by antigenic drift: the accumulation of mutations that result in changes in exposed regions of the viral surface proteins. Antigenic drift makes the virus less susceptible to immediate neutralization by the immune system in individuals who have had a previous influenza infection or vaccination. A biannual reevaluation of the vaccine composition is essential to maintain its effectiveness due to this immune escape. The study of influenza genomes is key to this endeavor, increasing our understanding of antigenic drift and enhancing the accuracy of vaccine strain selection. Recent large-scale genome sequencing and antigenic typing has considerably improved our understanding of influenza evolution: epidemics around the globe are seeded from a reservoir in East-Southeast Asia with year-round prevalence of influenza viruses; antigenically similar strains predominate in epidemics worldwide for several years before being replaced by a new antigenic cluster of strains. Future in-depth studies of the influenza reservoir, along with large-scale data mining of genomic resources and the integration of epidemiological, genomic, and antigenic data, should enhance our understanding of antigenic drift and improve the detection and control of antigenically novel emerging strains.

Power Spectral Density Specification and Analysis of Large Optical Surfaces

Science.gov (United States)

Sidick, Erkin

2009-01-01

The 2-dimensional Power Spectral Density (PSD) can be used to characterize the mid- and the high-spatial frequency components of the surface height errors of an optical surface. We found it necessary to have a complete, easy-to-use approach for specifying and evaluating the PSD characteristics of large optical surfaces, an approach that allows one to specify the surface quality of a large optical surface based on simulated results using a PSD function and to evaluate the measured surface profile data of the same optic in comparison with those predicted by the simulations during the specification-derivation process. This paper provides a complete mathematical description of PSD error, and proposes a new approach in which a 2-dimentional (2D) PSD is converted into a 1-dimentional (1D) one by azimuthally averaging the 2D-PSD. The 1D-PSD calculated this way has the same unit and the same profile as the original PSD function, thus allows one to compare the two with each other directly.

Prevention of Hepatitis B Virus and Hepatitis C Virus Transmission ...

African Journals Online (AJOL)

Introduction: Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in hemodialysis (HD) patients are associated with adverse outcomes, especially after kidney transplantation. Review: In the HD setting, cross-contamination to patients via environmental surfaces, supplies, equipment, multiple-dose medication vials ...

Mosaic amino acid conservation in 3D-structures of surface protein and polymerase of hepatitis B virus

NARCIS (Netherlands)

van Hemert, Formijn J.; Zaaijer, Hans L.; Berkhout, Ben; Lukashov, Vladimir V.

2008-01-01

Surface protein and polymerase of hepatitis B virus provide a striking example of gene overlap. Inclusion of more coding constraints in the phylogenetic analysis forces the tree toward accepted topology. Three-dimensional protein modeling demonstrates that participation in local protein function

Large-scale analysis of B-cell epitopes on influenza virus hemagglutinin - implications for cross-reactivity of neutralizing antibodies

DEFF Research Database (Denmark)

Sun, Jing; Kudahl, Ulrich J.; Simon, Christian

2014-01-01

Influenza viruses continue to cause substantial morbidity and mortality worldwide. Fast gene mutation on surface proteins of influenza virus result in increasing resistance to current vaccines and available antiviral drugs. Broadly neutralizing antibodies (bnAbs) represent targets for prophylacti......, and differences between historical influenza strains, we enhance our preparedness and the ability to respond to the emerging pandemic threats....... a method to assess the likely cross-reactivity potential of bnAbs for influenza strains, either newly emerged or existing. Our method catalogs influenza strains by a new concept named discontinuous peptide, and then provide assessment of cross-reactivity. Potentially cross-reactive strains are those...

Early diagnosis of influenza virus a using surface-enhanced Raman scattering-based lateral flow assay

International Nuclear Information System (INIS)

Park, Hyun Ji; Choo, Jae Bum; Yang, Sung Chul

2016-01-01

We report a surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) kit for the rapid diagnosis of influenza virus A. Influenza virus A is highly infectious and causes acute respiratory diseases. Therefore, it is important to diagnose the virus early to prevent a pandemic and to provide appropriate treatment to the patient and vaccination of high-risk individuals. Conventional diagnostic tests, including virus cell culture and real-time polymerase chain reaction, take longer than 1 day to confirm the disease. In contrast, a commercially available rapid influenza diagnostic test can detect the infection within 30 min, but it is hard to confirm viral infection using only this test because of its low sensitivity. Therefore, the development of a rapid and simple test for the early diagnosis of influenza infection is urgently needed. To resolve these problems, we developed a SERS-based LFA kit in which the gold nanoparticles in the commercial rapid kit were replaced with SERS-active nano tags. It is possible to quantitatively detect the influenza virus A with high sensitivity by measuring the enhanced Raman signal of these SERS nano tags on the LFA strip. The limit of detection (LOD) using our proposed SERS-based LFA kit was estimated to be 1.9 × 10"4 PFU/mL, which is approximately one order of magnitude more sensitive than the LOD determined from the colorimetric LFA kit

Early diagnosis of influenza virus a using surface-enhanced Raman scattering-based lateral flow assay

Energy Technology Data Exchange (ETDEWEB)

Park, Hyun Ji; Choo, Jae Bum [Dept. of Bionano Technology, Hanyang University, Ansan (Korea, Republic of); Yang, Sung Chul [School of Architectural Engineering, Hongik University, Sejong (Korea, Republic of)

2016-12-15

We report a surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) kit for the rapid diagnosis of influenza virus A. Influenza virus A is highly infectious and causes acute respiratory diseases. Therefore, it is important to diagnose the virus early to prevent a pandemic and to provide appropriate treatment to the patient and vaccination of high-risk individuals. Conventional diagnostic tests, including virus cell culture and real-time polymerase chain reaction, take longer than 1 day to confirm the disease. In contrast, a commercially available rapid influenza diagnostic test can detect the infection within 30 min, but it is hard to confirm viral infection using only this test because of its low sensitivity. Therefore, the development of a rapid and simple test for the early diagnosis of influenza infection is urgently needed. To resolve these problems, we developed a SERS-based LFA kit in which the gold nanoparticles in the commercial rapid kit were replaced with SERS-active nano tags. It is possible to quantitatively detect the influenza virus A with high sensitivity by measuring the enhanced Raman signal of these SERS nano tags on the LFA strip. The limit of detection (LOD) using our proposed SERS-based LFA kit was estimated to be 1.9 × 10{sup 4} PFU/mL, which is approximately one order of magnitude more sensitive than the LOD determined from the colorimetric LFA kit.

Relationships among hepatitis C virus, hepatocellular carcinoma, and diffuse large B cell lymphoma: A case report

Energy Technology Data Exchange (ETDEWEB)

Byun, Hyuk Jun; Kim, Seong Hoon [Dept. of Radiology, Daegu Fatima Hospital, Daegu (Korea, Republic of)

2015-07-15

Hepatitis C virus (HCV) is one of the main causes of hepatocellular carcinoma (HCC). Recent studies have reported various associations between HCV and the incidence of non-Hodgkin's lymphoma. We report the radiologic findings in a rare case of simultaneous occurrence of HCC and diffuse large B cell lymphoma in a HCV carrier.

Life-cycle and genome of OtV5, a large DNA virus of the pelagic marine unicellular green alga Ostreococcus tauri.

Directory of Open Access Journals (Sweden)

Evelyne Derelle

Full Text Available Large DNA viruses are ubiquitous, infecting diverse organisms ranging from algae to man, and have probably evolved from an ancient common ancestor. In aquatic environments, such algal viruses control blooms and shape the evolution of biodiversity in phytoplankton, but little is known about their biological functions. We show that Ostreococcus tauri, the smallest known marine photosynthetic eukaryote, whose genome is completely characterized, is a host for large DNA viruses, and present an analysis of the life-cycle and 186,234 bp long linear genome of OtV5. OtV5 is a lytic phycodnavirus which unexpectedly does not degrade its host chromosomes before the host cell bursts. Analysis of its complete genome sequence confirmed that it lacks expected site-specific endonucleases, and revealed the presence of 16 genes whose predicted functions are novel to this group of viruses. OtV5 carries at least one predicted gene whose protein closely resembles its host counterpart and several other host-like sequences, suggesting that horizontal gene transfers between host and viral genomes may occur frequently on an evolutionary scale. Fifty seven percent of the 268 predicted proteins present no similarities with any known protein in Genbank, underlining the wealth of undiscovered biological diversity present in oceanic viruses, which are estimated to harbour 200Mt of carbon.

Detection of norovirus virus-like particles using a surface plasmon resonance-assisted fluoroimmunosensor optimized for quantum dot fluorescent labels.

Science.gov (United States)

Ashiba, Hiroki; Sugiyama, Yuki; Wang, Xiaomin; Shirato, Haruko; Higo-Moriguchi, Kyoko; Taniguchi, Koki; Ohki, Yoshimichi; Fujimaki, Makoto

2017-07-15

A highly sensitive biosensor to detect norovirus in environment is desired to prevent the spread of infection. In this study, we investigated a design of surface plasmon resonance (SPR)-assisted fluoroimmunosensor to increase its sensitivity and performed detection of norovirus virus-like particles (VLPs). A quantum dot fluorescent dye was employed because of its large Stokes shift. The sensor design was optimized for the CdSe-ZnS-based quantum dots. The optimal design was applied to a simple SPR-assisted fluoroimmunosensor that uses a sensor chip equipped with a V-shaped trench. Excitation efficiency of the quantum dots, degree of electric field enhancement by SPR, and intensity of autofluorescence of a substrate of the sensor chip were theoretically and experimentally evaluated to maximize the signal-to-noise ratio. As the result, an excitation wavelength of 390nm was selected to excite SPR on an Al film of the sensor chip. The sandwich assay of norovirus VLPs was performed using the designed sensor. Minimum detectable concentration of 0.01ng/mL, which corresponds to 100 virus-like particles included in the detection region of the V-trench, was demonstrated. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Electrostatic Deposition of Large-Surface Graphene

Directory of Open Access Journals (Sweden)

Charles Trudeau

2018-01-01

Full Text Available This work describes a method for electrostatic deposition of graphene over a large area using controlled electrostatic exfoliation from a Highly Ordered Pyrolytic Graphite (HOPG block. Deposition over 130 × 130 µm2 with 96% coverage is achieved, which contrasts with sporadic micro-scale depositions of graphene with little control from previous works on electrostatic deposition. The deposition results are studied by Raman micro-spectroscopy and hyperspectral analysis using large fields of view to allow for the characterization of the whole deposition area. Results confirm that laser pre-patterning of the HOPG block prior to cleaving generates anchor points favoring a more homogeneous and defect-free HOPG surface, yielding larger and more uniform graphene depositions. We also demonstrate that a second patterning of the HOPG block just before exfoliation can yield features with precisely controlled geometries.

High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia.

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Steyer, Andrej; Torkar, Karmen Godič; Gutiérrez-Aguirre, Ion; Poljšak-Prijatelj, Mateja

2011-09-01

Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks

Computational sensing of herpes simplex virus using a cost-effective on-chip microscope

KAUST Repository

Ray, Aniruddha

2017-07-03

Caused by the herpes simplex virus (HSV), herpes is a viral infection that is one of the most widespread diseases worldwide. Here we present a computational sensing technique for specific detection of HSV using both viral immuno-specificity and the physical size range of the viruses. This label-free approach involves a compact and cost-effective holographic on-chip microscope and a surface-functionalized glass substrate prepared to specifically capture the target viruses. To enhance the optical signatures of individual viruses and increase their signal-to-noise ratio, self-assembled polyethylene glycol based nanolenses are rapidly formed around each virus particle captured on the substrate using a portable interface. Holographic shadows of specifically captured viruses that are surrounded by these self-assembled nanolenses are then reconstructed, and the phase image is used for automated quantification of the size of each particle within our large field-of-view, ~30 mm2. The combination of viral immuno-specificity due to surface functionalization and the physical size measurements enabled by holographic imaging is used to sensitively detect and enumerate HSV particles using our compact and cost-effective platform. This computational sensing technique can find numerous uses in global health related applications in resource-limited environments.

The full-length microRNA cluster in the intron of large latency transcript is associated with the virulence of pseudorabies virus.

Science.gov (United States)

Wang, Xin; Zhang, Mei-Mei; Yan, Kai; Tang, Qi; Wu, Yi-Quan; He, Wen-Bo; Chen, Huan-Chun; Liu, Zheng-Fei

2018-07-01

Pseudorabies virus (PRV), the etiological pathogen of Aujeszky's disease, belongs to the Alphaherpesvirus subfamily. Large latency transcript (LLT), the most abundant PRV transcript, harbors a ~ 4.6 kb microRNA (miRNA) cluster-encoding intron. To investigate the function of the LLT miRNA cluster during the life cycle of PRV, we generated a miRNA cluster mutation virus (PRV-∆miR cluster) and revertant virus. Analysis of the growth kinetics of PRV-ΔmiR cluster-infected cells revealed significantly smaller plaques and lower titers than the wild-type and revertant viruses. The mutation virus exhibited increased IE180 and decreased EP0 expression. The clinical symptoms observed in mice infected with PRV-ΔmiR cluster revealed that the miRNA cluster is involved in the pathogenesis of PRV. Physical parameters, virus shedding assays, and the SN 50 titers revealed that the miRNA cluster enhances PRV virulence in pigs. Collectively, our findings suggest that the full-length miRNA cluster is involved in PRV replication and virulence. Copyright © 2018 Elsevier Inc. All rights reserved.

How to collect and process large polyhedral viruses of insects

Science.gov (United States)

W. D. Rollinson; F. B. Lewis

1962-01-01

Polyhedral viruses have proved highly effective and very practical for control of certain pine sawflies; and a method of collecting and processing the small polyhedra (5 microns or less) characteristic of sawflies has been described. There is experimental evidence that the virus diseases of many Lepidopterous insects can be used similarly for direct control. The...

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses.

Science.gov (United States)

Roux, Simon; Brum, Jennifer R; Dutilh, Bas E; Sunagawa, Shinichi; Duhaime, Melissa B; Loy, Alexander; Poulos, Bonnie T; Solonenko, Natalie; Lara, Elena; Poulain, Julie; Pesant, Stéphane; Kandels-Lewis, Stefanie; Dimier, Céline; Picheral, Marc; Searson, Sarah; Cruaud, Corinne; Alberti, Adriana; Duarte, Carlos M; Gasol, Josep M; Vaqué, Dolors; Bork, Peer; Acinas, Silvia G; Wincker, Patrick; Sullivan, Matthew B

2016-09-29

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface- and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting 'global ocean virome' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they

Large Amounts of Reactivated Virus in Tears Precedes Recurrent Herpes Stromal Keratitis in Stressed Rabbits Latently Infected with Herpes Simplex Virus.

Science.gov (United States)

Perng, Guey-Chuen; Osorio, Nelson; Jiang, Xianzhi; Geertsema, Roger; Hsiang, Chinhui; Brown, Don; BenMohamed, Lbachir; Wechsler, Steven L

2016-01-01

Recurrent herpetic stromal keratitis (rHSK), due to an immune response to reactivation of herpes simplex virus (HSV-1), can cause corneal blindness. The development of therapeutic interventions such as drugs and vaccines to decrease rHSK have been hampered by the lack of a small and reliable animal model in which rHSK occurs at a high frequency during HSV-1 latency. The aim of this study is to develop a rabbit model of rHSK in which stress from elevated temperatures increases the frequency of HSV-1 reactivations and rHSK. Rabbits latently infected with HSV-1 were subjected to elevated temperatures and the frequency of viral reactivations and rHSK were determined. In an experiment in which rabbits latently infected with HSV-1 were subjected to ill-defined stress as a result of failure of the vivarium air conditioning system, reactivation of HSV-1 occurred at over twice the normal frequency. In addition, 60% of eyes developed severe rHSK compared to tears of that eye and whenever this unusually large amount of reactivated virus was detected in tears, rHSK always appeared 4-5 days later. In subsequent experiments using well defined heat stress the reactivation frequency was similarly increased, but no eyes developed rHSK. The results reported here support the hypothesis that rHSK is associated not simply with elevated reactivation frequency, but rather with rare episodes of very high levels of reactivated virus in tears 4-5 days earlier.

Utilization of Large Scale Surface Models for Detailed Visibility Analyses

Science.gov (United States)

Caha, J.; Kačmařík, M.

2017-11-01

This article demonstrates utilization of large scale surface models with small spatial resolution and high accuracy, acquired from Unmanned Aerial Vehicle scanning, for visibility analyses. The importance of large scale data for visibility analyses on the local scale, where the detail of the surface model is the most defining factor, is described. The focus is not only the classic Boolean visibility, that is usually determined within GIS, but also on so called extended viewsheds that aims to provide more information about visibility. The case study with examples of visibility analyses was performed on river Opava, near the Ostrava city (Czech Republic). The multiple Boolean viewshed analysis and global horizon viewshed were calculated to determine most prominent features and visibility barriers of the surface. Besides that, the extended viewshed showing angle difference above the local horizon, which describes angular height of the target area above the barrier, is shown. The case study proved that large scale models are appropriate data source for visibility analyses on local level. The discussion summarizes possible future applications and further development directions of visibility analyses.

Cell surface alteration in Epstein-Barr virus-transformed cells from patients with extreme insulin resistance

International Nuclear Information System (INIS)

Gorden, D.L.; Robert, A.; Moncada, V.Y.; Taylor, S.I.; Muehlhauser, J.C.; Carpentier, J.L.

1990-01-01

An abnormality was detected in the morphology of the cell surface of Epstein-Barr virus-transformed lymphocytes of patients with genetic forms of insulin resistance. In cells from two patients with leprechaunism and two patients with type A extreme insulin resistance, scanning electron microscopy demonstrated a decrease in the percentage of the cell surface occupied by microvilli in cells from the patients with leprechaunism and type A insulin resistance compared with control cells. When cells from a healthy control subject and one of the patients with leprechaunism (Lep/Ark-1) were incubated with 125 I-labeled insulin, there was a decrease in the percentage of 125 I-insulin associated with microvilli on the cell surface. Thus, the decreased localization of insulin receptors with the microvillous region of the cell surface was in proportion to the decrease in microvilli

CD81 Receptor Regions outside the Large Extracellular Loop Determine Hepatitis C Virus Entry into Hepatoma Cells

Directory of Open Access Journals (Sweden)

Pia Banse

2018-04-01

Full Text Available Hepatitis C virus (HCV enters human hepatocytes using four essential entry factors, one of which is human CD81 (hCD81. The tetraspanin hCD81 contains a large extracellular loop (LEL, which interacts with the E2 glycoprotein of HCV. The role of the non-LEL regions of hCD81 (intracellular tails, four transmembrane domains, small extracellular loop and intracellular loop is poorly understood. Here, we studied the contribution of these domains to HCV susceptibility of hepatoma cells by generating chimeras of related tetraspanins with the hCD81 LEL. Our results show that non-LEL regions in addition to the LEL determine susceptibility of cells to HCV. While closely related tetraspanins (X. tropicalis CD81 and D. rerio CD81 functionally complement hCD81 non-LEL regions, distantly related tetraspanins (C. elegans TSP9 amd D. melanogaster TSP96F do not and tetraspanins with intermediate homology (hCD9 show an intermediate phenotype. Tetraspanin homology and susceptibility to HCV correlate positively. For some chimeras, infectivity correlates with surface expression. In contrast, the hCD9 chimera is fully surface expressed, binds HCV E2 glycoprotein but is impaired in HCV receptor function. We demonstrate that a cholesterol-coordinating glutamate residue in CD81, which hCD9 lacks, promotes HCV infection. This work highlights the hCD81 non-LEL regions as additional HCV susceptibility-determining factors.

Infant outcomes among women with Zika virus infection during pregnancy: results of a large prenatal Zika screening program.

Science.gov (United States)

Adhikari, Emily H; Nelson, David B; Johnson, Kathryn A; Jacobs, Sara; Rogers, Vanessa L; Roberts, Scott W; Sexton, Taylor; McIntire, Donald D; Casey, Brian M

2017-03-01

Zika virus infection during pregnancy is a known cause of congenital microcephaly and other neurologic morbidities. We present the results of a large-scale prenatal screening program in place at a single-center health care system since March 14, 2016. Our aims were to report the baseline prevalence of travel-associated Zika infection in our pregnant population, determine travel characteristics of women with evidence of Zika infection, and evaluate maternal and neonatal outcomes compared to women without evidence of Zika infection. This is a prospective, observational study of prenatal Zika virus screening in our health care system. We screened all pregnant women for recent travel to a Zika-affected area, and the serum was tested for those considered at risk for infection. We compared maternal demographic and travel characteristics and perinatal outcomes among women with positive and negative Zika virus tests during pregnancy. Comprehensive neurologic evaluation was performed on all infants delivered of women with evidence of possible Zika virus infection during pregnancy. Head circumference percentiles by gestational age were compared for infants delivered of women with positive and negative Zika virus test results. From March 14 through Oct. 1, 2016, a total of 14,161 pregnant women were screened for travel to a Zika-affected country. A total of 610 (4.3%) women reported travel, and test results were available in 547. Of these, evidence of possible Zika virus infection was found in 29 (5.3%). In our population, the prevalence of asymptomatic or symptomatic Zika virus infection among pregnant women was 2/1000. Women with evidence of Zika virus infection were more likely to have traveled from Central or South America (97% vs 12%, P Zika virus infection. Additionally, there was no difference in mean head circumference of infants born to women with positive vs negative Zika virus testing. No microcephalic infants born to women with Zika infection were identified

Nanotechnological Advances in Catalytic Thin Films for Green Large-Area Surfaces

Directory of Open Access Journals (Sweden)

Suzan Biran Ay

2015-01-01

Full Text Available Large-area catalytic thin films offer great potential for green technology applications in order to save energy, combat pollution, and reduce global warming. These films, either embedded with nanoparticles, shaped with nanostructuring techniques, hybridized with other systems, or functionalized with bionanotechnological methods, can include many different surface properties including photocatalytic, antifouling, abrasion resistant and mechanically resistive, self-cleaning, antibacterial, hydrophobic, and oleophobic features. Thus, surface functionalization with such advanced structuring methods is of significance to increase the performance and wide usage of large-area thin film coatings specifically for environmental remediation. In this review, we focus on methods to increase the efficiency of catalytic reactions in thin film and hence improve the performance in relevant applications while eliminating high cost with the purpose of widespread usage. However, we also include the most recent hybrid architectures, which have potential to make a transformational change in surface applications as soon as high quality and large area production techniques are available. Hence, we present and discuss research studies regarding both organic and inorganic methods that are used to structure thin films that have potential for large-area and eco-friendly coatings.

Recombinant Vaccinia Virus: Immunization against Multiple Pathogens

Science.gov (United States)

Perkus, Marion E.; Piccini, Antonia; Lipinskas, Bernard R.; Paoletti, Enzo

1985-09-01

The coding sequences for the hepatitis B virus surface antigen, the herpes simplex virus glycoprotein D, and the influenza virus hemagglutinin were inserted into a single vaccinia virus genome. Rabbits inoculated intravenously or intradermally with this polyvalent vaccinia virus recombinant produced antibodies reactive to all three authentic foreign antigens. In addition, the feasibility of multiple rounds of vaccination with recombinant vaccinia virus was demonstrated.

Identification of Key Residues in Virulent Canine Distemper Virus Hemagglutinin That Control CD150/SLAM-Binding Activity▿

Science.gov (United States)

Zipperle, Ljerka; Langedijk, Johannes P. M.; Örvell, Claes; Vandevelde, Marc; Zurbriggen, Andreas; Plattet, Philippe

2010-01-01

Morbillivirus cell entry is controlled by hemagglutinin (H), an envelope-anchored viral glycoprotein determining interaction with multiple host cell surface receptors. Subsequent to virus-receptor attachment, H is thought to transduce a signal triggering the viral fusion glycoprotein, which in turn drives virus-cell fusion activity. Cell entry through the universal morbillivirus receptor CD150/SLAM was reported to depend on two nearby microdomains located within the hemagglutinin. Here, we provide evidence that three key residues in the virulent canine distemper virus A75/17 H protein (Y525, D526, and R529), clustering at the rim of a large recessed groove created by β-propeller blades 4 and 5, control SLAM-binding activity without drastically modulating protein surface expression or SLAM-independent F triggering. PMID:20631152

Deletions in the fifth alpha helix of HIV-1 matrix block virus release

International Nuclear Information System (INIS)

Sanford, Bridget; Li, Yan; Maly, Connor J.; Madson, Christian J.; Chen, Han; Zhou, You; Belshan, Michael

2014-01-01

The matrix (MA) protein of HIV-1 is the N-terminal component of the Gag structural protein and is critical for the early and late stages of viral replication. MA contains five α-helices (α1–α5). Deletions in the N-terminus of α5 as small as three amino acids impaired virus release. Electron microscopy of one deletion mutant (MA∆96-120) showed that its particles were tethered to the surface of cells by membranous stalks. Immunoblots indicated all mutants were processed completely, but mutants with large deletions had alternative processing intermediates. Consistent with the EM data, MA∆96-120 retained membrane association and multimerization capability. Co-expression of this mutant inhibited wild type particle release. Alanine scanning mutation in this region did not affect virus release, although the progeny virions were poorly infectious. Combined, these data demonstrate that structural ablation of the α5 of MA inhibits virus release. - Highlights: • Deletions were identified in the C-terminus of matrix that block virus release. • These deletion mutants still multimerized and associated with membranes. • TEM showed the mutant particles were tethered to the cell surface. • Amino acid mutagenesis of the region did not affect release. • The data suggests that disruption of matrix structure blocks virus release

Deletions in the fifth alpha helix of HIV-1 matrix block virus release

Energy Technology Data Exchange (ETDEWEB)

Sanford, Bridget; Li, Yan; Maly, Connor J.; Madson, Christian J. [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Chen, Han [Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE (United States); Zhou, You [Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE (United States); Nebraska Center for Virology, Lincoln, NE (United States); Belshan, Michael, E-mail: michaelbelshan@creighton.edu [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Nebraska Center for Virology, Lincoln, NE (United States)

2014-11-15

The matrix (MA) protein of HIV-1 is the N-terminal component of the Gag structural protein and is critical for the early and late stages of viral replication. MA contains five α-helices (α1–α5). Deletions in the N-terminus of α5 as small as three amino acids impaired virus release. Electron microscopy of one deletion mutant (MA∆96-120) showed that its particles were tethered to the surface of cells by membranous stalks. Immunoblots indicated all mutants were processed completely, but mutants with large deletions had alternative processing intermediates. Consistent with the EM data, MA∆96-120 retained membrane association and multimerization capability. Co-expression of this mutant inhibited wild type particle release. Alanine scanning mutation in this region did not affect virus release, although the progeny virions were poorly infectious. Combined, these data demonstrate that structural ablation of the α5 of MA inhibits virus release. - Highlights: • Deletions were identified in the C-terminus of matrix that block virus release. • These deletion mutants still multimerized and associated with membranes. • TEM showed the mutant particles were tethered to the cell surface. • Amino acid mutagenesis of the region did not affect release. • The data suggests that disruption of matrix structure blocks virus release.

A modular approach to creating large engineered cartilage surfaces.

Science.gov (United States)

Ford, Audrey C; Chui, Wan Fung; Zeng, Anne Y; Nandy, Aditya; Liebenberg, Ellen; Carraro, Carlo; Kazakia, Galateia; Alliston, Tamara; O'Connell, Grace D

2018-01-23

Native articular cartilage has limited capacity to repair itself from focal defects or osteoarthritis. Tissue engineering has provided a promising biological treatment strategy that is currently being evaluated in clinical trials. However, current approaches in translating these techniques to developing large engineered tissues remains a significant challenge. In this study, we present a method for developing large-scale engineered cartilage surfaces through modular fabrication. Modular Engineered Tissue Surfaces (METS) uses the well-known, but largely under-utilized self-adhesion properties of de novo tissue to create large scaffolds with nutrient channels. Compressive mechanical properties were evaluated throughout METS specimens, and the tensile mechanical strength of the bonds between attached constructs was evaluated over time. Raman spectroscopy, biochemical assays, and histology were performed to investigate matrix distribution. Results showed that by Day 14, stable connections had formed between the constructs in the METS samples. By Day 21, bonds were robust enough to form a rigid sheet and continued to increase in size and strength over time. Compressive mechanical properties and glycosaminoglycan (GAG) content of METS and individual constructs increased significantly over time. The METS technique builds on established tissue engineering accomplishments of developing constructs with GAG composition and compressive properties approaching native cartilage. This study demonstrated that modular fabrication is a viable technique for creating large-scale engineered cartilage, which can be broadly applied to many tissue engineering applications and construct geometries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electromagnetic surface waves for large-area RF plasma productions between large-area planar electrodes

International Nuclear Information System (INIS)

Nonaka, S.

1992-01-01

Recently, large-area plasma production has been tested by means of a 13.56 MHz radio-frequency (RF) discharge between a pair of large-area planar electrodes, approximately 0.5 m x 1.4 m, as one of the semiconductor technologies for fabrication of large-area amorphous silicon solar cells in the ''Sunshine Project'' of the Agency of Industrial Science and Technology in Japan. We also confirmed long plasma production between a pair of long electrodes. In this paper, normal electromagnetic (EM) waves propagating in a region between a planar waveguide with one plasma and two dielectric layers are analyzed in order to study the feasibility of large-area plasma productions by EM wave-discharges between a pair of large-area RF electrodes larger than the half-wavelength of RF wave. In conclusion, plasmas higher than an electron plasma frequency will be produced by an odd TMoo surface mode. (author) 4 refs., 3 figs

Far-UVC light applications: sterilization of MRSA on a surface and inactivation of aerosolized influenza virus

Science.gov (United States)

Welch, David; Buonanno, Manuela; Shuryak, Igor; Randers-Pehrson, Gerhard; Spotnitz, Henry M.; Brenner, David J.

2018-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) and influenza A virus are two of the major targets for new antimicrobial technologies. In contrast to conventional germicidal lamps emitting primarily at 254 nm, which are both carcinogenic and cataractogenic, recent work has shown the potential of far-UVC technology, mainly between 207 and 222 nm, to be an effective means of sterilization of pathogens without apparent harm to mammalian cells. This is because, due to its strong absorbance in biological materials, far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye; however, because bacteria and viruses are of micrometer or smaller dimensions, far-UVC can penetrate and inactivate them. With this report, we present progress on in vitro tests to inactivate MRSA on a surface using far-UVC light from a laser delivered using an optical diffuser. Qualitative and quantitative results show that this means of far-UVC exposure is adequate to inactivate MRSA with a dose comparable to that which would be required using a conventional germicidal lamp. Also included is a report on progress on inactivation of aerosolized influenza A virus. A custom benchtop aerosol exposure chamber was constructed and used to determine the effectiveness of far- UVC. Results indicate that far-UVC efficiently inactivates airborne aerosolized viruses, with a very low dose of 2 mJ/cm2 of 222-nm light inactivating >95% of aerosolized H1N1 influenza virus. Together these studies help to further establish far-UVC technology as a promising, safe and inexpensive tool for sterilization in many environments.

General seroprevalence of hepatitis and hepatitis B virus infections in population

International Nuclear Information System (INIS)

Khokar, N.; Gill, M.L.; Malik, G.J.

2004-01-01

Objective: To determine the prevalence of hepatitis C virus (HCV) and hepatitis B virus (HBV) infection by detection of anti-HCV and hepatitis B surface antigen (HbsAg) in general population of Pakistan. Materials and Methods: Sera of healthy adult individuals who presented for medical evaluation as a pre-employment criteria in the Gulf region were examined for presence of hepatitis B surface antigen and anti-HCV antibody. Alanine aminotransferase levels were also determined. Results: A total of 47,538 individuals were examined. Out of these, 2528 (5.31%) were positive for anti-HCV and 1221 (2.56%) individuals had positive HBsAg. Hepatitis B surface antigen and anti-HCV both were found in 92 (0.19%) individuals. Mean age of subjects, positive for HCV antibody was 44 years and 40.5 years for HBV. Ninety-four percent individuals were males and 6% were females. Alanine aminotransferase (ALT) was normal in 56% of subjects with positive HCV and 84% of individuals with HBV. Conclusion: This study which evaluated predominantly a healthy male population, showed a high seroprevalence of anti-HCV and average seroprevalence of hepatitis B virus infection. A large majority of these patients was young and had normal ALT. (author)

Influenza virus inactivated by artificial ribonucleases as a prospective killed virus vaccine.

Science.gov (United States)

Fedorova, Antonina A; Goncharova, Elena P; Kovpak, Mikhail P; Vlassov, Valentin V; Zenkova, Marina A

2012-04-19

The inactivation of viral particles with agents causing minimal damage to the structure of surface epitopes is a well-established approach for the production of killed virus vaccines. Here, we describe new agents for the inactivation of influenza virus, artificial ribonucleases (aRNases), which are chemical compounds capable of cleaving RNA molecules. Several aRNases were identified, exhibiting significant virucidal activity against the influenza A virus and causing a minimal effect on the affinity of monoclonal antibodies for the inactivated virus. Using a murine model of the influenza virus infection, a high protective activity of the aRNase-inactivated virus as a vaccine was demonstrated. The results of the experiments demonstrate the efficacy of novel chemical agents in the preparation of vaccines against influenza and, perhaps, against other infections caused by RNA viruses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hepatitis A virus antibody

International Nuclear Information System (INIS)

Novak, J.; Kselikova, M.; Urbankova, J.

1980-01-01

A description is presented of a radioimmunoassay designed to prove the presence of the antibody against the hepatitis A virus (HA Ab, anti-Ha) using an Abbott HAVAB set. This proof as well as the proof of the antibody against the nucleus of the hepatitis B virus is based on competition between a normal antibody against hepatitis A virus and a 125 I-labelled antibody for the binding sites of a specific antigen spread all over the surface of a tiny ball; this is then indirect proof of the antibody under investigation. The method is described of reading the results from the number of impulses per 60 seconds: the higher the titre of the antibody against the hepatitis A virus in the serum examined, the lower the activity of the specimen concerned. The rate is reported of incidence of the antibody against the hepatitis A virus in a total of 68 convalescents after hepatitis A; the antibody was found in 94.1%. The immunoglobulin made from the convalescents' plasma showed the presence of antibodies in dilutions as high as 1:250 000 while the comparable ratio for normal immunoglobulin Norga was only 1:2500. Differences are discussed in the time incidence of the antibodies against the hepatitis A virus, the antibodies against the surface antigen of hepatitis B, and the antibody against the nucleus of the hepatitis V virus. (author)

Virus-like-vaccines against HIV

DEFF Research Database (Denmark)

Andersson, Anne Marie C.; Schwerdtfeger, Melanie; Holst, Peter J.

2018-01-01

Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus-like-particle (......Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus...... of HIV. Such vaccines are immunologically perceived as viruses, as they infect cells and produce VLPs in situ, but they only resemble viruses, as the replication defective vectors and VLPs cannot propagate an infection. The inherent safety of such a platform, despite robust particle production...

Efficient large-scale protein production of larvae and pupae of silkworm by Bombyx mori nuclear polyhedrosis virus bacmid system

International Nuclear Information System (INIS)

Motohashi, Tomoko; Shimojima, Tsukasa; Fukagawa, Tatsuo; Maenaka, Katsumi; Park, Enoch Y.

2005-01-01

Silkworm is one of the most attractive hosts for large-scale production of eukaryotic proteins as well as recombinant baculoviruses for gene transfer to mammalian cells. The bacmid system of Autographa californica nuclear polyhedrosis virus (AcNPV) has already been established and widely used. However, the AcNPV does not have a potential to infect silkworm. We developed the first practical Bombyx mori nuclear polyhedrosis virus bacmid system directly applicable for the protein expression of silkworm. By using this system, the green fluorescence protein was successfully expressed in silkworm larvae and pupae not only by infection of its recombinant virus but also by direct injection of its bacmid DNA. This method provides the rapid protein production in silkworm as long as 10 days, is free from biohazard, thus will be a powerful tool for the future production factory of recombinant eukaryotic proteins and baculoviruses

Plasma Epstein-Barr virus and Hepatitis B virus in non-Hodgkin lymphomas: Two lymphotropic, potentially oncogenic, latently occurring DNA viruses.

Science.gov (United States)

Sinha, Mahua; Rao, Clementina Rama; Premalata, C S; Shafiulla, Mohammed; Lakshmaiah, K C; Jacob, Linu Abraham; Babu, Govind K; Viveka, B K; Appaji, L; Subramanyam, Jayshree R

2016-01-01

There is a need to study potential infective etiologies in lymphomas. Lymphocyte-transforming viruses can directly infect lymphocytes, disrupt normal cell functions, and promote cell division. Epstein-Barr virus (EBV) is known to be associated with several lymphomas, especially Hodgkin lymphomas (HLs). And recently, the lymphocyte-transforming role of hepatitis B virus (HBV) has been emphasized. The aim of this study was to elucidate the association of two potentially oncogenic, widely prevalent latent DNA viruses, EBV and HBV, in non-HL (NHL). In this prospective study, we estimated plasma EBV and HBV DNA in NHL patients. Peripheral blood was obtained from newly diagnosed, treatment na ïve, histologically confirmed NHL patients. Plasma EBV DNA was quantified by real-time polymerase chain reaction (PCR) targeting Epstein-Barr Nucleic acid 1 while the plasma HBV DNA was detected using nested PCR targeting HBX gene. In a small subset of patients, follow-up plasma samples post-anticancer chemotherapy were available and retested for viral DNA. Of the 110 NHL patients, ~79% were B-cell NHL and ~21% were T-cell NHL. Plasma EBV-DNA was detected in 10% NHLs with a higher EBV association in Burkitt lymphoma (33.3%) than other subtypes. Pretherapy HBV DNA was detected in 21% NHLs; most of them being diffuse large B-cell lymphoma (DLBCL). Moreover, 42% of DLBCL patients had HBV DNA in plasma. Since all patients were HBV surface antigen seronegative at diagnosis, baseline plasma HBV-DNAemia before chemotherapy was indicative of occult hepatitis B infection. Our findings indicate a significant association of HBV with newly diagnosed DLBCL.

Viruses infecting reptiles.

Science.gov (United States)

Marschang, Rachel E

2011-11-01

A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch's postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

Viruses Infecting Reptiles

Directory of Open Access Journals (Sweden)

Rachel E. Marschang

2011-11-01

Full Text Available A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

Human immunodeficiency virus (HIV) seropositivity and hepatitis B surface antigenemia (HBSAG) among blood donors in Benin city, Edo state, Nigeria.

Science.gov (United States)

Umolu, Patience Idia; Okoror, Lawrence Ehis; Orhue, Philip

2005-03-01

Human Immunodeficiency Virus and Hepatitis B virus are blood borne pathogens that can be transmitted through blood transfusion and could pose a huge problem in areas where mechanisms of ensuring blood safety are suspect. This study became necessary in a population where most of the blood for transfusion is from commercial blood donors. A total of 130 donors comprising 120 commercial donors and 10 voluntary donors were tested for antibodies to human immunodeficiency virus and hepatitis B surface antigen in Benin city using Immunocomb HIV - 1 and 2 Biospot kit and Quimica Clinica Aplicada direct latex agglutination method respectively. Thirteen (10%) samples were HIV seropositive and 7(5.8%) were HBsAg positive. The age bracket 18 - 25years had the highest numbers of donors and also had the highest number of HBsAg positive cases (7.8%) while the age group 29 - 38years had highest number of HIV seropositive cases. High prevalence of HIV antibodies and Hepatitis B surface antigen was found among commercial blood donors. Appropriate and compulsory screening of blood donors using sensitive methods, must be ensured to prevent post transfusion hepatitis and HIV.

Virus-host interaction in feline immunodeficiency virus (FIV) infection.

Science.gov (United States)

Taniwaki, Sueli Akemi; Figueiredo, Andreza Soriano; Araujo, João Pessoa

2013-12-01

Feline immunodeficiency virus (FIV) infection has been the focus of several studies because this virus exhibits genetic and pathogenic characteristics that are similar to those of the human immunodeficiency virus (HIV). FIV causes acquired immunodeficiency syndrome (AIDS) in cats, nevertheless, a large fraction of infected cats remain asymptomatic throughout life despite of persistent chronic infection. This slow disease progression may be due to the presence of factors that are involved in the natural resistance to infection and the immune response that is mounted by the animals, as well as due to the adaptation of the virus to the host. Therefore, the study of virus-host interaction is essential to the understanding of the different patterns of disease course and the virus persistence in the host, and to help with the development of effective vaccines and perhaps the cure of FIV and HIV infections. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses

KAUST Repository

Roux, Simon

2016-05-12

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface-and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting â global ocean virome\\' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses

KAUST Repository

Roux, Simon; Brum, Jennifer R; Dutilh, Bas E.; Sunagawa, Shinichi; Duhaime, Melissa B; Loy, Alexander; Poulos, Bonnie T; Solonenko, Natalie; Lara, Elena; Poulain, Julie; Pesant, Stephane; Kandels-Lewis, Stefanie; Dimier, Celine; Picheral, Marc; Searson, Sarah; Cruaud, Corinne; Alberti, Adriana; Duarte, Carlos M.; Gasol, Josep M M; Vaque, Dolors; Bork, Peer; Acinas, Silvia G; Wincker, Patrick; Sullivan, Matthew B

2016-01-01

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface-and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting â global ocean virome' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they

Distinctive receptor binding properties of the surface glycoprotein of a natural Feline Leukemia Virus isolate with unusual disease spectrum

Directory of Open Access Journals (Sweden)

Albritton Lorraine M

2011-05-01

Full Text Available Abstract Background Feline leukemia virus (FeLV-945, a member of the FeLV-A subgroup, was previously isolated from a cohort of naturally infected cats. An unusual multicentric lymphoma of non-T-cell origin was observed in natural and experimental infection with FeLV-945. Previous studies implicated the FeLV-945 surface glycoprotein (SU as a determinant of disease outcome by an as yet unknown mechanism. The present studies demonstrate that FeLV-945 SU confers distinctive properties of binding to the cell surface receptor. Results Virions bearing the FeLV-945 Env protein were observed to bind the cell surface receptor with significantly increased efficiency, as was soluble FeLV-945 SU protein, as compared to the corresponding virions or soluble protein from a prototype FeLV-A isolate. SU proteins cloned from other cohort isolates exhibited increased binding efficiency comparable to or greater than FeLV-945 SU. Mutational analysis implicated a domain containing variable region B (VRB to be the major determinant of increased receptor binding, and identified a single residue, valine 186, to be responsible for the effect. Conclusions The FeLV-945 SU protein binds its cell surface receptor, feTHTR1, with significantly greater efficiency than does that of prototype FeLV-A (FeLV-A/61E when present on the surface of virus particles or in soluble form, demonstrating a 2-fold difference in the relative dissociation constant. The results implicate a single residue, valine 186, as the major determinant of increased binding affinity. Computational modeling suggests a molecular mechanism by which residue 186 interacts with the receptor-binding domain through residue glutamine 110 to effect increased binding affinity. Through its increased receptor binding affinity, FeLV-945 SU might function in pathogenesis by increasing the rate of virus entry and spread in vivo, or by facilitating entry into a novel target cell with a low receptor density.

Virus interaction with the apical junctional complex.

Science.gov (United States)

Gonzalez-Mariscal, Lorenza; Garay, Erika; Lechuga, Susana

2009-01-01

In order to infect pathogens must breach the epithelial barriers that separate the organism from the external environment or that cover the internal cavities and ducts of the body. Epithelia seal the passage through the paracellular pathway with the apical junctional complex integrated by tight and adherens junctions. In this review we describe how viruses like coxsackie, swine vesicular disease virus, adenovirus, reovirus, feline calcivirus, herpes viruses 1 and 2, pseudorabies, bovine herpes virus 1, poliovirus and hepatitis C use as cellular receptors integral proteins present at the AJC of epithelial cells. Interaction with these proteins contributes in a significant manner in defining the particular tropism of each virus. Besides these proteins, viruses exhibit a wide range of cellular co-receptors among which proteins present in the basolateral cell surface like integrins are often found. Therefore targeting proteins of the AJC constitutes a strategy that might allow viruses to bypass the physical barrier that blocks their access to receptors expressed on the basolateral surface of epithelial cells.

Turbulent mixed convection from a large, high temperature, vertical flat surface

International Nuclear Information System (INIS)

Evans, G.; Greif, R.; Siebers, D.; Tieszen, S.

2005-01-01

Turbulent mixed convection heat transfer at high temperatures and large length scales is an important and seldom studied phenomenon that can represent a significant part of the overall heat transfer in applications ranging from solar central receivers to objects in fires. This work is part of a study to validate turbulence models for predicting heat transfer to or from surfaces at large temperature differences and large length scales. Here, turbulent, three-dimensional, mixed convection heat transfer in air from a large (3m square) vertical flat surface at high temperatures is studied using two RANS turbulence models: a standard k-ε model and the v2-bar -f model. Predictions for three cases spanning the range of the experiment (Siebers, D.L., Schwind, R.G., Moffat, R.F., 1982. Experimental mixed convection from a large, vertical plate in a horizontal flow. Paper MC13, vol. 3, Proc. 7th Int. Heat Transfer Conf., Munich; Siebers, D.L., 1983. Experimental mixed convection heat transfer from a large, vertical surface in a horizontal flow. PhD thesis, Stanford University) from forced (GrH/ReL2=0.18) to mixed (GrH/ReL2=3.06) to natural (GrH/ReL2=∼) convection are compared with data. The results show a decrease in the heat transfer coefficient as GrH/ReL2 is increased from 0.18 to 3.06, for a free-stream velocity of 4.4m/s. In the natural convection case, the experimental heat transfer coefficient is approximately constant in the fully turbulent region, whereas the calculated heat transfer coefficients show a slight increase with height. For the three cases studied, the calculated and experimental heat transfer coefficients agree to within 5-35% over most of the surface with the v2-bar -f model results showing better agreement with the data. Calculated temperature and velocity profiles show good agreement with the data

Isolation of avian influenza virus in Texas.

Science.gov (United States)

Glass, S E; Naqi, S A; Grumbles, L C

1981-01-01

An avian influenza virus with surface antigens similar to those of fowl plague virus (Hav 1 Nav 2) was isolated in 1979 from 2 commercial turkey flocks in Central Texas. Two flocks in contact with these infected flocks developed clinical signs, gross lesions, and seroconversion but yielded no virus. This was the first recorded incidence of clinical avian influenza in Texas turkeys and only the second time that an agent with these surface antigens was isolated from turkeys in U.S.

Hepatitis B virus surface antigen (HBsAg)-positive and HBsAg-negative hepatitis B virus infection among mother-teenager pairs 13 years after neonatal hepatitis B virus vaccination.

Science.gov (United States)

Yao, Qing-Qing; Dong, Xiao-Lian; Wang, Xue-Cai; Ge, Sheng-Xiang; Hu, An-Qun; Liu, Hai-Yan; Wang, Yueping Alex; Yuan, Quan; Zheng, Ying-Jie

2013-02-01

It is unclear whether a mother who is negative for hepatitis B virus surface antigen (HBsAg) but positive for hepatitis B virus (HBV) is at potential risk for mother-to-child transmission of HBV. This study, using a paired mother-teenager population, aimed to assess whether maternal HBsAg-negative HBV infection ((hn)HBI) is a significant source of child HBV infection (HBI). A follow-up study with blood collection has been conducted on the 93 mother-teenager pairs from the initial 135 pregnant woman-newborn pairs 13 years after neonatal HBV vaccination. Serological and viral markers of HBV have been tested, and phylogenetic analysis of HBV isolates has been done. The HBI prevalence was 1.9% (1 (hn)HBI/53) for teenage children of non-HBI mothers, compared with 16.7% (1 (hn)HBI/6) for those of (hn)HBI mothers and 2.9% (1 HBsAg-positive HBV infection [(hp)HBI]/34) for those of (hp)HBI mothers. Similar viral sequences have been found in one pair of whom both the mother and teenager have had (hn)HBI. In comparison with the (hp)HBI cases, those with (hn)HBI had a lower level of HBV load and a higher proportion of genotype-C strains, which were accompanied by differentiated mutations (Q129R, K141E, and Y161N) of the "a" determinant of the HBV surface gene. Our findings suggest that mother-to-teenager transmission of (hn)HBI can occur among those in the neonatal HBV vaccination program.

OCCURRENCE OF ENTERIC VIRUSES IN SURFACE WATERS

Science.gov (United States)

Human enteric viruses cause a number of diseases when individuals are exposed to contaminated drinking & recreational waters. Vaccination against poliovirus has virtually eliminated poliomyelitis from the planet. Other members of enterovirus group cause numerous diseases. Hepatit...

Systematic analysis of protein identity between Zika virus and other arthropod-borne viruses.

Science.gov (United States)

Chang, Hsiao-Han; Huber, Roland G; Bond, Peter J; Grad, Yonatan H; Camerini, David; Maurer-Stroh, Sebastian; Lipsitch, Marc

2017-07-01

To analyse the proportions of protein identity between Zika virus and dengue, Japanese encephalitis, yellow fever, West Nile and chikungunya viruses as well as polymorphism between different Zika virus strains. We used published protein sequences for the Zika virus and obtained protein sequences for the other viruses from the National Center for Biotechnology Information (NCBI) protein database or the NCBI virus variation resource. We used BLASTP to find regions of identity between viruses. We quantified the identity between the Zika virus and each of the other viruses, as well as within-Zika virus polymorphism for all amino acid k -mers across the proteome, with k ranging from 6 to 100. We assessed accessibility of protein fragments by calculating the solvent accessible surface area for the envelope and nonstructural-1 (NS1) proteins. In total, we identified 294 Zika virus protein fragments with both low proportion of identity with other viruses and low levels of polymorphisms among Zika virus strains. The list includes protein fragments from all Zika virus proteins, except NS3. NS4A has the highest number (190 k -mers) of protein fragments on the list. We provide a candidate list of protein fragments that could be used when developing a sensitive and specific serological test to detect previous Zika virus infections.

Multiple oncogenic viruses identified in Ocular surface squamous neoplasia in HIV-1 patients

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Bisson Gregory

2010-03-01

Full Text Available Abstract Background Ocular surface squamous neoplasia (OSSN is a rare cancer that has increased in incidence with the HIV pandemic in Africa. The underlying cause of this cancer in HIV-infected patients from Botswana is not well defined. Results Tissues were obtained from 28 OSSN and 8 pterygia patients. The tissues analyzed from OSSN patients were 83% positive for EBV, 75% were HPV positive, 70% were KSHV positive, 75% were HSV-1/2 positive, and 61% were CMV positive by PCR. Tissues from pterygium patients were 88% positive for EBV, 75% were HPV positive, 50% were KSHV positive, and 60% were CMV positive. None of the patients were JC or BK positive. In situ hybridization and immunohistochemistry analyses further identified HPV, EBV, and KSHV in a subset of the tissue samples. Conclusion We identified the known oncogenic viruses HPV, KSHV, and EBV in OSSN and pterygia tissues. The presence of these tumor viruses in OSSN suggests that they may contribute to the development of this malignancy in the HIV population. Further studies are necessary to characterize the molecular mechanisms associated with viral antigens and their potential role in the development of OSSN.

Inhibition of Interferon Induction and Action by the Nairovirus Nairobi Sheep Disease Virus/Ganjam Virus

OpenAIRE

Holzer, Barbara; Bakshi, Siddharth; Bridgen, Anne; Baron, Michael D.

2011-01-01

The Nairoviruses are an important group of tick-borne viruses that includes pathogens of man (Crimean Congo hemorrhagic fever virus) and livestock animals (Dugbe virus, Nairobi sheep disease virus (NSDV)). NSDV is found in large parts of East Africa and the Indian subcontinent (where it is known as Ganjam virus). We have investigated the ability of NSDV to antagonise the induction and actions of interferon. Both pathogenic and apathogenic isolates could actively inhibit the induction of type ...

Varicella Zoster Virus and Large Vessel Vasculitis, the Absence of an Association.

Science.gov (United States)

Procop, Gary W; Eng, Charis; Clifford, Alison; Villa-Forte, Alexandra; Calabrese, Leonard H; Roselli, Eric; Svensson, Lars; Johnston, Douglas; Pettersson, Gosta; Soltesz, Edward; Lystad, Lisa; Perry, Julian D; Blandford, Alexander; Wilson, Deborah A; Hoffman, Gary S

2017-01-01

It is controversial whether microorganisms play a role in the pathogenesis of large and medium vessel vasculitides (eg, giant cell arteritis [GCA], Takayasu arteritis [TAK] and focal idiopathic aortitis [FIA]). Recent studies have reported the presence of Varicella Zoster Virus (VZV) within formalin-fixed, paraffin-embedded temporal arteries and aortas of about three-quarters or more of patients with these conditions, and in a minority of controls. In a prospective study, we sought to confirm these findings using DNA extracted from vessels that were harvested under surgically aseptic conditions and snap frozen. DNA samples extracted from 11 surgically sterile temporal arteries and 31 surgically sterile thoracic aortas were used in an attempt to identify the vessel-associated VZV genome. Two different validated PCR methods were used. Thirty-one thoracic aorta aneurysm specimens included biopsies from 8 patients with GCA, 2 from patients with TAK, 6 from patients with FIA, and 15 from patients without vasculitis, who had non-inflammatory aneurysms. Eleven temporal artery biopsies were collected from 5 patients with GCA and 6 controls. The presence of VZV was not identified in either the specimens from patients with large vessel vasculitis or from the controls. Using surgically sterile snap-frozen specimens, we were unable to confirm recent reports of the presence of VZV in either aortas or temporal arteries from patients with large vessel vasculitis or controls.

Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients.

Science.gov (United States)

Hønge, Bl; Jespersen, S; Medina, C; Té, Ds; da Silva, Zj; Ostergaard, L; Laursen, Al; Wejse, C; Krarup, H; Erikstrup, C

2014-10-01

In the case of coinfection with HIV and hepatitis B virus (HBV) and/or hepatitis C virus (HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely to detect HBV surface antigen (HBsAg) and anti-HCV among HIV-infected patients in Guinea-Bissau. Blood samples from HIV-infected patients in Guinea-Bissau were stored after testing for HBsAg and anti-HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti-HCV in Denmark. Two rapid tests were used in Guinea-Bissau: HBsAg Strip Ref 2034 (VEDA.LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN (Bhat Bio-Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended on the antigen and antibody concentrations, respectively. Sex, age, CD4 cell count and antiretroviral therapy status did not differ between false negative and true positive samples in either of the tests. The study is limited by a low number of anti-HCV positive samples. New diagnostic rapid tests should always be evaluated in the setting in which they will be used before implementation. © 2014 British HIV Association.

Large area, surface discharge pumped, vacuum ultraviolet light source

Science.gov (United States)

Sze, R.C.; Quigley, G.P.

1996-12-17

Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

Host determinant residue lysine 627 lies on the surface of a discrete, folded domain of influenza virus polymerase PB2 subunit.

Directory of Open Access Journals (Sweden)

Franck Tarendeau

Full Text Available Understanding how avian influenza viruses adapt to human hosts is critical for the monitoring and prevention of future pandemics. Host specificity is determined by multiple sites in different viral proteins, and mutation of only a limited number of these sites can lead to inter-species transmission. Several of these sites have been identified in the viral polymerase, the best characterised being position 627 in the PB2 subunit. Efficient viral replication at the relatively low temperature of the human respiratory tract requires lysine 627 rather than the glutamic acid variant found systematically in avian viruses. However, the molecular mechanism by which any of these host specific sites determine host range are unknown, although adaptation to host factors is frequently evoked. We used ESPRIT, a library screening method, to identify a new PB2 domain that contains a high density of putative host specific sites, including residue 627. The X-ray structure of this domain (denoted the 627-domain exhibits a novel fold with the side-chain of Lys627 solvent exposed. The structure of the K627E mutated domain shows no structural differences but the charge reversal disrupts a striking basic patch on the domain surface. Five other recently proposed host determining sites of PB2 are also located on the 627-domain surface. The structure of the complete C-terminal region of PB2 comprising the 627-domain and the previously identified NLS-domain, which binds the host nuclear import factor importin alpha, was also determined. The two domains are found to pack together with a largely hydrophilic interface. These data enable a three-dimensional mapping of approximately half of PB2 sites implicated in cross-species transfer onto a single structural unit. Their surface location is consistent with roles in interactions with other viral proteins or host factors. The identification and structural characterization of these well-defined PB2 domains will help design

Behavior of plasma facing surface in the large helical device

International Nuclear Information System (INIS)

Hino, T.; Nobuta, Y.; Sagara, A.

2002-10-01

Material probes have been installed at the inner walls along poloidal direction in LHD from the first experimental campaign. After each the campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was considerably cleaned by helium glow discharge conditionings. For the 3rd and 4th campaigns, graphite tiles were installed at entire divertor strike region, and then the wall condition significantly changed compared to the case of stainless steel wall. The erosion of graphite took place during the main discharges and the eroded carbon deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, amount of retained discharge gas such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristics of the LHD wall is a large retention of helium gas since the wall temperature is limited below 368 K. In order to reduce the recycling of discharge gas, the wall heating before the experimental campaign and the surface heating between the main discharge shots are planned. (author)

Behavior of plasma facing surface in the large helical device

International Nuclear Information System (INIS)

Hino, T.; Nobuta, Y.; Sagara, A.

2002-01-01

Material probes have been installed at the inner walls along poloidal direction in LHD from the first experimental campaign. After each campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was considerably cleaned by helium glow discharge conditionings. For the 3rd and 4th campaigns, graphite tiles were installed at entire divertor strike region, and then the wall condition significantly changed compared to the case of stainless steel wall. The erosion of graphite took place during the main discharges and the eroded carbon deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, amount of retained discharge gas such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristics of the LHD wall is a large retention of helium gas since the wall temperature is limited below 368 K. In order to reduce the recycling of discharge gas, the wall heating before the experimental campaign and the surface heating between the main discharge shots are planned. (author)

Behavior of plasma facing surface in the large helical device

Energy Technology Data Exchange (ETDEWEB)

Hino, T.; Nobuta, Y. [Hokkaido Univ., Dept. of Nuclear Engineering, Sapporo, Hokkaido (Japan); Sagara, A. [National Inst. for Fusion Science, Toki, Gifu (Japan)] [and others

2002-11-01

Material probes have been installed at the inner walls along poloidal direction in LHD from the first experimental campaign. After each campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was considerably cleaned by helium glow discharge conditionings. For the 3rd and 4th campaigns, graphite tiles were installed at entire divertor strike region, and then the wall condition significantly changed compared to the case of stainless steel wall. The erosion of graphite took place during the main discharges and the eroded carbon deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, amount of retained discharge gas such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristics of the LHD wall is a large retention of helium gas since the wall temperature is limited below 368 K. In order to reduce the recycling of discharge gas, the wall heating before the experimental campaign and the surface heating between the main discharge shots are planned. (author)

West Nile virus meningitis in a patient with human immunodeficiency virus type 1 infection

Directory of Open Access Journals (Sweden)

D. Pilalas

2017-09-01

Full Text Available The emergence of West Nile virus lineage 2 in central Macedonia, Greece, in 2010 resulted in large outbreaks for 5 consecutive years. We report a case of viral meningitis in an individual infected with human immunodeficiency virus type 1, which preceded the recognition of the outbreak and was confirmed retrospectively as West Nile virus neuroinvasive disease.

Factors Influencing Virulence and Plaque Properties of Attenuated Venezuelan Equine Encephalomyelitis Virus Populations

Science.gov (United States)

Hearn, Henry J.; Seliokas, Zenonas V.; Andersen, Arthur A.

1969-01-01

A minority of stable large-plaque virus increased proportionally in stored unstable attenuated (9t) Venezuelan equine encephalomyelitis virus populations. L-cell-grown progeny (9t2) of stored 9t showed large amounts of large-plaque virus and increased virulence. Small-plaque virus inhibited large-plaque virus but not the reverse. Serial passage of small-plaque virus from 9t2 yielded a strain (20t) that was more attenuated than 9t. PMID:5823235

Novel antibody binding determinants on the capsid surface of serotype O foot-and-mouth disease virus

Science.gov (United States)

Asfor, Amin S.; Upadhyaya, Sasmita; Knowles, Nick J.; King, Donald P.; Paton, David J.

2014-01-01

Five neutralizing antigenic sites have been described for serotype O foot-and-mouth disease viruses (FMDV) based on monoclonal antibody (mAb) escape mutant studies. However, a mutant virus selected to escape neutralization of mAb binding at all five sites was previously shown to confer complete cross-protection with the parental virus in guinea pig challenge studies, suggesting that amino acid residues outside the mAb binding sites contribute to antibody-mediated in vivo neutralization of FMDV. Comparison of the ability of bovine antisera to neutralize a panel of serotype O FMDV identified three novel putative sites at VP2-74, VP2-191 and VP3-85, where amino acid substitutions correlated with changes in sero-reactivity. The impact of these positions was tested using site-directed mutagenesis to effect substitutions at critical amino acid residues within an infectious copy of FMDV O1 Kaufbeuren (O1K). Recovered viruses containing additional mutations at VP2-74 and VP2-191 exhibited greater resistance to neutralization with both O1K guinea pig and O BFS bovine antisera than a virus that was engineered to include only mutations at the five known antigenic sites. The changes at VP2-74 and VP3-85 are adjacent to critical amino acids that define antigenic sites 2 and 4, respectively. However VP2-191 (17 Å away from VP2-72), located at the threefold axis and more distant from previously identified antigenic sites, exhibited the most profound effect. These findings extend our knowledge of the surface features of the FMDV capsid known to elicit neutralizing antibodies, and will improve our strategies for vaccine strain selection and rational vaccine design. PMID:24584474

Serum Hepatitis C virus and hepatitis B surface antigenaemia in ...

African Journals Online (AJOL)

Acute hepatitis is common in Nigeria and hepatitis B virus (HBV) infection has been a major aetiological factor. However, the role of Hepatitis C virus (HCV) infection is yet undetermined. Forty-five consecutive Nigerian patients with acute Icteric hepatitis (AIH) attending the Medical Clinic of the University College Hospital, ...

Human Papilloma Virus Infection Does Not Predict Response to Interferon Therapy in Ocular Surface Squamous Neoplasia.

Science.gov (United States)

Galor, Anat; Garg, Nisha; Nanji, Afshan; Joag, Madhura; Nuovo, Gerard; Palioura, Sotiria; Wang, Gaofeng; Karp, Carol L

2015-11-01

To identify the frequency of human papilloma virus (HPV) in ocular surface squamous neoplasia (OSSN) and to evaluate differences in clinical features and treatment response of tumors with positive versus negative HPV results. Retrospective case series. Twenty-seven patients with OSSN. Ocular surface squamous neoplasia specimens were analyzed for the presence of HPV. Clinical features and response to interferon were determined retrospectively and linked to the presence (versus absence) of HPV. Clinical characteristics of OSSN by HPV status. Twenty-one of 27 tumors (78%) demonstrated positive HPV results. The HPV genotypes identified included HPV-16 in 10 tumors (48%), HPV-31 in 5 tumors, HPV-33 in 1 tumor, HPV-35 in 2 tumors, HPV-51 in 2 tumors, and a novel HPV in 3 tumors (total of 23 tumors because 1 tumor had 3 identified genotypes). Tumors found in the superior limbus were more likely to show positive HPV results (48% vs. 0%; P=0.06, Fisher exact test). Tumors with positive HPV-16 results were larger (68 vs. 34 mm2; P=0.08, Mann-Whitney U test) and were more likely to have papillomatous morphologic features (50% vs. 12%; P=0.07, Fisher exact test) compared with tumors showing negative results for HPV-16. Human papilloma virus status was not found to be associated with response to interferon therapy (P=1.0, Fisher exact test). Metrics found to be associated with a nonfavorable response to interferon were male gender and tumors located in the superior conjunctivae. The presence of HPV in OSSN seems to be more common in lesions located in the nonexposed, superior limbus. Human papilloma virus presence does not seem to be required for a favorable response to interferon therapy. Copyright © 2015 American Academy of Ophthalmology. All rights reserved.

Contact Mechanics of a Small Icosahedral Virus

NARCIS (Netherlands)

Zeng, Cheng; Hernando-Pérez, Mercedes; Ma, Xiang; Schoot, Paul van der; Zandi, Roya; Dragnea, Bogdan

2017-01-01

Virus binding to a surface results at least locally, at the contact area, in stress and potential structural perturbation of the virus cage. Here we address the question of the role of substrate-induced deformation in the overall virus mechanical response to the adsorption event. This question may

Investigation on large-area fabrication of vivid shark skin with superior surface functions

Science.gov (United States)

Chen, Huawei; Zhang, Xin; Ma, Lingxi; Che, Da; Zhang, Deyuan; Sudarshan, T. S.

2014-10-01

Shark skin has attracted worldwide attention because of its superior drag reduction, antifouling performance induced from its unique surface morphology. Although the vivid shark skin has been fabricated by a bio-replicated micro-imprinting approach in previous studies and superior drag reduction effect has been validated in water tunnel, continuous large-area fabrication is still an obstacle to wide apply. In this paper, one novel bio-replication coating technology is proposed for large-area transfer of shark skin based on rapid UV curable paint. Apart from design of coating system, bio-replication accuracy of surface morphology was validated about 97% by comparison between shark skin template and coating surface morphology. Finally, the drag reduction and anti-fouling function of coating surface were tested in water tunnel and open algae pond respectively. Drag reduction rate of coating surface was validated about 12% higher and anti-fouling was proved to about hundred times ameliorate, all of which are more excellent than simple 2D riblet surface.

Prevalence and clinical implications of epstein-barr virus infection in de novo diffuse large B-cell lymphoma in Western countries

DEFF Research Database (Denmark)

Ok, Chi Young; Li, Ling; Xu-Monette, Zijun Y

2014-01-01

PURPOSE: Epstein-Barr virus-positive (EBV(+)) diffuse large B-cell lymphoma (DLBCL) of the elderly is a variant of DLBCL with worse outcome that occurs most often in East-Asian countries and is uncommon in the Western hemisphere. We studied the largest cohort of EBV(+) DLBCL, independent of age...

Isotropic Surface Remeshing without Large and Small Angles

KAUST Repository

Wang, Yiqun; Yan, Dong-Ming; Liu, Xiaohan; Tang, Chengcheng; Guo, Jianwei; Zhang, Xiaopeng; Wonka, Peter

2018-01-01

We introduce a novel algorithm for isotropic surface remeshing which progressively eliminates obtuse triangles and improves small angles. The main novelty of the proposed approach is a simple vertex insertion scheme that facilitates the removal of large angles, and a vertex removal operation that improves the distribution of small angles. In combination with other standard local mesh operators, e.g., connectivity optimization and local tangential smoothing, our algorithm is able to remesh efficiently a low-quality mesh surface. Our approach can be applied directly or used as a post-processing step following other remeshing approaches. Our method has a similar computational efficiency to the fastest approach available, i.e., real-time adaptive remeshing [1]. In comparison with state-of-the-art approaches, our method consistently generates better results based on evaluations using different metrics.

Isotropic Surface Remeshing without Large and Small Angles

KAUST Repository

Wang, Yiqun

2018-05-18

We introduce a novel algorithm for isotropic surface remeshing which progressively eliminates obtuse triangles and improves small angles. The main novelty of the proposed approach is a simple vertex insertion scheme that facilitates the removal of large angles, and a vertex removal operation that improves the distribution of small angles. In combination with other standard local mesh operators, e.g., connectivity optimization and local tangential smoothing, our algorithm is able to remesh efficiently a low-quality mesh surface. Our approach can be applied directly or used as a post-processing step following other remeshing approaches. Our method has a similar computational efficiency to the fastest approach available, i.e., real-time adaptive remeshing [1]. In comparison with state-of-the-art approaches, our method consistently generates better results based on evaluations using different metrics.

Large Area Diamond Tribological Surfaces with Negligible Wear in Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In Phase I we propose to demonstrate the processing of very large area diamond sliding bearings and tribological surfaces. The bearings and surfaces will experience...

Cell surface antigens of radiation leukemia virus-induced BALB/c leukemias defined by syngeneic cytotoxic T lymphocytes

International Nuclear Information System (INIS)

Kaneko, Yukio; Oettgen, H.F.; Obata, Yuichi; Nakayama, Eiichi.

1989-01-01

Two cell surface antigens of mouse leukemias were defined by BALB/c cytotoxic T lymphocytes (CTL) generated against syngeneic radiation leukemia virus (RadLV)-induced leukemia, BALBRV1 or BALBRVD. Hyperimmunization of BALB/c mice with irradiated leukemias followed by in vitro sensitization of primed spleen cells resulted in the generation of CTL with high killing activity. The specificity of CTL was examined by direct cytotoxicity assays and competitive inhibition assays. A shared cell surface antigen, designated as BALBRV1 antigen, was detected by BALB/c anti-BALBRV1 CTL. BALBRV1 antigen was expressed not only on RadLV-induced BALB/c leukemias except for BALBRVD, but also on spontaneous or X-ray-induced BALB/c leukemias, chemically-induced leukemias with the H-2 d haplotype and some chemically-induced BALB/c sarcomas. In contrast, a unique cell surface antigen, designated as BALBRVD antigen, was detected by BALB/c anti-BALBRVD CTL. BALBRVD antigen was expressed only on BALBRVD, but not on thirty-nine normal lymphoid or tumor cells. These two antigens could be distinguished from those previously defined on Friend, Moloney, Rauscher or Gross murine leukemia virus (MuLV) leukemias, or MuLV-related antigens. Both cytotoxic responses were blocked by antisera against H-2K d , but not H-2D d . The relationship of BALBRV1 antigen and BALBRVD antigen to endogenous MuLV is discussed with regard to the antigenic distribution on tumor cell lines. (author)

Decontamination of large horizontal concrete surfaces outdoors

International Nuclear Information System (INIS)

Barbier, M.M.; Chester, C.V.

1980-01-01

A study is being conducted of the resources and planning that would be required to clean up an extensive contamination of the outdoor environment. As part of this study, an assessment of the fleet of machines needed for decontaminating large outdoor surfaces of horizontal concrete will be attempted. The operations required are described. The performance of applicable existing equipment is analyzed in terms of area cleaned per unit time, and the comprehensive cost of decontamination per unit area is derived. Shielded equipment for measuring directional radiation and continuously monitoring decontamination work are described. Shielding of drivers' cabs and remote control vehicles is addressed

Mouse Saliva Inhibits Transit of Influenza Virus to the Lower Respiratory Tract by Efficiently Blocking Influenza Virus Neuraminidase Activity.

Science.gov (United States)

Gilbertson, Brad; Ng, Wy Ching; Crawford, Simon; McKimm-Breschkin, Jenny L; Brown, Lorena E

2017-07-15

We previously identified a novel inhibitor of influenza virus in mouse saliva that halts the progression of susceptible viruses from the upper to the lower respiratory tract of mice in vivo and neutralizes viral infectivity in MDCK cells. Here, we investigated the viral target of the salivary inhibitor by using reverse genetics to create hybrid viruses with some surface proteins derived from an inhibitor-sensitive strain and others from an inhibitor-resistant strain. These viruses demonstrated that the origin of the viral neuraminidase (NA), but not the hemagglutinin or matrix protein, was the determinant of susceptibility to the inhibitor. Comparison of the NA sequences of a panel of H3N2 viruses with differing sensitivities to the salivary inhibitor revealed that surface residues 368 to 370 (N2 numbering) outside the active site played a key role in resistance. Resistant viruses contained an EDS motif at this location, and mutation to either EES or KDS, found in highly susceptible strains, significantly increased in vitro susceptibility to the inhibitor and reduced the ability of the virus to progress to the lungs when the viral inoculum was initially confined to the upper respiratory tract. In the presence of saliva, viral strains with a susceptible NA could not be efficiently released from the surfaces of infected MDCK cells and had reduced enzymatic activity based on their ability to cleave substrate in vitro This work indicates that the mouse has evolved an innate inhibitor similar in function, though not in mechanism, to what humans have created synthetically as an antiviral drug for influenza virus. IMPORTANCE Despite widespread use of experimental pulmonary infection of the laboratory mouse to study influenza virus infection and pathogenesis, to our knowledge, mice do not naturally succumb to influenza. Here, we show that mice produce their own natural form of neuraminidase inhibitor in saliva that stops the virus from reaching the lungs, providing a

Behavior of plasma facing surfaces in the large helical device

International Nuclear Information System (INIS)

Hino, T.; Nobuta, Y.; Sagara, A.

2003-01-01

Material probes have been installed at the inner walls along the poloidal direction in LHD from the first experimental campaign. After each campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was thoroughly cleaned by helium glow discharge conditioning. For the 3rd and 4th campaigns, graphite tiles were installed over the entire divertor strike region, and then the wall condition was significantly changed compared to the case of a stainless steel wall. Graphite erosion took place during the main discharges and the eroded carbon was deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, the amount of retained discharge gases such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristic of the LHD wall is a large retention of helium gas since the wall temperature is limited to below 368 K. In order to reduce the recycling of discharge gas, wall heating before the experimental campaign and surface heating between the main discharge shots are planned. (author)

A recombinant chimeric La Crosse virus expressing the surface glycoproteins of Jamestown Canyon virus is immunogenic and protective against challenge with either parental virus in mice or monkeys.

Science.gov (United States)

Bennett, R S; Gresko, A K; Nelson, J T; Murphy, B R; Whitehead, S S

2012-01-01

La Crosse virus (LACV) and Jamestown Canyon virus (JCV), family Bunyaviridae, are mosquito-borne viruses that are endemic in North America and recognized as etiologic agents of encephalitis in humans. Both viruses belong to the California encephalitis virus serogroup, which causes 70 to 100 cases of encephalitis a year. As a first step in creating live attenuated viral vaccine candidates for this serogroup, we have generated a recombinant LACV expressing the attachment/fusion glycoproteins of JCV. The JCV/LACV chimeric virus contains full-length S and L segments derived from LACV. For the M segment, the open reading frame (ORF) of LACV is replaced with that derived from JCV and is flanked by the untranslated regions of LACV. The resulting chimeric virus retained the same robust growth kinetics in tissue culture as observed for either parent virus, and the virus remains highly infectious and immunogenic in mice. Although both LACV and JCV are highly neurovirulent in 21 day-old mice, with 50% lethal dose (LD₅₀) values of 0.1 and 0.5 log₁₀ PFU, respectively, chimeric JCV/LACV is highly attenuated and does not cause disease even after intracerebral inoculation of 10³ PFU. Parenteral vaccination of mice with 10¹ or 10³ PFU of JCV/LACV protected against lethal challenge with LACV, JCV, and Tahyna virus (TAHV). The chimeric virus was infectious and immunogenic in rhesus monkeys and induced neutralizing antibodies to JCV, LACV, and TAHV. When vaccinated monkeys were challenged with JCV, they were protected against the development of viremia. Generation of highly attenuated yet immunogenic chimeric bunyaviruses could be an efficient general method for development of vaccines effective against these pathogenic viruses.

Selective interaction of heparin with the variable region 3 within surface glycoprotein of laboratory-adapted feline immunodeficiency virus.

Directory of Open Access Journals (Sweden)

Qiong-Ying Hu

Full Text Available Heparan sulfate proteoglycans (HSPG can act as binding receptors for certain laboratory-adapted (TCA strains of feline immunodeficiency virus (FIV and human immunodeficiency virus (HIV. Heparin, a soluble heparin sulfate (HS, can inhibit TCA HIV and FIV entry mediated by HSPG interaction in vitro. In the present study, we further determined the selective interaction of heparin with the V3 loop of TCA of FIV. Our current results indicate that heparin selectively inhibits infection by TCA strains, but not for field isolates (FS. Heparin also specifically interferes with TCA surface glycoprotein (SU binding to CXCR4, by interactions with HSPG binding sites on the V3 loop of the FIV envelope protein. Peptides representing either the N- or C-terminal side of the V3 loop and containing HSPG binding sites were able to compete away the heparin block of TCA SU binding to CXCR4. Heparin does not interfere with the interaction of SU with anti-V3 antibodies that target the CXCR4 binding region or with the interaction between FS FIV and anti-V3 antibodies since FS SU has no HSPG binding sites within the HSPG binding region. Our data show that heparin blocks TCA FIV infection or entry not only through its competition of HSPG on the cell surface interaction with SU, but also by its interference with CXCR4 binding to SU. These studies aid in the design and development of heparin derivatives or analogues that can inhibit steps in virus infection and are informative regarding the HSPG/SU interaction.

Large-eddy simulation of open channel flow with surface cooling

International Nuclear Information System (INIS)

Walker, R.; Tejada-Martínez, A.E.; Martinat, G.; Grosch, C.E.

2014-01-01

Highlights: • Open channel flow comparable to a shallow tidal ocean flow is simulated using LES. • Unstable stratification is imposed by a constant surface cooling flux. • Full-depth, convection-driven, rotating supercells develop when cooling is applied. • Strengthening of cells occurs corresponding to an increasing of the Rayleigh number. - Abstract: Results are presented from large-eddy simulations of an unstably stratified open channel flow, driven by a uniform pressure gradient and with zero surface shear stress and a no-slip lower boundary. The unstable stratification is applied by a constant cooling flux at the surface and an adiabatic bottom wall, with a constant source term present to ensure the temperature reaches a statistically steady state. The structure of the turbulence and the turbulence statistics are analyzed with respect to the Rayleigh number (Ra τ ) representative of the surface buoyancy relative to shear. The impact of the surface cooling-induced buoyancy on mean and root mean square of velocity and temperature, budgets of turbulent kinetic energy (and components), Reynolds shear stress and vertical turbulent heat flux will be investigated. Additionally, colormaps of velocity fluctuations will aid the visualization of turbulent structures on both vertical and horizontal planes in the flow. Under neutrally stratified conditions the flow is characterized by weak, full-depth, streamwise cells similar to but less coherent than Couette cells in plane Couette flow. Increased Ra τ and thus increased buoyancy effects due to surface cooling lead to full-depth convection cells of significantly greater spanwise size and coherence, thus termed convective supercells. Full-depth convective cell structures of this magnitude are seen for the first time in this open channel domain, and may have important implications for turbulence analysis in a comparable tidally-driven ocean boundary layer. As such, these results motivate further study of the

The Viral Transcription Group Determines the HLA Class I Cellular Immune Response Against Human Respiratory Syncytial Virus*

Science.gov (United States)

Johnstone, Carolina; Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Infantes, Susana; Lemonnier, François A.; David, Chella S.; Admon, Arie; López, Daniel

2015-01-01

The cytotoxic T-lymphocyte-mediated killing of virus-infected cells requires previous recognition of short viral antigenic peptides bound to human leukocyte antigen class I molecules that are exposed on the surface of infected cells. The cytotoxic T-lymphocyte response is critical for the clearance of human respiratory syncytial virus infection. In this study, naturally processed viral human leukocyte antigen class I ligands were identified with mass spectrometry analysis of complex human leukocyte antigen-bound peptide pools isolated from large amounts of human respiratory syncytial virus-infected cells. Acute antiviral T-cell response characterization showed that viral transcription determines both the immunoprevalence and immunodominance of the human leukocyte antigen class I response to human respiratory syncytial virus. These findings have clear implications for antiviral vaccine design. PMID:25635267

Spatial analysis of feline immunodeficiency virus infection in cougars.

Science.gov (United States)

Wheeler, David C; Waller, Lance A; Biek, Roman

2010-07-01

The cougar (Puma concolor) is a large predatory feline found widely in the Americas that is susceptible to feline immunodeficiency virus (FIV), a fast-evolving lentivirus found in wild feline species that is analogous to simian immunodeficiency viruses in wild primates and belongs to the same family of viruses as human immunodeficiency virus. FIV infection in cougars can lead to a weakened immune system that creates opportunities for other infecting agents. FIV prevalence and lineages have been studied previously in several areas in the western United States, but typically without spatially explicit statistical techniques. To describe the distribution of FIV in a sample of cougars located in the northern Rocky Mountain region of North America, we first used kernel density ratio estimation to map the log relative risk of FIV. The risk surface showed a significant cluster of FIV in northwestern Montana. We also used Bayesian cluster models for genetic data to investigate the spatial structure of the feline immunodeficiency virus with virus genetic sequence data. A result of the models was two spatially distinct FIV lineages that aligned considerably with an interstate highway in Montana. Our results suggest that the use of spatial information and models adds novel insight when investigating an infectious animal disease. The results also suggest that the influence of landscape features likely plays an important role in the spatiotemporal spread of an infectious disease within wildlife populations.

Plasma processing of large curved surfaces for superconducting rf cavity modification

Directory of Open Access Journals (Sweden)

J. Upadhyay

2014-12-01

Full Text Available Plasma-based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF cavities. We have demonstrated surface layer removal in an asymmetric nonplanar geometry, using a simple cylindrical cavity. The etching rate is highly correlated with the shape of the inner electrode, radio-frequency (rf circuit elements, gas pressure, rf power, chlorine concentration in the Cl_{2}/Ar gas mixtures, residence time of reactive species, and temperature of the cavity. Using variable radius cylindrical electrodes, large-surface ring-shaped samples, and dc bias in the external circuit, we have measured substantial average etching rates and outlined the possibility of optimizing plasma properties with respect to maximum surface processing effect.

Contact Mechanics of a Small Icosahedral Virus

Science.gov (United States)

Zeng, Cheng; Hernando-Pérez, Mercedes; Dragnea, Bogdan; Ma, Xiang; van der Schoot, Paul; Zandi, Roya

2017-07-01

A virus binding to a surface causes stress of the virus cage near the contact area. Here, we investigate the potential role of substrate-induced structural perturbation in the mechanical response of virus particles to adsorption. This is particularly relevant to the broad category of viruses stabilized by weak noncovalent interactions. We utilize atomic force microscopy to measure height distributions of the brome mosaic virus upon adsorption from solution on atomically flat substrates and present a continuum model that captures our observations and provides estimates of elastic properties and of the interfacial energy of the virus, without recourse to indentation.

Large-Scale Genomic Analysis of Codon Usage in Dengue Virus and Evaluation of Its Phylogenetic Dependence

Science.gov (United States)

Lara-Ramírez, Edgar E.; Salazar, Ma Isabel; López-López, María de Jesús; Salas-Benito, Juan Santiago; Sánchez-Varela, Alejandro

2014-01-01

The increasing number of dengue virus (DENV) genome sequences available allows identifying the contributing factors to DENV evolution. In the present study, the codon usage in serotypes 1–4 (DENV1–4) has been explored for 3047 sequenced genomes using different statistics methods. The correlation analysis of total GC content (GC) with GC content at the three nucleotide positions of codons (GC1, GC2, and GC3) as well as the effective number of codons (ENC, ENCp) versus GC3 plots revealed mutational bias and purifying selection pressures as the major forces influencing the codon usage, but with distinct pressure on specific nucleotide position in the codon. The correspondence analysis (CA) and clustering analysis on relative synonymous codon usage (RSCU) within each serotype showed similar clustering patterns to the phylogenetic analysis of nucleotide sequences for DENV1–4. These clustering patterns are strongly related to the virus geographic origin. The phylogenetic dependence analysis also suggests that stabilizing selection acts on the codon usage bias. Our analysis of a large scale reveals new feature on DENV genomic evolution. PMID:25136631

A molecular assembly system for presentation of antigens on the surface of HBc virus-like particles

International Nuclear Information System (INIS)

Blokhina, Elena A.; Kuprianov, Victor V.; Stepanova, Ludmila A.; Tsybalova, Ludmila M.; Kiselev, Oleg I.; Ravin, Nikolai V.; Skryabin, Konstantin G.

2013-01-01

Hepatitis B virus-like particles, icosahedral structures formed by multiple core protein dimers, are promising immune-enhancing vaccine carriers for foreign antigens. Insertions into the surface-exposed immunodominant loop are especially immunogenic. However, the need to conserve the particulate structure to ensure high immunogenicity imposes restraints on the nature of the heterologous sequence that can be inserted. We propose a new approach to constructing HBc particles linked to the target epitopes that relies on non-covalent interactions between the epitope and pre-assembled unmodified HBc particles. Interaction was enabled by fusion of the epitope to the GSLLGRMKGA peptide, binding to the spike tips. This peptide may be used as a “binding tag” allowing in vitro construction of HBc particles carrying the target peptide. Such virus-like particles carrying multiple copies of the extracellular domain of the M2 protein of different influenza strains appeared to be highly immunogenic and protected immunised mice against a lethal influenza challenge.

A molecular assembly system for presentation of antigens on the surface of HBc virus-like particles

Energy Technology Data Exchange (ETDEWEB)

Blokhina, Elena A.; Kuprianov, Victor V. [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); Stepanova, Ludmila A.; Tsybalova, Ludmila M. [Research Institute of Influenza, Russian Federation Ministry of Health and Social Development, St. Petersburg (Russian Federation); Kiselev, Oleg I. [Research Institute of Influenza, Russian Federation Ministry of Health and Social Development, St. Petersburg (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation); Ravin, Nikolai V., E-mail: nravin@biengi.ac.ru [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation); Skryabin, Konstantin G. [Centre ' Bioengineering' , Russian Academy of Sciences, 117312 Prosp. 60-letya Oktyabrya 7-1, Moscow (Russian Federation); GenNanotech Ltd, St. Petersburg (Russian Federation)

2013-01-20

Hepatitis B virus-like particles, icosahedral structures formed by multiple core protein dimers, are promising immune-enhancing vaccine carriers for foreign antigens. Insertions into the surface-exposed immunodominant loop are especially immunogenic. However, the need to conserve the particulate structure to ensure high immunogenicity imposes restraints on the nature of the heterologous sequence that can be inserted. We propose a new approach to constructing HBc particles linked to the target epitopes that relies on non-covalent interactions between the epitope and pre-assembled unmodified HBc particles. Interaction was enabled by fusion of the epitope to the GSLLGRMKGA peptide, binding to the spike tips. This peptide may be used as a 'binding tag' allowing in vitro construction of HBc particles carrying the target peptide. Such virus-like particles carrying multiple copies of the extracellular domain of the M2 protein of different influenza strains appeared to be highly immunogenic and protected immunised mice against a lethal influenza challenge.

The nairovirus nairobi sheep disease virus/ganjam virus induces the translocation of protein disulphide isomerase-like oxidoreductases from the endoplasmic reticulum to the cell surface and the extracellular space.

Science.gov (United States)

Lasecka, Lidia; Baron, Michael D

2014-01-01

Nairobi sheep disease virus (NSDV) of the genus Nairovirus causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%; the virus is found in East and Central Africa, and in India, where the virus is called Ganjam virus. NSDV is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus, which also causes a haemorrhagic disease. As with other nairoviruses, replication of NSDV takes place in the cytoplasm and the new virus particles bud into the Golgi apparatus; however, the effect of viral replication on cellular compartments has not been studied extensively. We have found that the overall structure of the endoplasmic reticulum (ER), the ER-Golgi intermediate compartment and the Golgi were unaffected by infection with NSDV. However, we observed that NSDV infection led to the loss of protein disulphide isomerase (PDI), an oxidoreductase present in the lumen of the endoplasmic reticulum (ER) and which assists during protein folding, from the ER. Further investigation showed that NSDV-infected cells have high levels of PDI at their surface, and PDI is also secreted into the culture medium of infected cells. Another chaperone from the PDI family, ERp57, was found to be similarly affected. Analysis of infected cells and expression of individual viral glycoproteins indicated that the NSDV PreGn glycoprotein is involved in redistribution of these soluble ER oxidoreductases. It has been suggested that extracellular PDI can activate integrins and tissue factor, which are involved respectively in pro-inflammatory responses and disseminated intravascular coagulation, both of which manifest in many viral haemorrhagic fevers. The discovery of enhanced PDI secretion from NSDV-infected cells may be an important finding for understanding the mechanisms underlying the pathogenicity of haemorrhagic nairoviruses.

The nairovirus nairobi sheep disease virus/ganjam virus induces the translocation of protein disulphide isomerase-like oxidoreductases from the endoplasmic reticulum to the cell surface and the extracellular space.

Directory of Open Access Journals (Sweden)

Lidia Lasecka

Full Text Available Nairobi sheep disease virus (NSDV of the genus Nairovirus causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%; the virus is found in East and Central Africa, and in India, where the virus is called Ganjam virus. NSDV is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus, which also causes a haemorrhagic disease. As with other nairoviruses, replication of NSDV takes place in the cytoplasm and the new virus particles bud into the Golgi apparatus; however, the effect of viral replication on cellular compartments has not been studied extensively. We have found that the overall structure of the endoplasmic reticulum (ER, the ER-Golgi intermediate compartment and the Golgi were unaffected by infection with NSDV. However, we observed that NSDV infection led to the loss of protein disulphide isomerase (PDI, an oxidoreductase present in the lumen of the endoplasmic reticulum (ER and which assists during protein folding, from the ER. Further investigation showed that NSDV-infected cells have high levels of PDI at their surface, and PDI is also secreted into the culture medium of infected cells. Another chaperone from the PDI family, ERp57, was found to be similarly affected. Analysis of infected cells and expression of individual viral glycoproteins indicated that the NSDV PreGn glycoprotein is involved in redistribution of these soluble ER oxidoreductases. It has been suggested that extracellular PDI can activate integrins and tissue factor, which are involved respectively in pro-inflammatory responses and disseminated intravascular coagulation, both of which manifest in many viral haemorrhagic fevers. The discovery of enhanced PDI secretion from NSDV-infected cells may be an important finding for understanding the mechanisms underlying the pathogenicity of haemorrhagic nairoviruses.

THE POSSIBLE COLLISIONS IN VIRUS INFECTION IMMUNODIAGNOSTICS AND VACCINATION

Directory of Open Access Journals (Sweden)

E. P. Kharchenko

2016-01-01

Full Text Available Antibodies (Ab, especially natural, display multiple specificity not only due to intrinsic conformational dynamics. With computational analysis the distribution of identical and homologous peptides has been studied in surface proteins from RNA and DNA viruses of widely distributed infections. It was established that each virus protein shared the fragments homologous to other virus proteins that allowed to propose the existence of the peptide continuum of the protein relationship (PCPR. Possible manifestations of PCPR are multiple reactivity and autoreactivity in Ab and therefore it is not possible to consider the immune methods of virus identification as high reliable because of crossing interactions. The PCPR excludes the existence of 100% specificity in immune tests for virus identification. Immunodiagnostic collisions may occur either in identification of virus itself or identification of Ab to viruses. Also PCPR may be responsible for heterologous immunity and consequently the infection associated with severe pathology. The comparative analysis of peptide relationship of H1N1 influenza virus nucleoprotein and human proteins found out, beyond early described its common motif with human hypocretin receptor 2, peptides homologous to those in melanotonin and glutamate receptors and three ion channels. It allows to propose that the sleep disorder narcolepsy associated with Pandemrix vaccination (an adjuvanted, influenza pandemic vaccine and also with infection by influenza virus during the 2009 A(H1N1 influenza pandemic may be determined not only by Ab to the peptide motif common to influenza nucleoprotein and hypocretin receptor but also Ab to melanotonin and glutamate receptors and ion channels. Decreasing and even avoiding risks of complications from vaccination may be feasible by means of a computer analysis of vaccine proteins for the occurrence of epitopes homologous to the human protein those and particularly by an analysis of Ab profiles

Large chiral diffeomorphisms on Riemann surfaces and W-algebras

International Nuclear Information System (INIS)

Bandelloni, G.; Lazzarini, S.

2006-01-01

The diffeomorphism action lifted on truncated (chiral) Taylor expansion of a complex scalar field over a Riemann surface is presented in the paper under the name of large diffeomorphisms. After an heuristic approach, we show how a linear truncation in the Taylor expansion can generate an algebra of symmetry characterized by some structure functions. Such a linear truncation is explicitly realized by introducing the notion of Forsyth frame over the Riemann surface with the help of a conformally covariant algebraic differential equation. The large chiral diffeomorphism action is then implemented through a Becchi-Rouet-Stora (BRS) formulation (for a given order of truncation) leading to a more algebraic setup. In this context the ghost fields behave as holomorphically covariant jets. Subsequently, the link with the so-called W-algebras is made explicit once the ghost parameters are turned from jets into tensorial ghost ones. We give a general solution with the help of the structure functions pertaining to all the possible truncations lower or equal to the given order. This provides another contribution to the relationship between Korteweg-de Vries (KdV) flows and W-diffeomorphims

Epidemiology of two large measles virus outbreaks in Catalonia

Science.gov (United States)

Torner, Núria; Anton, Andres; Barrabeig, Irene; Lafuente, Sara; Parron, Ignasi; Arias, César; Camps, Neus; Costa, Josep; Martínez, Ana; Torra, Roser; Godoy, Pere; Minguell, Sofia; Ferrús, Glòria; Cabezas, Carmen; Domínguez, Ángela; Elimination Program Surveillance Network of Spain, the Measles

2013-01-01

Measles cases in the European Region have been increasing in the last decade; this illustrates the challenge of what we are now encountering in the form of pediatric preventable diseases. In Catalonia, autochthonous measles was declared eliminated in the year 2000 as the result of high measles-mumps-rubella vaccine (MMR) coverage for first and second dose (15 mo and 4 y) since the mid-1990s. From then on, sporadic imported cases and small outbreaks appeared, until in 2006–2007 a large measles outbreak affecting mostly unvaccinated toddlers hit the Barcelona Health Region. Consequently, in January 2008, first dose administration of MMR was lowered from 15 to 12 mo of age. A new honeymoon period went by until the end of 2010, when several importations of cases triggered new sustained transmission of different wild measles virus genotypes, but this time striking young adults. The aim of this study is to show the effect of a change in MMR vaccination schedule policy, and the difference in age incidence and hospitalization rates of affected individuals between both outbreaks. Epidemiologic data were obtained by case interviews and review of medical records. Samples for virological confirmation and genotyping of cases were collected as established in the Measles Elimination plan guidelines. Incidence rate (IR), rate ratio (RR) and their 95% CI and hospitalization rate (HR) by age group were determined. Statistic z was used for comparing proportions. Total number of confirmed cases was 305 in the 2010 outbreak and 381 in the 2006–2007 outbreak; mean age 20 y (SD 14.8 y; 3 mo to 51 y) vs. 15 mo (SD 13.1 y; 1 mo to 50 y). Highest proportion of cases was set in ≥ 25 y (47%) vs. 24.2% in 2006 (p < 0.001). Differences in IR for ≤ 15 mo (49/100,000 vs. 278.2/100,000; RR: 3,9; 95%CI 2,9–5.4) and in overall HR 29.8% vs. 15.7% were all statistically significant (p < 0.001). The change of the month of age for the administration of the first MMR dose proved successful to

Vaccination with Recombinant Parainfluenza Virus 5 Expressing Neuraminidase Protects against Homologous and Heterologous Influenza Virus Challenge.

Science.gov (United States)

Mooney, Alaina J; Gabbard, Jon D; Li, Zhuo; Dlugolenski, Daniel A; Johnson, Scott K; Tripp, Ralph A; He, Biao; Tompkins, S Mark

2017-12-01

Seasonal human influenza virus continues to cause morbidity and mortality annually, and highly pathogenic avian influenza (HPAI) viruses along with other emerging influenza viruses continue to pose pandemic threats. Vaccination is considered the most effective measure for controlling influenza; however, current strategies rely on a precise vaccine match with currently circulating virus strains for efficacy, requiring constant surveillance and regular development of matched vaccines. Current vaccines focus on eliciting specific antibody responses against the hemagglutinin (HA) surface glycoprotein; however, the diversity of HAs across species and antigenic drift of circulating strains enable the evasion of virus-inhibiting antibody responses, resulting in vaccine failure. The neuraminidase (NA) surface glycoprotein, while diverse, has a conserved enzymatic site and presents an appealing target for priming broadly effective antibody responses. Here we show that vaccination with parainfluenza virus 5 (PIV5), a promising live viral vector expressing NA from avian (H5N1) or pandemic (H1N1) influenza virus, elicited NA-specific antibody and T cell responses, which conferred protection against homologous and heterologous influenza virus challenges. Vaccination with PIV5-N1 NA provided cross-protection against challenge with a heterosubtypic (H3N2) virus. Experiments using antibody transfer indicate that antibodies to NA have an important role in protection. These findings indicate that PIV5 expressing NA may be effective as a broadly protective vaccine against seasonal influenza and emerging pandemic threats. IMPORTANCE Seasonal influenza viruses cause considerable morbidity and mortality annually, while emerging viruses pose potential pandemic threats. Currently licensed influenza virus vaccines rely on the antigenic match of hemagglutinin (HA) for vaccine strain selection, and most vaccines rely on HA inhibition titers to determine efficacy, despite the growing

A Large Outbreak of Hepatitis C Virus Infections in a Hemodialysis Clinic

Science.gov (United States)

Nguyen, Duc B.; Gutowski, Jennifer; Ghiselli, Margherita; Cheng, Tabitha; Hamdounia, Shadia Bel; Suryaprasad, Anil; Xu, Fujie; Moulton-Meissner, Heather; Hayden, Tonya; Forbi, Joseph C.; Xia, Guo-liang; Arduino, Matthew J.; Patel, Ami; Patel, Priti R.

2016-01-01

BACKGROUND In November and December 2012, 6 patients at a hemodialysis clinic were given a diagnosis of new hepatitis C virus (HCV) infection. OBJECTIVE To investigate the outbreak to identify risk factors for transmission. METHODS A case patient was defined as a patient who was HCV-antibody negative on clinic admission but subsequently was found to be HCV-antibody positive from January 1, 2008, through April 30, 2013. Patient charts were reviewed to identify and describe case patients. The hypervariable region 1 of HCV from infected patients was tested to assess viral genetic relatedness. Infection control practices were evaluated via observations. A forensic chemiluminescent agent was used to identify blood contamination on environmental surfaces after cleaning. RESULTS Eighteen case patients were identified at the clinic from January 1, 2008, through April 30, 2013, resulting in an estimated 16.7% attack rate. Analysis of HCV quasispecies identified 4 separate clusters of transmission involving 11 case patients. The case patients and previously infected patients in each cluster were treated in neighboring dialysis stations during the same shift, or at the same dialysis station on 2 consecutive shifts. Lapses in infection control were identified. Visible and invisible blood was identified on multiple surfaces at the clinic. CONCLUSIONS Epidemiologic and laboratory data confirmed transmission of HCV among numerous patients at the dialysis clinic over 6 years. Infection control breaches were likely responsible. This outbreak highlights the importance of rigorous adherence to recommended infection control practices in dialysis settings. PMID:26573412

Functional interaction between the N- and C-terminal domains of murine leukemia virus surface envelope protein

International Nuclear Information System (INIS)

Lu, C.-W.; Roth, Monica J.

2003-01-01

A series of murine leukemia viruses (MuLVs) with chimeric envelope proteins (Env) was generated to map functional interactions between the N- and the C-terminal domains of surface proteins (SU). All these chimeras have the 4070A amphotropic receptor-binding region flanked by various lengths of Moloney ecotropic N- and C-terminal Env. A charged residue, E49 (E16 on the mature protein), was identified at the N-terminals of Moloney MuLV SU that is important for the interaction with the C-terminal domain of the SU. The region that interacts with E49 was localized between junction 4 (R265 of M-MuLV Env) and junction 6 (L374 of M-MuLV Env) of SU. Sequencing the viable chimeric Env virus populations identified residues within the SU protein that improved the replication kinetics of the input chimeric Env viruses. Mutations in the C-domain of SU (G387E/R, L435I, L442P) were found to improve chimera IV4, which displayed a delayed onset of replication. The replication of AE6, containing a chimeric junction in the SU C-terminus, was improved by mutations in the N-domain (N40H, E80K), the proline-rich region (Q252R), or the transmembrane protein (L538N). Altogether, these observations provide insights into the structural elements required for Env function

Genomic characterisation of Almpiwar virus, Harrison Dam virus and Walkabout Creek virus; three novel rhabdoviruses from northern Australia

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Jane McAllister

2014-09-01

Full Text Available Rhabdoviridae represent a diverse group of viruses with the potential to cause disease in humans, animals and plants. Currently there are nine genera in the family; however a large number of rhabdoviruses remain unassigned. Here we characterise three novel rhabdoviruses genomes. Almpiwar virus (ALMV, isolated from skinks in northern Queensland, is the first completely sequenced rhabdovirus from squamates, with serological studies indicating multiple animal host species. Harrison Dam virus (HARDV and Walkabout Creek virus (WACV were isolated from mosquitoes in the Northern Territory and biting midges in southern Queensland respectively and their vertebrate hosts remain unknown. Serological cross-neutralisation tests with other Australian rhabdoviruses indicate that ALMV, WACV and HARDV are distinct viruses with little antigenic cross-reactivity. Next-generation sequencing revealed that all viruses encode the core proteins common to rhabdoviruses (N, P, M, G and L, plus additional ORFs between the M and G genes. HARDV also contains a small ORF between the G and L genes. Phylogenetic analysis of N and L proteins suggests that HARDV and WACV share a common lineage with the tupaviruses and Sandjimba group, whereas ALMV is a distinct and divergent virus showing no clear relationship to any rhabdovirus except the recently characterised Niahka virus (NIAV.

Mucus and Mucins: do they have a role in the inhibition of the human immunodeficiency virus?

OpenAIRE

Mall, Anwar Suleman; Habte, Habtom; Mthembu, Yolanda; Peacocke, Julia; de Beer, Corena

2017-01-01

Background Mucins are large O-linked glycosylated proteins which give mucus their gel-forming properties. There are indications that mucus and mucins in saliva, breast milk and in the cervical plug inhibit the human immunodeficiency virus (HIV-1) in an in vitro assay. Main body of abstract Crude mucus gels form continuous layers on the epithelial surfaces of the major internal tracts of the body and protect these epithelial surfaces against aggressive luminal factors such as hydrochloric acid...

Assembly of tobacco mosaic virus into fibrous and macroscopic bundled arrays mediated by surface aniline polymerization.

Science.gov (United States)

Niu, Zhongwei; Bruckman, Michael A; Li, Siqi; Lee, L Andrew; Lee, Byeongdu; Pingali, Sai Venkatesh; Thiyagarajan, P; Wang, Qian

2007-06-05

One-dimensional (1D) polyaniline/tobacco mosaic virus (TMV) composite nanofibers and macroscopic bundles of such fibers were generated via a self-assembly process of TMV assisted by in-situ polymerization of polyaniline on the surface of TMV. At near-neutral reaction pH, branched polyaniline formed on the surface of TMV preventing lateral association. Therefore, long 1D nanofibers were observed with high aspect ratios and excellent processibility. At a lower pH, transmission electron microscopy (TEM) analysis revealed that initially long nanofibers were formed which resulted in bundled structures upon long-time reaction, presumably mediated by the hydrophobic interaction because of the polyaniline on the surface of TMV. In-situ time-resolved small-angle X-ray scattering study of TMV at different reaction conditions supported this mechanism. This novel strategy to assemble TMV into 1D and 3D supramolecular composites could be utilized in the fabrication of advanced materials for potential applications including electronics, optics, sensing, and biomedical engineering.

Potential of acylated peptides to target the influenza A virus

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Daniel Lauster

2015-04-01

Full Text Available For antiviral drug design, especially in the field of influenza virus research, potent multivalent inhibitors raise high expectations for combating epidemics and pandemics. Among a large variety of covalent and non-covalent scaffold systems for a multivalent display of inhibitors, we created a simple supramolecular platform to enhance the antiviral effect of our recently developed antiviral Peptide B (PeBGF, preventing binding of influenza virus to the host cell. By conjugating the peptide with stearic acid to create a higher-order structure with a multivalent display, we could significantly enhance the inhibitory effect against the serotypes of both human pathogenic influenza virus A/Aichi/2/1968 H3N2, and avian pathogenic A/FPV/Rostock/34 H7N1 in the hemagglutination inhibition assay. Further, the inhibitory potential of stearylated PeBGF (C18-PeBGF was investigated by infection inhibition assays, in which we achieved low micromolar inhibition constants against both viral strains. In addition, we compared C18-PeBGF to other published amphiphilic peptide inhibitors, such as the stearylated sugar receptor mimicking peptide (Matsubara et al. 2010, and the “Entry Blocker” (EB (Jones et al. 2006, with respect to their antiviral activity against infection by Influenza A Virus (IAV H3N2. However, while this strategy seems at a first glance promising, the native situation is quite different from our experimental model settings. First, we found a strong potential of those peptides to form large amyloid-like supramolecular assemblies. Second, in vivo, the large excess of cell surface membranes provides an unspecific target for the stearylated peptides. We show that acylated peptides insert into the lipid phase of such membranes. Eventually, our study reveals serious limitations of this type of self-assembling IAV inhibitors.

Verification of surface source's characteristics using large-area 2π gas flow counter

International Nuclear Information System (INIS)

Abu Naser Waheed, M.M.; Mikami, S.; Kobayashi, H.; Noda, K.

1998-09-01

Power Reactor and Nuclear Fuel Development Corporation (PNC) has large-area 2π gas flow counter for the purpose of measuring activity of surface sources of alpha or beta ray emitter. Surface sources are used for the calibration of radiation measuring equipment for radiation control. Due to sequent use of sources, the surface of these sources are inclined to go in bad condition because of unwanted accidental incidents. For the better calibration achievement of radiation measuring instruments the rate of emission of these sources are to be checked periodically by the large-area 2π gas flow counter. In this paper described that eight U 3 O 8 surface sources were selected from many sources of PNC Tokai Works and activity of these sources was measured by the 2π gas flow counter. The results were compared with the values certified by Japan Radio Isotope Association (JRIA). It is evident from the result of comparison that the surface sources are in good condition, i.e., the sources are reliable to calibrate the radiation control instruments. (author)

The viral transcription group determines the HLA class I cellular immune response against human respiratory syncytial virus.

Science.gov (United States)

Johnstone, Carolina; Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Infantes, Susana; Lemonnier, François A; David, Chella S; Admon, Arie; López, Daniel

2015-04-01

The cytotoxic T-lymphocyte-mediated killing of virus-infected cells requires previous recognition of short viral antigenic peptides bound to human leukocyte antigen class I molecules that are exposed on the surface of infected cells. The cytotoxic T-lymphocyte response is critical for the clearance of human respiratory syncytial virus infection. In this study, naturally processed viral human leukocyte antigen class I ligands were identified with mass spectrometry analysis of complex human leukocyte antigen-bound peptide pools isolated from large amounts of human respiratory syncytial virus-infected cells. Acute antiviral T-cell response characterization showed that viral transcription determines both the immunoprevalence and immunodominance of the human leukocyte antigen class I response to human respiratory syncytial virus. These findings have clear implications for antiviral vaccine design. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Molecular evolution in court: analysis of a large hepatitis C virus outbreak from an evolving source.

Science.gov (United States)

González-Candelas, Fernando; Bracho, María Alma; Wróbel, Borys; Moya, Andrés

2013-07-19

Molecular phylogenetic analyses are used increasingly in the epidemiological investigation of outbreaks and transmission cases involving rapidly evolving RNA viruses. Here, we present the results of such an analysis that contributed to the conviction of an anesthetist as being responsible for the infection of 275 of his patients with hepatitis C virus. We obtained sequences of the NS5B and E1-E2 regions in the viral genome for 322 patients suspected to have been infected by the doctor, and for 44 local, unrelated controls. The analysis of 4,184 cloned sequences of the E1-E2 region allowed us to exclude 47 patients from the outbreak. A subset of patients had known dates of infection. We used these data to calibrate a relaxed molecular clock and to determine a rough estimate of the time of infection for each patient. A similar analysis led to an estimate for the time of infection of the source. The date turned out to be 10 years before the detection of the outbreak. The number of patients infected was small at first, but it increased substantially in the months before the detection of the outbreak. We have developed a procedure to integrate molecular phylogenetic reconstructions of rapidly evolving viral populations into a forensic setting adequate for molecular epidemiological analysis of outbreaks and transmission events. We applied this procedure to a large outbreak of hepatitis C virus caused by a single source and the results obtained played a key role in the trial that led to the conviction of the suspected source.

Active RNA replication of hepatitis C virus downregulates CD81 expression.

Science.gov (United States)

Ke, Po-Yuan; Chen, Steve S-L

2013-01-01

So far how hepatitis C virus (HCV) replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS) protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp) infection and downregulated cell surface level of CD81, a critical HCV entry (co)receptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81.

Active RNA replication of hepatitis C virus downregulates CD81 expression.

Directory of Open Access Journals (Sweden)

Po-Yuan Ke

Full Text Available So far how hepatitis C virus (HCV replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp infection and downregulated cell surface level of CD81, a critical HCV entry (coreceptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81.

Structural basis for the development of avian virus capsids that display influenza virus proteins and induce protective immunity.

Science.gov (United States)

Pascual, Elena; Mata, Carlos P; Gómez-Blanco, Josué; Moreno, Noelia; Bárcena, Juan; Blanco, Esther; Rodríguez-Frandsen, Ariel; Nieto, Amelia; Carrascosa, José L; Castón, José R

2015-03-01

Bioengineering of viruses and virus-like particles (VLPs) is a well-established approach in the development of new and improved vaccines against viral and bacterial pathogens. We report here that the capsid of a major avian pathogen, infectious bursal disease virus (IBDV), can accommodate heterologous proteins to induce protective immunity. The structural units of the ~70-nm-diameter T=13 IBDV capsid are trimers of VP2, which is made as a precursor (pVP2). The pVP2 C-terminal domain has an amphipathic α helix that controls VP2 polymorphism. In the absence of the VP3 scaffolding protein, 466-residue pVP2 intermediates bearing this α helix assemble into genuine VLPs only when expressed with an N-terminal His6 tag (the HT-VP2-466 protein). HT-VP2-466 capsids are optimal for protein insertion, as they are large enough (cargo space, ~78,000 nm(3)) and are assembled from a single protein. We explored HT-VP2-466-based chimeric capsids initially using enhanced green fluorescent protein (EGFP). The VLP assembly yield was efficient when we coexpressed EGFP-HT-VP2-466 and HT-VP2-466 from two recombinant baculoviruses. The native EGFP structure (~240 copies/virion) was successfully inserted in a functional form, as VLPs were fluorescent, and three-dimensional cryo-electron microscopy showed that the EGFP molecules incorporated at the inner capsid surface. Immunization of mice with purified EGFP-VLPs elicited anti-EGFP antibodies. We also inserted hemagglutinin (HA) and matrix (M2) protein epitopes derived from the mouse-adapted A/PR/8/34 influenza virus and engineered several HA- and M2-derived chimeric capsids. Mice immunized with VLPs containing the HA stalk, an M2 fragment, or both antigens developed full protection against viral challenge. Virus-like particles (VLPs) are multimeric protein cages that mimic the infectious virus capsid and are potential candidates as nonliving vaccines that induce long-lasting protection. Chimeric VLPs can display or include foreign

Mesoporous Silicon with Modified Surface for Plant Viruses and Their Protein Particle Sensing

Directory of Open Access Journals (Sweden)

Kae Dal Kwack

2008-10-01

Full Text Available Changes in electric parameters of a mesoporous silicon treated by a plasma chemical etching with fluorine and hydrogen ions, under the adsorption of NEPO (Nematodetransmitted Polyhedral plant viruses such as TORSV (Tomato Ringspot Virus, GFLV (Grapevine Fan Leaf Virus and protein macromolecule from TORSV particles are described. The current response to the applied voltage is measured for each virus particle to investigate the material parameters which are sensitive to the adsorbed particles. The peculiar behaviors of the response are modeled by the current-voltage relationship in a MOSFET. This model explains the behavior well and the double gate model of the MOSFET informs that the mesoporous silicon is a highly sensitive means of detecting the viruses in the size range less than 50 nm.

Intravirion cohesion of matrix protein M1 with ribonucleocapsid is a prerequisite of influenza virus infectivity

International Nuclear Information System (INIS)

Zhirnov, O.P.; Manykin, A.A.; Rossman, J.S.; Klenk, H.D.

2016-01-01

Influenza virus has two major structural modules, an external lipid envelope and an internal ribonucleocapsid containing the genomic RNA in the form of the ribonucleoprotein (RNP) complex, both of which are interlinked by the matrix protein M1. Here we studied M1-RNP cohesion within virus exposed to acidic pH in vitro. The effect of acidification was dependent on the cleavage of the surface glycoprotein HA. Acidic pH caused a loss of intravirion RNP-M1 cohesion and activated RNP polymerase activity in virus with cleaved HA (HA1/2) but not in the uncleaved (HA0) virus. The in vitro acidified HA1/2 virus rapidly lost infectivity whereas the HA0 one retained infectivity, following activation by trypsin, suggesting that premature activation and release of the RNP is detrimental to viral infectivity. Rimantadine, an inhibitor of the M2 ion channel, was found to protect the HA1/2 virus interior against acidic disintegration, confirming that M2-dependent proton translocation is essential for the intravirion RNP release and suggesting that the M2 ion channel is only active in virions with cleaved HA. Acidic treatment of both HA0 and HA1/2 influenza viruses induces formation of spikeless bleb-like protrusion of ~25 nm in diameter on the surface of the virion, though only the HA1/2 virus was permeable to protons and permitted RNP release. It is likely that this bleb corresponds to the M2-enriched and M1-depleted focus arising from pinching off of the virus during the completion of budding. Cooperatively, the data suggest that the influenza virus has an asymmetric structure where the M1-mediated organization of the RNP inside the virion is a prerequisite for infectious entry into target cell. - Highlights: • The influenza A virus has a novel asymmetric internal structure. • The structure is largely maintained by M1-RNP cohesion within the virion. • This asymmetry plays an important role during viral entry, facilitating virus uncoating and the initiation of a productive

Intravirion cohesion of matrix protein M1 with ribonucleocapsid is a prerequisite of influenza virus infectivity

Energy Technology Data Exchange (ETDEWEB)

Zhirnov, O.P., E-mail: zhirnov@inbox.ru [D.I. Ivanovsky Institute of Virology, Moscow 123098 (Russian Federation); Manykin, A.A. [D.I. Ivanovsky Institute of Virology, Moscow 123098 (Russian Federation); Rossman, J.S. [School of Biosciences, University of Kent, Canterbury CT27NJ (United Kingdom); Klenk, H.D. [Institute of Virology, Philipps University, Marburg 35037 (Germany)

2016-05-15

Influenza virus has two major structural modules, an external lipid envelope and an internal ribonucleocapsid containing the genomic RNA in the form of the ribonucleoprotein (RNP) complex, both of which are interlinked by the matrix protein M1. Here we studied M1-RNP cohesion within virus exposed to acidic pH in vitro. The effect of acidification was dependent on the cleavage of the surface glycoprotein HA. Acidic pH caused a loss of intravirion RNP-M1 cohesion and activated RNP polymerase activity in virus with cleaved HA (HA1/2) but not in the uncleaved (HA0) virus. The in vitro acidified HA1/2 virus rapidly lost infectivity whereas the HA0 one retained infectivity, following activation by trypsin, suggesting that premature activation and release of the RNP is detrimental to viral infectivity. Rimantadine, an inhibitor of the M2 ion channel, was found to protect the HA1/2 virus interior against acidic disintegration, confirming that M2-dependent proton translocation is essential for the intravirion RNP release and suggesting that the M2 ion channel is only active in virions with cleaved HA. Acidic treatment of both HA0 and HA1/2 influenza viruses induces formation of spikeless bleb-like protrusion of ~25 nm in diameter on the surface of the virion, though only the HA1/2 virus was permeable to protons and permitted RNP release. It is likely that this bleb corresponds to the M2-enriched and M1-depleted focus arising from pinching off of the virus during the completion of budding. Cooperatively, the data suggest that the influenza virus has an asymmetric structure where the M1-mediated organization of the RNP inside the virion is a prerequisite for infectious entry into target cell. - Highlights: • The influenza A virus has a novel asymmetric internal structure. • The structure is largely maintained by M1-RNP cohesion within the virion. • This asymmetry plays an important role during viral entry, facilitating virus uncoating and the initiation of a productive

Carbohydrate determinants in ferret conjunctiva are affected by infection with influenza H1N1 virus

DEFF Research Database (Denmark)

Kirkeby, Svend; Martel, Cyril; Aasted, Bent

2013-01-01

Carbohydrates often accomplish as cell-surface receptors for microorganisms and influenza virus preferentially binds to sialic acid through the viral haemagglutinin. The virus may attach not only to the epithelium in the airways, but also to the surface ocular epithelium.......Carbohydrates often accomplish as cell-surface receptors for microorganisms and influenza virus preferentially binds to sialic acid through the viral haemagglutinin. The virus may attach not only to the epithelium in the airways, but also to the surface ocular epithelium....

A recombinant canine distemper virus expressing a modified rabies virus glycoprotein induces immune responses in mice.

Science.gov (United States)

Li, Zhili; Wang, Jigui; Yuan, Daoli; Wang, Shuang; Sun, Jiazeng; Yi, Bao; Hou, Qiang; Mao, Yaping; Liu, Weiquan

2015-06-01

Canine distemper virus (CDV) and rabies virus (RV) are two important pathogens of the dog. CDV, a member of the morbillivirus genus, has shown promise as an expression vector. The glycoprotein from RV is a main contributor to protective immunity and capable of eliciting the production of virus-neutralizing antibodies. In this study, we recovered an attenuated strain of canine distemper virus and constructed a recombinant virus, rCDV-RV-G, expressing a modified (R333Q) rabies virus glycoprotein (RV-G) of RV Flury strain LEP. RV-G expression by the recombinant viruses was confirmed. Furthermore, G was proved to be incorporated into the surface of CDV particles. While replication of the recombinant virus was slightly reduced compared with the parental CDV, it stably expressed the RV-G over ten serial passages. Inoculation of mice induced specific neutralizing antibodies against both RV-G and CDV. Therefore, the rCDV-RV-G has the potential as a vaccine that may be used to control rabies virus infection in dogs and other animals.

Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge

Directory of Open Access Journals (Sweden)

Akira Homma

1974-01-01

Full Text Available Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge filter. The use of ferric hydroxide gel, impregnated on the surface of glassfibre cartridge filter enable us to recover 62.5% of virus (Poliomylitis type I, Lsc strain exsogeneously added to 400 liters of tap-water. The virus concentrator system consists of four cartridge filters, in which the three first one are clarifiers, where the contaminants are removed physically, without significant virus loss at this stage. The last cartridge filter is impregnated with ferric hydroxide gel, where the virus is adsorbed. After the required volume of water has been processed, the last filter is removed from the system and the viruses are recovered from the gel, using 1 liter of glycine/NaOH buffer, at pH 11. Immediately the eluate is clarified through series of cellulose acetate membranes mounted in a 142mm Millipore filter. For the second step of virus concentration, HC1 1N is added slowly to the eluate to achieve pH 3.5-4. MgC1, is added to give a final concentration of 0.05M and the viruses are readsorbed on a 0.45 , porosity (HA cellulose acetate membrane, mounted in a 90 mm Millipore filter. The viruses are recovered using the same eluent plus 10% of fetal calf serum, to a final volume of 3 ml. In this way, it was possible to concentrate virus from 400 liters of tap-water, into 1 liter in the first stage of virus concentration and just to 3 ml of final volume in a second step. The efficiency, simplicity and low operational cost, provded by the method, make it feasible to study viral pollution of recreational and tap-water sources.Relata-se o emprego de um concentrador portátil, o qual se mostrou capaz de recuperar 62,5% dos vírus (Polio I, amostra Lsc experimentalmente dispersos em 400 litros de água, os quais foram reduzidos a 3 ml. O sistema concentrador de vírus é composto de quatro

A large-scale seroprevalence of Epstein-Barr virus in Taiwan.

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Chao-Yu Chen

Full Text Available Epstein-Barr virus (EBV causes a variety of clinical manifestations from asymptomatic infection to acute infectious mononucleosis in human. Moreover, the EBV infection is associated with malignancies. The large-scale EBV seroepidemiology across all age groups has been lacking in Taiwan.A total of 1411 serum samples were tested to examine the seroprevalence of EBV in 2007. The samples were collected during an island-wide seroepidemiological survey of vaccine preventable diseases in Taiwan. The enzyme-linked immunosorbent assay was performed to detect anti-EBV viral capsid IgG in sera. Demographic and personal health data were obtained by questionnaires.The overall weighted seropositive rate of EBV was 88.5% (95% CI, 86.7%-90.1%. The seropositive rate of EBV reached 52.8% (95% CI, 44.0%-61.6% in children aged 2 years, rapidly rose to 88.7% (95% CI, 79.0%-95.1% in those aged 5-7 years and 93.0% (95%CI, 83.0%-98.1% for those aged 14-16 years. Age and higher educational level were associated with the increased EBV seropositive rate.In Taiwan, people had the EBV infection early in life. Children under 7 years should be the primary target popution of public health measures in the future.

"Illustrating the Machinery of Life": Viruses

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Goodsell, David S.

2012-01-01

Data from electron microscopy, X-ray crystallography, and biophysical analysis are used to create illustrations of viruses in their cellular context. This report describes the scientific data and artistic methods used to create three illustrations: a depiction of the poliovirus lifecycle, budding of influenza virus from a cell surface, and a…

Large-Scale Genomic Analysis of Codon Usage in Dengue Virus and Evaluation of Its Phylogenetic Dependence

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Edgar E. Lara-Ramírez

2014-01-01

Full Text Available The increasing number of dengue virus (DENV genome sequences available allows identifying the contributing factors to DENV evolution. In the present study, the codon usage in serotypes 1–4 (DENV1–4 has been explored for 3047 sequenced genomes using different statistics methods. The correlation analysis of total GC content (GC with GC content at the three nucleotide positions of codons (GC1, GC2, and GC3 as well as the effective number of codons (ENC, ENCp versus GC3 plots revealed mutational bias and purifying selection pressures as the major forces influencing the codon usage, but with distinct pressure on specific nucleotide position in the codon. The correspondence analysis (CA and clustering analysis on relative synonymous codon usage (RSCU within each serotype showed similar clustering patterns to the phylogenetic analysis of nucleotide sequences for DENV1–4. These clustering patterns are strongly related to the virus geographic origin. The phylogenetic dependence analysis also suggests that stabilizing selection acts on the codon usage bias. Our analysis of a large scale reveals new feature on DENV genomic evolution.

Evaluation of recombinant influenza virus-simian immunodeficiency virus vaccines in macaques.

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Sexton, Amy; De Rose, Robert; Reece, Jeanette C; Alcantara, Sheilajen; Loh, Liyen; Moffat, Jessica M; Laurie, Karen; Hurt, Aeron; Doherty, Peter C; Turner, Stephen J; Kent, Stephen J; Stambas, John

2009-08-01

There is an urgent need for human immunodeficiency virus (HIV) vaccines that induce robust mucosal immunity. Influenza A viruses (both H1N1 and H3N2) were engineered to express simian immunodeficiency virus (SIV) CD8 T-cell epitopes and evaluated following administration to the respiratory tracts of 11 pigtail macaques. Influenza virus was readily detected from respiratory tract secretions, although the infections were asymptomatic. Animals seroconverted to influenza virus and generated CD8 and CD4 T-cell responses to influenza virus proteins. SIV-specific CD8 T-cell responses bearing the mucosal homing marker beta7 integrin were induced by vaccination of naïve animals. Further, SIV-specific CD8 T-cell responses could be boosted by recombinant influenza virus-SIV vaccination of animals with already-established SIV infection. Sequential vaccination with influenza virus-SIV recombinants of different subtypes (H1N1 followed by H3N2 or vice versa) produced only a limited boost in immunity, probably reflecting T-cell immunity to conserved internal proteins of influenza A virus. SIV challenge of macaques vaccinated with an influenza virus expressing a single SIV CD8 T cell resulted in a large anamnestic recall CD8 T-cell response, but immune escape rapidly ensued and there was no impact on chronic SIV viremia. Although our results suggest that influenza virus-HIV vaccines hold promise for the induction of mucosal immunity to HIV, broader antigen cover will be needed to limit cytotoxic T-lymphocyte escape.

Replacement of the V3 domain in the surface subunit of the feline immunodeficiency virus envelope glycoprotein with the equivalent region of a T cell-tropic human immunodeficiency virus type 1 results in a chimeric surface protein that efficiently binds to CXCR4.

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González, Silvia A; Falcón, Juan I; Affranchino, José L

2014-03-01

Feline immunodeficiency virus (FIV) and the T cell-tropic strains of human immunodeficiency virus type 1 (HIV-1) share the use of the chemokine receptor CXCR4 for cell entry. To study this process further we developed a cell surface binding assay based on the expression of a soluble version of the FIV SU C-terminally tagged with the influenza virus hemagglutinin epitope (HA). The specificity of the assay was demonstrated by the following evidence: (1) the SU-HA protein bound to HeLa cells that express CXCR4 but not to MDCK cells that lack this chemokine receptor; and (2) binding of the SU-HA to HeLa cells was blocked by incubation with the CXCR4 antagonist AMD3100 as well as with the anti-CXCR4 monoclonal antibody (MAb) 12G5. Deletion of the V3 region from the FIV SU glycoprotein abolished its ability to bind CXCR4-expressing cells. Remarkably, substitution of the V3 domain of the FIV SU by the equivalent region of the HIV-1 NL4-3 isolate resulted in efficient cell surface binding of the chimeric SU protein to CXCR4. Moreover, transfection of MDCK cells with a plasmid encoding human CXCR4 allowed the association of the chimeric SU-HA glycoprotein to the transfected cells. Interestingly, while cell binding of the chimeric FIV-HIV SU was inhibited by an anti-HIV-1 V3 MAb, its association with CXCR4 was found to be resistant to AMD3100. Of note, the chimeric FIV-HIV Env glycoprotein was capable of promoting CXCR4-dependent cell-to-cell fusion.

New Perspectives on Ebola Virus Evolution.

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Celeste J Brown

Full Text Available Since the recent devastating outbreak of Ebola virus disease in western Africa, there has been significant effort to understand the evolution of the deadly virus that caused the outbreak. There has been a considerable investment in sequencing Ebola virus (EBOV isolates, and the results paint an important picture of how the virus has spread in western Africa. EBOV evolution cannot be understood outside the context of previous outbreaks, however. We have focused this study on the evolution of the EBOV glycoprotein gene (GP because one of its products, the spike glycoprotein (GP1,2, is central to the host immune response and because it contains a large amount of the phylogenetic signal for this virus. We inferred the maximum likelihood phylogeny of 96 nonredundant GP gene sequences representing each of the outbreaks since 1976 up to the end of 2014. We tested for positive selection and considered the placement of adaptive amino acid substitutions along the phylogeny and within the protein structure of GP1,2. We conclude that: 1 the common practice of rooting the phylogeny of EBOV between the first known outbreak in 1976 and the next outbreak in 1995 provides a misleading view of EBOV evolution that ignores the fact that there is a non-human EBOV host between outbreaks; 2 the N-terminus of GP1 may be constrained from evolving in response to the host immune system by the highly expressed, secreted glycoprotein, which is encoded by the same region of the GP gene; 3 although the mucin-like domain of GP1 is essential for EBOV in vivo, it evolves rapidly without losing its twin functions: providing O-linked glycosylation sites and a flexible surface.

New Perspectives on Ebola Virus Evolution.

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Brown, Celeste J; Quates, Caleb J; Mirabzadeh, Christopher A; Miller, Craig R; Wichman, Holly A; Miura, Tanya A; Ytreberg, F Marty

2016-01-01

Since the recent devastating outbreak of Ebola virus disease in western Africa, there has been significant effort to understand the evolution of the deadly virus that caused the outbreak. There has been a considerable investment in sequencing Ebola virus (EBOV) isolates, and the results paint an important picture of how the virus has spread in western Africa. EBOV evolution cannot be understood outside the context of previous outbreaks, however. We have focused this study on the evolution of the EBOV glycoprotein gene (GP) because one of its products, the spike glycoprotein (GP1,2), is central to the host immune response and because it contains a large amount of the phylogenetic signal for this virus. We inferred the maximum likelihood phylogeny of 96 nonredundant GP gene sequences representing each of the outbreaks since 1976 up to the end of 2014. We tested for positive selection and considered the placement of adaptive amino acid substitutions along the phylogeny and within the protein structure of GP1,2. We conclude that: 1) the common practice of rooting the phylogeny of EBOV between the first known outbreak in 1976 and the next outbreak in 1995 provides a misleading view of EBOV evolution that ignores the fact that there is a non-human EBOV host between outbreaks; 2) the N-terminus of GP1 may be constrained from evolving in response to the host immune system by the highly expressed, secreted glycoprotein, which is encoded by the same region of the GP gene; 3) although the mucin-like domain of GP1 is essential for EBOV in vivo, it evolves rapidly without losing its twin functions: providing O-linked glycosylation sites and a flexible surface.

Stability of surface plastic flow in large strain deformation of metals

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Viswanathan, Koushik; Udapa, Anirduh; Sagapuram, Dinakar; Mann, James; Chandrasekar, Srinivasan

We examine large-strain unconstrained simple shear deformation in metals using a model two-dimensional cutting system and high-speed in situ imaging. The nature of the deformation mode is shown to be a function of the initial microstructure state of the metal and the deformation geometry. For annealed metals, which exhibit large ductility and strain hardening capacity, the commonly assumed laminar flow mode is inherently unstable. Instead, the imposed shear is accommodated by a highly rotational flow-sinuous flow-with vortex-like components and large-amplitude folding on the mesoscale. Sinuous flow is triggered by a plastic instability on the material surface ahead of the primary region of shear. On the other hand, when the material is extensively strain-hardened prior to shear, laminar flow again becomes unstable giving way to shear banding. The existence of these flow modes is established by stability analysis of laminar flow. The role of the initial microstructure state in determining the change in stability from laminar to sinuous / shear-banded flows in metals is elucidated. The implications for cutting, forming and wear processes for metals, and to surface plasticity phenomena such as mechanochemical Rehbinder effects are discussed.

Initial characterization of Vaccinia Virus B4 suggests a role in virus spread

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Burles, Kristin; Irwin, Chad R.; Burton, Robyn-Lee [Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2 (Canada); Schriewer, Jill [Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO (United States); Evans, David H. [Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2 (Canada); Buller, R. Mark [Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO (United States); Barry, Michele, E-mail: michele.barry@ualberta.ca [Li Ka Shing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2 (Canada)

2014-05-15

Currently, little is known about the ankyrin/F-box protein B4. Here, we report that B4R-null viruses exhibited reduced plaque size in tissue culture, and decreased ability to spread, as assessed by multiple-step growth analysis. Electron microscopy indicated that B4R-null viruses still formed mature and extracellular virions; however, there was a slight decrease of virions released into the media following deletion of B4R. Deletion of B4R did not affect the ability of the virus to rearrange actin; however, VACV811, a large vaccinia virus deletion mutant missing 55 open reading frames, had decreased ability to produce actin tails. Using ectromelia virus, a natural mouse pathogen, we demonstrated that virus devoid of EVM154, the B4R homolog, showed decreased spread to organs and was attenuated during infection. This initial characterization suggests that B4 may play a role in virus spread, and that other unidentified mediators of actin tail formation may exist in vaccinia virus. - Highlights: • B4R-null viruses show reduced plaque size, and decreased ability to spread. • B4R-null viruses formed mature and extracellular virions; and rearranged actin. • Virus devoid of EVM154, the B4R homolog, was attenuated during infection. • Initial characterization suggests that B4 may play a role in virus spread. • Unidentified mediators of actin tail formation may exist in vaccinia virus.

Initial characterization of Vaccinia Virus B4 suggests a role in virus spread

International Nuclear Information System (INIS)

Burles, Kristin; Irwin, Chad R.; Burton, Robyn-Lee; Schriewer, Jill; Evans, David H.; Buller, R. Mark; Barry, Michele

2014-01-01

Currently, little is known about the ankyrin/F-box protein B4. Here, we report that B4R-null viruses exhibited reduced plaque size in tissue culture, and decreased ability to spread, as assessed by multiple-step growth analysis. Electron microscopy indicated that B4R-null viruses still formed mature and extracellular virions; however, there was a slight decrease of virions released into the media following deletion of B4R. Deletion of B4R did not affect the ability of the virus to rearrange actin; however, VACV811, a large vaccinia virus deletion mutant missing 55 open reading frames, had decreased ability to produce actin tails. Using ectromelia virus, a natural mouse pathogen, we demonstrated that virus devoid of EVM154, the B4R homolog, showed decreased spread to organs and was attenuated during infection. This initial characterization suggests that B4 may play a role in virus spread, and that other unidentified mediators of actin tail formation may exist in vaccinia virus. - Highlights: • B4R-null viruses show reduced plaque size, and decreased ability to spread. • B4R-null viruses formed mature and extracellular virions; and rearranged actin. • Virus devoid of EVM154, the B4R homolog, was attenuated during infection. • Initial characterization suggests that B4 may play a role in virus spread. • Unidentified mediators of actin tail formation may exist in vaccinia virus

Superhydrophobic surfaces

Science.gov (United States)

Wang, Evelyn N; McCarthy, Matthew; Enright, Ryan; Culver, James N; Gerasopoulos, Konstantinos; Ghodssi, Reza

2015-03-24

Surfaces having a hierarchical structure--having features of both microscale and nanoscale dimensions--can exhibit superhydrophobic properties and advantageous condensation and heat transfer properties. The hierarchical surfaces can be fabricated using biological nanostructures, such as viruses as a self-assembled nanoscale template.

Tunable protease-activatable virus nanonodes.

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Judd, Justin; Ho, Michelle L; Tiwari, Abhinav; Gomez, Eric J; Dempsey, Christopher; Van Vliet, Kim; Igoshin, Oleg A; Silberg, Jonathan J; Agbandje-McKenna, Mavis; Suh, Junghae

2014-05-27

We explored the unique signal integration properties of the self-assembling 60-mer protein capsid of adeno-associated virus (AAV), a clinically proven human gene therapy vector, by engineering proteolytic regulation of virus-receptor interactions such that processing of the capsid by proteases is required for infection. We find the transfer function of our engineered protease-activatable viruses (PAVs), relating the degree of proteolysis (input) to PAV activity (output), is highly nonlinear, likely due to increased polyvalency. By exploiting this dynamic polyvalency, in combination with the self-assembly properties of the virus capsid, we show that mosaic PAVs can be constructed that operate under a digital AND gate regime, where two different protease inputs are required for virus activation. These results show viruses can be engineered as signal-integrating nanoscale nodes whose functional properties are regulated by multiple proteolytic signals with easily tunable and predictable response surfaces, a promising development toward advanced control of gene delivery.

Rapid fabrication of large-area, corrosion-resistant superhydrophobic Mg alloy surfaces.

Science.gov (United States)

Xu, Wenji; Song, Jinlong; Sun, Jing; Lu, Yao; Yu, Ziyuan

2011-11-01

A superhydrophobic magnesium (Mg) alloy surface was successfully fabricated via a facile electrochemical machining process, and subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphologies and chemical compositions were investigated using a scanning electron microscope (SEM) equipped with an energy-dispersive spectroscopy (EDS) and a Fourier-transform infrared spectrophotometer (FTIR). The results show hierarchal rough structures and an FAS film with a low surface energy on the Mg alloy surfaces, which confers good superhydrophobicity with a water contact angle of 165.2° and a water tilting angle of approximately 2°. The processing conditions, such as the processing time and removal rate per unit area at a constant removal mass per unit area, were investigated to determine their effects on the superhydrophobicity. Interestingly, when the removal mass per unit area is constant at approximately 11.10 mg/cm(2), the superhydrophobicity does not change with the removal rate per unit area. Therefore, a superhydrophobic Mg alloy surface can be rapidly fabricated based on this property. A large-area superhydrophobic Mg alloy surface was also fabricated for the first time using a small-area moving cathode. The corrosion resistance and durability of the superhydrophobic surfaces were also examined.

Comparison of seropositivity of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis among Hospital Cornea Retrieval Programme-Donors versus voluntary cornea donors at a large eye bank in Eastern India.

Science.gov (United States)

Basak, Soham; Basak, Samar K; Biswas, Bani

2017-11-01

To compare the serology profile of donors from Hospital Cornea Retrieval Programme-donors (HCRP-D) and voluntary cornea donors (VC-D) from a large eye bank in Eastern India. This is a retrospective analysis of donor details from January 2011 to December 2016. Donor demographics, cause of death, and serology reports were compiled. Postmortem blood was tested for human immunodeficiency virus 1 and 2 (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis using government-approved kits as per the National Programme for Control of Blindness Standards of Eye Banking. Donors for whom serology was not possible were excluded. A total of 4300 of 4353 donors were included of which 74.3% were hospital donors and 25.7% were voluntary donors. A total of 93 (2.2%) donors with 94 seropositive reports were noted: 79 (84.9%) from HCRP-D and 14 (15.1%) from VC-D which was statistically significantly higher (P = 0.02). Among seropositive reports, HIV, HBV, HCV, and syphilis accounted for 12 (12.8%), 38 (40.4%), 36 (38.3%), and eight (8.5%), respectively. There was no correlation between the cause of death and seropositivity. A statistically significant decreasing trend in seroprevalence among hospital donors was observed over the years (5.3% in 2011 to 1.4% in 2016; P = 0.004). Two (0.47%) of 421 hospital donors with prior negative serology were found to be seropositive. Seropositive rates are significantly higher among hospital donors in spite of medical prescreening compared to nonscreened voluntary donors. Serology should be repeated even when prior reports are available.

Beyond Massive MIMO: The Potential of Data Transmission With Large Intelligent Surfaces

Science.gov (United States)

Hu, Sha; Rusek, Fredrik; Edfors, Ove

2018-05-01

In this paper, we consider the potential of data-transmission in a system with a massive number of radiating and sensing elements, thought of as a contiguous surface of electromagnetically active material. We refer to this as a large intelligent surface (LIS). The "LIS" is a newly proposed concept, which conceptually goes beyond contemporary massive MIMO technology, that arises from our vision of a future where man-made structures are electronically active with integrated electronics and wireless communication making the entire environment "intelligent". We consider capacities of single-antenna autonomous terminals communicating to the LIS where the entire surface is used as a receiving antenna array. Under the condition that the surface-area is sufficiently large, the received signal after a matched-filtering (MF) operation can be closely approximated by a sinc-function-like intersymbol interference (ISI) channel. We analyze the capacity per square meter (m^2) deployed surface, \\hat{C}, that is achievable for a fixed transmit power per volume-unit, \\hat{P}. Moreover, we also show that the number of independent signal dimensions per m deployed surface is 2/\\lambda for one-dimensional terminal-deployment, and \\pi/\\lambda^2 per m^2 for two and three dimensional terminal-deployments. Lastly, we consider implementations of the LIS in the form of a grid of conventional antenna elements and show that, the sampling lattice that minimizes the surface-area of the LIS and simultaneously obtains one signal space dimension for every spent antenna is the hexagonal lattice. We extensively discuss the design of the state-of-the-art low-complexity channel shortening (CS) demodulator for data-transmission with the LIS.

Phospholipase A2 isolated from the venom of Crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope.

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Vanessa Danielle Muller

Full Text Available The Flaviviridae family includes several virus pathogens associated with human diseases worldwide. Within this family, Dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. Currently, there are no vaccines or specific antiviral drugs against Dengue virus or against most of the viruses of this family. Therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses remain a global public health priority. We previously showed that phospholipase A2 isolated from the venom of Crotalus durissus terrificus was able to inhibit Dengue virus and Yellow fever virus infection in Vero cells. Here, we present evidence that phospholipase A2 has a direct effect on Dengue virus particles, inducing a partial exposure of genomic RNA, which strongly suggests inhibition via the cleavage of glycerophospholipids at the virus lipid bilayer envelope. This cleavage might induce a disruption of the lipid bilayer that causes a destabilization of the E proteins on the virus surface, resulting in inactivation. We show by computational analysis that phospholipase A2 might gain access to the Dengue virus lipid bilayer through the pores found on each of the twenty 3-fold vertices of the E protein shell on the virus surface. In addition, phospholipase A2 is able to inactivate other enveloped viruses, highlighting its potential as a natural product lead for developing broad-spectrum antiviral drugs.

Large displacement bi-directional out-of-plane Lorentz actuator array for surface manipulation

International Nuclear Information System (INIS)

Park, Byoungyoul; Afsharipour, Elnaz; Chrusch, Dwayne; Shafai, Cyrus; Andersen, David; Burley, Greg

2017-01-01

This paper presents a large displacement out-of-plane Lorentz actuator array for surface manipulation. Actuators are formed from single crystal silicon flexible serpentine springs on either side of a rigid crossbar containing a narrow contact pillar. A rigid mounting rail system was employed to enable a 5  ×  5 array, which offers scalability of the array size. Analytical and finite element models were used to optimize actuator design. Individual actuators were tested to show linear deflection response of  ±150 µ m motion, using a  ±14.7 mA current in the presence of a 0.48 T magnetic field. This actuator array is suitable for various 2D surface modification applications due to its large deformation with low current and temperature of operation, and narrow contact area to a target surface. (paper)

Surface and Internal Waves due to a Moving Load on a Very Large Floating Structure

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Taro Kakinuma

2012-01-01

Full Text Available Interaction of surface/internal water waves with a floating platform is discussed with nonlinearity of fluid motion and flexibility of oscillating structure. The set of governing equations based on a variational principle is applied to a one- or two-layer fluid interacting with a horizontally very large and elastic thin plate floating on the water surface. Calculation results of surface displacements are compared with the existing experimental data, where a tsunami, in terms of a solitary wave, propagates across one-layer water with a floating thin plate. We also simulate surface and internal waves due to a point load, such as an airplane, moving on a very large floating structure in shallow water. The wave height of the surface or internal mode is amplified when the velocity of moving point load is equal to the surface- or internal-mode celerity, respectively.

Arthropods as a source of new RNA viruses.

Science.gov (United States)

Bichaud, L; de Lamballerie, X; Alkan, C; Izri, A; Gould, E A; Charrel, R N

2014-12-01

The discovery and development of methods for isolation, characterisation and taxonomy of viruses represents an important milestone in the study, treatment and control of virus diseases during the 20th century. Indeed, by the late-1950s, it was becoming common belief that most human and veterinary pathogenic viruses had been discovered. However, at that time, knowledge of the impact of improved commercial transportation, urbanisation and deforestation, on disease emergence, was in its infancy. From the late 1960s onwards viruses, such as hepatitis virus (A, B and C) hantavirus, HIV, Marburg virus, Ebola virus and many others began to emerge and it became apparent that the world was changing, at least in terms of virus epidemiology, largely due to the influence of anthropological activities. Subsequently, with the improvement of molecular biotechnologies, for amplification of viral RNA, genome sequencing and proteomic analysis the arsenal of available tools for virus discovery and genetic characterization opened up new and exciting possibilities for virological discovery. Many recently identified but "unclassified" viruses are now being allocated to existing genera or families based on whole genome sequencing, bioinformatic and phylogenetic analysis. New species, genera and families are also being created following the guidelines of the International Committee for the Taxonomy of Viruses. Many of these newly discovered viruses are vectored by arthropods (arboviruses) and possess an RNA genome. This brief review will focus largely on the discovery of new arthropod-borne viruses. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multiple virus lineages sharing recent common ancestry were associated with a Large Rift Valley fever outbreak among livestock in Kenya during 2006-2007.

Science.gov (United States)

Bird, Brian H; Githinji, Jane W K; Macharia, Joseph M; Kasiiti, Jacqueline L; Muriithi, Rees M; Gacheru, Stephen G; Musaa, Joseph O; Towner, Jonathan S; Reeder, Serena A; Oliver, Jennifer B; Stevens, Thomas L; Erickson, Bobbie R; Morgan, Laura T; Khristova, Marina L; Hartman, Amy L; Comer, James A; Rollin, Pierre E; Ksiazek, Thomas G; Nichol, Stuart T

2008-11-01

Rift Valley fever (RVF) virus historically has caused widespread and extensive outbreaks of severe human and livestock disease throughout Africa, Madagascar, and the Arabian Peninsula. Following unusually heavy rainfall during the late autumn of 2006, reports of human and animal illness consistent with RVF virus infection emerged across semiarid regions of the Garissa District of northeastern Kenya and southern Somalia. Following initial RVF virus laboratory confirmation, a high-throughput RVF diagnostic facility was established at the Kenyan Central Veterinary Laboratories in Kabete, Kenya, to support the real-time identification of infected livestock and to facilitate outbreak response and control activities. A total of 3,250 specimens from a variety of animal species, including domesticated livestock (cattle, sheep, goats, and camels) and wildlife collected from a total of 55 of 71 Kenyan administrative districts, were tested by molecular and serologic assays. Evidence of RVF infection was found in 9.2% of animals tested and across 23 districts of Kenya, reflecting the large number of affected livestock and the geographic extent of the outbreak. The complete S, M, and/or L genome segment sequence was obtained from a total of 31 RVF virus specimens spanning the entire known outbreak period (December-May) and geographic areas affected by RVF virus activity. Extensive genomic analyses demonstrated the concurrent circulation of multiple virus lineages, gene segment reassortment, and the common ancestry of the 2006/2007 outbreak viruses with those from the 1997-1998 east African RVF outbreak. Evidence of recent increases in genomic diversity and effective population size 2 to 4 years prior to the 2006-2007 outbreak also was found, indicating ongoing RVF virus activity and evolution during the interepizootic/epidemic period. These findings have implications for further studies of basic RVF virus ecology and the design of future surveillance/diagnostic activities, and

Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

Energy Technology Data Exchange (ETDEWEB)

Serra, R., E-mail: ricardo.serra@dem.uc.pt [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Oliveira, V. [ICEMS-Instituto de Ciência e Engenharia de Materiais e Superfícies, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Oliveira, J.C. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Kubart, T. [The Ångström Laboratory, Solid State Electronics, P.O. Box 534, SE-751 21 Uppsala (Sweden); Vilar, R. [Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Instituto Superior Técnico, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Cavaleiro, A. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal)

2015-03-15

Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm{sup 2}. Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under

Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

International Nuclear Information System (INIS)

Serra, R.; Oliveira, V.; Oliveira, J.C.; Kubart, T.; Vilar, R.; Cavaleiro, A.

2015-01-01

Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm 2 . Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under different

[Epidemiologic aspects of human immunodeficiency virus and hepatitis virus infections].

Science.gov (United States)

Diarra, M; Konate, A; Minta, D; Sounko, A; Dembele, M; Toure, C S; Kalle, A; Traore, H H; Maiga, M Y

2006-01-01

In order to determinate the prevalence of hepatitis B virus and hepatitis C virus among patients infected by the HIV, We realized a transverse survey case--control in hepato-gastro-enterological ward and serology unity of National Institute of Research in Public health (INRSP). Our sample was constituted with 100 patients HIV positive compared to 100 controls HIV negative. The viral markers research has been made by methods immuno-enzymatiqueses of ELISA 3rd generation. Tests permitted to get the following results: Hepatitis B surface antigen (HBs Ag) was positive among 21% with patients HIV positive versus 23% among control (p = 0,732); Antibody to hepatitis C virus (anti-HCV ab) was present among 23% with patients HIV positive versus 0% among control (p <0,05). Female was predominant among co-infections patient, but without statistic link (p = 0,9 and p = 0,45); The co-infection HBV- HCV was significatively linked to age beyond 40 years (p = 0,0005). Co-infections with HIV infection and hepatitis virus are not rare and deserve to be investigated.

Exploratory re-encoding of Yellow Fever Virus genome: new insights for the design of live-attenuated viruses

OpenAIRE

Klitting, Raphaelle; Riziki, Toilhata; Moureau, Gregory; De Lamballerie, Xavier; Piorkowski, Geraldine

2018-01-01

Virus attenuation by genome re-encoding is a pioneering approach for generating live-attenuated vaccine candidates. Its core principle is to introduce a large number of slightly deleterious synonymous mutations into the viral genome to produce a stable attenuation of the targeted virus. The large number of mutations introduced is supposed to guarantee the stability of the attenuated phenotype by lowering the risks of reversion and recombination for re-encoded sequences. In this prospect, iden...

Compact Wideband and Low-Profile Antenna Mountable on Large Metallic Surfaces

DEFF Research Database (Denmark)

Zhang, Shuai; Pedersen, Gert F.

2017-01-01

This paper proposes a compact wideband and low-profile antenna mountable on large metallic surfaces. Six rows of coupled microstrip resonators with different lengths are printed on a Teflon block. The lengths of the microstrip resonators in different rows are gradually reduced along the end-fire...

Functional RNA during Zika virus infection

NARCIS (Netherlands)

Göertz, Giel P.; Abbo, Sandra R.; Fros, Jelke J.; Pijlman, Gorben P.

2017-01-01

Zika virus (ZIKV; family Flaviviridae; genus Flavivirus) is a pathogenic mosquito-borne RNA virus that currently threatens human health in the Americas, large parts of Asia and occasionally elsewhere in the world. ZIKV infection is often asymptomatic but can cause severe symptoms including

Wipe-rinse technique for quantitating microbial contamination on large surfaces

Science.gov (United States)

Kirschner, L. E.; Puleo, J. R.

1979-01-01

The evaluation of an improved wipe-rinse technique for the bioassay of large areas was undertaken due to inherent inadequacies in the cotton swab-rinse technique to which assay of spacecraft is currently restricted. Four types of contamination control cloths were initially tested. A polyester-bonded cloth (PBC) was selected for further evaluation because of its superior efficiency and handling characteristics. Results from comparative tests with PBC and cotton swabs on simulated spacecraft surfaces indicated a significantly higher recovery efficiency for the PBC than for the cotton (90.4 versus 75.2%). Of the sampling area sites studied, PBC was found to be most effective on surface areas not exceeding 0.74 sq m (8.0 sq ft).

Animal Models of Zika Virus

Science.gov (United States)

Bradley, Michael P; Nagamine, Claude M

2017-01-01

Zika virus has garnered great attention over the last several years, as outbreaks of the disease have emerged throughout the Western Hemisphere. Until quite recently Zika virus was considered a fairly benign virus, with limited clinical severity in both people and animals. The size and scope of the outbreak in the Western Hemisphere has allowed for the identification of severe clinical disease that is associated with Zika virus infection, most notably microcephaly among newborns, and an association with Guillian–Barré syndrome in adults. This recent association with severe clinical disease, of which further analysis strongly suggested causation by Zika virus, has resulted in a massive increase in the amount of both basic and applied research of this virus. Both small and large animal models are being used to uncover the pathogenesis of this emerging disease and to develop vaccine and therapeutic strategies. Here we review the animal-model–based Zika virus research that has been performed to date. PMID:28662753

Influence of the water molecules near surface of viral protein on virus activation process

Energy Technology Data Exchange (ETDEWEB)

O, Shepelenko S; S, Salnikov A; V, Rak S; P, Goncharova E; B, Ryzhikov A, E-mail: shep@vector.nsc.r, E-mail: shep@ngs.r [Federal State Research Institution State Research Center of Virology and Biotechnology VECTOR of the Federal Service for Surveillance in Consumer Rights Protection and Human Well-being (FSRI SRC VB VECTOR) Koltsovo, Novosibirsk Region (Russian Federation)

2009-06-01

The infection of a cell with influenza virus comprises the stages of receptor binding to the cell membrane, endocytosis of virus particle, and fusion of the virus envelope and cell endosome membrane, which is determined by the conformational changes in hemagglutinin, a virus envelope protein, caused by pH decrease within the endosome. The pH value that induces conformation rearrangements of hemagglutinin molecule considerably varies for different influenza virus strains, first and foremost, due to the differences in amino acid structure of the corresponding proteins. The main goal of this study was to construct a model making it possible to assess the critical pH value characterizing the fusogenic activity of influenza virus hemagglutinin from the data on hemagglutinin structure and experimental verification of this model. Under this model, we assume that when the electrostatic force between interacting hemagglutinin molecules in the virus envelop exceeds a certain value, the hemagglutinin HA1 subunits are arranged so that they form a cavity sufficient for penetration of water molecules. This event leads to an irreversible hydration of the inner fragments of hemagglutinin molecule in a trimer and to the completion of conformational changes. The geometry of electrostatic field in hemagglutinin trimer was calculated taking into account the polarization effects near the interface of two dielectrics, aqueous medium and protein macromolecule. The critical pH values for the conformational changes in hemagglutinin were measured by the erythrocyte hemolysis induced by influenza virus particles when decreasing pH. The critical pH value conditionally separating the pH range into the regions with and without the conformational changes was calculated for several influenza virus H1N1 and H3N2 strains based on the data on the amino acid structure of the corresponding hemagglutinin molecules. Comparison of the theoretical and experimental values of critical pH values for

Emerging tropical diseases in Australia. Part 5. Hendra virus

DEFF Research Database (Denmark)

Tulsiani, Suhella; Graham, G C; Moore, P R

2011-01-01

gene of the virus and the discovery that the virus had an exceptionally large genome subsequently led to HeV being assigned to a new genus, Henipavirus, along with Nipah virus (a newly emergent virus in pigs). The regular outbreaks of HeV-related disease that have occurred in Australia since 1994 have...

Fine definition of the CXCR4-binding region on the V3 loop of feline immunodeficiency virus surface glycoprotein.

Directory of Open Access Journals (Sweden)

Qiong-Ying Hu

2010-05-01

Full Text Available The chemokine receptor CXCR4 is shared by primary and laboratory-adapted strains of feline immunodeficiency virus (FIV for viral entry. Our previous studies implicated a contiguous nine-amino-acid region of the V3 loop of the FIV envelope surface as important in CXCR4 binding and virus entry. The binding is specific for CXCR4 since it can be inhibited by AMD3100, a selective CXCR4 inhibitor. Additional site-directed mutagenesis was used to further reveal the key residues. Binding studies indicated that basic residues R395, K397, R399 as well as N398 are critical for CXCR4 binding. The effect of other amino acid residues on receptor binding depends on the type of amino acid residue substituted. The binding study results were confirmed on human CXCR4-expressing SupT1 cells and correlated with entry efficiency using a virus entry assay. Amino acid residues critical for CXCR4 are not critical for interactions with the primary binding receptor CD134, which has an equivalent role as CD4 for HIV-1 binding. The ELISA results show that W394 and W400 are crucial for the recognition by neutralizing anti-V3 antibodies. Since certain strains of HIV-1 also use CXCR4 as the entry receptor, the findings make the feline model attractive for development of broad-based entry antagonists and for study of the molecular mechanism of receptor/virus interactions.

[Viruses and civilization].

Science.gov (United States)

Chastel, C

1999-01-01

A few million years ago, when primates moved from the east African forest to the savannah, they were already infected with endogenous viruses and occultly transmitted them to the prime Homo species. However it was much later with the building of the first large cities in Mesopotamia that interhuman viral transmission began in earnest. Spreading was further enhanced with the organization of the Egyptian, Greek, Roman, and Arab empires around the Mediterranean. Discovery of the New World in 1492 led to an unprecedented clash of civilizations and the destruction of pre-Columbian Indian civilizations. It also led to a rapid spread of viruses across the Atlantic Ocean with the emergence of yellow fever and appearance of smallpox and measles throughout the world. However the greatest opportunities for worldwide viral development have been created by our present, modern civilization. This fact is illustrated by epidemic outbreaks of human immunodeficiency virus, Venezuela hemorrhagic fever, Rift valley fever virus, and monkey pox virus. Close analysis underscores the major role of human intervention in producing these events.

Large area smoothing of surfaces by ion bombardment: fundamentals and applications

International Nuclear Information System (INIS)

Frost, F; Fechner, R; Ziberi, B; Voellner, J; Flamm, D; Schindler, A

2009-01-01

Ion beam erosion can be used as a process for achieving surface smoothing at microscopic length scales and for the preparation of ultrasmooth surfaces, as an alternative to nanostructuring of various surfaces via self-organization. This requires that in the evolution of the surface topography different relaxation mechanisms dominate over the roughening, and smoothing of initially rough surfaces can occur. This contribution focuses on the basic mechanisms as well as potential applications of surface smoothing using low energy ion beams. In the first part, the fundamentals for the smoothing of III/V semiconductors, Si and quartz glass surfaces using low energy ion beams (ion energy: ≤2000 eV) are reviewed using examples. The topography evolution of these surfaces with respect to different process parameters (ion energy, ion incidence angle, erosion time, sample rotation) has been investigated. On the basis of the time evolution of different roughness parameters, the relevant surface relaxation mechanisms responsible for surface smoothing are discussed. In this context, physical constraints as regards the effectiveness of surface smoothing by direct ion bombardment will also be addressed and furthermore ion beam assisted smoothing techniques are introduced. In the second application-orientated part, recent technological developments related to ion beam assisted smoothing of optically relevant surfaces are summarized. It will be demonstrated that smoothing by direct ion bombardment in combination with the use of sacrificial smoothing layers and the utilization of appropriate broad beam ion sources enables the polishing of various technologically important surfaces down to 0.1 nm root mean square roughness level, showing great promise for large area surface processing. Specific examples are given for ion beam smoothing of different optical surfaces, especially for substrates used for advanced optical applications (e.g., in x-ray optics and components for extreme

Surface Nuclear Magnetic Resonance Imaging of Large Systems

International Nuclear Information System (INIS)

Weichman, P.B.; Lavely, E.M.; Ritzwoller, M.H.

1999-01-01

The general theory of surface NMR imaging of large electromagnetically active systems is considered, motivated by geophysical applications. A general imaging equation is derived for the NMR voltage response, valid for arbitrary transmitter and receiver loop geometry and arbitrary conductivity structure of the sample. When the conductivity grows to the point where the electromagnetic skin depth becomes comparable to the sample size, significant diffusive retardation effects occur that strongly affect the signal. Accounting for these now allows more accurate imaging than previously possible. It is shown that the time constant T 1 may in principle be inferred directly from the diffusive tail of the signal. copyright 1999 The American Physical Society

Comparison of seropositivity of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis among Hospital Cornea Retrieval Programme-Donors versus voluntary cornea donors at a large eye bank in Eastern India

Directory of Open Access Journals (Sweden)

Soham Basak

2017-01-01

Full Text Available Purpose: To compare the serology profile of donors from Hospital Cornea Retrieval Programme-donors (HCRP-D and voluntary cornea donors (VC-D from a large eye bank in Eastern India. Methods: This is a retrospective analysis of donor details from January 2011 to December 2016. Donor demographics, cause of death, and serology reports were compiled. Postmortem blood was tested for human immunodeficiency virus 1 and 2 (HIV, hepatitis B virus (HBV, hepatitis C virus (HCV, and syphilis using government-approved kits as per the National Programme for Control of Blindness Standards of Eye Banking. Donors for whom serology was not possible were excluded. Results: A total of 4300 of 4353 donors were included of which 74.3% were hospital donors and 25.7% were voluntary donors. A total of 93 (2.2% donors with 94 seropositive reports were noted: 79 (84.9% from HCRP-D and 14 (15.1% from VC-D which was statistically significantly higher (P = 0.02. Among seropositive reports, HIV, HBV, HCV, and syphilis accounted for 12 (12.8%, 38 (40.4%, 36 (38.3%, and eight (8.5%, respectively. There was no correlation between the cause of death and seropositivity. A statistically significant decreasing trend in seroprevalence among hospital donors was observed over the years (5.3% in 2011 to 1.4% in 2016; P = 0.004. Two (0.47% of 421 hospital donors with prior negative serology were found to be seropositive. Conclusion: Seropositive rates are significantly higher among hospital donors in spite of medical prescreening compared to nonscreened voluntary donors. Serology should be repeated even when prior reports are available.

A casein-kinase-2-related protein kinase is tightly associated with the large T antigen of simian virus 40

DEFF Research Database (Denmark)

Götz, C; Koenig, M G; Issinger, O G

1995-01-01

by the addition of protein kinase CK2 suggest that at least one of the T-antigen-associated protein kinases is CK2 or a protein-kinase-CK2-related enzyme. The association of recombinant CK2 with T antigen was strongly confirmed by in vitro binding studies. Experiments with temperature-sensitive SV40-transformed......The simian virus 40 (SV40) large T antigen is a multifunctional protein involved in SV40 cell transformation and lytic virus infection. Some of its activities are regulated by interaction with cellular proteins and/or by phosphorylation of T antigen by various protein kinases. In this study, we...... show that immuno-purified T antigen from SV40-transformed cells and from baculovirus-infected insect cells is tightly associated with a protein kinase that phosphorylates T antigen in vitro. In the presence of heparin or a peptide resembling a protein kinase CK2 recognition site, the phosphorylation...

Anterograde or Retrograde Transsynaptic Circuit Tracing in Vertebrates with Vesicular Stomatitis Virus Vectors.

Science.gov (United States)

Beier, Kevin T; Mundell, Nathan A; Pan, Y Albert; Cepko, Constance L

2016-01-04

Viruses have been used as transsynaptic tracers, allowing one to map the inputs and outputs of neuronal populations, due to their ability to replicate in neurons and transmit in vivo only across synaptically connected cells. To date, their use has been largely restricted to mammals. In order to explore the use of such viruses in an expanded host range, we tested the transsynaptic tracing ability of recombinant vesicular stomatitis virus (rVSV) vectors in a variety of organisms. Successful infection and gene expression were achieved in a wide range of organisms, including vertebrate and invertebrate model organisms. Moreover, rVSV enabled transsynaptic tracing of neural circuitry in predictable directions dictated by the viral envelope glycoprotein (G), derived from either VSV or rabies virus (RABV). Anterograde and retrograde labeling, from initial infection and/or viral replication and transmission, was observed in Old and New World monkeys, seahorses, jellyfish, zebrafish, chickens, and mice. These vectors are widely applicable for gene delivery, afferent tract tracing, and/or directional connectivity mapping. Here, we detail the use of these vectors and provide protocols for propagating virus, changing the surface glycoprotein, and infecting multiple organisms using several injection strategies. Copyright © 2016 John Wiley & Sons, Inc.

Primary Intra-aortic Epstein-Barr Virus-Positive Large B-Cell Lymphoma Presenting as Aortic Mural Thrombosis: An Entity Distinct From Intravascular Large B-Cell Lymphoma.

Science.gov (United States)

Nakao, Ryuta; Sakashita, Aki; Omoto, Atsushi; Sato, Osamu; Hino, Yoko; Yanagisawa, Akio; Urata, Yoji

2017-12-01

Intravascular selective growth of neoplastic B lymphocytes is a characteristic finding of intravascular large B-cell lymphoma (IVLBCL). However, because neoplastic B cells of IVLBCL grow merely in the lumina of capillaries or small vessels, primary IVLBCL of the great vessels is considered exceptional. To our knowledge, only 2 primary B-cell lymphomas in the lumina of the vena cava have been reported. However, there has been no report of primary B-cell lymphoma with intra-aortic growth. We describe a novel manifestation of primary Epstein-Barr virus-positive large B-cell lymphoma mainly affecting the lumina of the aorta and its major branches in a 76-year-old man. He had a long-term fever that was refractory to antibiotics and aortic mural thrombosis with visceral embolization. Because he had no detectable mass suggesting a malignancy, it was difficult to diagnose while he was alive. He died without anticancer treatment, and the confirmed diagnosis was made at autopsy.

Interferon-lambda contributes to innate immunity of mice against influenza A virus but not against hepatotropic viruses

DEFF Research Database (Denmark)

Mordstein, M; Kochs, G; Dumoutier, L

2008-01-01

Virus-infected cells secrete a broad range of interferon (IFN) subtypes which in turn trigger the synthesis of antiviral factors that confer host resistance. IFN-alpha, IFN-beta and other type I IFNs signal through a common universally expressed cell surface receptor, whereas IFN-lambda uses....... Mice lacking functional IFN-lambda receptors were only slightly more susceptible to influenza virus than wild-type mice. However, mice lacking functional receptors for both IFN-alpha/beta and IFN-lambda were hypersensitive and even failed to restrict usually non-pathogenic influenza virus mutants...

Prevalence of Human Parainfluenza Viruses and Noroviruses Genomes on Office Fomites.

Science.gov (United States)

Stobnicka, Agata; Gołofit-Szymczak, Małgorzata; Wójcik-Fatla, Angelina; Zając, Violetta; Korczyńska-Smolec, Joanna; Górny, Rafał L

2018-06-01

The aim of this study was to evaluate the potential role of office fomites in respiratory (human parainfluenza virus 1-HPIV1, human parainfluenza virus 3-HPIV3) and enteric (norovirus GI-NoV GI, norovirus GII-NoV GII) viruses transmission by assessing the occurrence of these viruses on surfaces in office buildings. Between 2016 and 2017, a total of 130 surfaces from open-space and non-open-space rooms in office buildings located in one city were evaluated for HPIV1, HPIV3, NoV GI, and NoV GII viral RNA presence. Detection of viruses was performed by RT-qPCR method. Study revealed 27 positive samples, among them 59.3% were HPIV3-positive, 25.9% HPIV1-positive, and 14.8% NoV GII-positive. All tested surfaces were NoV GI-negative. Statistical analysis of obtained data showed that the surfaces of office equipment including computer keyboards and mice, telephones, and desktops were significantly more contaminated with respiratory viruses than the surfaces of building equipment elements such as door handles, light switches, or ventilation tracts (χ 2 p = 0.006; Fisher's Exact p = 0.004). All examined surfaces were significantly more contaminated with HPIVs than NoVs (χ 2 p = 0.002; Fisher's Exact p = 0.003). Office fomites in open-space rooms were more often contaminated with HPIVs than with NoVs (χ 2 p = 0.016; Fisher's Exact p = 0.013). The highest average concentration of HPIVs RNA copies was observed on telephones (1.66 × 10 2 copies/100 cm 2 ), while NoVs on the light switches (1.40 × 10 2 copies/100 cm 2 ). However, the Kruskal-Wallis test did not show statistically significant differences in concentration levels of viral RNA copies on surfaces between the all tested samples. This study unequivocally showed that individuals in office environment may have contact with both respiratory and enteric viral particles present on frequently touched surfaces.

Methods for growth of relatively large step-free SiC crystal surfaces

Science.gov (United States)

Neudeck, Philip G. (Inventor); Powell, J. Anthony (Inventor)

2002-01-01

A method for growing arrays of large-area device-size films of step-free (i.e., atomically flat) SiC surfaces for semiconductor electronic device applications is disclosed. This method utilizes a lateral growth process that better overcomes the effect of extended defects in the seed crystal substrate that limited the obtainable step-free area achievable by prior art processes. The step-free SiC surface is particularly suited for the heteroepitaxial growth of 3C (cubic) SiC, AlN, and GaN films used for the fabrication of both surface-sensitive devices (i.e., surface channel field effect transistors such as HEMT's and MOSFET's) as well as high-electric field devices (pn diodes and other solid-state power switching devices) that are sensitive to extended crystal defects.

Localization and force analysis at the single virus particle level using atomic force microscopy

International Nuclear Information System (INIS)

Liu, Chih-Hao; Horng, Jim-Tong; Chang, Jeng-Shian; Hsieh, Chung-Fan; Tseng, You-Chen; Lin, Shiming

2012-01-01

Highlights: ► Localization of single virus particle. ► Force measurements. ► Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

Kinetic analysis of synthetic analogues of linear-epitope peptides of glycoprotein D of herpes simplex virus type 1 by surface plasmon resonance

NARCIS (Netherlands)

Lasonder, E; Schellekens, GA; Koedijk, DGAM; Damhof, RA; WellingWester, S; Feijlbrief, M; Scheffer, AJ; Welling, GW

1996-01-01

The interaction between mAb A16 and glycoprorein D (gD) of herpes simplex virus type 1 was analyzed by studying the kinetics of binding with a surface-plasmon-resonance biosensor. mAb A16 belongs to group VII antibodies, which recognize residues 11-19 of gD. In a previous study, three critical

Coronavirus and influenza virus proteolytic priming takes place in tetraspanin-enriched membrane microdomains.

Science.gov (United States)

Earnest, James T; Hantak, Michael P; Park, Jung-Eun; Gallagher, Tom

2015-06-01

Coronaviruses (CoVs) and low-pathogenicity influenza A viruses (LP IAVs) depend on target cell proteases to cleave their viral glycoproteins and prime them for virus-cell membrane fusion. Several proteases cluster into tetraspanin-enriched microdomains (TEMs), suggesting that TEMs are preferred virus entry portals. Here we found that several CoV receptors and virus-priming proteases were indeed present in TEMs. Isolated TEMs, when mixed with CoV and LP IAV pseudoparticles, cleaved viral fusion proteins to fusion-primed fragments and potentiated viral transductions. That entering viruses utilize TEMs as a protease source was further confirmed using tetraspanin antibodies and tetraspanin short hairpin RNAs (shRNAs). Tetraspanin antibodies inhibited CoV and LP IAV infections, but their virus-blocking activities were overcome by expressing excess TEM-associated proteases. Similarly, cells with reduced levels of the tetraspanin CD9 resisted CoV pseudoparticle transductions but were made susceptible by overproducing TEM-associated proteases. These findings indicated that antibodies and CD9 depletions interfere with viral proteolytic priming in ways that are overcome by surplus proteases. TEMs appear to be exploited by some CoVs and LP IAVs for appropriate coengagement with cell receptors and proteases. Enveloped viruses use their surface glycoproteins to catalyze membrane fusion, an essential cell entry step. Host cell components prime these viral surface glycoproteins to catalyze membrane fusion at specific times and places during virus cell entry. Among these priming components are proteases, which cleave viral surface glycoproteins, unleashing them to refold in ways that catalyze virus-cell membrane fusions. For some enveloped viruses, these proteases are known to reside on target cell surfaces. This research focuses on coronavirus and influenza A virus cell entry and identifies TEMs as sites of viral proteolysis, thereby defining subcellular locations of virus

ICTV Virus Taxonomy Profile: Pneumoviridae.

Science.gov (United States)

Rima, Bert; Collins, Peter; Easton, Andrew; Fouchier, Ron; Kurath, Gael; Lamb, Robert A; Lee, Benhur; Maisner, Andrea; Rota, Paul; Wang, Linfa; Ictv Report Consortium

2017-12-01

The family Pneumoviridae comprises large enveloped negative-sense RNA viruses. This taxon was formerly a subfamily within the Paramyxoviridae, but was reclassified in 2016 as a family with two genera, Orthopneumovirus and Metapneumovirus. Pneumoviruses infect a range of mammalian species, while some members of the Metapneumovirus genus may also infect birds. Some viruses are specific and pathogenic for humans, such as human respiratory syncytial virus and human metapneumovirus. There are no known vectors for pneumoviruses and transmission is thought to be primarily by aerosol droplets and contact. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Pneumoviridae, which is available at www.ictv.global/report/pneumoviridae.

Application of radioisotopes in biochemistry of proteins, hydrocarbons and lipids of viruses

International Nuclear Information System (INIS)

Budarkov, V.A.; Bakulov, I.A.; Makarov, V.V.; Chumak, R.M.

1990-01-01

The article desribes the methods of radioisotope application in biochemistry of proteins, hydrocarbons and lipids of viruses: - radionuclide analysis of immunocompetent cell surface components; - technique of radionuclide introduction into viruse and cell proteins; - method of investigating of viruse glycoproteins; - method of measuring viruse ferment activity. 383 refs.; 2 figs.; 4 tabs

Modifying a dynamic global vegetation model for simulating large spatial scale land surface water balance

Science.gov (United States)

Tang, G.; Bartlein, P. J.

2012-01-01

Water balance models of simple structure are easier to grasp and more clearly connect cause and effect than models of complex structure. Such models are essential for studying large spatial scale land surface water balance in the context of climate and land cover change, both natural and anthropogenic. This study aims to (i) develop a large spatial scale water balance model by modifying a dynamic global vegetation model (DGVM), and (ii) test the model's performance in simulating actual evapotranspiration (ET), soil moisture and surface runoff for the coterminous United States (US). Toward these ends, we first introduced development of the "LPJ-Hydrology" (LH) model by incorporating satellite-based land covers into the Lund-Potsdam-Jena (LPJ) DGVM instead of dynamically simulating them. We then ran LH using historical (1982-2006) climate data and satellite-based land covers at 2.5 arc-min grid cells. The simulated ET, soil moisture and surface runoff were compared to existing sets of observed or simulated data for the US. The results indicated that LH captures well the variation of monthly actual ET (R2 = 0.61, p 0.46, p 0.52) with observed values over the years 1982-2006, respectively. The modeled spatial patterns of annual ET and surface runoff are in accordance with previously published data. Compared to its predecessor, LH simulates better monthly stream flow in winter and early spring by incorporating effects of solar radiation on snowmelt. Overall, this study proves the feasibility of incorporating satellite-based land-covers into a DGVM for simulating large spatial scale land surface water balance. LH developed in this study should be a useful tool for studying effects of climate and land cover change on land surface hydrology at large spatial scales.

Prevalence of hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus and hepatitis E virus as causes of acute viral hepatitis in North India: a hospital based study.

Science.gov (United States)

Jain, P; Prakash, S; Gupta, S; Singh, K P; Shrivastava, S; Singh, D D; Singh, J; Jain, A

2013-01-01

Acute viral hepatitis (AVH) is a major public health problem and is an important cause of morbidity and mortality. The aim of the present study is to determine the prevalence of hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV) as causes of AVH in a tertiary care hospital of North India. Blood samples and clinical information was collected from cases of AVH referred to the Grade I viral diagnostic laboratory over a 1-year period. Samples were tested for hepatitis B surface antigen, anti-HCV total antibodies, anti-HAV immunoglobulin M (IgM) and anti-HEV IgM by the enzyme-linked immunosorbent assay. PCR for nucleic acid detection of HBV and HCV was also carried out. Those positive for HBV infection were tested for anti-HDV antibodies. Fisher's exact test was used and a P hepatitis cases, 62 (23.22%) patients presented as acute hepatic failure. HAV (26.96%) was identified as the most common cause of acute hepatitis followed by HEV (17.97%), HBV (16.10%) and HCV (11.98%). Co-infections with more than one virus were present in 34 cases; HAV-HEV co-infection being the most common. HEV was the most important cause of acute hepatic failure followed by co-infection with HAV and HEV. An indication towards epidemiological shift of HAV infection from children to adults with a rise in HAV prevalence was seen. To the best of our knowledge, this is the first report indicating epidemiological shift of HAV in Uttar Pradesh.

Forced synchronization of large-scale circulation to increase predictability of surface states

Science.gov (United States)

Shen, Mao-Lin; Keenlyside, Noel; Selten, Frank; Wiegerinck, Wim; Duane, Gregory

2016-04-01

Numerical models are key tools in the projection of the future climate change. The lack of perfect initial condition and perfect knowledge of the laws of physics, as well as inherent chaotic behavior limit predictions. Conceptually, the atmospheric variables can be decomposed into a predictable component (signal) and an unpredictable component (noise). In ensemble prediction the anomaly of ensemble mean is regarded as the signal and the ensemble spread the noise. Naturally the prediction skill will be higher if the signal-to-noise ratio (SNR) is larger in the initial conditions. We run two ensemble experiments in order to explore a way to reduce the SNR of surface winds and temperature. One ensemble experiment is AGCM with prescribing sea surface temperature (SST); the other is AGCM with both prescribing SST and nudging the high-level temperature and winds to ERA-Interim. Each ensemble has 30 members. Larger SNR is expected and found over the tropical ocean in the first experiment because the tropical circulation is associated with the convection and the associated surface wind convergence as these are to a large extent driven by the SST. However, small SNR is found over high latitude ocean and land surface due to the chaotic and non-synchronized atmosphere states. In the second experiment the higher level temperature and winds are forced to be synchronized (nudged to reanalysis) and hence a larger SNR of surface winds and temperature is expected. Furthermore, different nudging coefficients are also tested in order to understand the limitation of both synchronization of large-scale circulation and the surface states. These experiments will be useful for the developing strategies to synchronize the 3-D states of atmospheric models that can be later used to build a super model.

Postvaccination seroconversion against the surface antigen of Hepatitis B virus, in nursing students

Directory of Open Access Journals (Sweden)

Gladys Amanda Mera-Urbano

2013-09-01

Full Text Available Objective: To determine the status of seroconversion after vaccination against the surface antigen of hepatitis B virus in nursing students, University of Cauca. Methods: Cross sectional study in students of V and VI semester. The sample was taken from 37 students, 15 of V and 22 of VI semester. The instrument used was a survey that included 11 questions of multiple selections. Records for weight, height and laboratory results were collected; blood samples for antibody titers were performed with informed consent. The data were tabulated and analyzed using SPSS, version 17.0. Results: 89.2% of students had levels of antibodies to the surface antigen. This value was greater than 10 mUI/ml, considered by the scientific community as a protector value of Hepatitis B. 10.8% of had lesser values. Regarding vaccination scheme, 24% had a dose, 19% two, 48% three and 8% had a one dose. The population with 3 doses and reinforcement seroconverted by 100%. Conclusion: This study demonstrated failings in the scheme of vaccination of the students of nursing and that 10.8 % presented lower values than 10 mIU/ml. It is necessary to apply the institutional rules with more strength as a preventive measure for hepatitis B.

Expression of the Surface Glycoproteins of Human Parainfluenza Virus Type 3 by Bovine Parainfluenza Virus Type 3, a Novel Attenuated Virus Vaccine Vector

OpenAIRE

Haller, Aurelia A.; Miller, Tessa; Mitiku, Misrach; Coelingh, Kathleen

2000-01-01

Bovine parainfluenza virus type 3 (bPIV3) is being evaluated as an intranasal vaccine for protection against human PIV3 (hPIV3). In young infants, the bPIV3 vaccine appears to be infectious, attenuated, immunogenic, and genetically stable, which are desirable characteristics for an RNA virus vector. To test the potential of the bPIV3 vaccine strain as a vector, an infectious DNA clone of bPIV3 was assembled and recombinant bPIV3 (r-bPIV3) was rescued. r-bPIV3 displayed a temperature-sensitive...

Jump rates for surface diffusion of large molecules from first principles

Energy Technology Data Exchange (ETDEWEB)

Shea, Patrick, E-mail: patrick.shea@dal.ca; Kreuzer, Hans Jürgen [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 3J5 (Canada)

2015-04-21

We apply a recently developed stochastic model for the surface diffusion of large molecules to calculate jump rates for 9,10-dithioanthracene on a Cu(111) surface. The necessary input parameters for the stochastic model are calculated from first principles using density functional theory (DFT). We find that the inclusion of van der Waals corrections to the DFT energies is critical to obtain good agreement with experimental results for the adsorption geometry and energy barrier for diffusion. The predictions for jump rates in our model are in excellent agreement with measured values and show a marked improvement over transition state theory (TST). We find that the jump rate prefactor is reduced by an order of magnitude from the TST estimate due to frictional damping resulting from energy exchange with surface phonons, as well as a rotational mode of the diffusing molecule.

Orf virus interferes with MHC class I surface expression by targeting vesicular transport and Golgi

Directory of Open Access Journals (Sweden)

Rohde Jörg

2012-07-01

Full Text Available Abstract Background The Orf virus (ORFV, a zoonotic Parapoxvirus, causes pustular skin lesions in small ruminants (goat and sheep. Intriguingly, ORFV can repeatedly infect its host, despite the induction of a specific immunity. These immune modulating and immune evading properties are still unexplained. Results Here, we describe that ORFV infection of permissive cells impairs the intracellular transport of MHC class I molecules (MHC I as a result of structural disruption and fragmentation of the Golgi apparatus. Depending on the duration of infection, we observed a pronounced co-localization of MHC I and COP-I vesicular structures as well as a reduction of MHC I surface expression of up to 50%. These subversion processes are associated with early ORFV gene expression and are accompanied by disturbed carbohydrate trimming of post-ER MHC I. The MHC I population remaining on the cell surface shows an extended half-life, an effect that might be partially controlled also by late ORFV genes. Conclusions The presented data demonstrate that ORFV down-regulates MHC I surface expression in infected cells by targeting the late vesicular export machinery and the structure and function of the Golgi apparatus, which might aid to escape cellular immune recognition.

Effect of air gap on uniformity of large-scale surface-wave plasma

International Nuclear Information System (INIS)

Lan Chaohui; Hu Xiwei; Jiang Zhonghe; Liu Minghai

2009-01-01

The effect of air gap on the uniformity of large-scale surface-wave plasma (SWP) in a rectangular chamber device is studied by using three-dimensional numerical analyses based on the finite difference time-domain (FDTD) approximation to Maxwell's equations and plasma fluid model. The spatial distributions of surface wave excited by slot-antenna array and the plasma parameters such as electron density and temperature are presented. For different air gap thicknesses, the results show that the existence of air gap would severely weaken the excitations of the surface wave and thereby the SWP. Thus the air gap should be eliminated completely in the design of the SWP source, which is opposite to the former research results. (authors)

Monoclonal antibodies against plant viruses

International Nuclear Information System (INIS)

Sandler, E.; Dietzgen, R.G.

1984-01-01

Ever since antigenic properties of plant viruses were discovered antisera have been raised and used for plant virus diagnosis and for the analysis of virus structure as well. From the early qualitative diagnosis method of precipitating the virus in clarified sap of an infected plant and the first quantitative application of the precipitin test vast progress has been made with regard to the development of highly sensitive and highly quantitative methods for virus detection. Of equal importance was the improvement of methods for separating virus from host cell components since the specificity of antisera raised against a virus could be increased by using an antigen for immunization highly concentrated and largely freed from contaminating host substances. The introduction of the enzyme-linked immunosorbent assay (ELISA) into plant virology allows detection of virus in nanogram quantities. Still, the conventionally raised antisera, no matter how pure an antigen was used for immunization, are polyclonal. They contain products of thousands of different antibody-secreting plasma cell clones which can be directed against all antigenic determinants (epitopes) of the virus, but also against antigens of the host plant that may not have been entirely separated from the immunizing virus during the purification procedure. Even after cross adsorption of polyclonal antisera some residual heterogeneity can be expected to remain. Within these boundaries the information gained with polyclonal antisera on virus structure and on virus diagnosis has to be interpreted

Complete replication of hepatitis B virus and hepatitis C virus in a newly developed hepatoma cell line.

Science.gov (United States)

Yang, Darong; Zuo, Chaohui; Wang, Xiaohong; Meng, Xianghe; Xue, Binbin; Liu, Nianli; Yu, Rong; Qin, Yuwen; Gao, Yimin; Wang, Qiuping; Hu, Jun; Wang, Ling; Zhou, Zebin; Liu, Bing; Tan, Deming; Guan, Yang; Zhu, Haizhen

2014-04-01

The absence of a robust cell culture system for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection has limited the analysis of the virus lifecycle and drug discovery. We have established a hepatoma cell line, HLCZ01, the first cell line, to the authors' knowledge, supporting the entire lifecycle of both HBV and HCV. HBV surface antigen (HBsAg)-positive particles can be observed in the supernatant and the lumen of the endoplasmic reticulum of the cells via electron microscopy. Interestingly, HBV and HCV clinical isolates propagate in HLCZ01 cells. Both viruses replicate in the cells without evidence of overt interference. HBV and HCV entry are blocked by antibodies against HBsAg and human CD81, respectively, and the replication of HBV and HCV is inhibited by antivirals. HLCZ01 cells mount an innate immune response to virus infection. The cell line provides a powerful tool for exploring the mechanisms of virus entry and replication and the interaction between host and virus, facilitating the development of novel antiviral agents and vaccines.

Evasion of T cell immunity by Epstein-Barr virus

NARCIS (Netherlands)

Horst, D.

2011-01-01

Immune evasion strategies are thought to contribute essentially to the life cycle of persistent viruses by delaying the elimination of the infected cell long enough to enable the virus to replicate. Exemplary in this context are the herpesviruses, large DNA viruses that are carried as a persistent

Using Bovine Viral Diarrhea Virus (BVDV) As Surrogate for Human Hepatitis C Virus

Science.gov (United States)

This test is designed to validate virucidal effectiveness claims for a product to be registered as a virucide. It determines the potential of the test agent to disinfect hard surfaces contaminated with human Hepatitis C virus (HCV).

RECOVIR Software for Identifying Viruses

Science.gov (United States)

Chakravarty, Sugoto; Fox, George E.; Zhu, Dianhui

2013-01-01

Most single-stranded RNA (ssRNA) viruses mutate rapidly to generate a large number of strains with highly divergent capsid sequences. Determining the capsid residues or nucleotides that uniquely characterize these strains is critical in understanding the strain diversity of these viruses. RECOVIR (an acronym for "recognize viruses") software predicts the strains of some ssRNA viruses from their limited sequence data. Novel phylogenetic-tree-based databases of protein or nucleic acid residues that uniquely characterize these virus strains are created. Strains of input virus sequences (partial or complete) are predicted through residue-wise comparisons with the databases. RECOVIR uses unique characterizing residues to identify automatically strains of partial or complete capsid sequences of picorna and caliciviruses, two of the most highly diverse ssRNA virus families. Partition-wise comparisons of the database residues with the corresponding residues of more than 300 complete and partial sequences of these viruses resulted in correct strain identification for all of these sequences. This study shows the feasibility of creating databases of hitherto unknown residues uniquely characterizing the capsid sequences of two of the most highly divergent ssRNA virus families. These databases enable automated strain identification from partial or complete capsid sequences of these human and animal pathogens.

Antibody neutralization of retargeted measles viruses

Science.gov (United States)

Lech, Patrycja J.; Pappoe, Roland; Nakamura, Takafumi; Tobin, Gregory J.; Nara, Peter L.; Russell, Stephen J.

2014-01-01

The measles virus (MV) vaccine lineage is a promising oncolytic but prior exposure to the measles vaccine or wild-type MV strains limits treatment utility due to the presence of anti-measles antibodies. MV entry can be redirected by displaying a polypeptide ligand on the Hemagglutinin (H) C-terminus. We hypothesized that retargeted MV would escape neutralization by monoclonal antibodies (mAbs) recognizing the H receptor-binding surface and be less susceptible to neutralization by human antisera. Using chimeric H proteins, with and without mutations that ablate MV receptor binding, we show that retargeted MVs escape mAbs that target the H receptor-binding surface by virtue of mutations that ablate infection via SLAM and CD46. However, C-terminally displayed domains do not mediate virus entry in the presence of human antibodies that bind to the underlying H domain. In conclusion, utility of retargeted oncolytic measles viruses does not extend to evasion of human serum neutralization. PMID:24725950

Morphogenesis of respiratory syncytial virus in human primary nasal ciliated epithelial cells occurs at surface membrane microdomains that are distinct from cilia

International Nuclear Information System (INIS)

Jumat, Muhammad Raihan; Yan, Yan; Ravi, Laxmi Iyer; Wong, Puisan; Huong, Tra Nguyen; Li, Chunwei; Tan, Boon Huan; Wang, De Yun; Sugrue, Richard J.

2015-01-01

The distribution of cilia and the respiratory syncytial virus (RSV) nucleocapsid (N) protein, fusion (F) protein, attachment (G) protein, and M2-1 protein in human ciliated nasal epithelial cells was examined at between 1 and 5 days post-infection (dpi). All virus structural proteins were localized at cell surface projections that were distinct from cilia. The F protein was also trafficked into the cilia, and while its presence increased as the infection proceeded, the N protein was not detected in the cilia at any time of infection. The presence of the F protein in the cilia correlated with cellular changes in the cilia and reduced cilia function. At 5 dpi extensive cilia loss and further reduced cilia function was noted. These data suggested that although RSV morphogenesis occurs at non-cilia locations on ciliated nasal epithelial cells, RSV infection induces changes in the cilia body that leads to extensive cilia loss. - Highlights: • Respiratory syncytial virus (RSV) infects nasal ciliated epithelial cells. • Virus morphogenesis occurs within filamentous projections distinct from cilia. • The RSV N protein was not detected in the cilia at any time during infection. • Trafficking of the F protein into the cilia occurred early in infection. • Presence of the F protein in cilia correlated with impaired cilia function

Morphogenesis of respiratory syncytial virus in human primary nasal ciliated epithelial cells occurs at surface membrane microdomains that are distinct from cilia

Energy Technology Data Exchange (ETDEWEB)

Jumat, Muhammad Raihan [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Yan, Yan [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Ravi, Laxmi Iyer [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Wong, Puisan [Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510 (Singapore); Huong, Tra Nguyen [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Li, Chunwei [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Tan, Boon Huan [Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510 (Singapore); Wang, De Yun [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Sugrue, Richard J., E-mail: rjsugrue@ntu.edu.sg [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore)

2015-10-15

The distribution of cilia and the respiratory syncytial virus (RSV) nucleocapsid (N) protein, fusion (F) protein, attachment (G) protein, and M2-1 protein in human ciliated nasal epithelial cells was examined at between 1 and 5 days post-infection (dpi). All virus structural proteins were localized at cell surface projections that were distinct from cilia. The F protein was also trafficked into the cilia, and while its presence increased as the infection proceeded, the N protein was not detected in the cilia at any time of infection. The presence of the F protein in the cilia correlated with cellular changes in the cilia and reduced cilia function. At 5 dpi extensive cilia loss and further reduced cilia function was noted. These data suggested that although RSV morphogenesis occurs at non-cilia locations on ciliated nasal epithelial cells, RSV infection induces changes in the cilia body that leads to extensive cilia loss. - Highlights: • Respiratory syncytial virus (RSV) infects nasal ciliated epithelial cells. • Virus morphogenesis occurs within filamentous projections distinct from cilia. • The RSV N protein was not detected in the cilia at any time during infection. • Trafficking of the F protein into the cilia occurred early in infection. • Presence of the F protein in cilia correlated with impaired cilia function.

Temperature-sensitive mutants of influenza A virus. XIV. Production and evaluation of influenza A/Georgia/74-ts-1[E] recombinant viruses in human adults.

Science.gov (United States)

Richman, D D; Murphy, B R; Belshe, R B; Rusten, H M; Chanock, R M; Blacklow, N R; Parrino, T A; Rose, F B; Levine, M M; Caplan, E

1977-08-01

The two temperature-sensitive (ts) lesions present in influenza A/Hong Kong/68-ts-1[E] (H3N2 68) virus were transferred via genetic reassortment to influenza A/Georgia/74 (H3N2 74) wild-type virus. A recombinant clone possessing both ts lesions and the shutoff temperature of 38 C of the Hong Kong/68 ts donor and the two surface antigens of the Georgia/74 wild-type virus was administered to 32 seronegative adult volunteers. Thirty-one volunteers were infected, of whom only five experienced mild afebrile upper respiratory tract illness. The wild-type recipient virus was a cloned population that induced illness in five of six infected volunteers. Therfore, the attenuation exhibited by the Georgia/74-ts-1[E] virus could reasonably be assumed to be due to the acquisition of the two ts-1[E] lesions by the Georgia/74 wild-type virus. The serum and nasal wash antibody responses of the ts-1[E] vaccinees were equivalent to those of the volunteers who received wild-type virus. The two ts lesions present in the Hong Kong/68-ts-1[E] virus have now been transferred three times to a wild-type virus bearing a new hemagglutinin, and in each instance the new ts recombination exhibited a similar, satisfactory level of attenuation and antigenicity for adults. It seems likely that the transfer of the ts-1[E] lesions to any new influenza virus will regularly result in attenuation of a recombinat virus possessing the new surface antigens.

[Research progress on ebola virus glycoprotein].

Science.gov (United States)

Ding, Guo-Yong; Wang, Zhi-Yu; Gao, Lu; Jiang, Bao-Fa

2013-03-01

Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans and there are no effective therapeutic or prophylactic treatments available. The glycoprotein (GP) of EBOV is a transmembrane envelope protein known to play multiple functions including virus attachment and entry, cell rounding and cytotoxicity, down-regulation of host surface proteins, and enhancement of virus assembly and budding. GP is the primary target of protective immunity and the key target for developing neutralizing antibodies. In this paper, the research progress on genetic structure, pathogenesis and immunogenicity of EBOV GP in the last 5 years is reviewed.

Life Cycle Characterization of Sulfolobus Monocaudavirus 1, an Extremophilic Spindle-Shaped Virus with Extracellular Tail Development.

Science.gov (United States)

Uldahl, Kristine B; Jensen, Signe B; Bhoobalan-Chitty, Yuvaraj; Martínez-Álvarez, Laura; Papathanasiou, Pavlos; Peng, Xu

2016-06-15

We provide here, for the first time, insights into the initial infection stages of a large spindle-shaped archaeal virus and explore the following life cycle events. Our observations suggest that Sulfolobus monocaudavirus 1 (SMV1) exhibits a high adsorption rate and that virions adsorb to the host cells via three distinct attachment modes: nosecone association, body association, and body/tail association. In the body/tail association mode, the entire virion, including the tail(s), aligns to the host cell surface and the main body is greatly flattened, suggesting a possible fusion entry mechanism. Upon infection, the intracellular replication cycle lasts about 8 h, at which point the virions are released as spindle-shaped tailless particles. Replication of the virus retarded host growth but did not cause lysis of the host cells. Once released from the host and at temperatures resembling that of its natural habitat, SMV1 starts developing one or two tails. This exceptional property of undergoing a major morphological development outside, and independently of, the host cell has been reported only once before for the related Acidianus two-tailed virus. Here, we show that SMV1 can develop tails of more than 900 nm in length, more than quadrupling the total virion length. Very little is known about the initial life cycle stages of viruses infecting hosts of the third domain of life, Archaea This work describes the first example of an archaeal virus employing three distinct association modes. The virus under study, Sulfolobus monocaudavirus 1, is a representative of the large spindle-shaped viruses that are frequently found in acidic hot springs. The results described here will add valuable knowledge about Archaea, the least studied domain in the virology field. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Biomolecular surface construction by PDE transform.

Science.gov (United States)

Zheng, Qiong; Yang, Siyang; Wei, Guo-Wei

2012-03-01

This work proposes a new framework for the surface generation based on the partial differential equation (PDE) transform. The PDE transform has recently been introduced as a general approach for the mode decomposition of images, signals, and data. It relies on the use of arbitrarily high-order PDEs to achieve the time-frequency localization, control the spectral distribution, and regulate the spatial resolution. The present work provides a new variational derivation of high-order PDE transforms. The fast Fourier transform is utilized to accomplish the PDE transform so as to avoid stringent stability constraints in solving high-order PDEs. As a consequence, the time integration of high-order PDEs can be done efficiently with the fast Fourier transform. The present approach is validated with a variety of test examples in two-dimensional and three-dimensional settings. We explore the impact of the PDE transform parameters, such as the PDE order and propagation time, on the quality of resulting surfaces. Additionally, we utilize a set of 10 proteins to compare the computational efficiency of the present surface generation method and a standard approach in Cartesian meshes. Moreover, we analyze the present method by examining some benchmark indicators of biomolecular surface, that is, surface area, surface-enclosed volume, solvation free energy, and surface electrostatic potential. A test set of 13 protein molecules is used in the present investigation. The electrostatic analysis is carried out via the Poisson-Boltzmann equation model. To further demonstrate the utility of the present PDE transform-based surface method, we solve the Poisson-Nernst-Planck equations with a PDE transform surface of a protein. Second-order convergence is observed for the electrostatic potential and concentrations. Finally, to test the capability and efficiency of the present PDE transform-based surface generation method, we apply it to the construction of an excessively large biomolecule, a

Localization and force analysis at the single virus particle level using atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, Chih-Hao [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Horng, Jim-Tong [Department of Biochemistry, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan (China); Chang, Jeng-Shian [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Hsieh, Chung-Fan [Graduate Institute of Biomedical Sciences, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China); Tseng, You-Chen [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Lin, Shiming, E-mail: til@ntu.edu.tw [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Center for Optoelectronic Biomedicine, College of Medicine, Nation Taiwan University, 1-1 Jen-Ai Road, Taipei 10051, Taiwan (China)

2012-01-06

Highlights: Black-Right-Pointing-Pointer Localization of single virus particle. Black-Right-Pointing-Pointer Force measurements. Black-Right-Pointing-Pointer Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

Hydrothermal Synthesis of Highly Water-dispersible Anatase Nanoparticles with Large Specific Surface Area and Their Adsorptive Properties

Directory of Open Access Journals (Sweden)

Hu Xueting

2016-01-01

Full Text Available Highly water-dispersible and very small TiO2 nanoparticles (~3 nm anatase with large specific surface area have been synthesized by hydrolysis and hydrothermal reactions of titanium butoxide and used for the removal of three azo dyes (Congo red, orange II, and methyl orange with different molecular structure from simulated wastewaters. The synthesized TiO2 nanoparticles are well dispersed in water with large specific surface area up to 417 m2 g−1. Adsorption experiments demonstrated that the water-dispersible TiO2 nanoparticles possess excellent adsorption capacities for Congo red, orange II, and methyl orange, which could be attributed to their good water-dispersibility and large specific surface area.

The use of large surface area for particle and power deposition

International Nuclear Information System (INIS)

Seigneur, A.; Guilhem, D.; Hogan, J.

1993-01-01

Since the parallel heat flux passing through the LCFS has increased dramatically with the size of machines one has to cope with very large particle and power fluxes on the limiters. Thus the size of the limiters has been increased by the use of inner bumper limiters (for example in JET, TFTR, TORE-SUPRA and JT60). The 'exponential-sine' model is widely used to estimate the heat flux (Q) to a wall for a plasma flux surface with incident angle θ. The model predict Q = q || (0) sinθ e -ρ/λ q + q(0) cosθ e -ρ/λ q , (where θ=0 o when the flux surface is exactly tangential to the limiting surface), ρ is the minor radius measured from the last closed flux surface (LCFS), λ q is the SOL decay length of the heat flux density and q(0) is the heat flux density at the last closed surface. If we approximate the heat flux as Q = q || (0) e -ρ/λ q sin(θ+α), with α ≡ tan -1 [q(0)/q || (0)], then α can be interpreted as an effective 'minimum angle of incidence'. Under conditions where the geometric angle θ has been made almost grazing (below 5 o ) the predictions of the simplest model (with α=0 o ) is not adequate to represent the observation made in TORE-SUPRA; a similar result is found in TFTR. Experimental observations of heat and particle deposition on the large area limiter on the inner wall of TORE-SUPRA are presented. These results have been analyzed with a Monte Carlo code (THOR) describing the diffusion of hydrogenic particles across the LCFS to the limiting objects in the Scrape Off Layer (SOL), and by impurity generation calculations using the full 'exponential-sine' model (α ≠ 0) used as input to an impurity (carbon) Monte Carlo code (BBQ). (author) 6 refs., 3 figs., 1 tab

Characterization of foot- and mouth disease virus antigen by surface-enhanced laser desorption ionization-time of flight-mass spectrometry in aqueous and oil-emulsion formulations

NARCIS (Netherlands)

Harmsen, M.M.; Jansen, J.; Westra, D.F.; Coco-Martin, J.M.

2010-01-01

We have used a novel method, surface-enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS), to characterize foot-and-mouth disease virus (FMDV) vaccine antigens. Using specific capture with FMDV binding recombinant antibody fragments and tryptic digestion of FMDV

Antigens of hepatitis B virus: failure to detect HBeAg on the surfaces of HBsAg forms

Energy Technology Data Exchange (ETDEWEB)

Gerin, J L [Oak Ridge National Lab., Rockville, MD; Shih, J W.K.; McAuliffee, V J; Purcell, R H

1978-01-01

The particulate forms of HBsAg were analysed for the presence of HBeAG on their surfaces. By immunodiffusion analysis, anti-HBe did not form precipitin bands with the purified forms of HBsAg and hyperimmune guinea pig antisera to these forms did not react with HBeAg. Lines of non-identity were observed between the HBeAg determinants (e/sub 1/ and e/sub 2/) and the Dane particles and filaments isolated from an HBeAg-positive serum. Finally, anti-HBe failed to precipitate the polymerase-positive subpopulation of Dane particles, indicating that anti-HBe has no direct role in virus neutralization.

Epstein-Barr virus-positive diffuse large B-cell lymphoma in children: a disease reminiscent of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly.

Science.gov (United States)

Uccini, Stefania; Al-Jadiry, Mazin F; Scarpino, Stefania; Ferraro, Daniela; Alsaadawi, Adel R; Al-Darraji, Amir F; Moleti, Maria Luisa; Testi, Anna Maria; Al-Hadad, Salma A; Ruco, Luigi

2015-05-01

Pediatric Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (EBV+ DLBCL) is a rare disease in nonimmunocompromised hosts. In a review of 231 cases of malignant lymphoma (87 Hodgkin lymphoma and 144 non-Hodgkin lymphoma) occurring in Iraqi children, 7 cases (5% of NHLs) were classified as EBV+ DLBCL. Six children presented with nodal disease, and 1 presented with extranodal localization (bone). In all cases, the disease was at an advanced clinical stage (III/IV). Evidence of immunodeficiency (Evans syndrome and selective IgA deficiency) was observed in a single case. Two cases were "monomorphic" with immunoblastic histology, and 5 cases were "polymorphic" with histologic aspects reminiscent of nodular lymphocyte-predominant Hodgkin lymphoma (2 cases) and of CD30+ classical Hodgkin lymphoma (3 cases). In all cases, tumor cells were EBV infected (EBER+/LMP-1+), were medium-large B-cells (CD20+/CD79a+/PAX-5+/BOB-1+/OCT-2+) of non-germinal center (non-GC) origin (CD10-/MUM-1+), and had high proliferative activity (50%-70%). Chromosomal translocations involving BCL2, MYC, and IGH genes were not observed. IGH monoclonality could be demonstrated in 3 of 3 investigated cases. Six cases of EBV-negative DLBCL (4% of NHL) were present in the same series. All had monomorphic histology with centroblastic/immunoblastic morphology; 3 cases were of GC type and 3 of non-GC type. Our findings indicate that in Iraq, DLBCLs are 9% of NHLs. Moreover, 2 different types of the disease do exist; the EBV-positive cases, with strong histologic and immunohistochemical resemblance with EBV+ DLBCL of the elderly, and the EBV-negative cases, which are similar to the pediatric DLBCL usually observed in Western populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Attenuation of Recombinant Yellow Fever 17D Viruses Expressing Foreign Protein Epitopes at the Surface

Science.gov (United States)

Bonaldo, Myrna C.; Garratt, Richard C.; Marchevsky, Renato S.; Coutinho, Evandro S. F.; Jabor, Alfredo V.; Almeida, Luís F. C.; Yamamura, Anna M. Y.; Duarte, Adriana S.; Oliveira, Prisciliana J.; Lizeu, Jackeline O. P.; Camacho, Luiz A. B.; Freire, Marcos S.; Galler, Ricardo

2005-01-01

The yellow fever (YF) 17D vaccine is a live attenuated virus. Three-dimensional (3D) homology modeling of the E protein structure from YF 17D virus and its comparison with that from tick-borne encephalitis virus revealed that it is possible to accommodate inserts of different sizes and amino acid compositions in the flavivirus E protein fg loop. This is consistent with the 3D structures of both the dimeric and trimeric forms in which the fg loop lies exposed to solvents. We demonstrate here that YF 17D viruses bearing foreign humoral (17D/8) and T-cell (17D/13) epitopes, which vary in sequence and length, displayed growth restriction. It is hypothesized that interference with the dimer-trimer transition and with the formation of a ring of such trimers in order to allow fusion compromises the capability of the E protein to induce fusion of viral and endosomal membranes, and a slower rate of fusion may delay the extent of virus production. This would account for the lower levels of replication in cultured cells and of viremia in monkeys, as well as for the more attenuated phenotype of the recombinant viruses in monkeys. Testing of both recombinant viruses (17D/8 and 17D/13) for monkey neurovirulence also suggests that insertion at the 17D E protein fg loop does not compromise the attenuated phenotype of YF 17D virus, further confirming the potential use of this site for the development of new live attenuated 17D virus-based vaccines. PMID:15956601

Seroprevalence of Hepatitis B surface antigen, antibodies to the Hepatitis C virus, and human immunodeficiency virus in a hospital-based population in Jaipur, Rajasthan

Directory of Open Access Journals (Sweden)

Sood Smita

2010-01-01

Full Text Available Background: Hepatitis B, hepatitis C, and HIV infections are a serious global and public health problem. To assess the magnitude and dynamics of disease transmission and for its prevention and control, the study of its seroprevalence is important. A private hospital catering to the needs of a large population represents an important center for serological surveys. Available data, at Rajasthan state level, on the seroprevalence of these bloodborne pathogens is also very limited. Objective: A study was undertaken to estimate the seroprevalence of hepatitis B surface antigen (HBsAg and antibodies to hepatitis C (anti-HCV Ab and human immunodeficiency virus (anti-HIV Ab in both the sexes and different age groups in a hospital-based population in Jaipur, Rajasthan. Materials and Methods: Serum samples collected over a period of 14 months from patients attending OPDs and admitted to various IPDs of Fortis Escorts Hospital, Jaipur, were subjected within the hospital-based lab for the detection of HBsAg and anti-HCV Ab and anti-HIV Ab using rapid card tests. This was followed by further confirmation of all reactive samples by a microparticle enzyme immunoassay (Abbott AxSYM at Super Religare Laboratories (formerly SRL Ranbaxy Reference Lab, Mumbai. Results: The seroprevalence of HBsAg was found to be 0.87%, of anti-HCV Ab as 0.28%, and of anti-HIV Ab as 0.35%. Conclusion: The study throws light on the magnitude of viral transmission in the community in the state of Rajasthan and provides a reference for future studies.

No Love Lost Between Viruses and Interferons.

Science.gov (United States)

Fensterl, Volker; Chattopadhyay, Saurabh; Sen, Ganes C

2015-11-01

The interferon system protects mammals against virus infections. There are several types of interferons, which are characterized by their ability to inhibit virus replication and resultant pathogenesis by triggering both innate and cell-mediated immune responses. Virus infection is sensed by a variety of cellular pattern-recognition receptors and triggers the synthesis of interferons, which are secreted by the infected cells. In uninfected cells, cell surface receptors recognize the secreted interferons and activate intracellular signaling pathways that induce the expression of interferon-stimulated genes; the proteins encoded by these genes inhibit different stages of virus replication. To avoid extinction, almost all viruses have evolved mechanisms to defend themselves against the interferon system. Consequently, a dynamic equilibrium of survival is established between the virus and its host, an equilibrium that can be shifted to the host's favor by the use of exogenous interferon as a therapeutic antiviral agent.

Specifics of surface runoff contents and treatment in large cities

OpenAIRE

V.N. Chechevichkin; N.I. Vatin

2014-01-01

The degree of surface runoff pollution in large cities has been assessed in modern conditions in the case study of production sites of St. Petersburg. Increased content of petroleum derivatives and heavy metal ions both in rainwater runoff and especially in snowmelt runoff has been revealed. It has been established that the composition of infiltration runoff from the newly built-up sites within the city limits commonly depends on their background, especially in the places of former unaut...

Infection of phytoplankton by aerosolized marine viruses

Science.gov (United States)

Sharoni, Shlomit; Trainic, Miri; Schatz, Daniella; Lehahn, Yoav; Flores, Michel J.; Bidle, Kay D.; Ben-Dor, Shifra; Rudich, Yinon; Vardi, Assaf

2015-01-01

Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E. huxleyi and show that EhV are emitted to the atmosphere as primary marine aerosols. Using a laboratory-based setup, we showed that the dynamic of EhV aerial emission is strongly coupled to the host–virus dynamic in the culture media. In addition, we recovered EhV DNA from atmospheric samples collected over an E. huxleyi bloom in the North Atlantic, providing evidence for aerosolization of marine viruses in their natural environment. Decay rate analysis in the laboratory revealed that aerosolized viruses can remain infective under meteorological conditions prevailing during E. huxleyi blooms in the ocean, allowing potential dispersal and infectivity over hundreds of kilometers. Based on the combined laboratory and in situ findings, we propose that atmospheric transport of EhV is an effective transmission mechanism for spreading viral infection over large areas in the ocean. This transmission mechanism may also have an important ecological impact on the large-scale host–virus “arms race” during bloom succession and consequently the turnover of carbon in the ocean. PMID:25964340

Emerging mosquito-borne viruses: transmission and modulation of host defence

NARCIS (Netherlands)

Fros, J.J.

2015-01-01

Summary

Two highly pathogenic arthropod-borne (arbo)viruses, West Nile virus (WNV) and chikungunya virus (CHIKV), recently (re-)emerged in both Europe and the Americas. This resulted in large-scale epidemics of severe encephalitic and arthritogenic human disease,

The Zika Virus | NIH MedlinePlus the Magazine

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... please turn JavaScript on. Feature: Infectious Diseases The Zika Virus Past Issues / Spring 2016 Table of Contents A ... Photo Courtesy of NIH "You could have a Zika virus vaccine in large-scale clinical trials in 2017, ...

Recent progress in West Nile virus diagnosis and vaccination

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De Filette Marina

2012-03-01

Full Text Available Abstract West Nile virus (WNV is a positive-stranded RNA virus belonging to the Flaviviridae family, a large family with 3 main genera (flavivirus, hepacivirus and pestivirus. Among these viruses, there are several globally relevant human pathogens including the mosquito-borne dengue virus (DENV, yellow fever virus (YFV, Japanese encephalitis virus (JEV and West Nile virus (WNV, as well as tick-borne viruses such as tick-borne encephalitis virus (TBEV. Since the mid-1990s, outbreaks of WN fever and encephalitis have occurred throughout the world and WNV is now endemic in Africa, Asia, Australia, the Middle East, Europe and the Unites States. This review describes the molecular virology, epidemiology, pathogenesis, and highlights recent progress regarding diagnosis and vaccination against WNV infections.

[Behavior of Orf virus in permissive and nonpermissive systems].

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Büttner, M; Czerny, C P; Schumm, M

1995-04-01

Dogs were immunized i.m. with attenuated poxvirus vaccines (vaccinia virus, Orf-virus) and a bovine herpesvirus-1 (BHV-1) vaccine. After intradermal (i.d.) application of the vaccine viruses a specific delayed type hypersensitivity (DTH) reaction of the skin occurred only with vaccinia virus. The i.d. application of Orf-virus caused a short-term, non-specific inflammatory reaction of the skin, even in dogs not immunized with Orf-virus. Out of 30 sera from Orf-virus immunized beagles (n = 4) only eight were found reactive to Orf-virus in a competition ELISA. Three sera from dogs not Orf-virus immunized but skin-tested with the virus contained low antibody titers. Using indirect immunofluorescence (IIF) in flow cytometry, the existence of Orf-virus antigens was examined on the surface and in the cytoplasm of permissive (BFK and Vero)- and questionable permissive MDCK cells. The canine kidney MDCK cell line was found to be non-permissive for Orf-virus replication; the occurrence of an Orf-(ecthyma contagiosum) like disease in dogs is unlikely.

Wipes coated with a singlet-oxygen-producing photosensitizer are effective against human influenza virus but not against norovirus

NARCIS (Netherlands)

Verhaelen, Katharina; Bouwknegt, Martijn; Rutjes, Saskia; de Roda Husman, Ana Maria; Duizer, Erwin

2014-01-01

Transmission of enteric and respiratory viruses, including human norovirus (hNoV) and human influenza virus, may involve surfaces. In food preparation and health care settings, surfaces are cleaned with wipes; however, wiping may not efficiently reduce contamination or may even spread viruses,

Cell-surface antigens associated with dualtropic and thymotropic murine leukemia viruses inducing thymic and nonthymic lymphomas

International Nuclear Information System (INIS)

Haas, M.; Patch, V.

1980-01-01

Unique type-specific antigens were detected on cells infected with dualtropic and thymotropic viruses and x-ray-induced T cell- and B cell-malignant lymphomas of C57BL/6 mice. These findings support the contention that T cell lymphoma (TCL)-inducing and B cell lymphoma (BCL)-indcing viruses isolated from x-irradiated C57BL/6 mice are env gene recombinants in which ecotropic gene sequences have been substituted by xenotropic sequences. We found that unique antigenicities are associated with each TCL-inducing and BCL-inducing dualtropic virus, and that the thymotropic TCL-inducing virus isolates represent a separate serologic group. These virus mapping experiments indicated that many serologically different recombinant viruses can be isolated from C57BL/6 mice. It is suggested that many distinct recombinant viruses may exist in lymphomagenic C57BL/6 mice, some of which are associated with specific lyphoma induction

Viral gene products and replication of the human immunodeficiency type 1 virus.

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Morrow, C D; Park, J; Wakefield, J K

1994-05-01

The acquired immunodeficiency syndrome (AIDS) epidemic represents a modern-day plague that has not only resulted in a tragic loss of people from a wide spectrum of society but has reshaped our viewpoints regarding health care, the treatment of infectious diseases, and social issues regarding sexual behavior. There is little doubt now that the cause of the disease AIDS is a virus known as the human immunodeficiency virus (HIV). The HIV virus is a member of a large family of viruses termed retroviruses, which have as a hallmark the capacity to convert their RNA genome into a DNA form that then undergoes a process of integration into the host cell chromosome, followed by the expression of the viral genome and translation of viral proteins in the infected cell. This review describes the organization of the HIV-1 viral genome, the expression of viral proteins, as well as the functions of the accessory viral proteins in HIV replication. The replication of the viral genome is divided into two phases, the early phase and the late phase. The early phase consists of the interaction of the virus with the cell surface receptor (CD4 molecule in most cases), the uncoating and conversion of the viral RNA genome into a DNA form, and the integration into the host cell chromosome. The late phase consists of the expression of the viral proteins from the integrated viral genome, the translation of viral proteins, and the assembly and release of the virus. Points in the HIV-1 life cycle that are targets for therapeutic intervention are also discussed.

Linear DNA vaccine prepared by large-scale PCR provides protective immunity against H1N1 influenza virus infection in mice.

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Wang, Fei; Chen, Quanjiao; Li, Shuntang; Zhang, Chenyao; Li, Shanshan; Liu, Min; Mei, Kun; Li, Chunhua; Ma, Lixin; Yu, Xiaolan

2017-06-01

Linear DNA vaccines provide effective vaccination. However, their application is limited by high cost and small scale of the conventional polymerase chain reaction (PCR) generally used to obtain sufficient amounts of DNA effective against epidemic diseases. In this study, a two-step, large-scale PCR was established using a low-cost DNA polymerase, RKOD, expressed in Pichia pastoris. Two linear DNA vaccines encoding influenza H1N1 hemagglutinin (HA) 1, LEC-HA, and PTO-LEC-HA (with phosphorothioate-modified primers), were produced by the two-step PCR. Protective effects of the vaccines were evaluated in a mouse model. BALB/c mice were immunized three times with the vaccines or a control DNA fragment. All immunized animals were challenged by intranasal administration of a lethal dose of influenza H1N1 virus 2 weeks after the last immunization. Sera of the immunized animals were tested for the presence of HA-specific antibodies, and the total IFN-γ responses induced by linear DNA vaccines were measured. The results showed that the DNA vaccines but not the control DNA induced strong antibody and IFN-γ responses. Additionally, the PTO-LEC-HA vaccine effectively protected the mice against the lethal homologous mouse-adapted virus, with a survival rate of 100% versus 70% in the LEC-HA-vaccinated group, showing that the PTO-LEC-HA vaccine was more effective than LEC-HA. In conclusion, the results indicated that the linear H1N1 HA-coding DNA vaccines induced significant immune responses and protected mice against a lethal virus challenge. Thus, the low-cost, two-step, large-scale PCR can be considered a potential tool for rapid manufacturing of linear DNA vaccines against emerging infectious diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Human and bovine viruses in the Milwaukee River Watershed: hydrologically relevant representation and relations with environmental variables

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Corsi, Steven R.; Borchardt, M. A.; Spencer, S. K.; Hughes, Peter E.; Baldwin, Austin K.

2014-01-01

To examine the occurrence, hydrologic variability, and seasonal variability of human and bovine viruses in surface water, three stream locations were monitored in the Milwaukee River watershed in Wisconsin, USA, from February 2007 through June 2008. Monitoring sites included an urban subwatershed, a rural subwatershed, and the Milwaukee River at the mouth. To collect samples that characterize variability throughout changing hydrologic periods, a process control system was developed for unattended, large-volume (56–2800 L) filtration over extended durations. This system provided flow-weighted mean concentrations during runoff and extended (24-h) low-flow periods. Human viruses and bovine viruses were detected by real-time qPCR in 49% and 41% of samples (n = 63), respectively. All human viruses analyzed were detected at least once including adenovirus (40% of samples), GI norovirus (10%), enterovirus (8%), rotavirus (6%), GII norovirus (1.6%) and hepatitis A virus (1.6%). Three of seven bovine viruses analyzed were detected including bovine polyomavirus (32%), bovine rotavirus (19%), and bovine viral diarrhea virus type 1 (5%). Human viruses were present in 63% of runoff samples resulting from precipitation and snowmelt, and 20% of low-flow samples. Maximum human virus concentrations exceeded 300 genomic copies/L. Bovine viruses were present in 46% of runoff samples resulting from precipitation and snowmelt and 14% of low-flow samples. The maximum bovine virus concentration was 11 genomic copies/L. Statistical modeling indicated that stream flow, precipitation, and season explained the variability of human viruses in the watershed, and hydrologic condition (runoff event or low-flow) and season explained the variability of the sum of human and bovine viruses; however, no model was identified that could explain the variability of bovine viruses alone. Understanding the factors that affect virus fate and transport in rivers will aid watershed management for minimizing

Glycoprotein-G-gene-based molecular and phylogenetic analysis of rabies viruses associated with a large outbreak of bovine rabies in southern Brazil.

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Cargnelutti, Juliana F; de Quadros, João M; Martins, Mathias; Batista, Helena B C R; Weiblen, Rudi; Flores, Eduardo F

2017-12-01

A large outbreak of hematophagous-bat-associated bovine rabies has been occurring in Rio Grande do Sul (RS), the southernmost Brazilian state, since 2011, with official estimates exceeding 50,000 cattle deaths. The present article describes a genetic characterization of rabies virus (RABV) recovered from 59 affected cattle and two sheep, from 56 herds in 16 municipalities (2012-2016). Molecular analysis was performed using the nucleotide (nt) and predicted amino acid (aa) sequences of RABV glycoprotein G (G). A high level of nt and aa sequence identity was observed among the examined G sequences, ranging from 98.4 to 100%, and from 97.3 to 100%, respectively. Likewise, high levels of nt and aa sequence identity were observed with bovine (nt, 99.8%; aa, 99.8%) and hematophagous bat (nt, 99.5%; aa, 99.4%) RABV sequences from GenBank, and lower levels were observed with carnivore RABV sequences (nt, 92.8%; aa, 88.1%). Some random mutations were observed in the analyzed sequences, and a few consistent mutations were observed in some sequences belonging to cluster 2, subcluster 2b. The clustering of the sequences was observed in a phylogenetic tree, where two distinct clusters were evident. Cluster 1 comprised RABV sequences covering the entire study period (2012 to 2016), but subclusters corresponding to different years could be identified, indicating virus evolution and/or introduction of new viruses into the population. In some cases, viruses from the same location obtained within a short period grouped into different subclusters, suggesting co-circulation of viruses of different origins. Subcluster segregation was also observed in sequences obtained in the same region during different periods, indicating the involvement of different viruses in the cases at different times. In summary, our results indicate that the outbreaks occurring in RS (2012 to 2016) probably involved RABV of different origins, in addition to a possible evolution of RABV isolates within this

The cellular receptors for infectious bursal disease virus | Zhu ...

African Journals Online (AJOL)

Virus receptors are simplistically defined as cell surface molecules that mediate binding (attachment, adsorption) and/or trigger membrane fusion or entry through other processes. Infectious bursal disease virus (IBDV) entry into host cells occurs by recognition of specific cellular receptor(s) with viral envelope glycoprotein, ...

Clinical and virological improvement of hepatitis B virus-related or hepatitis C virus-related chronic hepatitis with concomitant hepatitis A virus infection.

Science.gov (United States)

Sagnelli, Evangelista; Coppola, Nicola; Pisaturo, Mariantonietta; Pisapia, Raffaella; Onofrio, Mirella; Sagnelli, Caterina; Catuogno, Antonio; Scolastico, Carlo; Piccinino, Felice; Filippini, Pietro

2006-06-01

We evaluated the clinical and virological characteristics of hepatitis A virus infection in persons concomitantly infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). We enrolled 21 patients with acute hepatitis A and chronic hepatitis with no sign of liver cirrhosis, 13 patients who were positive for hepatitis B surface antigen (case B group), 8 patients who were anti-HCV positive (case C group), and 21 patients with acute hepatitis A without a preexisting liver disease (control A group). Two control groups of patients with chronic hepatitis B (control B group) or C (control C group) were also chosen. All control groups were pair-matched by age and sex with the corresponding case group. Fulminant hepatitis A was never observed, and hepatitis A had a severe course in 1 patient in the case B group and in 1 patient in the control A group. Both patients recovered. On admission, HBV DNA was detected in 1 patient in the case B group (7.7%) and in 13 patients (50%) in the control B group; HCV RNA was found in no patient in the case C group and in 16 patients (81.2%) in the control C group. Of 9 patients in the case B group who were followed up for 6 months, 3 became negative for hepatitis B surface antigen and positive for hepatitis B surface antibody, 2 remained positive for hepatitis B surface antigen and negative for HBV DNA, and 4 became positive for HBV DNA with a low viral load [corrected] Of 6 patients in the case C group who were followed up for 6 months, 3 remained negative for HCV RNA, and 3 had persistently low viral loads. Concomitant hepatitis A was always self-limited, associated with a marked inhibition of HBV and HCV genomes, and possibly had a good prognosis for the underlying chronic hepatitis.

Ebola virus acceptors

African Journals Online (AJOL)

STORAGESEVER

2009-05-18

May 18, 2009 ... genome sequencing centre; HSP, High scoring Segment pair;. NHGRI, National ... the genome of the rhesus monkey (rhesus macaque, Macaca mulatta). The sequencing and comparative analysis was funded by the National ... Definition. Accession ..... Marburg virus genomics and association with a large.

Ultramicroscopic observation of recombinant adenoassociated virus ...

African Journals Online (AJOL)

Ultramicroscopic observation of recombinant adenoassociated virus type 2 on the surface of formvarcarbon coated copper grids under different relative humidity and incubation time using negative stain transmission electron microscopy.

Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins

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Yadvinder S. Ahi

2016-11-01

Full Text Available Gammaretroviruses, such as murine leukemia viruses (MLVs, encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called “glycogag” (glycosylated Gag. MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes.

Feline infectious peritonitis virus with a large deletion in the 5'-terminal region of the spike gene retains its virulence for cats.

Science.gov (United States)

Terada, Yutaka; Shiozaki, Yuto; Shimoda, Hiroshi; Mahmoud, Hassan Youssef Abdel Hamid; Noguchi, Keita; Nagao, Yumiko; Shimojima, Masayuki; Iwata, Hiroyuki; Mizuno, Takuya; Okuda, Masaru; Morimoto, Masahiro; Hayashi, Toshiharu; Tanaka, Yoshikazu; Mochizuki, Masami; Maeda, Ken

2012-09-01

In this study, the Japanese strain of type I feline infectious peritonitis virus (FIPV), C3663, was found to have a large deletion of 735 bp within the gene encoding the spike (S) protein, with a deduced loss of 245 aa of the N-terminal region of the S protein. This deletion is similar to that observed in porcine respiratory coronavirus (PRCoV) when compared to transmissible gastroenteritis virus, which correlates with reduced virulence. By analogy to PRCoV, we expected that the pathogenicity of C3663 may be attenuated in cats. However, two of four cats inoculated with C3663 died of FIP, and a third C3663-inoculated cat showed FIP lesions at 91 days after challenge. These results indicate that the 5'-terminal region of the S gene is not essential for the development of FIP.

Production of Japanese Encephalitis Virus Antigens in Plants Using Bamboo Mosaic Virus-Based Vector

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Tsung-Hsien Chen

2017-05-01

Full Text Available Japanese encephalitis virus (JEV is among the major threats to public health in Asia. For disease control and prevention, the efficient production of safe and effective vaccines against JEV is in urgent need. In this study, we produced a plant-made JEV vaccine candidate using a chimeric virus particle (CVP strategy based on bamboo mosaic virus (BaMV for epitope presentation. The chimeric virus, designated BJ2A, was constructed by fusing JEV envelope protein domain III (EDIII at the N-terminus of BaMV coat protein, with an insertion of the foot-and-mouth disease virus 2A peptide to facilitate the production of both unfused and epitope-presenting for efficient assembly of the CVP vaccine candidate. The strategy allowed stable maintenance of the fusion construct over long-term serial passages in plants. Immuno-electron microscopy examination and immunization assays revealed that BJ2A is able to present the EDIII epitope on the surface of the CVPs, which stimulated effective neutralizing antibodies against JEV infection in mice. This study demonstrates the efficient production of an effective CVP vaccine candidate against JEV in plants by the BaMV-based epitope presentation system.

Effect of surface roughness on the heating rates of large-angled hypersonic blunt cones

Science.gov (United States)

Irimpan, Kiran Joy; Menezes, Viren

2018-03-01

Surface-roughness caused by the residue of an ablative Thermal Protection System (TPS) can alter the turbulence level and surface heating rates on a hypersonic re-entry capsule. Large-scale surface-roughness that could represent an ablated TPS, was introduced over the forebody of a 120° apex angle blunt cone, in order to test for its influence on surface heating rates in a hypersonic freestream of Mach 8.8. The surface heat transfer rates measured on smooth and roughened models under the same freestream conditions were compared. The hypersonic flow-fields of the smooth and rough-surfaced models were visualized to analyse the flow physics. Qualitative numerical simulations and pressure measurements were carried out to have an insight into the high-speed flow physics. Experimental observations under moderate Reynolds numbers indicated a delayed transition and an overall reduction of 17-46% in surface heating rates on the roughened model.

The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells

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Eiden Maribeth V

2011-07-01

Full Text Available Abstract Background Over the last several decades it has been noted, using a variety of different methods, that cells infected by a specific gammaretrovirus are resistant to infection by other retroviruses that employ the same receptor; a phenomenon termed receptor interference. Receptor masking is thought to provide an earlier means of blocking superinfection, whereas receptor down regulation is generally considered to occur in chronically infected cells. Results We used replication-competent GFP-expressing viruses containing either an amphotropic murine leukemia virus (A-MLV or the gibbon ape leukemia virus (GALV envelope. We also constructed similar viruses containing fluorescence-labeled Gag proteins for the detection of viral particles. Using this repertoire of reagents together with a wide range of antibodies, we were able to determine the presence and availability of viral receptors, and detect viral envelope proteins and particles presence on the cell surface of chronically infected cells. Conclusions A-MLV or GALV receptors remain on the surface of chronically infected cells and are detectable by respective antibodies, indicating that these receptors are not downregulated in these infected cells as previously proposed. We were also able to detect viral envelope proteins on the infected cell surface and infected cells are unable to bind soluble A-MLV or GALV envelopes indicating that receptor binding sites are masked by endogenously expressed A-MLV or GALV viral envelope. However, receptor masking does not completely prevent A-MLV or GALV superinfection.

Vaccine potential of Nipah virus-like particles.

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Pramila Walpita

2011-04-01

Full Text Available Nipah virus (NiV was first recognized in 1998 in a zoonotic disease outbreak associated with highly lethal febrile encephalitis in humans and a predominantly respiratory disease in pigs. Periodic deadly outbreaks, documentation of person-to-person transmission, and the potential of this virus as an agent of agroterror reinforce the need for effective means of therapy and prevention. In this report, we describe the vaccine potential of NiV virus-like particles (NiV VLPs composed of three NiV proteins G, F and M. Co-expression of these proteins under optimized conditions resulted in quantifiable amounts of VLPs with many virus-like/vaccine desirable properties including some not previously described for VLPs of any paramyxovirus: The particles were fusogenic, inducing syncytia formation; PCR array analysis showed NiV VLP-induced activation of innate immune defense pathways; the surface structure of NiV VLPs imaged by cryoelectron microscopy was dense, ordered, and repetitive, and consistent with similarly derived structure of paramyxovirus measles virus. The VLPs were composed of all the three viral proteins as designed, and their intracellular processing also appeared similar to NiV virions. The size, morphology and surface composition of the VLPs were consistent with the parental virus, and importantly, they retained their antigenic potential. Finally, these particles, formulated without adjuvant, were able to induce neutralizing antibody response in Balb/c mice. These findings indicate vaccine potential of these particles and will be the basis for undertaking future protective efficacy studies in animal models of NiV disease.

Ebola Virus and Marburg Virus

Science.gov (United States)

Ebola virus and Marburg virus Overview Ebola virus and Marburg virus are related viruses that cause hemorrhagic fevers — illnesses marked by severe bleeding (hemorrhage), organ failure and, in many ...

Mechanism of lymphocytic choriomeningitis virus entry into cells.

Science.gov (United States)

Borrow, P; Oldstone, M B

1994-01-01

The path that the arenavirus lymphocytic choriomeningitis virus (LCMV) uses to enter rodent fibroblastic cell lines was dissected by infectivity and inhibition studies and immunoelectron microscopy. Lysosomotropic weak bases (chloroquine and ammonium chloride) and carboxylic ionophores (monensin and nigericin) inhibited virus entry, assessed as virus nucleoprotein expression at early times post-infection, indicating that the entry process involved a pH-dependent fusion step in intracellular vesicles. That entry occurred in vesicles rather than by direct fusion of virions with the plasma membrane was confirmed by immunoelectron microscopy. The vesicles involved were large (150-300 nm diameter), smooth-walled, and not associated with clathrin. Unlike classical phagocytosis, virus uptake in these vesicles was a microfilament-independent process, as it was not blocked by cytochalasins. LCMV entry into rodent fibroblast cell lines thus involves viropexis in large smooth-walled vesicles, followed by a pH-dependent fusion event inside the cell.

Specific Antibodies Reacting with SV40 Large T Antigen Mimotopes in Serum Samples of Healthy Subjects.

Directory of Open Access Journals (Sweden)

Mauro Tognon

Full Text Available Simian Virus 40, experimentally assayed in vitro in different animal and human cells and in vivo in rodents, was classified as a small DNA tumor virus. In previous studies, many groups identified Simian Virus 40 sequences in healthy individuals and cancer patients using PCR techniques, whereas others failed to detect the viral sequences in human specimens. These conflicting results prompted us to develop a novel indirect ELISA with synthetic peptides, mimicking Simian Virus 40 capsid viral protein antigens, named mimotopes. This immunologic assay allowed us to investigate the presence of serum antibodies against Simian Virus 40 and to verify whether Simian Virus 40 is circulating in humans. In this investigation two mimotopes from Simian Virus 40 large T antigen, the viral replication protein and oncoprotein, were employed to analyze for specific reactions to human sera antibodies. This indirect ELISA with synthetic peptides from Simian Virus 40 large T antigen was used to assay a new collection of serum samples from healthy subjects. This novel assay revealed that serum antibodies against Simian Virus 40 large T antigen mimotopes are detectable, at low titer, in healthy subjects aged from 18-65 years old. The overall prevalence of reactivity with the two Simian Virus 40 large T antigen peptides was 20%. This new ELISA with two mimotopes of the early viral regions is able to detect in a specific manner Simian Virus 40 large T antigen-antibody responses.

A study of nucleo-cytoplasmic large DNA viruses: detection and characterization of viruses in environmental amoeba

OpenAIRE

Fugas, Mariana Costa

2012-01-01

Tese de mestrado. Biologia (Biologia Molecular e Genética). Universidade de Lisboa, Faculdade de Ciências, 2012 Amoeba associated microorganisms (ARMs) are bacteria or viruses that share a symbiotic relationship with amoebas. Many ARMs are associated with human diseases and it has been reported the acquisition of resistance inside their host. These facts highlight the importance of finding and characterizing ARMs in a public health’s perspective. In the present work, amoebas from environme...

Theoretical treatment of high-frequency, large-amplitude ac voltammetry applied to ideal surface-confined redox systems

International Nuclear Information System (INIS)

Bell, Christopher G.; Anastassiou, Costas A.; O’Hare, Danny; Parker, Kim H.; Siggers, Jennifer H.

2012-01-01

Highlights: ► Theory of ac voltammetry on ideal surface-confined redox systems. ► Analytical description of the harmonics and transient of the current response. ► Solution valid for high frequency, large-amplitude sinusoidal input voltage. ► Protocol for determining system parameters from experimental current responses. - Abstract: Large-amplitude ac voltammetry, where the applied voltage is a large-amplitude sinusoidal waveform superimposed onto a dc ramp, is a powerful method for investigating the reaction kinetics of surface-confined redox species. Here we consider the large-amplitude ac voltammetric current response of a quasi-reversible, ideal, surface-confined redox system, for which the redox reaction is described by Butler–Volmer theory. We derive an approximate analytical solution, which is valid whenever the angular frequency of the sine-wave is much larger than the rate of the dc ramp and the standard kinetic rate constant of the redox reaction. We demonstrate how the third harmonic and the initial transient of the current response can be used to estimate parameters of the electrochemical system, namely the kinetic rate constant, the electron transfer coefficient, the adsorption formal potential, the initial proportion of oxidised molecules and the linear double-layer capacitance.

Suppression of chikungunya virus replication and differential innate responses of human peripheral blood mononuclear cells during co-infection with dengue virus

NARCIS (Netherlands)

Silva, Mariana Ruiz; Briseno, Jose A. Aguilar; Upasani, Vinit; van der Ende-Metselaar, Heidi; Smit, Jolanda M.; Rodenhuis-Zybert, Izabela A.

2017-01-01

Dengue and chikungunya are viral diseases transmitted to humans by infected Aedes spp. mosquitoes. With an estimated 390 million infected people per year dengue virus (DENV) currently causes the most prevalent arboviral disease. During the last decade chikungunya virus (CHIKV) has caused large

Inactivated Recombinant Rabies Viruses Displaying Canine Distemper Virus Glycoproteins Induce Protective Immunity against Both Pathogens.

Science.gov (United States)

da Fontoura Budaszewski, Renata; Hudacek, Andrew; Sawatsky, Bevan; Krämer, Beate; Yin, Xiangping; Schnell, Matthias J; von Messling, Veronika

2017-04-15

The development of multivalent vaccines is an attractive methodology for the simultaneous prevention of several infectious diseases in vulnerable populations. Both canine distemper virus (CDV) and rabies virus (RABV) cause lethal disease in wild and domestic carnivores. While RABV vaccines are inactivated, the live-attenuated CDV vaccines retain residual virulence for highly susceptible wildlife species. In this study, we developed recombinant bivalent vaccine candidates based on recombinant vaccine strain rabies virus particles, which concurrently display the protective CDV and RABV glycoprotein antigens. The recombinant viruses replicated to near-wild-type titers, and the heterologous glycoproteins were efficiently expressed and incorporated in the viral particles. Immunization of ferrets with beta-propiolactone-inactivated recombinant virus particles elicited protective RABV antibody titers, and animals immunized with a combination of CDV attachment protein- and fusion protein-expressing recombinant viruses were protected from lethal CDV challenge. However, animals that were immunized with only a RABV expressing the attachment protein of CDV vaccine strain Onderstepoort succumbed to infection with a more recent wild-type strain, indicating that immune responses to the more conserved fusion protein contribute to protection against heterologous CDV strains. IMPORTANCE Rabies virus and canine distemper virus (CDV) cause high mortality rates and death in many carnivores. While rabies vaccines are inactivated and thus have an excellent safety profile and high stability, live-attenuated CDV vaccines can retain residual virulence in highly susceptible species. Here we generated recombinant inactivated rabies viruses that carry one of the CDV glycoproteins on their surface. Ferrets immunized twice with a mix of recombinant rabies viruses carrying the CDV fusion and attachment glycoproteins were protected from lethal CDV challenge, whereas all animals that received

Negative-strand RNA viruses: The plant-infecting counterparts

NARCIS (Netherlands)

Kormelink, R.J.M.; Garcia, M.L.; Goodin, M.; Sasaya, T.; Haenni, A.L.

2011-01-01

While a large number of negative-strand (-)RNA viruses infect animals and humans, a relative small number have plants as their primary host. Some of these have been classified within families together with animal/human infecting viruses due to similarities in particle morphology and genome

Characterization of Vesicular Stomatitis Virus Recombinants That Express and Incorporate High Levels of Hepatitis C Virus Glycoproteins

OpenAIRE

Buonocore, Linda; Blight, Keril J.; Rice, Charles M.; Rose, John K.

2002-01-01

We generated recombinant vesicular stomatitis viruses (VSV) expressing genes encoding hybrid proteins consisting of the extracellular domains of hepatitis C virus (HCV) glycoproteins fused at different positions to the transmembrane and cytoplasmic domains of the VSV G glycoprotein (E1G and E2G). We show that these chimeric proteins are transported to the cell surface and incorporated into VSV virions efficiently. We also generated VSV recombinants in which the gene encoding the VSV G protein...

Screening for influenza viruses in 7804 patients with influenza-like symptoms

International Nuclear Information System (INIS)

Xuehui Li; Nan Lv; Chen Hangwe; Lanhua You; Huimin Wang

2010-01-01

To screen a large number of patients with influenza-like symptoms by using the gold-immunochromatographic assay kit. All patients with influenza-like symptoms visiting the outpatient department of the General Hospital of Beijing Military Region, Beijing, China between May 2009 and January 2010 were enrolled in the study. Nasopharyngeal swabs were collected immediately after the patient visited, then a gold-immunochromatographic assay was performed for screening of influenza A and B viruses according to the kit protocol. Among the 7804 patients enrolled in this study, 202 patients were influenza virus-positive; the positive cases accounted for 2.6% of all cases detected. Among the 202 influenza virus-positive patients, 171 patients were influenza virus A-positive, 24 were influenza virus B-positive, and 7 were co-infected with influenza virus A and B. More than 57% of the virus-positive patients were younger than 30 years old. Symptoms such as fever, sore throat, nasal congestion, sneezing, runny nose, and joint pain were more frequently observed in influenza virus A-positive patients than in influenza virus B-positive and influenza virus-negative patients. The gold immunochromatographic assay kit is very useful for screening a large number of patients with influenza-like symptoms. A higher number of influenza virus A-positive patients have sore throat, nasal congestion, sneezing, runny nose, and joint pain than influenza virus B-positive and influenza virus-negative patients (Author).

Surgical excision for recurrent herpes simplex virus 2 (HSV-2) anogenital infection in a patient with human immunodeficiency virus (HIV).

Science.gov (United States)

Arinze, Folasade; Shaver, Aaron; Raffanti, Stephen

2017-10-01

Recurrent anogenital herpes simplex virus infections are common in patients with human immunodeficiency virus (HIV), of whom approximately 5% develop resistance to acyclovir. We present a case of a 49-year-old man with HIV who had an 8-year history of recurrent left inguinal herpes simplex virus type 2 ulcerations. He initially responded to oral acyclovir, but developed resistance to acyclovir and eventually foscarnet. The lesion progressed to a large hypertrophic mass that required surgical excision, which led to resolution without recurrences. Our case highlights the importance of surgical excision as a treatment option in refractory herpes simplex virus anogenital infections.

Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

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Markus Hoffmann

Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.

Hepatitis B, C and Human Immunodeficiency Virus (HIV) Co ...

African Journals Online (AJOL)

TNHJOURNALPH

BACKGROUND. Nigeria which has one of the world's highest burden of children living with. Sickle cell anaemia is also endemic for hepatitis B, C and the Human immunodeficiency virus (HIV). This study set out to determine the prevalence of. Hepatitis B surface antigen (HBsAg), antibodies to Hepatitis C Virus (HCV) and.

Multiple proteins of White spot syndrome virus involved in ...

Indian Academy of Sciences (India)

The recognition and attachment of virus to its host cell surface is a critical step for viral infection. Recent research revealed that -integrin was involved in White spot syndrome virus (WSSV) infection. In this study, the interaction of -integrin with structure proteins of WSSV and motifs involved in WSSV infection was ...

Development of a HIV-1 Virus Detection System Based on Nanotechnology

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Jin-Ho Lee

2015-04-01

Full Text Available Development of a sensitive and selective detection system for pathogenic viral agents is essential for medical healthcare from diagnostics to therapeutics. However, conventional detection systems are time consuming, resource-intensive and tedious to perform. Hence, the demand for sensitive and selective detection system for virus are highly increasing. To attain this aim, different aspects and techniques have been applied to develop virus sensor with improved sensitivity and selectivity. Here, among those aspects and techniques, this article reviews HIV virus particle detection systems incorporated with nanotechnology to enhance the sensitivity. This review mainly focused on four different detection system including vertically configured electrical detection based on scanning tunneling microscopy (STM, electrochemical detection based on direct electron transfer in virus, optical detection system based on localized surface plasmon resonance (LSPR and surface enhanced Raman spectroscopy (SERS using plasmonic nanoparticle.

Development of a HIV-1 Virus Detection System Based on Nanotechnology.

Science.gov (United States)

Lee, Jin-Ho; Oh, Byung-Keun; Choi, Jeong-Woo

2015-04-27

Development of a sensitive and selective detection system for pathogenic viral agents is essential for medical healthcare from diagnostics to therapeutics. However, conventional detection systems are time consuming, resource-intensive and tedious to perform. Hence, the demand for sensitive and selective detection system for virus are highly increasing. To attain this aim, different aspects and techniques have been applied to develop virus sensor with improved sensitivity and selectivity. Here, among those aspects and techniques, this article reviews HIV virus particle detection systems incorporated with nanotechnology to enhance the sensitivity. This review mainly focused on four different detection system including vertically configured electrical detection based on scanning tunneling microscopy (STM), electrochemical detection based on direct electron transfer in virus, optical detection system based on localized surface plasmon resonance (LSPR) and surface enhanced Raman spectroscopy (SERS) using plasmonic nanoparticle.

Email networks and the spread of computer viruses

Science.gov (United States)

Newman, M. E.; Forrest, Stephanie; Balthrop, Justin

2002-09-01

Many computer viruses spread via electronic mail, making use of computer users' email address books as a source for email addresses of new victims. These address books form a directed social network of connections between individuals over which the virus spreads. Here we investigate empirically the structure of this network using data drawn from a large computer installation, and discuss the implications of this structure for the understanding and prevention of computer virus epidemics.

Molecular and structural characterization of fluorescent human parvovirus B19 virus-like particles

International Nuclear Information System (INIS)

Gilbert, Leona; Toivola, Jouni; White, Daniel; Ihalainen, Teemu; Smith, Wesley; Lindholm, Laura; Vuento, Matti; Oker-Blom, Christian

2005-01-01

Although sharing a T = 1 icosahedral symmetry with other members of the Parvoviridae family, it has been suggested that the fivefold channel of the human parvovirus B19 VP2 capsids is closed at its outside end. To investigate the possibility of placing a relatively large protein moiety at this site of B19, fluorescent virus-like particles (fVLPs) of B19 were developed. The enhanced green fluorescent protein (EGFP) was inserted at the N-terminus of the structural protein VP2 and assembly of fVLPs from this fusion protein was obtained. Electron microscopy revealed that these fluorescent protein complexes were very similar in size when compared to wild-type B19 virus. Further, fluorescence correlation spectroscopy showed that an average of nine EGFP domains were associated with these virus-like structures. Atomic force microscopy and immunoprecipitation studies showed that EGFP was displayed on the surface of these fVLPs. Confocal imaging indicated that these chimeric complexes were targeted to late endosomes when expressed in insect cells. The fVLPs were able to efficiently enter cancer cells and traffic to the nucleus via the microtubulus network. Finally, immunoglobulins present in human parvovirus B19 acute and past-immunity serum samples were able to detect antigenic epitopes present in these fVLPs. In summary, we have developed fluorescent virus-like nanoparticles displaying a large heterologous entity that should be of help to elucidate the mechanisms of infection and pathogenesis of human parvovirus B19. In addition, these B19 nanoparticles serve as a model in the development of targetable vehicles designed for delivery of biomolecules

Epstein-Barr virus large tegument protein BPLF1 contributes to innate immune evasion through interference with toll-like receptor signaling.

Directory of Open Access Journals (Sweden)

Michiel van Gent

2014-02-01

Full Text Available Viral infection triggers an early host response through activation of pattern recognition receptors, including Toll-like receptors (TLR. TLR signaling cascades induce production of type I interferons and proinflammatory cytokines involved in establishing an anti-viral state as well as in orchestrating ensuing adaptive immunity. To allow infection, replication, and persistence, (herpesviruses employ ingenious strategies to evade host immunity. The human gamma-herpesvirus Epstein-Barr virus (EBV is a large, enveloped DNA virus persistently carried by more than 90% of adults worldwide. It is the causative agent of infectious mononucleosis and is associated with several malignant tumors. EBV activates TLRs, including TLR2, TLR3, and TLR9. Interestingly, both the expression of and signaling by TLRs is attenuated during productive EBV infection. Ubiquitination plays an important role in regulating TLR signaling and is controlled by ubiquitin ligases and deubiquitinases (DUBs. The EBV genome encodes three proteins reported to exert in vitro deubiquitinase activity. Using active site-directed probes, we show that one of these putative DUBs, the conserved herpesvirus large tegument protein BPLF1, acts as a functional DUB in EBV-producing B cells. The BPLF1 enzyme is expressed during the late phase of lytic EBV infection and is incorporated into viral particles. The N-terminal part of the large BPLF1 protein contains the catalytic site for DUB activity and suppresses TLR-mediated activation of NF-κB at, or downstream of, the TRAF6 signaling intermediate. A catalytically inactive mutant of this EBV protein did not reduce NF-κB activation, indicating that DUB activity is essential for attenuating TLR signal transduction. Our combined results show that EBV employs deubiquitination of signaling intermediates in the TLR cascade as a mechanism to counteract innate anti-viral immunity of infected hosts.

Frequent hepatitis B virus rebound among HIV-hepatitis B virus-coinfected patients following antiretroviral therapy interruption

DEFF Research Database (Denmark)

Dore, Gregory J; Soriano, Vicente; Rockstroh, Jürgen

2010-01-01

.0002), nondetectable HBV DNA at baseline (P = 0.007), and black race (P = 0.03). Time to ART reinitiation was shorter (7.5, 15.6, and 17.8 months; P hepatitis C virus-positive and non-HBV/hepatitis...... C virus participants in the drug conservation arm. No hepatic decompensation events occurred among HBV-positive participants in either arm. CONCLUSION: HBV DNA rebound following ART interruption is common and may be associated with accelerated immune deficiency in HIV-HBV-coinfected patients.......BACKGROUND: The impact of antiretroviral therapy (ART) interruption in HIV-hepatitis B virus (HBV)-coinfected patients was examined in the Strategic Management of AntiRetroviral Therapy (SMART) study. METHODS: Plasma HBV DNA was measured in all hepatitis B surface antigen-positive (HBV...

Band gaps and localization of surface water waves over large-scale sand waves with random fluctuations

Science.gov (United States)

Zhang, Yu; Li, Yan; Shao, Hao; Zhong, Yaozhao; Zhang, Sai; Zhao, Zongxi

2012-06-01

Band structure and wave localization are investigated for sea surface water waves over large-scale sand wave topography. Sand wave height, sand wave width, water depth, and water width between adjacent sand waves have significant impact on band gaps. Random fluctuations of sand wave height, sand wave width, and water depth induce water wave localization. However, random water width produces a perfect transmission tunnel of water waves at a certain frequency so that localization does not occur no matter how large a disorder level is applied. Together with theoretical results, the field experimental observations in the Taiwan Bank suggest band gap and wave localization as the physical mechanism of sea surface water wave propagating over natural large-scale sand waves.

Stability of RNA silencing-based traits after virus infection

DEFF Research Database (Denmark)

Jørgensen, Bodil; Albrechtsen, Merete

2007-01-01

with constructs based on virus coat protein (CP) genes or other viral genes has been successfully used to engineer PTGS-mediated virus resistance into a large number of crop plants and some transgenic lines have been commercially exploited. However the discovery that plant viruses encode suppressors of gene...... silencing has raised concerns that virus infection of crop plants might reverse the new silencing-based traits. Most studies of virus suppression of silencing have used model systems based on silencing of reporter genes. A few studies have analysed the effects of virus infections on plants with genetically...... engineered virus resistance based on either a simple sense or an inverted repeat construct. We decided to use genetically engineered virus resistance in potato as a model system for further studies of the effect of virus infection on genetically engineered traits. We present for the first time a comparison...

Prevalence of hepatitis B virus among immunocompromised ...

African Journals Online (AJOL)

Hepatitis B is an infectious inflammatory illness of the liver caused by the hepatitis B virus (HBV) which is transmitted to a large population through blood transfusion or by exposure to other body fluids. HBV is a member of the family Hepadnaviridae and also a DNA virus. In this study, the prevalence of hepatitis B infection ...

Immunity to VHS virus in rainbow trout

DEFF Research Database (Denmark)

Lorenzen, Niels; Olesen, Niels Jørgen; Koch, C.

1999-01-01

Viral hemorrhagic septicemia virus (VHSV) is the rhabdovirus that causes most disease problems in farmed rainbow trout in Europe. Survivors of infection are usually immune to reinfection but as with other fish viruses, development of a modern recombinant vaccine has been complicated by the limited...... knowledge of the immune mechanisms and antigens involved in induction of immunity. Neutralizing and protective monoclonal antibodies recognize the envelope glycoprotein (G protein) which is the only viral protein known to be present on the surface of the virus particle. Immunoblotting analyses...... with monoclonal antibodies as well as with sera from immunized trout have indicated that protein conformation plays an important role in neutralization epitopes. The virus neutralizing activity often found in sera from convalescent trout is highly dependent on a poorly defined complementing activity in normal...

Culturing of respiratory viruses in well-differentiated pseudostratified human airway epithelium as a tool to detect unknown viruses

Science.gov (United States)

Jazaeri Farsani, Seyed Mohammad; Deijs, Martin; Dijkman, Ronald; Molenkamp, Richard; Jeeninga, Rienk E; Ieven, Margareta; Goossens, Herman; van der Hoek, Lia

2015-01-01

Background Currently, virus discovery is mainly based on molecular techniques. Here, we propose a method that relies on virus culturing combined with state-of-the-art sequencing techniques. The most natural ex vivo culture system was used to enable replication of respiratory viruses. Method Three respiratory clinical samples were tested on well-differentiated pseudostratified tracheobronchial human airway epithelial (HAE) cultures grown at an air–liquid interface, which resemble the airway epithelium. Cells were stained with convalescent serum of the patients to identify infected cells and apical washes were analyzed by VIDISCA-454, a next-generation sequencing virus discovery technique. Results Infected cells were observed for all three samples. Sequencing subsequently indicated that the cells were infected by either human coronavirus OC43, influenzavirus B, or influenzavirus A. The sequence reads covered a large part of the genome (52%, 82%, and 57%, respectively). Conclusion We present here a new method for virus discovery that requires a virus culture on primary cells and an antibody detection. The virus in the harvest can be used to characterize the viral genome sequence and cell tropism, but also provides progeny virus to initiate experiments to fulfill the Koch's postulates. PMID:25482367

Giant viruses of amoebas: an update

Directory of Open Access Journals (Sweden)

Sarah eAherfi

2016-03-01

Full Text Available During the 12 past years, five new or putative virus families encompassing several members, namely Mimiviridae, Marseilleviridae, pandoraviruses, faustoviruses, and virophages were described. In addition, Pithovirus sibericum and Mollivirus sibericum represent type strains of putative new giant virus families. All these viruses were isolated using amoebal coculture methods. These giant viruses were linked by phylogenomic analyses to other large DNA viruses. They were then proposed to be classified in a new viral order, the Megavirales, on the basis of their common origin, as shown by a set of ancestral genes encoding key viral functions, a common virion architecture, and shared major biological features including replication inside cytoplasmic factories. Megavirales is increasingly demonstrated to stand in the tree of life aside Bacteria, Archaea and Eukarya, and the megavirus ancestor is suspected to be as ancient as cellular ancestors. In addition, giant amoebal viruses are visible under a light microscope and display many phenotypic and genomic features not found in other viruses, while they share other characteristics with parasitic microbes. Moreoever, these organisms appear to be common inhabitants of our biosphere, and mimiviruses and marseilleviruses were isolated from human samples and associated to diseases. In the present review, we describe the main features and recent findings on these giant amoebal viruses and virophages.

Optical fiber sensor based on surface plasmon resonance for rapid detection of avian influenza virus subtype H6: Initial studies.

Science.gov (United States)

Zhao, Xihong; Tsao, Yu-Chia; Lee, Fu-Jung; Tsai, Woo-Hu; Wang, Ching-Ho; Chuang, Tsung-Liang; Wu, Mu-Shiang; Lin, Chii-Wann

2016-07-01

A side-polished fiber optic surface plasmon resonance (SPR) sensor was fabricated to expose the core surface and then deposited with a 40 nm thin gold film for the near surface sensing of effective refractive index changes with surface concentration or thickness of captured avian influenza virus subtype H6. The detection surface of the SPR optical fiber sensor was prepared through the plasma modification method for binding a self-assembled monolayer of isopropanol chemically on the gold surface of the optical fiber. Subsequently, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide was activated to enable EB2-B3 monoclonal antibodies to capture A/chicken/Taiwan/2838V/00 (H6N1) through a flow injection system. The detection limit of the fabricated optical fiber sensor for A/chicken/Taiwan/2838V/00 was 5.14 × 10(5) EID50/0.1 mL, and the response time was 10 min on average. Moreover, the fiber optic sensor has the advantages of a compact size and low cost, thus rendering it suitable for online and remote sensing. The results indicated that the optical fiber sensor can be used for epidemiological surveillance and diagnosing of avian influenza subtype H6 rapidly. Copyright © 2016 Elsevier B.V. All rights reserved.

Receptors for Theiler's murine encephalomyelitis virus: characterization by using rabbit antiviral antiserum

International Nuclear Information System (INIS)

Rubio, N.; Cuesta, A.

1988-01-01

An immunological assay was developed to characterize the binding of Theiler's murine encephalomyelitis virus to BHK-21 cell receptors. After absorption of the virus and formaldehyde fixation, rabbit antibodies and Staphylococcus aureus protein A labeled with 125 I formed a specific complex on the surfaces of the cells. The optimal multiplicity of infection in this system was 10 PFU per cell. The virus was internalized at 33 and 37 0 C, but internalization did not take place at 25 or 4 0 C. The binding was proportional to the number of cells and was significant within 30 s. Cell surface receptors were still active after fixation, and only intact viruses were bound, as demonstrated by the lack of binding of the purified, isolated virion proteins VP1, VP2, and VP3

Virus-Assembled Flexible Electrode-Electrolyte Interfaces for Enhanced Polymer-Based Battery Applications

Directory of Open Access Journals (Sweden)

Ayan Ghosh

2012-01-01

Full Text Available High-aspect-ratio cobalt-oxide-coated Tobacco mosaic virus (TMV- assembled polytetrafluoroethylene (PTFE nonstick surfaces were integrated with a solvent-free polymer electrolyte to create an anode-electrolyte interface for use in lithium-ion batteries. The virus-assembled PTFE surfaces consisted primarily of cobalt oxide and were readily intercalated with a low-molecular-weight poly (ethylene oxide (PEO based diblock copolymer electrolyte to produce a solid anode-electrolyte system. The resulting polymer-coated virus-based system was then peeled from the PTFE backing to produce a flexible electrode-electrolyte component. Electrochemical studies indicated the virus-structured metal-oxide PEO-based interface was stable and displayed robust charge transfer kinetics. Combined, these studies demonstrate the development of a novel solid-state electrode architecture with a unique peelable and flexible processing attribute.

Validating modeled turbulent heat fluxes across large freshwater surfaces

Science.gov (United States)

Lofgren, B. M.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Fitzpatrick, L.; Blanken, P.; Spence, C.; Lenters, J. D.; Xiao, C.; Charusambot, U.

2017-12-01

Turbulent fluxes of latent and sensible heat are important physical processes that influence the energy and water budgets of the Great Lakes. Validation and improvement of bulk flux algorithms to simulate these turbulent heat fluxes are critical for accurate prediction of hydrodynamics, water levels, weather, and climate over the region. Here we consider five heat flux algorithms from several model systems; the Finite-Volume Community Ocean Model, the Weather Research and Forecasting model, and the Large Lake Thermodynamics Model, which are used in research and operational environments and concentrate on different aspects of the Great Lakes' physical system, but interface at the lake surface. The heat flux algorithms were isolated from each model and driven by meteorological data from over-lake stations in the Great Lakes Evaporation Network. The simulation results were compared with eddy covariance flux measurements at the same stations. All models show the capacity to the seasonal cycle of the turbulent heat fluxes. Overall, the Coupled Ocean Atmosphere Response Experiment algorithm in FVCOM has the best agreement with eddy covariance measurements. Simulations with the other four algorithms are overall improved by updating the parameterization of roughness length scales of temperature and humidity. Agreement between modelled and observed fluxes notably varied with geographical locations of the stations. For example, at the Long Point station in Lake Erie, observed fluxes are likely influenced by the upwind land surface while the simulations do not take account of the land surface influence, and therefore the agreement is worse in general.

Electrochemical machining of internal built-up surfaces of large-sized vessels for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Ryabchenko, N N; Pulin, V Ya [Vsesoyuznyj Proektno-Tekhnologicheskij Inst. Atomnogo Mashinostroeniya i Kotlostroeniya, Rostov-na-Donu (USSR)

1977-01-01

Electrochemical machining (ECM) has been employed for finishing of mechanically processed inner surfaces of large lateral parts of construction bodies with welded 0Kh18N10T steel overlayer. The finishing technology developed reduces the surface roughness from 10 mcm to the standard 2.5 mcm at the efficiency of machining of 2-4 m/sup 2/ per hour.

Surface slip during large Owens Valley earthquakes

KAUST Repository

Haddon, E. K.; Amos, C. B.; Zielke, Olaf; Jayko, A. S.; Burgmann, R.

2016-01-01

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from approximate to 1.0 to 6.0 m and average 3.31.1 m (2 sigma). Vertical offsets are predominantly east-down between approximate to 0.1 and 2.4 m, with a mean of 0.80.5 m. The average lateral-to-vertical ratio compiled at specific sites is approximate to 6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.41.5 m, corresponding to a geologic M-w approximate to 7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.12.0 m, 12.8 +/- 1.5 m, and 16.6 +/- 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between approximate to 0.6 and 1.6 mm/yr (1 sigma) over the late Quaternary.

Surface slip during large Owens Valley earthquakes

Science.gov (United States)

Haddon, E.K.; Amos, C.B.; Zielke, O.; Jayko, Angela S.; Burgmann, R.

2016-01-01

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from ∼1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east-down between ∼0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral-to-vertical ratio compiled at specific sites is ∼6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7–11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ∼7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.1 ± 2.0 m, 12.8 ± 1.5 m, and 16.6 ± 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between ∼0.6 and 1.6 mm/yr (1σ) over the late Quaternary.

Surface slip during large Owens Valley earthquakes

KAUST Repository

Haddon, E. K.

2016-01-10

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from approximate to 1.0 to 6.0 m and average 3.31.1 m (2 sigma). Vertical offsets are predominantly east-down between approximate to 0.1 and 2.4 m, with a mean of 0.80.5 m. The average lateral-to-vertical ratio compiled at specific sites is approximate to 6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.41.5 m, corresponding to a geologic M-w approximate to 7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.12.0 m, 12.8 +/- 1.5 m, and 16.6 +/- 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between approximate to 0.6 and 1.6 mm/yr (1 sigma) over the late Quaternary.

Pharmacological inhibition of feline immunodeficiency virus (FIV).

Science.gov (United States)

Mohammadi, Hakimeh; Bienzle, Dorothee

2012-05-01

Feline immunodeficiency virus (FIV) is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS) in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV). Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1) inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2) inhibition of fusion of the virus membrane with the cell membrane; (3) blockade of reverse transcription of viral genomic RNA; (4) interruption of nuclear translocation and viral DNA integration into host genomes; (5) prevention of viral transcript processing and nuclear export; and (6) inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats.

Design of Fusion Proteins for Efficient and Soluble Production of Immunogenic Ebola Virus Glycoprotein in Escherichia coli.

Science.gov (United States)

Ji, Yang; Lu, Yuan; Yan, Yishu; Liu, Xinxin; Su, Nan; Zhang, Chong; Bi, Shengli; Xing, Xin-Hui

2018-03-03

The Ebola hemorrhagic fever caused by Ebola virus is an extremely dangerous disease, and effective therapeutic agents are still lacking. Platforms for the efficient production of vaccines are crucial to ensure quick response against an Ebola virus outbreak. Ebola virus glycoprotein (EbolaGP) on the virion surface is responsible for membrane binding and virus entry, thus becoming the key target for vaccine development. However, heterologous expression of this protein still faces engineering challenges such as low production levels and insoluble aggregation. Here, the authors design and compare various fusion strategies, attaching great importance to the solubility-enhancing effect, and tag removal process. It is found that a C-terminal intein-based tag greatly enhances the solubility of EbolaGP and allows one-step chromatographic purification of the untagged EbolaGP through thiol-catalyzed self-cleavage. The purified untagged EbolaGP alone or with Freund's adjuvant are highly immunogenic, as confirmed in a mouse model. Consequently, the present study puts forward a new strategy for the efficient and soluble expression of untagged immunogenic EbolaGP. The intein-based protein fusion approach may be of importance for the large-scale production of Ebola virus subunit vaccine. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zika virus from a Southeast Asian perspective

Institute of Scientific and Technical Information of China (English)

Nitwara Wikan; Duncan R. Smith

2017-01-01

Phylogenic evidence suggests that the strain of Zika virus causing an unprecedented outbreak of disease in the Americas had its origin in Southeast Asia, where reports of isolated cases of Zika virus infection have occurred since 2010. Why there has been no large outbreak of Zika infection in Southeast Asia remains unclear and whether such an outbreak will occur in the future is a question of significant concern. This review looks at Zika virus from a Southeast Asian perspective and highlights some of the possible scenarios with regards to Zika virus in this part of the world as well as highlighting some of the research questions that need to be urgently addressed.

Global Mapping of O-Glycosylation of Varicella Zoster Virus, Human Cytomegalovirus, and Epstein-Barr Virus*

Science.gov (United States)

Bagdonaite, Ieva; Nordén, Rickard; Joshi, Hiren J.; King, Sarah L.; Vakhrushev, Sergey Y.; Olofsson, Sigvard; Wandall, Hans H.

2016-01-01

Herpesviruses are among the most complex and widespread viruses, infection and propagation of which depend on envelope proteins. These proteins serve as mediators of cell entry as well as modulators of the immune response and are attractive vaccine targets. Although envelope proteins are known to carry glycans, little is known about the distribution, nature, and functions of these modifications. This is particularly true for O-glycans; thus we have recently developed a “bottom up” mass spectrometry-based technique for mapping O-glycosylation sites on herpes simplex virus type 1. We found wide distribution of O-glycans on herpes simplex virus type 1 glycoproteins and demonstrated that elongated O-glycans were essential for the propagation of the virus. Here, we applied our proteome-wide discovery platform for mapping O-glycosites on representative and clinically significant members of the herpesvirus family: varicella zoster virus, human cytomegalovirus, and Epstein-Barr virus. We identified a large number of O-glycosites distributed on most envelope proteins in all viruses and further demonstrated conserved patterns of O-glycans on distinct homologous proteins. Because glycosylation is highly dependent on the host cell, we tested varicella zoster virus-infected cell lysates and clinically isolated virus and found evidence of consistent O-glycosites. These results present a comprehensive view of herpesvirus O-glycosylation and point to the widespread occurrence of O-glycans in regions of envelope proteins important for virus entry, formation, and recognition by the host immune system. This knowledge enables dissection of specific functional roles of individual glycosites and, moreover, provides a framework for design of glycoprotein vaccines with representative glycosylation. PMID:27129252

Focused ion beam-fabricated Au micro/nanostructures used as a surface enhanced Raman scattering-active substrate for trace detection of molecules and influenza virus

Energy Technology Data Exchange (ETDEWEB)

Lin, Ying-Yi; Liao, Jiunn-Der; Ju, Yu-Hung; Chang, Chia-Wei [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Shiau, Ai-Li, E-mail: jdliao@mail.ncku.edu.tw [Department of Microbiology and Immunology, National Cheng Kung University, No 1, University Road, Tainan 70101, Taiwan (China)

2011-05-06

The focused ion beam (FIB) technique was used to precisely fabricate patterned Au micro/nanostructures (fibAu). The effects of surface enhanced Raman scattering (SERS) on the fibAu samples were investigated by adjusting the geometrical, dimensional, and spacing factors. The SERS mechanism was evaluated using low-concentration rhodamine 6G (R6G) molecules, physically adsorbed or suspended on/within the micro/nanostructures. The results indicated that for detecting R6G molecules, hexagon-like micro/nanostructures induced a higher electromagnetic mechanism (EM) due to the availability of multiple edges and small curvature. By decreasing the dimensions from 300 to 150 nm, the laser-focused area contained an increasing number of micro/nanostructures and therefore intensified the excitation of SERS signals. Moreover, with an optimized geometry and dimensions of the micro/nanostructures, the relative intensity/surface area value reached a maximum as the spacing was 22 nm. An exponential decrease was found as the spacing was increased, which most probably resulted from the loss of EM. The spacing between the micro/nanostructures upon the fibAu was consequently regarded as the dominant factor for the detection of R6G molecules. By taking an optimized fibAu to detect low-concentration influenza virus, the amino acids from the outermost surface of the virus can be well distinguished through the SERS mechanism.

Detection of Pathogenic Viruses in Sewage Provided Early Warnings of Hepatitis A Virus and Norovirus Outbreaks

Science.gov (United States)

Hellmér, Maria; Paxéus, Nicklas; Magnius, Lars; Enache, Lucica; Arnholm, Birgitta; Johansson, Annette; Bergström, Tomas

2014-01-01

Most persons infected with enterically transmitted viruses shed large amounts of virus in feces for days or weeks, both before and after onset of symptoms. Therefore, viruses causing gastroenteritis may be detected in wastewater, even if only a few persons are infected. In this study, the presence of eight pathogenic viruses (norovirus, astrovirus, rotavirus, adenovirus, Aichi virus, parechovirus, hepatitis A virus [HAV], and hepatitis E virus) was investigated in sewage to explore whether their identification could be used as an early warning of outbreaks. Samples of the untreated sewage were collected in proportion to flow at Ryaverket, Gothenburg, Sweden. Daily samples collected during every second week between January and May 2013 were pooled and analyzed for detection of viruses by concentration through adsorption to milk proteins and PCR. The largest amount of noroviruses was detected in sewage 2 to 3 weeks before most patients were diagnosed with this infection in Gothenburg. The other viruses were detected at lower levels. HAV was detected between weeks 5 and 13, and partial sequencing of the structural VP1protein identified three different strains. Two strains were involved in an ongoing outbreak in Scandinavia and were also identified in samples from patients with acute hepatitis A in Gothenburg during spring of 2013. The third strain was unique and was not detected in any patient sample. The method used may thus be a tool to detect incipient outbreaks of these viruses and provide early warning before the causative pathogens have been recognized in health care. PMID:25172863

Feline immunodeficiency virus in South America.

Science.gov (United States)

Teixeira, Bruno M; Hagiwara, Mitika K; Cruz, Juliano C M; Hosie, Margaret J

2012-03-01

The rapid emergence of AIDS in humans during the period between 1980 and 2000 has led to extensive efforts to understand more fully similar etiologic agents of chronic and progressive acquired immunodeficiency disease in several mammalian species. Lentiviruses that have gene sequence homology with human immunodeficiency virus (HIV) have been found in different species (including sheep, goats, horses, cattle, cats, and several Old World monkey species). Lentiviruses, comprising a genus of the Retroviridae family, cause persistent infection that can lead to varying degrees of morbidity and mortality depending on the virus and the host species involved. Feline immunodeficiency virus (FIV) causes an immune system disease in domestic cats (Felis catus) involving depletion of the CD4+ population of T lymphocytes, increased susceptibility to opportunistic infections, and sometimes death. Viruses related to domestic cat FIV occur also in a variety of nondomestic felids. This is a brief overview of the current state of knowledge of this large and ancient group of viruses (FIVs) in South America.

Efficient inactivation of MS-2 virus in water by hydrodynamic cavitation.

Science.gov (United States)

Kosel, Janez; Gutiérrez-Aguirre, Ion; Rački, Nejc; Dreo, Tanja; Ravnikar, Maja; Dular, Matevž

2017-11-01

The aim of this study was to accurately quantify the impact of hydrodynamic cavitation on the infectivity of bacteriophage MS2, a norovirus surrogate, and to develop a small scale reactor for testing the effect of hydrodynamic cavitation on human enteric viruses, which cannot be easily prepared in large quantities. For this purpose, 3 mL scale and 1 L scale reactors were constructed and tested. Both devices were efficient in generating hydrodynamic cavitation and in reducing the infectivity of MS2 virus. Furthermore, they reached more than 4 logs reductions of viral infectivity, thus confirming the scalability of hydrodynamic cavitation for this particular application. As for the mechanism of page inactivation, we suspect that cavitation generated OH - radicals formed an advanced oxidation process, which could have damaged the host's recognition receptors located on the surface of the bacteriophage. Additional damage could arise from the high shear forces inside the cavity. Moreover, the effectiveness of the cavitation was higher for suspensions containing low initial viral titers that are in similar concentration to the ones found in real water samples. According to this, cavitation generators could prove to be a useful tool for treating virus-contaminated wastewaters in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Successful application of FTA Classic Card technology and use of bacteriophage phi29 DNA polymerase for large-scale field sampling and cloning of complete maize streak virus genomes.

Science.gov (United States)

Owor, Betty E; Shepherd, Dionne N; Taylor, Nigel J; Edema, Richard; Monjane, Adérito L; Thomson, Jennifer A; Martin, Darren P; Varsani, Arvind

2007-03-01

Leaf samples from 155 maize streak virus (MSV)-infected maize plants were collected from 155 farmers' fields in 23 districts in Uganda in May/June 2005 by leaf-pressing infected samples onto FTA Classic Cards. Viral DNA was successfully extracted from cards stored at room temperature for 9 months. The diversity of 127 MSV isolates was analysed by PCR-generated RFLPs. Six representative isolates having different RFLP patterns and causing either severe, moderate or mild disease symptoms, were chosen for amplification from FTA cards by bacteriophage phi29 DNA polymerase using the TempliPhi system. Full-length genomes were inserted into a cloning vector using a unique restriction enzyme site, and sequenced. The 1.3-kb PCR product amplified directly from FTA-eluted DNA and used for RFLP analysis was also cloned and sequenced. Comparison of cloned whole genome sequences with those of the original PCR products indicated that the correct virus genome had been cloned and that no errors were introduced by the phi29 polymerase. This is the first successful large-scale application of FTA card technology to the field, and illustrates the ease with which large numbers of infected samples can be collected and stored for downstream molecular applications such as diversity analysis and cloning of potentially new virus genomes.

Large-scale Validation of AMIP II Land-surface Simulations: Preliminary Results for Ten Models

Energy Technology Data Exchange (ETDEWEB)

Phillips, T J; Henderson-Sellers, A; Irannejad, P; McGuffie, K; Zhang, H

2005-12-01

This report summarizes initial findings of a large-scale validation of the land-surface simulations of ten atmospheric general circulation models that are entries in phase II of the Atmospheric Model Intercomparison Project (AMIP II). This validation is conducted by AMIP Diagnostic Subproject 12 on Land-surface Processes and Parameterizations, which is focusing on putative relationships between the continental climate simulations and the associated models' land-surface schemes. The selected models typify the diversity of representations of land-surface climate that are currently implemented by the global modeling community. The current dearth of global-scale terrestrial observations makes exacting validation of AMIP II continental simulations impractical. Thus, selected land-surface processes of the models are compared with several alternative validation data sets, which include merged in-situ/satellite products, climate reanalyses, and off-line simulations of land-surface schemes that are driven by observed forcings. The aggregated spatio-temporal differences between each simulated process and a chosen reference data set then are quantified by means of root-mean-square error statistics; the differences among alternative validation data sets are similarly quantified as an estimate of the current observational uncertainty in the selected land-surface process. Examples of these metrics are displayed for land-surface air temperature, precipitation, and the latent and sensible heat fluxes. It is found that the simulations of surface air temperature, when aggregated over all land and seasons, agree most closely with the chosen reference data, while the simulations of precipitation agree least. In the latter case, there also is considerable inter-model scatter in the error statistics, with the reanalyses estimates of precipitation resembling the AMIP II simulations more than to the chosen reference data. In aggregate, the simulations of land-surface latent and

Hydrothermal Synthesis of Highly Water-dispersible Anatase Nanoparticles with Large Specific Surface Area and Their Adsorptive Properties

OpenAIRE

Hu Xueting; Zhang Dongyun; Zhao Siqin; Asuha Sin

2016-01-01

Highly water-dispersible and very small TiO2 nanoparticles (~3 nm anatase) with large specific surface area have been synthesized by hydrolysis and hydrothermal reactions of titanium butoxide and used for the removal of three azo dyes (Congo red, orange II, and methyl orange) with different molecular structure from simulated wastewaters. The synthesized TiO2 nanoparticles are well dispersed in water with large specific surface area up to 417 m2 g−1. Adsorption experiments demonstrated that th...

Canine distemper virus from diseased large felids: Biological properties and phylogenetic relationships.

NARCIS (Netherlands)

T.C. Harder (Timm); M.J.H. Kenter (Marcel); H. Vos; C.H.J. Siebelink (Kees); W. Huisman (Willem); C. Örvell; T. Barrett (Thomas); M.J.G. Appel (Max); A.D.M.E. Osterhaus (Albert); G. van Amerongen (Geert)

1996-01-01

textabstractSpecific pathogen free (SPF) domestic cats were inoculated with tissue homogenate obtained from a Chinese leopard (Panthera pardus japonensis) that had died in a North American zoo from a natural infection with canine distemper virus (CDV). The cats developed a transient cell-associated

Beyond Massive MIMO: The Potential of Positioning With Large Intelligent Surfaces

Science.gov (United States)

Hu, Sha; Rusek, Fredrik; Edfors, Ove

2018-04-01

We consider the potential for positioning with a system where antenna arrays are deployed as a large intelligent surface (LIS), which is a newly proposed concept beyond massive-MIMO where future man-made structures are electronically active with integrated electronics and wireless communication making the entire environment \\lq\\lq{}intelligent\\rq\\rq{}. In a first step, we derive Fisher-information and Cram\\'{e}r-Rao lower bounds (CRLBs) in closed-form for positioning a terminal located perpendicular to the center of the LIS, whose location we refer to as being on the central perpendicular line (CPL) of the LIS. For a terminal that is not on the CPL, closed-form expressions of the Fisher-information and CRLB seem out of reach, and we alternatively find approximations of them which are shown to be accurate. Under mild conditions, we show that the CRLB for all three Cartesian dimensions ($x$, $y$ and $z$) decreases quadratically in the surface-area of the LIS, except for a terminal exactly on the CPL where the CRLB for the $z$-dimension (distance from the LIS) decreases linearly in the same. In a second step, we analyze the CRLB for positioning when there is an unknown phase $\\varphi$ presented in the analog circuits of the LIS. We then show that the CRLBs are dramatically increased for all three dimensions but decrease in the third-order of the surface-area. Moreover, with an infinitely large LIS the CRLB for the $z$-dimension with an unknown $\\varphi$ is 6 dB higher than the case without phase uncertainty, and the CRLB for estimating $\\varphi$ converges to a constant that is independent of the wavelength $\\lambda$. At last, we extensively discuss the impact of centralized and distributed deployments of LIS, and show that a distributed deployment of LIS can enlarge the coverage for terminal-positioning and improve the overall positioning performance.

Investigation on the growth of DAST crystals of large surface area for THz applications

International Nuclear Information System (INIS)

Vijay, R. Jerald; Melikechi, N.; Thomas, Tina; Gunaseelan, R.; Arockiaraj, M. Antony; Sagayaraj, P.

2012-01-01

Graphical abstract: It is evident from the photographs that the crystal tend to grow as a needle (Fig. 1a) in the lower concentration region (2–3 g/200 mL); whereas, in the high concentration region (5 g/200 mL) though there is a marked enlargement in the size of the crystal, the morphology of the resulting DAST crystal is slightly irregular (Fig. 1d) in nature. Among the four concentrations employed, best result was obtained with the DAST–methanol solution of concentration 4 g/200 mL; which resulted in the DAST crystal of large surface area (270 mm 2 ) with high transparency and nearly square shape (Fig. 1c) in a growth period of 20–25 days. Highlights: ► DAST crystals of different sizes are obtained for different concentrations. ► The main focus is to grow DAST crystals with large surface area. ► Structural, optical, thermal and mechanical properties are investigated. - Abstract: The growth of high quality 4-N,N-dimethylamino-4-N-methyl-stilbazoliumtosylate (DAST) crystal with large surface area is reported by adopting the slope nucleation coupled slow evaporation method (SNM-SE). The structure and composition of the crystal are studied by single crystal X-ray diffraction and CHN analyses. The linear optical properties are investigated by UV–vis absorption. The melting point and thermal behavior of DAST are investigated using differential scanning calorimetric (DSC) and thermogravimetric analyses (TGA). The Vickers microhardness number (VHN) and work hardening coefficient of the grown crystal have been determined. The surface features of the DAST crystal are analyzed by scanning electron microscopy (SEM) and it confirmed the presence of narrow line defects (NLDs) in the sample.

The prevalence of hepatitis B virus E antigen among Ghanaian ...

African Journals Online (AJOL)

We studied the prevalence of hepatitis B virus 'e' antigen (HBeAg) among individuals determined to be hepatitis B virus (HBV) surface antigen- positive and analyzed the gender/age category associated with more active HBV infection and whether alteration in the levels of alanine aminotransferase could be associated with ...

Varroa destructor Macula-like virus, Lake Sinai virus and other new RNA viruses in wild bumblebee hosts (Bombus pascuorum, Bombus lapidarius and Bombus pratorum).

Science.gov (United States)

Parmentier, Laurian; Smagghe, Guy; de Graaf, Dirk C; Meeus, Ivan

2016-02-01

Pollinators such as bumblebees (Bombus spp.) are in decline worldwide which poses a threat not only for ecosystem biodiversity but also to human crop production services. One main cause of pollinator decline may be the infection and transmission of diseases including RNA viruses. Recently, new viruses have been discovered in honeybees, but information on the presence of these in wild bumblebees is largely not available. In this study, we investigated the prevalence of new RNA viruses in Bombus species, and can report for the first time Varroa destructor Macula-like virus (VdMLV) and Lake Sinai virus (LSV) infection in multiple wild bumblebee hosts of Bombus pascuorum, Bombus lapidarius and Bombus pratorum. We sampled in 4 locations in Flanders, Belgium. Besides, we confirmed Slow bee paralysis virus (SBPV) in wild bumblebees, but no positive samples were obtained for Big Sioux river virus (BSRV). Secondly, we screened for the influence of apiaries on the prevalence of these viruses. Our results indicated a location effect for the prevalence of VdMLV in Bombus species, with a higher prevalence in the proximity of honeybee apiaries mainly observed in one location. For LSV, the prevalence was not different in the proximity or at a 1.5 km-distance of apiaries, but we reported a different isolate with similarities to LSV-2 and "LSV-clade A" as described by Ravoet et al. (2015), which was detected both in Apis mellifera and Bombus species. In general, our results indicate the existence of a disease pool of new viruses that seems to be associated to a broad range of Apoidae hosts, including multiple Bombus species. Copyright © 2015 Elsevier Inc. All rights reserved.

Extrahepatic Manifestations of Hepatitis B Virus Infection: Addison’s Disease and Myelofibrosis in a Patient with Persistent Hepatitis B Surface Antigenemia

Directory of Open Access Journals (Sweden)

François Somlo

1993-01-01

Full Text Available A 60-year-old white male patient was admitted to the hospital with acute abdominal pain, seemingly a self-limited ileus. He was found to be hepatitis B surface antigen (HBsAg-positive. Previous dental treatment was suspected to be the initial source of the infection with hepatitis B virus. Five months later he was re-admitted with a diagnosis of adrenal insufficiency (Addison’s disease which responded well to steroids. Four years later he developed fever and leucocytosis. A bone marrow biopsy revealed myelofibrosis. He had several episodes of pyrexia during his lifetime. After a 12-year period the patient suffered a fatal myocardial infarction. At autopsy the adrenal glands were reduced to scarred remnants and HBsAg was found to be present in the residual adrenocortical cells by immunoflouresence methods. Bone marrow at autopsy revealed myelosclerosis as well HBsAg (via immunofluoresence. Hepatitis B virus was therefore closely correlated with the development of Addison’s disease and myelofibrosis in this case.

The highly virulent variola and monkeypox viruses express secreted inhibitors of type I interferon

Science.gov (United States)

Fernández de Marco, María del Mar; Alejo, Alí; Hudson, Paul; Damon, Inger K.; Alcami, Antonio

2010-01-01

Variola virus (VARV) caused smallpox, one of the most devastating human diseases and the first to be eradicated, but its deliberate release represents a dangerous threat. Virulent orthopoxviruses infecting humans, such as monkeypox virus (MPXV), could fill the niche left by smallpox eradication and the cessation of vaccination. However, immunomodulatory activities and virulence determinants of VARV and MPXV remain largely unexplored. We report the molecular characterization of the VARV- and MPXV-secreted type I interferon-binding proteins, which interact with the cell surface after secretion and prevent type I interferon responses. The proteins expressed in the baculovirus system have been purified, and their interferon-binding properties characterized by surface plasmon resonance. The ability of these proteins to inhibit a broad range of interferons was investigated to identify potential adaptation to the human immune system. Furthermore, we demonstrate by Western blot and activity assays the expression of the type I interferon inhibitor during VARV and MPXV infections. These findings are relevant for the design of new vaccines and therapeutics to smallpox and emergent virulent orthopoxviruses because the type I interferon-binding protein is a major virulence factor in animal models, vaccination with this protein induces protective immunity, and its neutralization prevents disease progression.—Fernández de Marco, M. M., Alejo, A., Hudson, P., Damon, I. K., Alcami, A. The highly virulent variola and monkeypox viruses express secreted inhibitors of type I interferon. PMID:20019241

Design and calibration of a scanning tunneling microscope for large machined surfaces

Energy Technology Data Exchange (ETDEWEB)

Grigg, D.A.; Russell, P.E.; Dow, T.A.

1988-12-01

During the last year the large sample STM has been designed, built and used for the observation of several different samples. Calibration of the scanner for prope dimensional interpretation of surface features has been a chief concern, as well as corrections for non-linear effects such as hysteresis during scans. Several procedures used in calibration and correction of piezoelectric scanners used in the laboratorys STMs are described.

RNASEK Is a V-ATPase-Associated Factor Required for Endocytosis and the Replication of Rhinovirus, Influenza A Virus, and Dengue Virus

Directory of Open Access Journals (Sweden)

Jill M. Perreira

2015-08-01

Full Text Available Human rhinovirus (HRV causes upper respiratory infections and asthma exacerbations. We screened multiple orthologous RNAi reagents and identified host proteins that modulate HRV replication. Here, we show that RNASEK, a transmembrane protein, was needed for the replication of HRV, influenza A virus, and dengue virus. RNASEK localizes to the cell surface and endosomal pathway and closely associates with the vacuolar ATPase (V-ATPase proton pump. RNASEK is required for endocytosis, and its depletion produces enlarged clathrin-coated pits (CCPs at the cell surface. These enlarged CCPs contain endocytic cargo and are bound by the scissioning GTPase, DNM2. Loss of RNASEK alters the localization of multiple V-ATPase subunits and lowers the levels of the ATP6AP1 subunit. Together, our results show that RNASEK closely associates with the V-ATPase and is required for its function; its loss prevents the early events of endocytosis and the replication of multiple pathogenic viruses.

Mechanisms of immune evasion in Epstein-Barr virus infection

NARCIS (Netherlands)

Gram., A.M.

2016-01-01

The human herpesvirus Epstein-Barr virus (EBV) is a large DNA virus that infects over 90% of the adult world population. EBV is the causative agent of infectious mononucleosis and EBV infection is associated with various malignancies. EBV establishes lifelong infections in immunocompetent hosts. To

Surface mineralization and characterization of tobacco mosaic virus biotemplated nanoparticles

Science.gov (United States)

Freer, Alexander S.

The genetically engineered tobacco mosaic virus (TMV) has been utilized as a biotemplate in the formation of nanoparticles with the intent of furthering the understanding of the biotemplated nanoparticles formed in the absence of an external reducing agent. Specifically, the work aims to provide better knowledge of the final particle characteristics and how these properties could be altered to better fit the need of functional devices. Three achievements have been accomplished including a method for controlling final particle size, characterizing the resistivity of palladium coated TMV, and the application of TMV as an additive in nanometric calcium carbonate synthesis. Until the last 5 years, formation of metal nanoparticles on the surface of TMV has always occurred with the addition of an external reducing agent. The surface functionalities of genetically engineered TMV allow for the reduction of palladium in the absence of an external reducing agent. This process has been furthered to understand how palladium concentration affects the final coating uniformity and thickness. By confirming an ideal ratio of palladium and TMV concentrations, a uniform coat of palladium is formed around the viral nanorod. Altering the number of palladium coating cycles at these concentrations allows for a controllable average diameter of the final nanorods. The average particle diameter was determined by small angle x-ray scattering (SAXS) analysis by comparing the experimental results to the model of scattering by an infinitely long cylinder. The SAXS results were confirmed through transmission electron microscopy images of individual Pd-TMV nanorods. Secondly, methodologies to determine the electrical resistivity of the genetically engineered TMV biotemplated palladium nanoparticles were created to provide valuable previously missing information. Two fairly common nanoelectronic characterization techniques were combined to create the novel approach to obtain the desired

Presence and Distribution of Oilseed Pumpkin Viruses and Molecular Detection of Zucchini Yellow Mosaic Virus

Directory of Open Access Journals (Sweden)

Ana Vučurović

2009-01-01

Full Text Available Over the past decade, intensive spread of virus infections of oilseed pumpkin has resulted in significant economic losses in pumpkin crop production, which is currently expanding in our country. In 2007 and 2008, a survey for the presence and distribution of oilseed pumpkin viruses was carried out in order to identify viruses responsible for epidemics and incidences of very destructive symptoms on cucurbit leaves and fruits. Monitoring andcollecting samples of oil pumpkin, as well as other species such as winter and butternut squash and buffalo and bottle gourd with viral infection symptoms, was conducted in several localities of Vojvodina Province. The collected plant samples were tested by DAS-ELISA using polyclonal antisera specific for the detection of six most economically harmful pumpkin viruses: Cucumber mosaic virus (CMV, Zucchini yellow mosaic virus (ZYMV, Watermelon mosaic virus (WMW, Squash mosaic virus (SqMV, Papaya ringspot virus (PRSV and Tobaccoringspot virus (TRSV that are included in A1 quarantine list of harmful organisms in Serbia.Identification of viruses in the collected samples indicated the presence of three viruses, ZYMV, WMV and CMV, in individual and mixed infections. Frequency of the identified viruses varied depending on locality and year of investigations. In 2007, WMV was the most frequent virus (94.2%, while ZYMV was prevalent (98.04% in 2008. High frequency of ZYMV determined in both years of investigation indicated the need for its rapid and reliable molecular detection. During this investigation, a protocol for ZYMVdetection was developed and optimized using specific primers CPfwd/Cprev and commercial kits for total RNA extraction, as well as for RT-PCR. In RT-PCR reaction using these primers, a DNA fragment of approximately 1100 bp, which included coat protein gene, was amplified in the samples of infected pumkin leaves. Although serological methods are still useful for large-scale testing of a great number of

Virions at the gates: receptors and the host-virus arms race.

Science.gov (United States)

Coffin, John M

2013-01-01

All viruses need to bind to specific receptor molecules on the surface of target cells to initiate infection. Virus-receptor binding is highly specific, and this specificity determines both the species and the cell type that can be infected by a given virus. In some well-studied cases, the virus-binding region on the receptor has been found to be unrelated to the receptor's normal cellular function. Resistance to virus infection can thus evolve by selection of mutations that alter amino acids in the binding region with minimal effect on normal function. This sort of positive selection can be used to infer the history of the host-virus "arms race" during their coevolution. In a new study, Demogines et al. use a combination of phylogenetic, structural, and virological analysis to infer the history and significance of positive selection on the transferrin receptor TfR1, a housekeeping protein required for iron uptake and the cell surface receptor for at least three different types of virus. The authors show that only two parts of the rodent TfR1 molecule have been subject to positive selection and that these correspond to the binding sites for two of these viruses-the mouse mammary tumor virus (a retrovirus) and Machupo virus (an arenavirus). They confirmed this result by introducing the inferred binding site mutations into the wild-type protein and testing for receptor function. Related arenaviruses are beginning to spread in human populations in South America as the cause of often fatal hemorrhagic fevers, and, although Demogines et al. could find no evidence of TfR1 mutations in this region that might have been selected as a consequence of human infection, the authors identified one such mutation in Asian populations that affects infection with these viruses.

Virions at the gates: receptors and the host-virus arms race.

Directory of Open Access Journals (Sweden)

John M Coffin

Full Text Available All viruses need to bind to specific receptor molecules on the surface of target cells to initiate infection. Virus-receptor binding is highly specific, and this specificity determines both the species and the cell type that can be infected by a given virus. In some well-studied cases, the virus-binding region on the receptor has been found to be unrelated to the receptor's normal cellular function. Resistance to virus infection can thus evolve by selection of mutations that alter amino acids in the binding region with minimal effect on normal function. This sort of positive selection can be used to infer the history of the host-virus "arms race" during their coevolution. In a new study, Demogines et al. use a combination of phylogenetic, structural, and virological analysis to infer the history and significance of positive selection on the transferrin receptor TfR1, a housekeeping protein required for iron uptake and the cell surface receptor for at least three different types of virus. The authors show that only two parts of the rodent TfR1 molecule have been subject to positive selection and that these correspond to the binding sites for two of these viruses-the mouse mammary tumor virus (a retrovirus and Machupo virus (an arenavirus. They confirmed this result by introducing the inferred binding site mutations into the wild-type protein and testing for receptor function. Related arenaviruses are beginning to spread in human populations in South America as the cause of often fatal hemorrhagic fevers, and, although Demogines et al. could find no evidence of TfR1 mutations in this region that might have been selected as a consequence of human infection, the authors identified one such mutation in Asian populations that affects infection with these viruses.

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses.

Science.gov (United States)

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-09-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51-92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research.

Polyelectrolyte-modified cowpea mosaic virus for the synthesis of gold nanoparticles.

Science.gov (United States)

Aljabali, Alaa A A; Evans, David J

2014-01-01

Polyelectrolyte surface-modified cowpea mosaic virus (CPMV) can be used for the templated synthesis of narrowly dispersed gold nanoparticles. Cationic polyelectrolyte, poly(allylamine) hydrochloride, is electrostatically bound to the external surface of the virus capsid. The polyelectrolyte-coated CPMV promotes adsorption of aqueous gold hydroxide anionic species, prepared from gold(III) chloride and potassium carbonate, that are easily reduced to form CPMV-templated gold nanoparticles. The process is simple and environmentally benign using only water as solvent at ambient temperature.

Surface States Effect on the Large Photoluminescence Redshift in GaN Nanostructures

KAUST Repository

Ben Slimane, Ahmed

2013-01-01

We report on the large photoluminescence redshift observed in nanostructures fabricated using n-type GaN by ultraviolet (UV) metal-assisted electroless chemical-etching method. The scanning electron microscopy (SEM) characterization showed nanostructures with size dispersion ranging from 10 to 100 nm. We observed the crystalline structure using high resolution transmission electron microscopy (HRTEM) and electron energy loss (EELS) techniques. In contrast to 362 nm UV emission from the GaN epitaxy, the nanostructures emitted violet visible-light in photoluminescence (PL) characterization with increasing optical excitation. An energy band model was presented to shed light on the large PL redshift under the influence of surface states, which resulted in two competing photoluminescence mechanisms depending on excitation conditions.

Evaluation of 405 nm monochromatic light for inactivation of tulane virus on blueberry surfaces

Science.gov (United States)

The aim of this study was to evaluate the potential of 405 nm light as an intervention for virus contaminated blueberries. Tulane virus-contaminated-blueberries were treated with 4.2 mW/sq cm of 405 nm light for 5 to 30 min. To mitigate thermal heating due to the intense light, a dry ice-chilled ni...

Virus-Vectored Influenza Virus Vaccines

Science.gov (United States)

Tripp, Ralph A.; Tompkins, S. Mark

2014-01-01

Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

Strawberry crinkle virus, a Cytorhabdovirus needing more attention from virologists.

Science.gov (United States)

Posthuma, K I; Adams, A N; Hong, Y

2000-11-01

Summary Taxonomic relationship: A member of nonsegmented, negative-sense, single-stranded RNA viruses of the genus Cytorhabdovirus (type member: Lettuce necrotic yellows virus), family Rhabdoviridae, order Mononegavirales. Members of the family Rhabdoviridae can infect vertebrates, invertebrates and plants. Physical properties: Virions are bacilliform, 74-88 nm in diameter and 163-383 nm in length with surface projections probably composed of trimers of the glycoprotein G, occurring in the cytoplasm in either the coated or the uncoated form (Fig. 1). The nucleocapsid is enclosed in a host-derived envelope. Within the virion, the SCV genome consists of a single negative-sense single-stranded RNA molecule of approximately 13 kb. Viral proteins: The SCV genome encodes at least five proteins: the nucleocapsid (N) protein (45 kDa), the matrix (M) protein (77 kDa), the nonstructural protein [Ns, 55 kDa, also known as phosphoprotein (P)], the glycoprotein (G, 23 kDa) and the large (L) protein. Hosts: The natural host range of SCV is limited to species of the genus Fragaria L. Experimental hosts include Physalis pubescens L., P. floridana Rydb., Nicotiana occidentalis, N. glutinosa L. and N. clevelandi Gray. SCV also replicates in its insect vectors Chaetosiphon fragaefolii Cockerell and C. jacobi Hille Ris Lamberts. When injected as purified virus, SCV replicates in aphids Hyperomyzus lactucae (L.), Macrosiphon euphorbiae Thomas, Myzus ornatus Laing, Megoura viciae Buckton, and Acyrthosiphoa pisum (Harris).

Cowpea Mosaic Virus-Encoded Protease Does Not Recognize Primary Translation Products of M RNAs from Other Comoviruses.

Science.gov (United States)

Goldbach, R; Krijt, J

1982-09-01

The protease encoded by the large (B) RNA segment of cowpea mosaic virus was tested for its ability to recognize the in vitro translation products of the small (M) RNA segment from the comoviruses squash mosaic virus, red clover mottle virus, and cowpea severe mosaic virus (CPsMV, strains Dg and Ark), and from the nepovirus tomato black ring virus. Like M RNA from cowpea mosaic virus, the M RNAs from squash mosaic virus, red clover mottle virus, CPsMV-Dg, and CPsMV-Ark were all translated into two large polypeptides with apparent molecular weights which were different for each virus and even for the two CPsMV strains. Neither the in vitro products from squash mosaic virus, red clover mottle virus, and CPsMV M RNAs nor the in vitro product from tomato black ring virus RNA-2 were processed by the cowpea mosaic virus-encoded protease, indicating that the activity of this enzyme is highly specific.

Surface growth mechanisms and structural faulting in the growth of large single and spherulitic titanosilicate ETS-4 crystals

Science.gov (United States)

Miraglia, Peter Q.; Yilmaz, Bilge; Warzywoda, Juliusz; Sacco, Albert

2004-10-01

Morphological, surface and crystallographic analyses of titanosilicate ETS-4 products, with diverse habits ranging from spherulitic particles composed of submicron crystallites to large single crystals, are presented. Pole figures revealed that crystal surfaces with a-, b- and c- axes corresponded to , and directions, respectively. Thus, technologically important 8-membered ring pores and titania chains in ETS-4 run along the b-axis of single crystals and terminate at the smallest crystal face. Height of the spiral growth steps observed on {1 0 0} and {0 0 1} surfaces corresponded to the interplanar spacings associated with their crystallographic orientation, and is equivalent to the thickness of building units that form the ETS-4 framework. Data suggest that the more viscous synthesis mixtures, with a large driving force for growth, increased the two- and three-dimensional nucleation, while limiting the transport of nutrients to the growth surface. These conditions increase the tendency for stacking fault formation on {1 0 0} surfaces and small angle branching, which eventually results in spherulitic growth. The growth of high quality ETS-4 single crystals (from less viscous synthesis mixtures) occurred at lower surface nucleation rates. Data suggest that these high quality, large crystals grew due to one-dimensional nucleation at spiral hillocks, and indicate that under these conditions un-faulted growth is preferred.

Investigation of Low-Cost Surface Processing Techniques for Large-Size Multicrystalline Silicon Solar Cells

OpenAIRE

Cheng, Yuang-Tung; Ho, Jyh-Jier; Lee, William J.; Tsai, Song-Yeu; Lu, Yung-An; Liou, Jia-Jhe; Chang, Shun-Hsyung; Wang, Kang L.

2010-01-01

The subject of the present work is to develop a simple and effective method of enhancing conversion efficiency in large-size solar cells using multicrystalline silicon (mc-Si) wafer. In this work, industrial-type mc-Si solar cells with area of 125×125 mm2 were acid etched to produce simultaneously POCl3 emitters and silicon nitride deposition by plasma-enhanced chemical vapor deposited (PECVD). The study of surface morphology and reflectivity of different mc-Si etched surfaces has also been d...

In vitro selection of high-infectious, leukemogenic virus from low-infectious, non-leukemogenic type C virus from a malignant ST/a mouse cell line

DEFF Research Database (Denmark)

Willumsen, B M

1979-01-01

; however, virus was detected in supernatant fluids only after two to four subcultures of the infected cells. The virus thus produced was XC(+) and a large plaque former. The virus released from infected SC-1 cells was N-tropic, whereas the viruses from infected NIH/3T3 and BALB/3T3 cells were NB...... nanogram of p30, was 30- to 60-fold lower for the virus released from the ST-L1 cell line than that of the viruses after passage in SC-1, NIH/3T3, and BALB/3T3 cells. None of the viruses could infect rabbit or mink cells. Inoculation of the viruses into newborn mice showed that the ST-L1 virus was non......-leukemogenic, whereas the NB-tropic virus selected from this after passage in BALB/3T3 or NIH/3T3 cells was highly leukemogenic. Viruses isolated from leukemic animals were indistinguishable with respect to host range and protein mobilities in SDS gels from the ones with which the mice were inoculated. Although the SC...

Prime focus architectures for large space telescopes: reduce surfaces to save cost

Science.gov (United States)

Breckinridge, J. B.; Lillie, C. F.

2016-07-01

Conceptual architectures are now being developed to identify future directions for post JWST large space telescope systems to operate in the UV Optical and near IR regions of the spectrum. Here we show that the cost of optical surfaces within large aperture telescope/instrument systems can exceed $100M/reflection when expressed in terms of the aperture increase needed to over come internal absorption loss. We recommend a program in innovative optical design to minimize the number of surfaces by considering multiple functions for mirrors. An example is given using the Rowland circle imaging spectrometer systems for UV space science. With few exceptions, current space telescope architectures are based on systems optimized for ground-based astronomy. Both HST and JWST are classical "Cassegrain" telescopes derived from the ground-based tradition to co-locate the massive primary mirror and the instruments at the same end of the metrology structure. This requirement derives from the dual need to minimize observatory dome size and cost in the presence of the Earth's 1-g gravitational field. Space telescopes, however function in the zero gravity of space and the 1- g constraint is relieved to the advantage of astronomers. Here we suggest that a prime focus large aperture telescope system in space may have potentially have higher transmittance, better pointing, improved thermal and structural control, less internal polarization and broader wavelength coverage than Cassegrain telescopes. An example is given showing how UV astronomy telescopes use single optical elements for multiple functions and therefore have a minimum number of reflections.

Replication fidelity assessment of large area sub-μm structured polymer surfaces using scatterometry

International Nuclear Information System (INIS)

Calaon, M; Hansen, H N; Tosello, G; Madsen, M H; Weirich, J; Hansen, P E; Garnaes, J; Tang, P T

2015-01-01

The present study addresses one of the key challenges in the product quality control of transparent structured polymer substrates, the replication fidelity of sub-μm structures over a large area. Additionally the work contributes to the development of new techniques focused on in-line characterization of large nanostructured surfaces using scatterometry. In particular an approach to quantify the replication fidelity of high volume manufacturing processes such as polymer injection moulding is presented. Both periodic channels and semi-spherical structures were fabricated on nickel shims used for later injection moulding of Cyclic-olefin-copolymer (COC) substrate were the sub-μm features where ultimately transferred. The scatterometry system was validated using calibrated atomic force microscopy measurements and a model based on scalar diffraction theory employed to calculate the expected angular distribution of the reflected and the transmitted intensity for the nickel surfaces and structured COC and, respectively. (paper)

Point contact tunneling spectroscopy apparatus for large scale mapping of surface superconducting properties

Energy Technology Data Exchange (ETDEWEB)

Groll, Nickolas; Pellin, Michael J. [Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States); Zasadzinksi, John F. [Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Proslier, Thomas, E-mail: prolier@anl.gov [Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States); High Energy Physics Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)

2015-09-15

We describe the design and testing of a point contact tunneling spectroscopy device that can measure material surface superconducting properties (i.e., the superconducting gap Δ and the critical temperature T{sub C}) and density of states over large surface areas with size up to mm{sup 2}. The tip lateral (X,Y) motion, mounted on a (X,Y,Z) piezo-stage, was calibrated on a patterned substrate consisting of Nb lines sputtered on a gold film using both normal (Al) and superconducting (PbSn) tips at 1.5 K. The tip vertical (Z) motion control enables some adjustment of the tip-sample junction resistance that can be measured over 7 orders of magnitudes from a quasi-ohmic regime (few hundred Ω) to the tunnel regime (from tens of kΩ up to few GΩ). The low noise electronic and LabVIEW program interface are also presented. The point contact regime and the large-scale motion capabilities are of particular interest for mapping and testing the superconducting properties of macroscopic scale superconductor-based devices.

Chikungunya virus infection in travellers to Australia.

Science.gov (United States)

Johnson, Douglas F; Druce, Julian D; Chapman, Scott; Swaminathan, Ashwin; Wolf, Josh; Richards, Jack S; Korman, Tony; Birch, Chris; Richards, Michael J

2008-01-07

We report eight recent cases of Chikungunya virus infection in travellers to Australia. Patients presented with fevers, rigors, headaches, arthralgia, and rash. The current Indian Ocean epidemic and Italian outbreak have featured prominently on Internet infectious disease bulletins, and Chikungunya virus infection had been anticipated in travellers from the outbreak areas. Diagnosis was by a generic alphavirus reverse transcriptase polymerase chain reaction with confirmatory sequencing. Prompt diagnosis of Chikungunya virus infections is of public health significance as the mosquito vectors for transmission exist in Australia. There is potential for this infection to spread in the largely naïve Australian population.

Studies of archaeal virus-host systems in thermal environments

DEFF Research Database (Denmark)

Erdmann, Susanne

Since the first organisms were isolated from hot springs, a large number of viruses were found in these geothermal active environments, most of them infecting Archaea. Archaeal viruses form a separate lineage from those of Eukarya and Bacteria often showing exceptional morphologies and genomic...... features. Most of the isolated archaeal viruses infecting members of the Crenarchaeota have been characterized regarding their genome, the structure of their virions and their influence on the host viability. Only a few, SIRV a rod-shaped and STIV an icosahedrical virus, have been subjected to more...... extensive studies. This work investigates tailed spindle-shaped viruses that we have isolated from different geographical acidothermal, terrestrial hot springs and they primarily infect members of the genus Sulfolobales. The wide distribution of these viruses was established and, moreover, genomic...

Exploiting Herpes Simplex Virus Entry for Novel Therapeutics

Directory of Open Access Journals (Sweden)

Deepak Shukla

2013-06-01

Full Text Available Herpes Simplex virus (HSV is associated with a variety of diseases such as genital herpes and numerous ocular diseases. At the global level, high prevalence of individuals who are seropositive for HSV, combined with its inconspicuous infection, remains a cause for major concern. At the molecular level, HSV entry into a host cell involves multiple steps, primarily the interaction of viral glycoproteins with various cell surface receptors, many of which have alternate substitutes. The molecular complexity of the virus to enter a cell is also enhanced by the existence of different modes of viral entry. The availability of many entry receptors, along with a variety of entry mechanisms, has resulted in a virus that is capable of infecting virtually all cell types. While HSV uses a wide repertoire of viral and host factors in establishing infection, current therapeutics aimed against the virus are not as diversified. In this particular review, we will focus on the initial entry of the virus into the cell, while highlighting potential novel therapeutics that can control this process. Virus entry is a decisive step and effective therapeutics can translate to less virus replication, reduced cell death, and detrimental symptoms.

Image-based Exploration of Iso-surfaces for Large Multi- Variable Datasets using Parameter Space.

KAUST Repository

Binyahib, Roba S.

2013-05-13

With an increase in processing power, more complex simulations have resulted in larger data size, with higher resolution and more variables. Many techniques have been developed to help the user to visualize and analyze data from such simulations. However, dealing with a large amount of multivariate data is challenging, time- consuming and often requires high-end clusters. Consequently, novel visualization techniques are needed to explore such data. Many users would like to visually explore their data and change certain visual aspects without the need to use special clusters or having to load a large amount of data. This is the idea behind explorable images (EI). Explorable images are a novel approach that provides limited interactive visualization without the need to re-render from the original data [40]. In this work, the concept of EI has been used to create a workflow that deals with explorable iso-surfaces for scalar fields in a multivariate, time-varying dataset. As a pre-processing step, a set of iso-values for each scalar field is inferred and extracted from a user-assisted sampling technique in time-parameter space. These iso-values are then used to generate iso- surfaces that are then pre-rendered (from a fixed viewpoint) along with additional buffers (i.e. normals, depth, values of other fields, etc.) to provide a compressed representation of iso-surfaces in the dataset. We present a tool that at run-time allows the user to interactively browse and calculate a combination of iso-surfaces superimposed on each other. The result is the same as calculating multiple iso- surfaces from the original data but without the memory and processing overhead. Our tool also allows the user to change the (scalar) values superimposed on each of the surfaces, modify their color map, and interactively re-light the surfaces. We demonstrate the effectiveness of our approach over a multi-terabyte combustion dataset. We also illustrate the efficiency and accuracy of our

A transgenic plant cell-suspension system for expression of epitopes on chimeric Bamboo mosaic virus particles.

Science.gov (United States)

Muthamilselvan, Thangarasu; Lee, Chin-Wei; Cho, Yu-Hsin; Wu, Feng-Chao; Hu, Chung-Chi; Liang, Yu-Chuan; Lin, Na-Sheng; Hsu, Yau-Heiu

2016-01-01

We describe a novel strategy to produce vaccine antigens using a plant cell-suspension culture system in lieu of the conventional bacterial or animal cell-culture systems. We generated transgenic cell-suspension cultures from Nicotiana benthamiana leaves carrying wild-type or chimeric Bamboo mosaic virus (BaMV) expression constructs encoding the viral protein 1 (VP1) epitope of foot-and-mouth disease virus (FMDV). Antigens accumulated to high levels in BdT38 and BdT19 transgenic cell lines co-expressing silencing suppressor protein P38 or P19. BaMV chimeric virus particles (CVPs) were subsequently purified from the respective cell lines (1.5 and 2.1 mg CVPs/20 g fresh weight of suspended biomass, respectively), and the resulting CVPs displayed VP1 epitope on the surfaces. Guinea pigs vaccinated with purified CVPs produced humoral antibodies. This study represents an important advance in the large-scale production of immunopeptide vaccines in a cost-effective manner using a plant cell-suspension culture system. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Generation of herpesvirus entry mediator (HVEM)-restricted herpes simplex virus type 1 mutant viruses: resistance of HVEM-expressing cells and identification of mutations that rescue nectin-1 recognition.

Science.gov (United States)

Uchida, Hiroaki; Shah, Waris A; Ozuer, Ali; Frampton, Arthur R; Goins, William F; Grandi, Paola; Cohen, Justus B; Glorioso, Joseph C

2009-04-01

Both initial infection and cell-to-cell spread by herpes simplex virus type 1 (HSV-1) require the interaction of the viral glycoprotein D (gD) with an entry receptor on the cell surface. The two major HSV entry receptors, herpesvirus entry mediator (HVEM) and nectin-1, mediate infection independently but are coexpressed on a variety of cells. To determine if both receptors are active in these instances, we have established mutant viruses that are selectively impaired for recognition of one or the other receptor. In plaque assays, these viruses showed approximately 1,000-fold selectivity for the matched receptor over the mismatched receptor. Separate assays showed that each virus is impaired for both infection and spread through the mismatched receptor. We tested several human tumor cell lines for susceptibility to these viruses and observed that HT29 colon carcinoma cells are susceptible to infection by nectin-1-restricted virus but are highly resistant to HVEM-restricted virus infection, despite readily detectable HVEM expression on the cell surface. HVEM cDNA isolated from HT29 cells rendered HSV-resistant cells permissive for infection by the HVEM-restricted virus, suggesting that HT29 cells lack a cofactor for HVEM-mediated infection or express an HVEM-specific inhibitory factor. Passaging of HVEM-restricted virus on nectin-1-expressing cells yielded a set of gD missense mutations that each restored functional recognition of nectin-1. These mutations identify residues that likely play a role in shaping the nectin-1 binding site of gD. Our findings illustrate the utility of these receptor-restricted viruses in studying the early events in HSV infection.

Aptasensor development for detection of virus in water

DEFF Research Database (Denmark)

Kirkegaard, Julie

of three types of waterborne viruses: norovirus, rotavirus and hepatitis A virus. The development of the aptasensor involved sample preparation for aptamer selection of rotavirus and hepatitis A virus, an iterative design process of the aptasensor, investigation of the surface immobilisation of aptamers...... and finally an impedimetric electrical characterisation of the sensor. The sample preparation of the rotavirus was based on purification and biotinylation of the virus to meet the requirements of the aptamer selection process. The selection process, performed by an external collaborator, was based...... on streptavidin coated magnetic bead separation, hence the needed biotinylation. It was found that the BPH linker gave the highest yield when the biotinylated rotavirus were immobilised onto the beads. The design of the viral aptasensor was determined by an iterative design process. The final chip design...

A magnetic particle micro-trap for large trapping surfaces

KAUST Repository

Gooneratne, Chinthaka P.

2012-01-08

Manipulation of micron-size magnetic particles of the superparamagnetic type contributes significantly in many applications like controlling the antibody/antigen binding process in immunoassays. Specifically, more target biomolecules can be attached/tagged and analyzed since the three dimensional structure of the magnetic particles increases the surface to volume ratio. Additionally, such biomolecular-tagged magnetic particles can be easily manipulated by an external magnetic field due to their superparamagnetic behavior. Therefore, magnetic particle- based immunoassays are extensively applied in micro-flow cytometry. The design of a square-loop micro-trap as a magnetic particle manipulator as well as numerical and experimental analysis is presented. Experimental results showed that the micro-trap could successfully trap and concentrate magnetic particles from a large to a small area with a high spatial range.

A magnetic particle micro-trap for large trapping surfaces

KAUST Repository

Gooneratne, Chinthaka P.; Liang, Cai; Giouroudi, Ioanna; Kosel, Jü rgen

2012-01-01

Manipulation of micron-size magnetic particles of the superparamagnetic type contributes significantly in many applications like controlling the antibody/antigen binding process in immunoassays. Specifically, more target biomolecules can be attached/tagged and analyzed since the three dimensional structure of the magnetic particles increases the surface to volume ratio. Additionally, such biomolecular-tagged magnetic particles can be easily manipulated by an external magnetic field due to their superparamagnetic behavior. Therefore, magnetic particle- based immunoassays are extensively applied in micro-flow cytometry. The design of a square-loop micro-trap as a magnetic particle manipulator as well as numerical and experimental analysis is presented. Experimental results showed that the micro-trap could successfully trap and concentrate magnetic particles from a large to a small area with a high spatial range.

Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

Energy Technology Data Exchange (ETDEWEB)

Li, Kai; Ma, Chun–Fang; Ling, Yuan; Li, Meng [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Gao, Qiang, E-mail: gaoqiang@cug.edu.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Engineering Research Center of Nano-Geo Materials of Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Luo, Wen–Jun, E-mail: heartnohome@yahoo.com.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China)

2015-07-15

Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N{sub 2} adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m{sup 2} g{sup −1}) and pore volume (0.016 cm{sup 3} g{sup −1}), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m{sup 2} g{sup −1} and 0.701 cm{sup 3} g{sup −1}, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH{sub 2}) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH{sub 2} bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds.

High-efficiency targeted editing of large viral genomes by RNA-guided nucleases.

Science.gov (United States)

Bi, Yanwei; Sun, Le; Gao, Dandan; Ding, Chen; Li, Zhihua; Li, Yadong; Cun, Wei; Li, Qihan

2014-05-01

A facile and efficient method for the precise editing of large viral genomes is required for the selection of attenuated vaccine strains and the construction of gene therapy vectors. The type II prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas)) RNA-guided nuclease system can be introduced into host cells during viral replication. The CRISPR-Cas9 system robustly stimulates targeted double-stranded breaks in the genomes of DNA viruses, where the non-homologous end joining (NHEJ) and homology-directed repair (HDR) pathways can be exploited to introduce site-specific indels or insert heterologous genes with high frequency. Furthermore, CRISPR-Cas9 can specifically inhibit the replication of the original virus, thereby significantly increasing the abundance of the recombinant virus among progeny virus. As a result, purified recombinant virus can be obtained with only a single round of selection. In this study, we used recombinant adenovirus and type I herpes simplex virus as examples to demonstrate that the CRISPR-Cas9 system is a valuable tool for editing the genomes of large DNA viruses.

High-efficiency targeted editing of large viral genomes by RNA-guided nucleases.

Directory of Open Access Journals (Sweden)

Yanwei Bi

2014-05-01

Full Text Available A facile and efficient method for the precise editing of large viral genomes is required for the selection of attenuated vaccine strains and the construction of gene therapy vectors. The type II prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats (CRISPR-associated (Cas RNA-guided nuclease system can be introduced into host cells during viral replication. The CRISPR-Cas9 system robustly stimulates targeted double-stranded breaks in the genomes of DNA viruses, where the non-homologous end joining (NHEJ and homology-directed repair (HDR pathways can be exploited to introduce site-specific indels or insert heterologous genes with high frequency. Furthermore, CRISPR-Cas9 can specifically inhibit the replication of the original virus, thereby significantly increasing the abundance of the recombinant virus among progeny virus. As a result, purified recombinant virus can be obtained with only a single round of selection. In this study, we used recombinant adenovirus and type I herpes simplex virus as examples to demonstrate that the CRISPR-Cas9 system is a valuable tool for editing the genomes of large DNA viruses.

Structure of viruses: a short history.

Science.gov (United States)

Rossmann, Michael G

2013-05-01

. Starting in the 1990s, these enveloped viruses were studied by combining cryo-electron microscopy of the whole virus with X-ray crystallography of their protein components. These structures gave information on virus assembly, virus neutralization by antibodies, and virus fusion with and entry into the host cell. The same techniques were also employed in the study of complex bacteriophages that were too large to crystallize. Nevertheless, there still remained many pleomorphic, highly pathogenic viruses that lacked the icosahedral symmetry and homogeneity that had made the earlier structural investigations possible. Currently some of these viruses are starting to be studied by combining X-ray crystallography with cryo-electron tomography.

A novel single virus infection system reveals that influenza virus preferentially infects cells in g1 phase.

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Ryuta Ueda

Full Text Available BACKGROUND: Influenza virus attaches to sialic acid residues on the surface of host cells via the hemagglutinin (HA, a glycoprotein expressed on the viral envelope, and enters into the cytoplasm by receptor-mediated endocytosis. The viral genome is released and transported in to the nucleus, where transcription and replication take place. However, cellular factors affecting the influenza virus infection such as the cell cycle remain uncharacterized. METHODS/RESULTS: To resolve the influence of cell cycle on influenza virus infection, we performed a single-virus infection analysis using optical tweezers. Using this newly developed single-virus infection system, the fluorescence-labeled influenza virus was trapped on a microchip using a laser (1064 nm at 0.6 W, transported, and released onto individual H292 human lung epithelial cells. Interestingly, the influenza virus attached selectively to cells in the G1-phase. To clarify the molecular differences between cells in G1- and S/G2/M-phase, we performed several physical and chemical assays. Results indicated that: 1 the membranes of cells in G1-phase contained greater amounts of sialic acids (glycoproteins than the membranes of cells in S/G2/M-phase; 2 the membrane stiffness of cells in S/G2/M-phase is more rigid than those in G1-phase by measurement using optical tweezers; and 3 S/G2/M-phase cells contained higher content of Gb3, Gb4 and GlcCer than G1-phase cells by an assay for lipid composition. CONCLUSIONS: A novel single-virus infection system was developed to characterize the difference in influenza virus susceptibility between G1- and S/G2/M-phase cells. Differences in virus binding specificity were associated with alterations in the lipid composition, sialic acid content, and membrane stiffness. This single-virus infection system will be useful for studying the infection mechanisms of other viruses.

Virus fitness differences observed between two naturally occurring isolates of Ebola virus Makona variant using a reverse genetics approach.

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Albariño, César G; Guerrero, Lisa Wiggleton; Chakrabarti, Ayan K; Kainulainen, Markus H; Whitmer, Shannon L M; Welch, Stephen R; Nichol, Stuart T

2016-09-01

During the large outbreak of Ebola virus disease that occurred in Western Africa from late 2013 to early 2016, several hundred Ebola virus (EBOV) genomes have been sequenced and the virus genetic drift analyzed. In a previous report, we described an efficient reverse genetics system designed to generate recombinant EBOV based on a Makona variant isolate obtained in 2014. Using this system, we characterized the replication and fitness of 2 isolates of the Makona variant. These virus isolates are nearly identical at the genetic level, but have single amino acid differences in the VP30 and L proteins. The potential effects of these differences were tested using minigenomes and recombinant viruses. The results obtained with this approach are consistent with the role of VP30 and L as components of the EBOV RNA replication machinery. Moreover, the 2 isolates exhibited clear fitness differences in competitive growth assays. Published by Elsevier Inc.

The biology of herpes simplex virus infection in humans.

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Baringer, J R

1976-01-01

Herpes simplex virus is a frequent cause of recurrent ocular, oral, genital or cutaneous eruptions in man. Lesions are highly localized and tend to recur at the same site. Among the most consistent factors provoking recurrence is root section of the trigeminal nerve. Clinical and experimental data suggest that herpes simplex virus is commonly resident within the trigeminal ganglia of man, where it may be responsible for recurrent oral or lip lesions, and is less frequently a resident of the second or third sacral ganglia where it might be responsible for genital eruptions. Generally, the trigeminal virus is type 1 and the sacral virus is type 2; the virus is only rarely recoverable from other sensory ganglia. Factors provoking the reactivation from the virus' latent site and the mechanism for reactivation remain largely unknown. Further study is needed to understand the behavior of HSV and other viruses in nervous system tissue.

Human and bovine viruses in the Milwaukee River watershed: Hydrologically relevant representation and relations with environmental variables

Energy Technology Data Exchange (ETDEWEB)

Corsi, S.R., E-mail: srcorsi@usgs.gov [U.S. Geological Survey, Wisconsin Water Science Center, Middleton, WI 53562 (United States); Borchardt, M.A.; Spencer, S.K. [U.S. Department of Agriculture, Agricultural Research Service, 2615 Yellowstone Dr., Marshfield, WI 54449 (United States); Hughes, P.E.; Baldwin, A.K. [U.S. Geological Survey, Wisconsin Water Science Center, Middleton, WI 53562 (United States)

2014-08-15

To examine the occurrence, hydrologic variability, and seasonal variability of human and bovine viruses in surface water, three stream locations were monitored in the Milwaukee River watershed in Wisconsin, USA, from February 2007 through June 2008. Monitoring sites included an urban subwatershed, a rural subwatershed, and the Milwaukee River at the mouth. To collect samples that characterize variability throughout changing hydrologic periods, a process control system was developed for unattended, large-volume (56–2800 L) filtration over extended durations. This system provided flow-weighted mean concentrations during runoff and extended (24-h) low-flow periods. Human viruses and bovine viruses were detected by real-time qPCR in 49% and 41% of samples (n = 63), respectively. All human viruses analyzed were detected at least once including adenovirus (40% of samples), GI norovirus (10%), enterovirus (8%), rotavirus (6%), GII norovirus (1.6%) and hepatitis A virus (1.6%). Three of seven bovine viruses analyzed were detected including bovine polyomavirus (32%), bovine rotavirus (19%), and bovine viral diarrhea virus type 1 (5%). Human viruses were present in 63% of runoff samples resulting from precipitation and snowmelt, and 20% of low-flow samples. Maximum human virus concentrations exceeded 300 genomic copies/L. Bovine viruses were present in 46% of runoff samples resulting from precipitation and snowmelt and 14% of low-flow samples. The maximum bovine virus concentration was 11 genomic copies/L. Statistical modeling indicated that stream flow, precipitation, and season explained the variability of human viruses in the watershed, and hydrologic condition (runoff event or low-flow) and season explained the variability of the sum of human and bovine viruses; however, no model was identified that could explain the variability of bovine viruses alone. Understanding the factors that affect virus fate and transport in rivers will aid watershed management for minimizing

Human and bovine viruses in the Milwaukee River watershed: Hydrologically relevant representation and relations with environmental variables

International Nuclear Information System (INIS)

Corsi, S.R.; Borchardt, M.A.; Spencer, S.K.; Hughes, P.E.; Baldwin, A.K.

2014-01-01

To examine the occurrence, hydrologic variability, and seasonal variability of human and bovine viruses in surface water, three stream locations were monitored in the Milwaukee River watershed in Wisconsin, USA, from February 2007 through June 2008. Monitoring sites included an urban subwatershed, a rural subwatershed, and the Milwaukee River at the mouth. To collect samples that characterize variability throughout changing hydrologic periods, a process control system was developed for unattended, large-volume (56–2800 L) filtration over extended durations. This system provided flow-weighted mean concentrations during runoff and extended (24-h) low-flow periods. Human viruses and bovine viruses were detected by real-time qPCR in 49% and 41% of samples (n = 63), respectively. All human viruses analyzed were detected at least once including adenovirus (40% of samples), GI norovirus (10%), enterovirus (8%), rotavirus (6%), GII norovirus (1.6%) and hepatitis A virus (1.6%). Three of seven bovine viruses analyzed were detected including bovine polyomavirus (32%), bovine rotavirus (19%), and bovine viral diarrhea virus type 1 (5%). Human viruses were present in 63% of runoff samples resulting from precipitation and snowmelt, and 20% of low-flow samples. Maximum human virus concentrations exceeded 300 genomic copies/L. Bovine viruses were present in 46% of runoff samples resulting from precipitation and snowmelt and 14% of low-flow samples. The maximum bovine virus concentration was 11 genomic copies/L. Statistical modeling indicated that stream flow, precipitation, and season explained the variability of human viruses in the watershed, and hydrologic condition (runoff event or low-flow) and season explained the variability of the sum of human and bovine viruses; however, no model was identified that could explain the variability of bovine viruses alone. Understanding the factors that affect virus fate and transport in rivers will aid watershed management for minimizing

vConTACT: an iVirus tool to classify double-stranded DNA viruses that infect Archaea and Bacteria

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Benjamin Bolduc

2017-05-01

Full Text Available Taxonomic classification of archaeal and bacterial viruses is challenging, yet also fundamental for developing a predictive understanding of microbial ecosystems. Recent identification of hundreds of thousands of new viral genomes and genome fragments, whose hosts remain unknown, requires a paradigm shift away from traditional classification approaches and towards the use of genomes for taxonomy. Here we revisited the use of genomes and their protein content as a means for developing a viral taxonomy for bacterial and archaeal viruses. A network-based analytic was evaluated and benchmarked against authority-accepted taxonomic assignments and found to be largely concordant. Exceptions were manually examined and found to represent areas of viral genome ‘sequence space’ that are under-sampled or prone to excessive genetic exchange. While both cases are poorly resolved by genome-based taxonomic approaches, the former will improve as viral sequence space is better sampled and the latter are uncommon. Finally, given the largely robust taxonomic capabilities of this approach, we sought to enable researchers to easily and systematically classify new viruses. Thus, we established a tool, vConTACT, as an app at iVirus, where it operates as a fast, highly scalable, user-friendly app within the free and powerful CyVerse cyberinfrastructure.

Loss of Anti-Viral Immunity by Infection with a Virus Encoding a Cross-Reactive Pathogenic Epitope

OpenAIRE

Chen, Alex T.; Cornberg, Markus; Gras, Stephanie; Guillonneau, Carole; Rossjohn, Jamie; Trees, Andrew; Emonet, Sebastien; de la Torre, Juan C.; Welsh, Raymond M.; Selin, Liisa K.

2012-01-01

Author Summary The purpose of vaccination against viruses is to induce strong neutralizing antibody responses that inactivate viruses on contact and strong T cell responses that attack and kill virus-infected cells. Some viruses, however, like HIV and hepatitis C virus, are only weakly controlled by neutralizing antibody, so T cell immunity is very important for control of these infections. T cells recognize small virus-encoded peptides, called epitopes, presented on the surface of infected c...

Digital detection system of surface defects for large aperture optical elements

International Nuclear Information System (INIS)

Fan Yong; Chen Niannian; Gao Lingling; Jia Yuan; Wang Junbo; Cheng Xiaofeng

2009-01-01

Based on the light defect images against the dark background in a scattering imaging system, a digital detection system of surface defects for large aperture optical elements has been presented. In the system, the image is segmented by a multi-area self-adaptive threshold segmentation method, then a pixel labeling method based on replacing arrays is adopted to extract defect features quickly, and at last the defects are classified through back-propagation neural networks. Experiment results show that the system can achieve real-time detection and classification. (authors)

Observation of near-infrared surface brightness of the large Magellanic cloud

International Nuclear Information System (INIS)

Hayakawa, Satio; Koizumi, Yutaka; Matsumoto, Toshio; Murakami, Hiroshi; Uyama, Kiichiro.

1981-01-01

The near-infrared surface brightness of the large Magellanic cloud was observed by an infrared telescope carried by a balloon. The balloon flight was made at Australian Balloon Launching Station. The brightness distribution of 2.4 Mu m radiation was obtained. A part of Bar was bright, and the expansion of the contour at the east end of Bar corresponded to the 30 Dor region. Many near-infrared sources distribute in this region. Discussions on the color and brightness of the center of Bar and the 30 Dor region are presented. (Kato, T.)

Feline Immunodeficiency Virus in South America

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Bruno M. Teixeira

2012-03-01

Full Text Available The rapid emergence of AIDS in humans during the period between 1980 and 2000 has led to extensive efforts to understand more fully similar etiologic agents of chronic and progressive acquired immunodeficiency disease in several mammalian species. Lentiviruses that have gene sequence homology with human immunodeficiency virus (HIV have been found in different species (including sheep, goats, horses, cattle, cats, and several Old World monkey species. Lentiviruses, comprising a genus of the Retroviridae family, cause persistent infection that can lead to varying degrees of morbidity and mortality depending on the virus and the host species involved. Feline immunodeficiency virus (FIV causes an immune system disease in domestic cats (Felis catus involving depletion of the CD4+ population of T lymphocytes, increased susceptibility to opportunistic infections, and sometimes death. Viruses related to domestic cat FIV occur also in a variety of nondomestic felids. This is a brief overview of the current state of knowledge of this large and ancient group of viruses (FIVs in South America.

Pharmacological Inhibition of Feline Immunodeficiency Virus (FIV

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Dorothee Bienzle

2012-04-01

Full Text Available Feline immunodeficiency virus (FIV is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV. Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1 inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2 inhibition of fusion of the virus membrane with the cell membrane; (3 blockade of reverse transcription of viral genomic RNA; (4 interruption of nuclear translocation and viral DNA integration into host genomes; (5 prevention of viral transcript processing and nuclear export; and (6 inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats.

Characterization of Viral Load, Viability and Persistence of Influenza A Virus in Air and on Surfaces of Swine Production Facilities.

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Victor Neira

Full Text Available Indirect transmission of influenza A virus (IAV in swine is poorly understood and information is lacking on levels of environmental exposure encountered by swine and people during outbreaks of IAV in swine barns. We characterized viral load, viability and persistence of IAV in air and on surfaces during outbreaks in swine barns. IAV was detected in pigs, air and surfaces from five confirmed outbreaks with 48% (47/98 of oral fluid, 38% (32/84 of pen railing and 43% (35/82 of indoor air samples testing positive by IAV RT-PCR. IAV was isolated from air and oral fluids yielding a mixture of subtypes (H1N1, H1N2 and H3N2. Detection of IAV RNA from air was sustained during the outbreaks with maximum levels estimated between 7 and 11 days from reported onset. Our results indicate that during outbreaks of IAV in swine, aerosols and surfaces in barns contain significant levels of IAV potentially representing an exposure hazard to both swine and people.

Optimized preparation for large surface area activated carbon from date (Phoenix dactylifera L.) stone biomass

International Nuclear Information System (INIS)

Danish, Mohammed; Hashim, Rokiah; Ibrahim, M.N. Mohamad; Sulaiman, Othman

2014-01-01

The preparation of activated carbon from date stone treated with phosphoric acid was optimized using rotatable central composite design of response surface methodology (RSM). The chemical activating agent concentration and temperature of activation plays a crucial role in preparation of large surface area activated carbons. The optimized activated carbon was characterized using thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the larger surface area of activated carbon from date stone can be achieved under optimum activating agent (phosphoric acid) concentration, 50.0% (8.674 mol L −1 ) and activation temperature, 900 °C. The Brunauer–Emmett–Teller (BET) surface area of optimized activated carbon was found to be 1225 m 2  g −1 , and thermogravimetric analysis revealed that 55.2% mass of optimized activated carbon was found thermally stable till 900 °C. The leading chemical functional groups found in the date stone activated carbon were aliphatic carboxylic acid salt ν(C=O) 1561.22 cm −1 and 1384.52 cm −1 , aliphatic hydrocarbons ν(C–H) 2922.99 cm −1 (C–H sym./asym. stretch frequency), aliphatic phosphates ν(P–O–C) 1054.09 cm −1 , and secondary aliphatic alcohols ν(O–H) 3419.81 cm −1 and 1159.83 cm −1 . - Highlights: • RSM optimization was done for the production of large surface area activated carbon. • Two independent variables with two responses were selected for optimization. • Characterization was done for surface area, morphology and chemical constituents. • Optimized date stone activated carbon achieved surface area 1225 m 2  g −1

From human behavior to the spread of mobile phone viruses

Science.gov (United States)

Wang, Pu

Percolation theory was initiated some 50 years ago as a mathematical framework for the study of random physical processes such as the flow of a fluid through a disordered porous medium. It has been proved to be a remarkably rich theory, with applications from thermodynamic phase transitions to complex networks. In this dissertation percolation theory is used to study the diffusion process of mobile phone viruses. Some methodologies widely used in statistical physics are also applied to uncover the underlying statistical laws of human behavior and simulate the spread of mobile phone viruses in a large population. I find that while Bluetooth viruses can reach all susceptible handsets with time, they spread slowly due to human mobility, offering ample opportunities to deploy antiviral software. In contrast, viruses utilizing multimedia messaging services (MMS) could infect all users in hours, but currently a phase transition on the underlying call graph limits them to only a small fraction of the susceptible users. These results explain the lack of a major mobile virus breakout so far and predict that once a mobile operating system's market share reaches the phase transition point, viruses will pose a serious threat to mobile communications. These studies show how the large datasets and tools of statistical physics can be used to study some specific and important problems, such as the spread of mobile phone viruses.

Placental expression of asialoglycoprotein receptor associated with Hepatitis B virus transmission from mother to child.

Science.gov (United States)

Vyas, Ashish Kumar; Ramakrishna, Usha; Sen, Bijoya; Islam, Mojahidul; Ramakrishna, Gayatri; Patra, Sharda; Rastogi, Archana; Sarin, Shiv Kumar; Trehanpati, Nirupma

2018-04-30

Asialoglycoprotein receptor expression on hepatocytes has been associated with endocytosis, binding and uptake of hepatitis B virus. The role of asialoglycoprotein receptor in hepatitis B virus vertical transmission and its expression on placenta has not yet been studied. Thirty-four HBsAg+ve and 13 healthy pregnant mothers along with their newborns were enrolled. The former were categorized into transmitting and non-transmitting mothers based on their newborns being hepatitis B surface antigen and hepatitis B virus DNA positive. Expression of asialoglycoprotein receptor and hepatitis B surface antigen in placenta and isoform of asialoglycoprotein receptor on dendritic cell in peripheral and cord blood dendritic cells were analysed using flowcytometry, immune histochemistry, immune florescence and qRT-PCR. Twelve HBsAg+ve mothers transmitted hepatitis B virus to their newborns whereas the rest (n = 22) did not. Hepatitis B virus-transmitting mothers showed increased expression of asialoglycoprotein receptor in trophoblasts of placenta. Immunofluorescence microscopy revealed colocalization of hepatitis B surface antigen and asialoglycoprotein receptor in placenta as well as in DCs of transmitting mothers. There was no significant difference in the expression of asialoglycoprotein receptor on peripheral blood mononuclear cells or chord blood mononuclear cells between the 2 groups. However, hepatitis B virus-transmitting mothers and their HBsAg+ve newborns showed increased mRNA levels of isoform of asialoglycoprotein receptor on dendritic cell in peripheral blood mononuclear cells. Hepatitis B virus-transmitting mothers and their HBsAg+ve newborns showed an increased expression of isoform of asialoglycoprotein receptor on dendritic cell on circulating dendritic cells compared to hepatitis B virus non-transmitting mothers and their negative newborns. This study revealed that increased expression of asialoglycoprotein receptor in placenta and colocalization with

Surface accuracy analysis and mathematical modeling of deployable large aperture elastic antenna reflectors

Science.gov (United States)

Coleman, Michael J.

One class of deployable large aperture antenna consists of thin light-weight parabolic reflectors. A reflector of this type is a deployable structure that consists of an inflatable elastic membrane that is supported about its perimeter by a set of elastic tendons and is subjected to a constant hydrostatic pressure. A design may not hold the parabolic shape to within a desired tolerance due to an elastic deformation of the surface, particularly near the rim. We can compute the equilibrium configuration of the reflector system using an optimization-based solution procedure that calculates the total system energy and determines a configuration of minimum energy. Analysis of the equilibrium configuration reveals the behavior of the reflector shape under various loading conditions. The pressure, film strain energy, tendon strain energy, and gravitational energy are all considered in this analysis. The surface accuracy of the antenna reflector is measured by an RMS calculation while the reflector phase error component of the efficiency is determined by computing the power density at boresight. Our error computation methods are tailored for the faceted surface of our model and they are more accurate for this particular problem than the commonly applied Ruze Equation. Previous analytical work on parabolic antennas focused on axisymmetric geometries and loads. Symmetric equilibria are not assumed in our analysis. In addition, this dissertation contains two principle original findings: (1) the typical supporting tendon system tends to flatten a parabolic reflector near its edge. We find that surface accuracy can be significantly improved by fixing the edge of the inflated reflector to a rigid structure; (2) for large membranes assembled from flat sheets of thin material, we demonstrate that the surface accuracy of the resulting inflated membrane reflector can be improved by altering the cutting pattern of the flat components. Our findings demonstrate that the proper choice

Incidence of viruses in highbush blueberry (Vaccinium corymbosum L. in Serbia

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Jevremović Darko

2016-01-01

Full Text Available A large-scale survey for highbush blueberry (Vaccinium corymbosum L. viruses in Serbia was performed from 2011 to 2015. A total of 81 leaf samples from 15 locations were collected and analyzed for the presence of 8 viruses. Serological ELISA assay was performed to determine the presence of: Blueberry scorch virus (BlScV, Blueberry shock virus (BlShV, Blueberry shoestring virus (BSSV, Blueberry leaf mottle virus (BLMoV, Tobacco ringspot virus (TRSV and Tomato ringspot virus (ToRSV. All samples were tested for the presence of Blueberry red ringspot virus (BRRV by PCR and for Blueberry mosaic-associated virus (BlMaV by RT-PCR test. The analyses confirmed the presence of BlMaV in 8 (9.9% samples and BRRV in 1 (1.2% sample. No BlScV, BlShV, BLMoV, BSSV, TRSV or ToRSV viruses were detected in any of the analyzed samples.

Radiobiological inactivation of Epstein-Barr virus

International Nuclear Information System (INIS)

Henderson, E.; Heston, L.; Grogan, E.; Miller, G.

1978-01-01

Lymphocyte transforming properties of B95-8 strain Epstein-Barr virus (EBV) are very sensitive to inactivation by either uv or x irradiation. No dose of irradiation increases the transforming capacity of EBV. The x-ray dose needed for inactivation of EBV transformation (dose that results in 37% survival, 60,000 rads) is similar to the dose required for inactivation of plaque formation by herpes simplex virus type 1 (Fischer strain). Although herpes simplex virus is more sensitive than EBV to uv irradiation, this difference is most likely due to differences in the kinetics or mechanisms of repair of uv damage to the two viruses. The results lead to the hypothesis that a large part, or perhaps all, of the EBV genome is in some way needed to initiate transformation. The abilities of EBV to stimulate host cell DNA synthesis, to induce nuclear antigen, and to immortalize are inactivated in parallel. All clones of marmoset cells transformed by irradiated virus produce extracellular transforming virus. These findings suggest that the abilities of the virus to transform and to replicate complete progeny are inactivated together. The amounts of uv and x irradiation that inactivate transformation by B95-8 virus are less than the dose needed to inactivate early antigen induction by the nontransforming P 3 HR-1 strain of EBV. Based on radiobiological inactivation, 10 to 50% of the genome is needed for early antigen induction

Tetraspanin Assemblies in Virus Infection

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Luise Florin

2018-05-01

Full Text Available Tetraspanins (Tspans are a family of four-span transmembrane proteins, known as plasma membrane “master organizers.” They form Tspan-enriched microdomains (TEMs or TERMs through lateral association with one another and other membrane proteins. If multiple microdomains associate with each other, larger platforms can form. For infection, viruses interact with multiple cell surface components, including receptors, activating proteases, and signaling molecules. It appears that Tspans, such as CD151, CD82, CD81, CD63, CD9, Tspan9, and Tspan7, coordinate these associations by concentrating the interacting partners into Tspan platforms. In addition to mediating viral attachment and entry, these platforms may also be involved in intracellular trafficking of internalized viruses and assist in defining virus assembly and exit sites. In conclusion, Tspans play a role in viral infection at different stages of the virus replication cycle. The present review highlights recently published data on this topic, with a focus on events at the plasma membrane. In light of these findings, we propose a model for how Tspan interactions may organize cofactors for viral infection into distinct molecular platforms.

Evaluation of hepatitis B surface antigen and hepatitis B virus-DNA results in postmortem plasma specimens

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Nihan Ziyade

2015-03-01

Full Text Available Objective: To assess the presence of hepatitis B surface antigen, one of the serologic markers of hepatitis B virus (HBV infection, in postmortem blood samples from autopsy cases using ELISA, and to compare the results with those obtained by PCR, which is the gold standard method in assessing HBV infection. Methods: The HBV test results of the blood samples from 880 autopsy cases determined in our laboratory, were retrospectively studied. Results: When compared with the gold standard method PCR, the sensitivity and specificity of postmortem ELISA were 100% and 84.1%, respectively. Conclusions: The increasingly used molecular diagnostic methods, such as PCR, should be used in cases where serological tests remain insufficient.We think that prospective studies on the comparison of ELISA and PCR assessment of postmortem blood samples with larger material should be carried out.

Infection of endothelial cells by common human viruses.

Science.gov (United States)

Friedman, H M

1989-01-01

Common human viruses were evaluated for their ability to replicate in the endothelial cells of human umbilical vein and bovine thoracic aorta in vitro. Infection occurred with most viruses. The susceptibilities of endothelial cells derived from bovine aorta, pulmonary artery, and vena cava were compared. Among the viruses studied, no differences were noted in the ability to grow in endothelial cells from these three large vessels. One virus, herpes simplex virus type 1, was evaluated for its ability to produce persistent infection of endothelial cells. Infection developed and persisted for up to 3 months. After the first week, productive infection was found in less than 1% of cells. Nevertheless, the infection markedly affected the growth and morphology of the endothelial monolayer. Infection with any of several different viruses was noted to alter endothelial cell functions, including adherence of granulocytes, production of colony-stimulating factor, and synthesis of matrix protein. In addition, herpes simplex virus type 1 induced receptors for the Fc portion of IgG and for complement component C3b. These findings indicate that common human viruses can profoundly affect the biology of the endothelium.

Characterization of Chemokine Receptor Utilization of Viruses in the Latent Reservoir for Human Immunodeficiency Virus Type 1

Science.gov (United States)

Pierson, Theodore; Hoffman, Trevor L.; Blankson, Joel; Finzi, Diana; Chadwick, Karen; Margolick, Joseph B.; Buck, Christopher; Siliciano, Janet D.; Doms, Robert W.; Siliciano, Robert F.

2000-01-01

Latently infected resting CD4+ T cells provide a long-term reservoir for human immunodeficiency virus type 1 (HIV-1) and are likely to represent the major barrier to virus eradication in patients on combination antiretroviral therapy. The mechanisms by which viruses enter the latent reservoir and the nature of the chemokine receptors involved have not been determined. To evaluate the phenotype of the virus in this compartment with respect to chemokine receptor utilization, full-length HIV-1 env genes were cloned from latently infected cells and assayed functionally. We demonstrate that the majority of the viruses in the latent reservoir utilize CCR5 during entry, although utilization of several other receptors, including CXCR4, was observed. No alternative coreceptors were shown to be involved in a systematic fashion. Although R5 viruses are present in the latent reservoir, CCR5 was not expressed at high levels on resting CD4+ T cells. To understand the mechanism by which R5 viruses enter latent reservoir, the ability of an R5 virus, HIV-1 Ba-L, to infect highly purified resting CD4+ T lymphocytes from uninfected donors was evaluated. Entry of Ba-L could be observed when virus was applied at a multiplicity approaching 1. However, infection was limited to a subset of cells expressing low levels of CCR5 and markers of immunologic memory. Naive cells could not be infected by an R5 virus even when challenged with a large inoculum. Direct cell fractionation studies showed that latent virus is present predominantly in resting memory cells but also at lower levels in resting naive cells. Taken together, these findings provide support for the hypothesis that the direct infection of naive T cells is not the major mechanism by which the latent infection of resting T cells is established. PMID:10933689

Spread of Staphylococcus aureus between medical staff and high-frequency contact surfaces in a large metropolitan hospital

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Li-sha Shi

2015-12-01

Conclusion: Cross-contamination of S. aureus or MRSA on medical workers' hands and contact surfaces was demonstrated within and between departments of a large metropolitan hospital. Improvements are needed in medical staff hygiene habits and in the cleaning of high-frequency contact surfaces to help prevent and control nosocomial infections.

Novel Threadlike Structures May Be Present on the Large Animal Organ Surface: Evidence in Swine Model

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Kyoung-Hee Bae

2013-01-01

Full Text Available Background. The types of embryonic development probably provoke different paths of novel threadlike structure (NTS development. The authors hypothesized that NTS may be easily observed on the surface of swine intestines by using trypan blue staining method and visualization under an optical microscope. Methods. General anesthesia was administered to 2 Yorkshire pigs. The abdominal walls of the pigs were carefully dissected along the medial alba. NTSs were identified on organ surfaces under a stereoscopic microscope after trypan blue staining. Isolated NTS specimens obtained from the large intestine were subjected to 4′,6-diamidino-2-phenylindole (DAPI staining and observed using the polarized light microscopy to confirm whether the obtained structure fits the definition of NTS. Results. We found elastic, semitransparent threadlike structures (forming a network structure that had a milky-white color in situ and in vivo in swine large intestines. The samples showed distinct extinction of polarized light at every 90 degrees, and nucleus was shown to be rod shaped by DAPI staining, indicating that they meet the criteria of NTS. Conclusion. We used a swine model to demonstrate that NTS may be present on large animal organ surfaces. Our results may permit similar studies by using human specimens.

Viruses of insects reared for food and feed

DEFF Research Database (Denmark)

Maciel Vergara, Gabriela; Ros, Vera I.D.

2017-01-01

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even...... with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks...... for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays...

Coinfection of Hepatic Cell Lines with Human Immunodeficiency Virus and Hepatitis B Virus Leads to an Increase in Intracellular Hepatitis B Surface Antigen▿

Science.gov (United States)

Iser, David M.; Warner, Nadia; Revill, Peter A.; Solomon, Ajantha; Wightman, Fiona; Saleh, Suha; Crane, Megan; Cameron, Paul U.; Bowden, Scott; Nguyen, Tin; Pereira, Cândida F.; Desmond, Paul V.; Locarnini, Stephen A.; Lewin, Sharon R.

2010-01-01

Liver-related mortality is increased in the setting of HIV-hepatitis B virus (HBV) coinfection. However, interactions between HIV and HBV to explain this observation have not been described. We hypothesized that HIV infection of hepatocytes directly affects the life cycle of HBV. We infected human hepatic cell lines expressing HBV (Hep3B and AD38 cells) or not expressing HBV (Huh7, HepG2, and AD43 cells) with laboratory strains of HIV (NL4-3 and AD8), as well as a vesicular stomatitis virus (VSV)-pseudotyped HIV expressing enhanced green fluorescent protein (EGFP). Following HIV infection with NL4-3 or AD8 in hepatic cell lines, we observed a significant increase in HIV reverse transcriptase activity which was infectious. Despite no detection of surface CD4, CCR5, and CXCR4 by flow cytometry, AD8 infection of AD38 cells was inhibited by maraviroc and NL4-3 was inhibited by AMD3100, demonstrating that HIV enters AD38 hepatic cell lines via CCR5 or CXCR4. High-level infection of AD38 cells (50%) was achieved using VSV-pseudotyped HIV. Coinfection of the AD38 cell line with HIV did not alter the HBV DNA amount or species as determined by Southern blotting or nucleic acid signal amplification. However, coinfection with HIV was associated with a significant increase in intracellular HBsAg when measured by Western blotting, quantitative HBsAg, and fluorescence microscopy. We conclude that HIV infection of HBV-infected hepatic cell lines significantly increased intracellular HBsAg but not HBV DNA synthesis and that increased intrahepatic HBsAg secondary to direct infection by HIV may contribute to accelerated liver disease in HIV-HBV-coinfected individuals. PMID:20357083

Coinfection of hepatic cell lines with human immunodeficiency virus and hepatitis B virus leads to an increase in intracellular hepatitis B surface antigen.

Science.gov (United States)

Iser, David M; Warner, Nadia; Revill, Peter A; Solomon, Ajantha; Wightman, Fiona; Saleh, Suha; Crane, Megan; Cameron, Paul U; Bowden, Scott; Nguyen, Tin; Pereira, Cândida F; Desmond, Paul V; Locarnini, Stephen A; Lewin, Sharon R

2010-06-01

Liver-related mortality is increased in the setting of HIV-hepatitis B virus (HBV) coinfection. However, interactions between HIV and HBV to explain this observation have not been described. We hypothesized that HIV infection of hepatocytes directly affects the life cycle of HBV. We infected human hepatic cell lines expressing HBV (Hep3B and AD38 cells) or not expressing HBV (Huh7, HepG2, and AD43 cells) with laboratory strains of HIV (NL4-3 and AD8), as well as a vesicular stomatitis virus (VSV)-pseudotyped HIV expressing enhanced green fluorescent protein (EGFP). Following HIV infection with NL4-3 or AD8 in hepatic cell lines, we observed a significant increase in HIV reverse transcriptase activity which was infectious. Despite no detection of surface CD4, CCR5, and CXCR4 by flow cytometry, AD8 infection of AD38 cells was inhibited by maraviroc and NL4-3 was inhibited by AMD3100, demonstrating that HIV enters AD38 hepatic cell lines via CCR5 or CXCR4. High-level infection of AD38 cells (50%) was achieved using VSV-pseudotyped HIV. Coinfection of the AD38 cell line with HIV did not alter the HBV DNA amount or species as determined by Southern blotting or nucleic acid signal amplification. However, coinfection with HIV was associated with a significant increase in intracellular HBsAg when measured by Western blotting, quantitative HBsAg, and fluorescence microscopy. We conclude that HIV infection of HBV-infected hepatic cell lines significantly increased intracellular HBsAg but not HBV DNA synthesis and that increased intrahepatic HBsAg secondary to direct infection by HIV may contribute to accelerated liver disease in HIV-HBV-coinfected individuals.

Inhibition of herpes simplex virus infection by lactoferrin is dependent on interference with the virus binding to glycosaminoglycans

International Nuclear Information System (INIS)

Marchetti, Magda; Trybala, Edward; Superti, Fabiana; Johansson, Maria; Bergstroem, Tomas

2004-01-01

Previous reports have indicated that lactoferrin inhibits herpes simplex virus (HSV) infection during the very early phases of the viral replicative cycle. In the present work we investigated the mechanism of the antiviral activity of lactoferrin in mutant glycosaminoglycan (GAG)-deficient cells. Bovine lactoferrin (BLf) was a strong inhibitor of HSV-1 infection in cells expressing either heparan sulfate (HS) or chondroitin sulfate (CS) or both, but was ineffective or less efficient in GAG-deficient cells or in cells treated with GAG-degrading enzymes. In contrast to wild-type HSV-1, virus mutants devoid of glycoprotein C (gC) were significantly less inhibited by lactoferrin in GAG-expressing cells, indicating that lactoferrin interfered with the binding of viral gC to cell surface HS and/or CS. Finally, we demonstrated that lactoferrin bound directly to both HS and CS isolated from surfaces of the studied cells, as well as to commercial preparations of GAG chains. The results support the hypothesis that the inhibition of HSV-1 infectivity by lactoferrin is dependent on its interaction with cell surface GAG chains of HS and CS

Baculovirus display of fusion protein of Peste des petits ruminants virus and hemagglutination protein of Rinderpest virus and immunogenicity of the displayed proteins in mouse model

International Nuclear Information System (INIS)

Masmudur Rahman, Md.; Shaila, M.S.; Gopinathan, Karumathil P.

2003-01-01

Recombinant Bombyx mori nucleopolyhedroviruses (BmNPV) displaying the immunodominant ectodomains of fusion glycoprotein (F) of Peste des petitis ruminants virus (PPRV) and the hemagglutinin protein (H) of Rinderpest virus (RPV), on the budded virions as well as the surface of the infected host cells have been constructed. The F and H protein sequences were inserted in-frame within the amino-terminal region of BmNPV envelope glycoprotein GP64 expressing under the strong viral polyhedrin (polh) promoter. We improved the recombinant virus selection in BmNPV by incorporating the green fluorescent protein gene (gfp) as selection marker under a separate promoter within the transfer cassette harboring the desired genes. Following infection of the insect larvae or the host-derived BmN cells with these recombinant BmNPVs, the expressed GP64 fusion proteins were displayed on the host cell surface and the budded virions. The antigenic epitopes of the recombinant proteins were properly displayed and the recombinant virus particles induced immune response in mice against PPRV or RPV

Assessment of large aperture scintillometry for large-area surface ...

Indian Academy of Sciences (India)

29

1995), flat pastoral surfaces. (McAneny ... heat flux using net radiometer and soil heat flux plate, respectively and synchronized with ..... order to facilitates development of satellite based application for ET and drought monitoring, the .... daytime sensible heat flux and momentum fluxes;Boundary- Layer Meteorol.,68 357-373.

ICTV virus taxonomy profile: Pneumoviridae

NARCIS (Netherlands)

B.K. Rima (Bert); Collins, P. (Peter); Easton, A. (Andrew); R.A.M. Fouchier (Ron); Kurath, G. (Gael); Lamb, R.A. (Robert A.); Lee, B. (Benhur); A. Maisner (Andrea); P.A. Rota (Paul); Wang, L. (Linfa); Lefkowitz, E.J. (Elliot J.); Davison, A.J. (Andrew J.); Simmonds, P. (Peter); Sabanadzovic, S. (Sead); Smith, D.B. (Donald B.); Orton, R.J. (Richard J.); Siddell, S.G. (Stuart G.)

2017-01-01

textabstractThe family Pneumoviridae comprises large enveloped negative-sense RNA viruses. This taxon was formerly a subfamily within the Paramyxoviridae, but was reclassified in 2016 as a family with two genera, Orthopneumovirus and Metapneumovirus. Pneumoviruses infect a range of mammalian

Structural and Nonstructural Viral Proteins Are Targets of T-Helper Immune Response against Human Respiratory Syncytial Virus.

Science.gov (United States)

Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Mir, Carmen; Gebe, John A; Admon, Arie; López, Daniel

2016-06-01

Proper antiviral humoral and cellular immune responses require previous recognition of viral antigenic peptides that are bound to HLA class II molecules, which are exposed on the surface of antigen-presenting cells. The helper immune response is critical for the control and the clearance of human respiratory syncytial virus (HRSV) infection, a virus with severe health risk in infected pediatric, immunocompromised, and elderly populations. In this study, using a mass spectrometry analysis of complex HLA class II-bound peptide pools that were isolated from large amounts of HRSV-infected cells, 19 naturally processed HLA-DR ligands, most of them included in a complex nested set of peptides, were identified. Both the immunoprevalence and the immunodominance of the HLA class II response to HRSV were focused on one nonstructural (NS1) and two structural (matrix and mainly fusion) proteins of the infective virus. These findings have clear implications for analysis of the helper immune response as well as for antiviral vaccine design. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Zika Virus: Critical Information for Emergency Providers.

Science.gov (United States)

Shastry, Siri; Koenig, Kristi L; Hirshon, Jon Mark

2016-08-01

Zika virus is an arbovirus of the Flaviviridae family. It is primarily a minimally symptomatic mosquito-borne infection. However, with Zika's 2015 to 2016 introduction into the Western Hemisphere and its dramatic and rapid spread, it has become a public health concern, in large part due to congenital abnormalities associated with infection in pregnant women. In early 2016, the World Health Organization declared the microcephaly and other neurologic conditions associated with Zika virus infection a public health emergency of international concern. This article discusses the current epidemiologic and clinical understanding of Zika virus, focusing on critical information needed by emergency providers. Copyright © 2016 Elsevier Inc. All rights reserved.

Host-Primed Ebola Virus GP Exposes a Hydrophobic NPC1 Receptor-Binding Pocket, Revealing a Target for Broadly Neutralizing Antibodies

Directory of Open Access Journals (Sweden)

Zachary A. Bornholdt

2016-02-01

Full Text Available The filovirus surface glycoprotein (GP mediates viral entry into host cells. Following viral internalization into endosomes, GP is cleaved by host cysteine proteases to expose a receptor-binding site (RBS that is otherwise hidden from immune surveillance. Here, we present the crystal structure of proteolytically cleaved Ebola virus GP to a resolution of 3.3 Å. We use this structure in conjunction with functional analysis of a large panel of pseudotyped viruses bearing mutant GP proteins to map the Ebola virus GP endosomal RBS at molecular resolution. Our studies indicate that binding of GP to its endosomal receptor Niemann-Pick C1 occurs in two distinct stages: the initial electrostatic interactions are followed by specific interactions with a hydrophobic trough that is exposed on the endosomally cleaved GP1 subunit. Finally, we demonstrate that monoclonal antibodies targeting the filovirus RBS neutralize all known filovirus GPs, making this conserved pocket a promising target for the development of panfilovirus therapeutics.

Mutants of alfalfa mosaic virus

International Nuclear Information System (INIS)

Roosien, J.

1983-01-01

In this thesis the isolation and characterization of a number of mutants of alfalfa mosaic virus, a plant virus with a coat protein dependent genome, is described. Thermo-sensitive (ts) mutants were selected since, at least theoretically, ts mutations can be present in all virus coded functions. It was found that a high percentage of spontaneous mutants, isolated because of their aberrant symptoms, were ts. The majority of these isolates could grow at the non-permissive temperature in the presence of a single wild type (wt) component. To increase the mutation rate virus preparations were treated with several mutagens. After nitrous acid treatment or irradiation with ultraviolet light, an increase in the level of mutations was observed. UV irradiation was preferred since it did not require large amounts of purified viral components. During the preliminary characterization of potential ts mutants the author also obtained one structural and several symptom mutants which were analysed further (chapter 7, 8 and 9). The properties of the ts mutants are described in chapter 3-7. (Auth.)

Virus removal efficiency of Cambodian ceramic pot water purifiers.

Science.gov (United States)

Salsali, Hamidreza; McBean, Edward; Brunsting, Joseph