Sample records for aislamiento del virus

  1. Caracterización molecular de aislamientos mexicanos del virus de la anemia infecciosa del pollo, a través del polimorfi smo en la longitud de fragmentos de restricción Molecular characterization of Mexican isolates of chicken infectious anemia virus through restriction fragment length polymorphism

    Microsoft Academic Search

    Néstor Ledesma Martínez; Tamas Fehervari; Rogelio Alonso

    Chicken infectious anemia is the main immunosuppressive disease of poultry. It is caused by a Gyrovirus. Thirty positive samples for chicken infectious anemia virus (CIAV) were identifi ed by PCR amplifi cation of a fragment of 675 bp of the amino-terminal end of the VP1 gene protein. Amplifi ed fragments were characterized by restriction fragment length polymorphism, digesting with HaeIII,

  2. Vacunas contra el virus del papiloma humano

    Microsoft Academic Search

    Aureli Torné; Alfonso Alba; Xavier Castellsagué; Javier Cortés

    2006-01-01

    Persistent infection by human papilloma virus (HPV) is considered to be the main cause of cervical cancer and other ano-genital cancers. Of more than 30 genotypes able to infect the anogenital tract, it is estimated that, worldwide, HPV 16 and 18 cause 70% of cervical cancers and that HPV 6 and 11 cause more than 90% of genital warts. In

  3. Datura GENUS WEEDS AS AN EPIDEMIOLOGICAL FACTOR OF Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), AND Potato virus Y (PVY) ON SOLANACEUS CROPS Malezas del género Datura como factor epidemiológico del Virus del mosaico de la alfalfa (AMV), Virus del mosaico del pepino (CMV) y Virus Y de la papa (PVY) en Solanáceas cultivadas

    Microsoft Academic Search

    Juan Ormeño; Paulina Sepúlveda; Ricardo Rojas; Jaime E. Araya

    A B S T R A C T Plant samples of jimsonweed (Datura stramonium L.) and thornapple (D. ferox L.) were collected to determine the presence of Cucumber mosaic virus (CMV), Alfalfa mosaic virus (AMV), and Potato virus Y (PVY) in Santiago, Chile (33º34' S lat, 70º38' W long, altitude 625 m.o.s.l.), using double stranded RNA (dsRNA) analysis and ELISA.

  4. DETECCIÓN CUANTITATIVA DEL VIRUS PSOROSIS DE CÍTRICOS MEDIANTE RT-PCR TIEMPO REAL QUANTITATIVE DIAGNOSIS OF CITRUS PSOROSIS VIRUS BY REAL TIME RT-PCR

    Microsoft Academic Search

    Gabriela Barragán-Valencia; Alberto Morales-Loredo; M. Genoveva Álvarez-Ojeda; M. Ángeles; Peña-del Río; Isela Quintero-Zapata; Manuel L. Barragán; Nuevo León

    2008-01-01

    Real time RT-PCR is useful for detecting citrus psorosis virus (CPsV) and also permits the evaluation of the viral concentration that can be used to study some aspects of the disease. In this study a protocol of real time RT-PCR was implemented for the quantitative detection of CPsV, for which a group of primers were designed along with a Taqman

  5. TGF-?-induced IL-6 prevents development of acute lung injury in influenza A virus-infected F508del CFTR-heterozygous mice.

    PubMed

    Woods, Parker S; Tazi, Mia F; Chesarino, Nicholas M; Amer, Amal O; Davis, Ian C

    2015-06-01

    As the eighth leading cause of annual mortality in the USA, influenza A viruses are a major public health concern. In 20% of patients, severe influenza progresses to acute lung injury (ALI). However, pathophysiological mechanisms underlying ALI development are poorly defined. We reported that, unlike wild-type (WT) C57BL/6 controls, influenza A virus-infected mice that are heterozygous for the F508del mutation in the cystic fibrosis transmembrane conductance regulator (HETs) did not develop ALI. This effect was associated with higher IL-6 and alveolar macrophages (AMs) at 6 days postinfection (d.p.i.) in HET bronchoalveolar lavage fluid (BALF). In the present study, we found that HET AMs were an important source of IL-6 at 6 d.p.i. Infection also induced TGF-? production by HET but not WT mice at 2 d.p.i. TGF-? neutralization at 2 d.p.i. (TGF-N) significantly reduced BALF IL-6 in HETs at 6 d.p.i. Neither TGF-N nor IL-6 neutralization at 4 d.p.i. (IL-6-N) altered postinfection weight loss or viral replication in either mouse strain. However, both treatments increased influenza A virus-induced hypoxemia, pulmonary edema, and lung dysfunction in HETs to WT levels at 6 d.p.i. TGF-N and IL-6-N did not affect BALF AM and neutrophil numbers but attenuated the CXCL-1/keratinocyte chemokine response in both strains and reduced IFN-? production in WT mice. Finally, bone marrow transfer experiments showed that HET stromal and myeloid cells are both required for protection from ALI in HETs. These findings indicate that TGF-?-dependent production of IL-6 by AMs later in infection prevents ALI development in influenza A virus-infected HET mice. PMID:25840995

  6. TGF-?-induced IL-6 prevents development of acute lung injury in influenza A virus-infected F508del CFTR-heterozygous mice

    PubMed Central

    Woods, Parker S.; Tazi, Mia F.; Chesarino, Nicholas M.; Amer, Amal O.

    2015-01-01

    As the eighth leading cause of annual mortality in the USA, influenza A viruses are a major public health concern. In 20% of patients, severe influenza progresses to acute lung injury (ALI). However, pathophysiological mechanisms underlying ALI development are poorly defined. We reported that, unlike wild-type (WT) C57BL/6 controls, influenza A virus-infected mice that are heterozygous for the F508del mutation in the cystic fibrosis transmembrane conductance regulator (HETs) did not develop ALI. This effect was associated with higher IL-6 and alveolar macrophages (AMs) at 6 days postinfection (d.p.i.) in HET bronchoalveolar lavage fluid (BALF). In the present study, we found that HET AMs were an important source of IL-6 at 6 d.p.i. Infection also induced TGF-? production by HET but not WT mice at 2 d.p.i. TGF-? neutralization at 2 d.p.i. (TGF-N) significantly reduced BALF IL-6 in HETs at 6 d.p.i. Neither TGF-N nor IL-6 neutralization at 4 d.p.i. (IL-6-N) altered postinfection weight loss or viral replication in either mouse strain. However, both treatments increased influenza A virus-induced hypoxemia, pulmonary edema, and lung dysfunction in HETs to WT levels at 6 d.p.i. TGF-N and IL-6-N did not affect BALF AM and neutrophil numbers but attenuated the CXCL-1/keratinocyte chemokine response in both strains and reduced IFN-? production in WT mice. Finally, bone marrow transfer experiments showed that HET stromal and myeloid cells are both required for protection from ALI in HETs. These findings indicate that TGF-?-dependent production of IL-6 by AMs later in infection prevents ALI development in influenza A virus-infected HET mice. PMID:25840995

  7. Determinación del potencial irritante de un candidato vacunal nasal que combina al antígeno de superficie del virus de la hepatitis B con el antígeno de la nucleocápsida

    Microsoft Academic Search

    Delia N Porras; Karelia Cosme; Lizet Aldana; Dania Bacardí; Nelson Merino; Carmen Valenzuela; Lorelys Milá; José Suárez; Rubén Amaya; Ariel Vázquez; José García; Yadira Lobaina; Mabel Alonso; Julio Aguilar; Verena Muzio

    Determination of assesment of the irritant potential of a nasal vaccine candidate, which combines Hepatitis B surface antigen and Hepatitis B core antigen. Hepatitis B virus antigen (HBsAg) is the pharmaceutical active ingredient of the Cuban Hepatitis B vaccine against this disease, which has demonstrated high rates of efficacy and safety. HBsAg has been combined with nucleocapside or Core antigen

  8. Evaluación de Anticuerpos Desarrollados Contra la Proteína Recombinante de la Cápside del Virus Tristeza de los Cítricos

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyclonal antibodies specific for the recombinant coat protein (rCP) p25 gene of (Citrus tristeza virus = CTV), were developed for isolates MX08 and MX14 from México and B227 from India. The reactivity of rCP antibodies was evaluated using healthy and CTV infected tissue. The combination of rCP ant...

  9. Virus-Like Attachment Sites and Plastic CpG Islands: Landmarks of Diversity in Plant Del Retrotransposons

    PubMed Central

    de Setta, Nathalia; Cruz, Edgar A. O.; Vieira, Andréia Prata; Medina, Rosario; Van Sluys, Marie-Anne

    2014-01-01

    Full-length Del elements from ten angiosperm genomes, 5 monocot and 5 dicot, were retrieved and putative attachment (att) sites were identified. In the 2432 Del elements, two types of U5 att sites and a single conserved type of U3 att site were identified. Retroviral att sites confer specificity to the integration process, different att sites types therefore implies lineage specificity. While some features are common to all Del elements, CpG island patterns within the LTRs were particular to lineage specific clusters. All eudicot copies grouped into one single clade while the monocots harbour a more diverse collection of elements. Furthermore, full-length Del elements and truncated copies were unevenly distributed amongst chromosomes. Elements of Del lineage are organized in plants into three clusters and each cluster is composed of elements with distinct LTR features. Our results suggest that the Del lineage efficiently amplified in the monocots and that one branch is probably a newly emerging sub-lineage. Finally, sequences in all groups are under purifying selection. These results show the LTR region is dynamic and important in the evolution of LTR-retrotransposons, we speculate that it is a trigger for retrotransposon diversification. PMID:24849372

  10. La infección por el virus del papiloma humano, un posible marcador biológico de comportamiento sexual en estudiantes universitarios

    Microsoft Academic Search

    Miguel A Sánchez-Alemán; Felipe Uribe-Salas; Carlos J Conde-González

    2002-01-01

    Objective. To estimate the prevalence of Human papillomavirus (HPV) among university students and to use it as a biological marker to assess sexual behavior. Material and Methods. A cross-sectional study was carried out between 2000 and 2001 among 194 students at Universidad Autónoma del Estado de Morelos, Mexico. A data collection instrument was applied and genital samples were taken to

  11. Asociación entre anticuerpos contra el virus del síndrome disgenésico y respiratorio porcino y anticuerpos contra otros patógenos Association between antibodies against porcine reproductive and respiratory syndrome virus and other pathogens

    Microsoft Academic Search

    Fernando Diosdado Vargas; Dolores González-Vega; Luis Pedro Moles-Cervantes; Antonio Morilla González

    In order to investigate a possible association between porcine reproductive and respiratory syndrome virus (PRRSV) and other viral and bacterial pathogenic agents found in swine, a serological model was followed. For this study, 3600, 4 to 6 month-old fi nishers were bled and tested for antibodies against various infectious agents. The specifi c antibodies against PRRSV, Aujeszky's disease virus (ADV),

  12. Foodborne viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Testing for human pathogenic viruses in foods represents a formidable task requiring the extraction, concentration, and assay of a host of viruses from a wide range of food matrices. The enteric viruses, particularly genogroup I and II (GI and GII) noroviruses and hepatitis A virus, are the princip...

  13. Computer viruses

    Microsoft Academic Search

    S. R. Subramanya; N. Lakshminarasimhan

    2001-01-01

    Computer viruses have been around since the mid 1980s. Over 40,000 different viruses have been cataloged so far and the number of viruses is increasing dramatically. The damage they cause is estimated to be several billions of U.S. dollars per year. Most often, the origin of the virus is difficult to trace. Various kinds of anti-virus software have been developed

  14. Revisión de patogénesis y estrategias moleculares contra el virus del síndrome de la mancha blanca en camarones peneidos A review of pathogenesis and molecular strategies against white spot syndrome virus of penaeid shrimp

    Microsoft Academic Search

    Martin I. Bustillo-Ruiz; César M. Escobedo-Bonilla; Rogerio R. Sotelo-Mundo

    2009-01-01

    White spot syndrome virus (WSSV) causes high mortality to farmed shrimp and serious economic losses. Its unique sequence and genome structure has placed WSSV in its own new family Nimaviridae. Recently, high performance molecular techniques have made it possible to identify and characterize several WSSV structural proteins. These include 'shotgun' sequencing and isobaric tags for relative and absolute quantification (iTRAQ).

  15. Oncolytic Viruses

    Microsoft Academic Search

    John Nemunaitis

    1999-01-01

    Viruses capable of inducing lysis of malignant cells through theirreplication process are known as ``oncolytic'' viruses. Clinicaltrials in oncology have been performed with oncolytic viruses fornearly fifty years. Both systemic and intratumoral routes ofadministration have been explored. Toxicity has generally beenlimited to injection site pain, transient fever and tumor necrosis.Responses with early crude materials were usually short induration; however, recent

  16. Virus Maturation

    PubMed Central

    Veesler, David; Johnson, John E.

    2013-01-01

    We examined virus maturation of selected non-enveloped and enveloped ssRNA viruses; retroviruses; bacteriophages and herpes virus. Processes associated with maturation in the RNA viruses range from subtle (noda and picornaviruses) to dramatic (tetraviruses and togaviruses). The elaborate assembly and maturation pathway of HIV is discussed in contrast to the less sophisticated but highly efficient processes associated with togaviruses. Bacteriophage assembly and maturation are discussed in general terms with specific examples chosen for emphasis. Finally the herpes viruses are compared with bacteriophages. The data support divergent evolution of noda, picorna and tetraviruses from a common ancestor and divergent evolution of alpha and flaviviruses from a common ancestor. Likewise, bacteriophages and herpes viruses almost certainly share a common ancestor in their evolution. Comparing all the viruses, we conclude that maturation is a convergent process that is required to solve conflicting requirements in biological dynamics and function. PMID:22404678

  17. Obesity Virus

    NSDL National Science Digital Library

    Science Update (AAAS; )

    2007-06-12

    Obesity has many causes, but there is growing evidence that common viruses may contribute to the condition in some people. Recently, Nikhil Dhurandhar and his colleagues at the Pennington Biomedical Research Center infected human stem cells with Ad-36, a common virus known to be associated with obesity in humans. They found that the cells they exposed to the virus accumulated a much higher amount of fat than uninfected cells.

  18. Phytophthora viruses.

    PubMed

    Cai, Guohong; Hillman, Bradley I

    2013-01-01

    Phytophthora sp. is a genus in the oomycetes, which are similar to filamentous fungi in morphology and habitat, but phylogenetically more closely related to brown algae and diatoms and fall in the kingdom Stramenopila. In the past few years, several viruses have been characterized in Phytophthora species, including four viruses from Phytophthora infestans, the late blight pathogen, and an endornavirus from an unnamed Phytophthora species from Douglas fir. Studies on Phytophthora viruses have revealed several interesting systems. Phytophthora infestans RNA virus 1 (PiRV-1) and PiRV-2 are likely the first members of two new virus families; studies on PiRV-3 support the establishment of a new virus genus that is not affiliated with established virus families; PiRV-4 is a member of Narnaviridae, most likely in the genus Narnavirus; and Phytophthora endornavirus 1 (PEV1) was the first nonplant endornavirus at the time of reporting. Viral capsids have not been found in any of the above-mentioned viruses. PiRV-1 demonstrated a unique genome organization that requires further examination, and PiRV-2 may have played a role in late blight resurgence in 1980s-1990s. PMID:23498912

  19. Diseases Caused by Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The symptoms, causal agents, epidemiology and management of important virus diseases in chickpea and lentil crops were reviewed in depth. The virus diseases include.Alflafa mosaic virus, Cucumber mosaiv virus, Faba bean necrotic yellows virus, Pea enation mosaic virus, Pea seed-borne mosaci virus,...

  20. Emerging Viruses

    NSDL National Science Digital Library

    Lee, Amy.

    Emerging viruses are those "whose incidence in humans has increased in the past 2 decades or threatens to increase in the near future." This week's Topic in Depth focuses on sites related to viruses, particularly those that are considered "emerging."The first site (1) is an essay by Alison Jacobson of the University of Capetown that discusses some emerging and potentially emerging viruses, along with factors that contribute to the threat. From a US government interagency working group, the second report (2) focuses on the responses to infectious disease outbreaks, including drugs, vaccines, and government response. A World Health Organization site (3) highlights recent reports of infectious disease, archived by date and by disease. This ThinkQuest site (4) gives a basic introduction to viruses and how they cause infections. An online virology tutorial (5) by Ed Rybicki of the University of Cape Town serves as a lesson on the basics of virology for a more advanced student. The next two sites focus on the specifics of selected viruses. From the Institute for Molecular Virology (6) comes a resource on Marburg and Ebola viruses, and from the National Biological Information Infrastructure (7) is a site on West Nile Virus. The last resource (8) is a scholarly journal from the Centers for Disease Control that presents some of the latest scientific research on emerging diseases.

  1. Comparative Evaluation of Vaccine Efficacy of Recombinant Marek's Disease Virus Vaccine Lacking Meq Oncogene in Commercial Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek's disease virus oncogene meq has been identified as the gene involved in tumorigenesis in chickens. We have recently developed a Meq-null virus, rMd5delMeq, in which the oncogene Meq was deleted. Vaccine efficacy experiments conducted in ADOL 15I5 x 71 chickens vaccinated with rMd5delMeq virus...

  2. HIV virus

    NSDL National Science Digital Library

    Carl Henderson (National Institutes of Health; )

    2005-12-09

    HIV is a virus that can be transmitted through fluids exchanged in sexual activity. HIV eventually causes AIDS. AIDS patients have compromised immune systems and they eventually die from diseases that healthy humans would normally fight off very easily.

  3. Calf w/ Virus 

    E-print Network

    Unknown

    2011-08-17

    ). One of the best animal models of MS is the demyelination induced by Theiler's virus. The early events that occur during Theiler's virus infection are crucial in the effective clearance of virus from the CNS. Failure to clear virus results...

  4. Ebola Virus Disease

    MedlinePLUS

    Ebola virus disease Fact sheet N°103 Updated April 2015 Key facts Ebola virus disease (EVD), formerly ... live Ebola virus in vaginal secretions. Symptoms of Ebola virus disease The incubation period, that is, the ...

  5. Computer viruses

    SciTech Connect

    Cohen, F.B.

    1986-01-01

    This thesis investigates a recently discovered vulnerability in computer systems which opens the possibility that a single individual with an average user's knowledge could cause widespread damage to information residing in computer networks. This vulnerability is due to a transitive integrity corrupting mechanism called a computer virus which causes corrupted information to spread from program to program. Experiments have shown that a virus can spread at an alarmingly rapid rate from user to user, from system to system, and from network to network, even when the best-availability security techniques are properly used. Formal definitions of self-replication, evolution, viruses, and protection mechanisms are used to prove that any system that allows sharing, general functionality, and transitivity of information flow cannot completely prevent viral attack. Computational aspects of viruses are examined, and several undecidable problems are shown. It is demonstrated that a virus may evolve so as to generate any computable sequence. Protection mechanisms are explored, and the design of computer networks that prevent both illicit modification and dissemination of information are given. Administration and protection of information networks based on partial orderings are examined, and probably correct automated administrative assistance is introduced.

  6. RISCHIO BIOLOGICO DA VIRUS EMATICI IN OPERATORI SANITARI

    Microsoft Academic Search

    M. A. Di Benedetto; F. Vitale; L. Cannova; D. Cabibi

    Introduzione Negli ultimi anni l'attenzione del mondo scientifico per il rischio infettivo occupazionale ha ricevuto un nuovo impulso in conseguenza dell'epidemia da virus dell'Immunodeficienza Acquisita (HIV). Tale interesse, infatti , centrato fino a qualche decennio fa sul rischio di tra- smissione del virus dell'epatite B, era diminuito grazie alla prevenzione di questa infezione con l'introduzione della vaccinazione. Dopo il primo

  7. Computer Viruses

    Microsoft Academic Search

    Robyn P. Weems

    1998-01-01

    This paper presents a description of the major characteristics of disk and network borne viruses for the convenience of library and archival systems administrators. It includes a brief history of the use of destructive software by computer hackers, noting some of the early and more recent forms of attack, and suggests that computer languages newly developed for use with the

  8. Computer viruses

    Microsoft Academic Search

    Frederick B. Cohen

    1986-01-01

    This thesis investigates a recently discovered vulnerability in computer systems which opens the possibility that a single individual with an average user's knowledge could cause widespread damage to information residing in computer networks. This vulnerability is due to a transitive integrity corrupting mechanism called a computer virus which causes corrupted information to spread from program to program. Experiments have shown

  9. Computer viruses

    Microsoft Academic Search

    C. E. Pelaez; John Bowles

    1991-01-01

    This paper presents an overview of the main categories of malicious programs known as Trojan horses, viruses, bacteria, worms, and logic bombs. The focus is on their general behavior and the properties seen in their implementations rather than the ultimate effects or their intended destructive behavior. Possible preventive measures are also discussed

  10. Exploring computer viruses

    Microsoft Academic Search

    R. Davis

    1988-01-01

    The author presents some thoughts on viruses and explores the anatomy of a sample computer virus. He details, using C language programs, some of the fundamental parts associated with viruses and how these viruses can be detected. It is concluded that the final decision for virus control rests with risk management. It is suggested that, at the very least, contingency

  11. METHODOLOGY Open Access Virus replicon particle based Chikungunya virus

    E-print Network

    Boyer, Edmond

    METHODOLOGY Open Access Virus replicon particle based Chikungunya virus neutralization assay using Mareike Kümmerer1* Abstract Background: Chikungunya virus (CHIKV) has been responsible for large epidemic antibodies without the need of using infectious CHIKV. Keywords: Chikungunya virus, Virus replicon particles

  12. Plant Virus Metagenomics: Advances in Virus Discovery.

    PubMed

    Roossinck, Marilyn J; Martin, Darren P; Roumagnac, Philippe

    2015-06-01

    In recent years plant viruses have been detected from many environments, including domestic and wild plants and interfaces between these systems-aquatic sources, feces of various animals, and insects. A variety of methods have been employed to study plant virus biodiversity, including enrichment for virus-like particles or virus-specific RNA or DNA, or the extraction of total nucleic acids, followed by next-generation deep sequencing and bioinformatic analyses. All of the methods have some shortcomings, but taken together these studies reveal our surprising lack of knowledge about plant viruses and point to the need for more comprehensive studies. In addition, many new viruses have been discovered, with most virus infections in wild plants appearing asymptomatic, suggesting that virus disease may be a byproduct of domestication. For plant pathologists these studies are providing useful tools to detect viruses, and perhaps to predict future problems that could threaten cultivated plants. PMID:26056847

  13. Dengue Virus

    Microsoft Academic Search

    Greg Smith

    \\u000a Dengue Virus (DENV) diagnosis can be performed by isolation of DENV from blood or autopsy samples; demonstration of a four-fold\\u000a or greater rise in reciprocal IgG or IgM antibody titres to one or more DENV in paired serum samples (acute and convascent);\\u000a use of the newer rapid diagnostic test kit (also differentiates between primary and secondary dengue infections – these

  14. Virus Movement Maintains Local Virus Population Diversity

    SciTech Connect

    J. Snyder; B. Wiedenheft; M. Lavin; F. Roberto; J. Spuhler; A. Ortmann; T. Douglas; M. Young

    2007-11-01

    Viruses are the largest reservoir of genetic material on the planet, yet little is known about the population dynamics of any virus within its natural environment. Over a 2-year period, we monitored the diversity of two archaeal viruses found in hot springs within Yellowstone National Park (YNP). Both temporal phylogeny and neutral biodiversity models reveal that virus diversity in these local environments is not being maintained by mutation but rather by high rates of immigration from a globally distributed metacommunity. These results indicate that geographically isolated hot springs are readily able to exchange viruses. The importance of virus movement is supported by the detection of virus particles in air samples collected over YNP hot springs and by their detection in metacommunity sequencing projects conducted in the Sargasso Sea. Rapid rates of virus movement are not expected to be unique to these archaeal viruses but rather a common feature among virus metacommunities. The finding that virus immigration rather than mutation can dominate community structure has significant implications for understanding virus circulation and the role that viruses play in ecology and evolution by providing a reservoir of mobile genetic material.

  15. Viruses and Virus Diseases of Rubus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rubus species are propagated vegetatively and are subject to infection by viruses during development, propagation and fruit production stages. Reports of initial detection and symptoms of more than 30 viruses, virus-like diseases and phytoplasmas affecting Rubus spp. have been reviewed more than 20 ...

  16. Diferencias en las características sociales, conductas de riesgo y prevalencia de infección por el virus de la inmunodeficiencia humana e infecciones de transmisión sexual entre trabajadoras del sexo españolas e inmigrantes en Cataluña

    Microsoft Academic Search

    Cinta Folch; Cristina Sanclemente; Anna Esteve; Elisa Martró; Sonia Molinos; Jordi Casabona

    2009-01-01

    Background and objectiveTo describe and compare the social characteristics, human immunodeficiency virus (HIV), Chlamydia trachomatis and Neisseria gonorrhoae prevalences, and risk behaviours among immigrant female sex workers (FSW) according to their geographical area of origin.

  17. The nature of measles virus

    Microsoft Academic Search

    J. G. Atherton; K. S. K. Lain

    1965-01-01

    Summary Observations of the effect of halogen derivatives of deoxyuridine, known to affect the synthesis of deoxyviruses (DNA-containing viruses) show that measles virus replication is unaffected. This suggests that measles virus is a ribovirus (RNA-containing virus).

  18. Molecular evolution of primate immunodeficiency viruses and hepatitis delta virus

    Microsoft Academic Search

    Julia Samuilovna Krushkal

    1996-01-01

    Primate immunodeficiency viruses, or lentiviruses (HIV-1, HIV-2, and SIV), and hepatitis delta virus (HDV) are RNA viruses characterized by rapid evolution. Infection by primate immunodeficiency viruses usually results in the development of acquired immunodeficiency syndrome (AIDS) in humans and AIDS-like illnesses in Asian macaques. Similarly, hepatitis delta virus infection causes hepatitis and liver cancer in humans. These viruses are heterogeneous

  19. Viruses and cancer

    SciTech Connect

    Rigby, P.W.J.; Wilkie, N.M.

    1985-01-01

    This book contains 14 selections. Some of the titles are: Immortalising gene(s) encoded by Epstein-Barr Virus; Adenovirus genes involved in transformation. What determines the oncogenic phenotype.; Oncogenesis by mouse mammary tumour virus; and Transforming ras genes.

  20. BOVINE VIRAL DIARRHEA VIRUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine viral diarrhea virus (BVDV) is an umbrella term for two species of viruses, BVDV1 and BVDV2, within the Pestivirus genus of the Flavivirus family. BVDV viruses are further subclassified as cytopathic and noncytopathic based on their activity in cultured epithelial cells. Noncytopathic BVDV p...

  1. Ecology of prokaryotic viruses

    Microsoft Academic Search

    Markus G Weinbauer

    2004-01-01

    The finding that total viral abundance is higher than total prokaryotic abundance and that a significant fraction of the prokaryotic community is infected with phages in aquatic systems has stimulated research on the ecology of prokaryotic viruses and their role in ecosystems. This review treats the ecology of prokaryotic viruses (`phages') in marine, freshwater and soil systems from a `virus

  2. MAIZE FINE STREAK VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The report outlines the salient features of maize fine streak virus (MFSV) including a general description of the causal virus species, virion properties, genome description, the relationship of the virus to other taxa, biological properties of the disease and agronomic aspects of the disease. Maize...

  3. Chikungunya Virus, Cameroon, 2006

    Microsoft Academic Search

    Christophe N. Peyrefi; Dominique Rousset; Boris A. M. Pastorino; Regis Pouillot; Maël Bessaud; Fabienne Tock; Helene Mansaray; Olivier L. Merle; Aurelie M. Pascual; Christophe Paupy; Aurelia Vessiere; Patrice Imbert; Jean-Paul Durand; Hugues J. Tolou; Marc Grandadam

    2007-01-01

    We report the isolation of chikungunya virus from a pa- tient during an outbreak of a denguelike syndrome in Cam- eroon in 2006. The virus was phylogenetically grouped in the Democratic Republic of the Congo cluster, indicating a continuous circulation of a genetically similar chikungunya virus population during 6 years in Central Africa.

  4. VIRUSES IN WASTEWATER

    EPA Science Inventory

    Viruses of animals, plants, and bacteria abound in sewage and receiving waters. Their ecological impact has, for the most part, gone unheeded except as it relates to viruses from human sources. Viruses present at levels infective to man have been recovered from waters used for re...

  5. Encephalitis Virus, Kyrgyzstan

    E-print Network

    Baker, Robert J.

    Tick-Borne Encephalitis Virus, Kyrgyzstan Benjamin J. Briggs, Barry Atkinson, Donna M. Czechowski-borne encephalitis virus (TBEV) is an emerging pathogen in Europe and Asia. We investigated TBEV in Kyrgyzstan reported. Tick-borne encephalitis virus (TBEV) is a flavivirus in the family Flaviviridae. The TBEV

  6. Prevalence and Transmission of Honeybee Viruses

    Microsoft Academic Search

    Y. P. Chen; J. S. Pettis; A. Collins; M. F. Feldlaufer

    2006-01-01

    Transmission mechanisms of six honeybee viruses, including acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood bee virus (SBV), in honey bee colonies were investigated by reverse transcription-PCR (RT-PCR) methods. The virus status of individual queens was evaluated by examining the presence of viruses

  7. Detección de Virus por Serología y Plantas Indicadoras en el Tubérculo-Semilla y Plantas de Cultivo de Meristemos en Papa (Solanum tuberosum L.) var. Alfa

    Microsoft Academic Search

    Víctor Valenzuela-Herrera; Rafael Bujanos-Muñiz

    2003-01-01

    Viral detection in Alpha potato tubers from Tenango del Valle, State of Mexico, was performed by ELISA and indicator plants. Potato tubers were planted in the greenhouse, and the plants were kept in insect-proof cages; sap was extracted from top leaflets to mechanically inoculate indicator plants for Potato leafroll virus (PLRV), Potato virus A (PVA), Potato virus X (PVX), Potato

  8. Viruses of asparagus.

    PubMed

    Tomassoli, Laura; Tiberini, Antonio; Vetten, Heinrich-Josef

    2012-01-01

    The current knowledge on viruses infecting asparagus (Asparagus officinalis) is reviewed. Over half a century, nine virus species belonging to the genera Ilarvirus, Cucumovirus, Nepovirus, Tobamovirus, Potexvirus, and Potyvirus have been found in this crop. The potyvirus Asparagus virus 1 (AV1) and the ilarvirus Asparagus virus 2 (AV2) are widespread and negatively affect the economic life of asparagus crops reducing yield and increasing the susceptibility to biotic and abiotic stress. The main properties and epidemiology of AV1 and AV2 as well as diagnostic techniques for their detection and identification are described. Minor viruses and control are briefly outlined. PMID:22682173

  9. Serodiagnosis for tumor viruses.

    PubMed

    Morrison, Brian J; Labo, Nazzarena; Miley, Wendell J; Whitby, Denise

    2015-04-01

    The known human tumor viruses include the DNA viruses Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV), Merkel cell polyomavirus (MCPyV), human papillomavirus (HPV), and hepatitis B virus (BV). RNA tumor viruses include human T-cell lymphotrophic virus type 1 (HTLV-1) and hepatitis C virus (HCV). The serological identification of antigens/antibodies in serum is a rapidly progressing field with utility for both scientists and clinicians. Serology is useful for conducting seroepidemiology studies and to inform on the pathogenesis and host immune response to a particular viral agent. Clinically, serology is useful for diagnosing current or past infection and for aiding in clinical management decisions. Serology is useful for screening blood donations for infectious agents and for monitoring the outcome of vaccination against these viruses. Serodiagnosis of human tumor viruses has improved in recent years with increased specificity and sensitivity of the assays, as well as reductions in cost and the ability to assess multiple antibody/antigens in single assays. Serodiagnosis of tumor viruses plays an important role in our understanding of the prevalence and transmission of these viruses and ultimately in the ability to develop treatments/preventions for these globally important diseases. PMID:25843726

  10. Lipids of Archaeal Viruses

    PubMed Central

    Roine, Elina; Bamford, Dennis H.

    2012-01-01

    Archaeal viruses represent one of the least known territory of the viral universe and even less is known about their lipids. Based on the current knowledge, however, it seems that, as in other viruses, archaeal viral lipids are mostly incorporated into membranes that reside either as outer envelopes or membranes inside an icosahedral capsid. Mechanisms for the membrane acquisition seem to be similar to those of viruses infecting other host organisms. There are indications that also some proteins of archaeal viruses are lipid modified. Further studies on the characterization of lipids in archaeal viruses as well as on their role in virion assembly and infectivity require not only highly purified viral material but also, for example, constant evaluation of the adaptability of emerging technologies for their analysis. Biological membranes contain proteins and membranes of archaeal viruses are not an exception. Archaeal viruses as relatively simple systems can be used as excellent tools for studying the lipid protein interactions in archaeal membranes. PMID:23049284

  11. VIRUS AND VIRUS-LIKE DISEASES OF CITRUS IN EPIRUS

    Microsoft Academic Search

    L. Barbarossa; G. Loconsole; C. Vovlas

    2007-01-01

    SUMMARY In 2005 a survey was conducted in the main citrus- growing areas of Epirus. Commercial groves and nurs- eries were inspected for symptoms of virus and virus- like diseases and a total of 123 samples were collected. Molecular hybridisation was used to test for Citrus tris- teza virus (CTV), Citrus psorosis virus (CPsV), Citrus in- fectious variegation virus (CVV),

  12. Other Viruses and Viruslike Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diseases reported under 'Virus and Virus-like Agents' in the first volume of this compendium, with the exception of Cherry rasp leaf virus and Rubus chinese seed-borne virus, should be considered oddities since there are no known type isolates available for these reported viruses. Without a po...

  13. RNA Viruses Infecting Pest Insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RNA viruses are viruses whose genetic material is ribonucleic acid (RNA). RNA viruses may be double or single-stranded based on the type of RNA they contain. Single-stranded RNA viruses can be further grouped into negative sense or positive-sense viruses according to the polarity of their RNA. Fur...

  14. Postmortem Stability of Ebola Virus

    PubMed Central

    Prescott, Joseph; Bushmaker, Trenton; Fischer, Robert; Miazgowicz, Kerri; Judson, Seth

    2015-01-01

    The ongoing Ebola virus outbreak in West Africa has highlighted questions regarding stability of the virus and detection of RNA from corpses. We used Ebola virus–infected macaques to model humans who died of Ebola virus disease. Viable virus was isolated <7 days posteuthanasia; viral RNA was detectable for 10 weeks. PMID:25897646

  15. Viruses in Antarctic lakes

    NASA Technical Reports Server (NTRS)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Suttle, C. A.; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Water samples collected from four perennially ice-covered Antarctic lakes during the austral summer of 1996-1997 contained high densities of extracellular viruses. Many of these viruses were found to be morphologically similar to double-stranded DNA viruses that are known to infect algae and protozoa. These constitute the first observations of viruses in perennially ice-covered polar lakes. The abundance of planktonic viruses and data suggesting substantial production potential (relative to bacteria] secondary and photosynthetic primary production) indicate that viral lysis may be a major factor in the regulation of microbial populations in these extreme environments. Furthermore, we suggest that Antarctic lakes may be a reservoir of previously undescribed viruses that possess novel biological and biochemical characteristics.

  16. Cell transformation by viruses

    Microsoft Academic Search

    Joseph L. Melnick; Janet S. Butel; Satvir S. Tevethia; Nilambar Biswal; Matilda Benyesh-Melnick

    1971-01-01

    Summary  This paper describes some current work pertaining to transformation of cells by oncogenic viruses.\\u000a \\u000a Part I includes: (1) the effect of a deoxyribonucleic acid (DNA) tumor virus (SV40) on the antigenic characteristics of transformed\\u000a cells; (2) in vitro and in vivo methods of detecting virus-specific surface antigens; (3) the role that the host cell may\\u000a play in the expression of

  17. Virus entry paradigms

    Microsoft Academic Search

    Manjula Kalia; Shahid Jameel

    Viruses, despite being relatively simple in structure and composition, have evolved to exploit complex cellular processes\\u000a for their replication in the host cell. After binding to their specific receptor on the cell surface, viruses (or viral genomes)\\u000a have to enter cells to initiate a productive infection. Though the entry processes of many enveloped viruses is well understood,\\u000a that of most

  18. Wheat Streak Mosaic Virus 

    E-print Network

    Morgan, Gaylon

    2005-01-26

    . Infected wheat plants normally are stunted, with leaves mottled and streaked in green-yellow, parallel and discontinuous patterns (Fig. 1). This disease?s negative impact varies from year to year depending on its severity and distribution...; in the Southern Great Plains states, crop losses due to WSMV exceed $30 million in some years but are in- significant in others. High Plains Virus High Plains Virus (HPV), occasionally called High Plains Disease, is a relatively new virus identified...

  19. Water system virus detection

    NASA Technical Reports Server (NTRS)

    Fraser, A. S.; Wells, A. F.; Tenoso, H. J.

    1975-01-01

    A monitoring system developed to test the capability of a water recovery system to reject the passage of viruses into the recovered water is described. A nonpathogenic marker virus, bacteriophage F2, is fed into the process stream before the recovery unit and the reclaimed water is assayed for its presence. Detection of the marker virus consists of two major components, concentration and isolation of the marker virus, and detection of the marker virus. The concentration system involves adsorption of virus to cellulose acetate filters in the presence of trivalent cations and low pH with subsequent desorption of the virus using volumes of high pH buffer. The detection of the virus is performed by a passive immune agglutination test utilizing specially prepared polystyrene particles. An engineering preliminary design was performed as a parallel effort to the laboratory development of the marker virus test system. Engineering schematics and drawings of a fully functional laboratory prototype capable of zero-G operation are presented. The instrument consists of reagent pump/metering system, reagent storage containers, a filter concentrator, an incubation/detector system, and an electronic readout and control system.

  20. CDC: West Nile Virus

    NSDL National Science Digital Library

    This Web site contains the most recent West Nile virus data from the Centers for Disease Control. The main features include a 2003 Human Case Count and updated maps representing the spread of the virus. A downloadable document outlines the CDC's West Nile virus surveillance and control program, which involves weekly data collection for wild birds, sentinel chicken flocks, human cases, veterinary cases, and mosquito surveillance. The site also provides links to general information about the virus, from the ecology and virology of West Nile to epidemiological and laboratory issues.

  1. Newcastle disease virus (velogens)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Newcastle disease virus (NDV) is also known as avian paramyxovirus serotype-1 (APMV-1). While all NDV are referred to as APMV-1 and are of one serotype, only infections with virulent NDV (vNDV) cause Newcastle disease (ND). Newcastle disease virus strains are defined as virulent if they 1) have th...

  2. Lettuce Necrotic Yellows Virus

    Microsoft Academic Search

    L. L. Stubbs; R. G. GROGAN

    1963-01-01

    A DESTRUCTIVE virus disease of lettuce, causing extensive crop losses sometimes as high as 100 per cent, was recognized in Victoria in 1954 as being distinct from the lettuce mosaic disease. Until 1959, however, all attempts to transmit the virus to lettuce with aphids which commonly infest lettuce, with thrips, leaf-hoppers and sap inoculation methods were unsuccessful. In that year

  3. Papaya ringspot virus (Potyviridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Papaya ringspot virus, a member of the family Potyviridae, is single stranded RNA plant virus with a monocistronic genome of about 10,326 nucleotides that is expressed via a large polyprotein subsequently cleaved into functional proteins. It causes severe damage on cucurbit crops such as squash and...

  4. Papaya Ringspot Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The term papaya ringspot virus (PRSV) was coined by Jensen in 1949, to describe a papaya disease in Hawaii. Later work showed that diseases such as papaya mosaic and watermelon mosaic virus-1 were caused by PRSV. The primary host range of PRSV is papaya and cucurbits, with Chenopium amaranticolor ...

  5. Human Papilloma Virus Infections

    PubMed Central

    Wright, V. Cecil

    1989-01-01

    Genital warts are believed to be caused by human papilloma viruses and to be sexually transmitted. The viruses are classified by DNA types, which appear to cause different types of disease. The choice of treatment, and usually its success rate, vary according to the type of disease and its location. PMID:21248973

  6. DETECTING VIRUSES IN WATER

    EPA Science Inventory

    This article, which reviews the subject of detecting viruses in water, encompasses two topics. he first topic consists of methods used for concentrating viruses from large volumes of water into smaller, more manageable volumes. he second topic consists of assay methods used for e...

  7. Towards synthetic viruses

    Microsoft Academic Search

    Guy Zuber; Emmanuel Dauty; Marc Nothisen; Pascale Belguise; Jean-Paul Behr

    2001-01-01

    Gene delivery is too complex to be performed with a single carrier molecule. Synthetic multicomponent vectors are being designed that mimic key properties of viruses. Some solutions, such as diverting cell-anchoring molecules or the endogenous nuclear import machinery from their normal function, are directly copied from bacteria and viruses. Some other solutions are original ones: monomolecular genome condensation via detergent

  8. Biological versus computer viruses

    Microsoft Academic Search

    Daniel GUINIER

    1989-01-01

    To understand biological viruses, some notions of the fundamental knowledge of the structure of DNA, the genetic code, the biosynthesis of proteins, the transcription, replication and transfer processes,... are presented so as to give an idea as to how the genetic information is decrypted by biological mechanisms and consequently, how viruses work.A computer \\

  9. Virus separation using membranes.

    PubMed

    Grein, Tanja A; Michalsky, Ronald; Czermak, Peter

    2014-01-01

    Industrial manufacturing of cell culture-derived viruses or virus-like particles for gene therapy or vaccine production are complex multistep processes. In addition to the bioreactor, such processes require a multitude of downstream unit operations for product separation, concentration, or purification. Similarly, before a biopharmaceutical product can enter the market, removal or inactivation of potential viral contamination has to be demonstrated. Given the complexity of biological solutions and the high standards on composition and purity of biopharmaceuticals, downstream processing is the bottleneck in many biotechnological production trains. Membrane-based filtration can be an economically attractive and efficient technology for virus separation. Viral clearance, for instance, of up to seven orders of magnitude has been reported for state of the art polymeric membranes under best conditions.This chapter summarizes the fundamentals of virus ultrafiltration, diafiltration, or purification with adsorptive membranes. In lieu of an impractical universally applicable protocol for virus filtration, application of these principles is demonstrated with two examples. The chapter provides detailed methods for production, concentration, purification, and removal of a rod-shaped baculovirus (Autographa californica M nucleopolyhedrovirus, about 40 × 300 nm in size, a potential vector for gene therapy, and an industrially important protein expression system) or a spherical parvovirus (minute virus of mice, 22-26 nm in size, a model virus for virus clearance validation studies). PMID:24297430

  10. Equine Arteritis Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    03. Nidovirales : 03.004. Arteriviridae : 03.004.0. {03.004.0. unknown} : 03.004.0.01. Arterivirus : 03.004.0.01.001. Equine arteritis virus will be published online. The article details the phenotypic and genotypic makeup of equine arteritis virus (EAV), and summarizes its biological properties....

  11. Rift Valley Fever Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  12. Cutthroat Trout Virus

    USGS Multimedia Gallery

    Electron micrograph of the cutthroat trout virus (CTV) showing the small, round virions of approximately 30 nanometers in diameter containing a single-stranded RNA genome. CTV, whose genome was first characterized by USGS researchers, is being used in research into the human virus Hepatitis E....

  13. Characterization and identification of two virus diseases of spinach in South Texas 

    E-print Network

    Adams, Edward Blair

    1979-01-01

    mosaic virus Beet western yellows virus Beet yellows virus Broad bean wilt virus Carnation ring spot virus Clover yellow mosaic virus Cucumber green mottle mosaic virus Cucumber mosaic virus Lettuce mosaic virus Radish mosaic virus Raspberry...

  14. Replication of Sendai Virus

    PubMed Central

    Blair, Carol D.; Robinson, William S.

    1970-01-01

    Chick embryo fibroblast cultures infected with Sendai virus were incubated with 3H-uridine in the presence of actinomycin D beginning at 18 hr after infection. The 35 and 18S virus-specific ribonucleic acid (RNA) components were found in a ribonuclease-sensitive form in the cell and appeared to be associated with polyribosomes. Newly synthesized 57S viral RNA was rapidly coated with protein to form intracellular viral nucleocapsid, and no 57S RNA was found “free” (ribonucleasesensitive) in the 2,000 × g supernatant fraction of disrupted cells. The nucleocapsid from detergent-disrupted Sendai virus and that from disrupted cells were indistinguishable in ultrastructure and buoyant density, and neither was found to be infectious or have hemagglutinating activity. Kinetic studies of nucleocapsid and virus formation indicated a relative block in conversion of viral nucleocapsid to complete enveloped virus in these cells, resulting in accumulation of large amounts of nucleocapsid in the cell cytoplasm. Images PMID:4315961

  15. Is The Virus Problem Getting Worse?

    Microsoft Academic Search

    Jan Hruska

    2001-01-01

    The number of known viruses exceeded 50?000 in August 2000. The vast majority of those (74%) are parasitic viruses (attacking executables), second most populous are macro viruses (19%) and 7% are boot sector viruses. In May 2000, 88% of infections reported to Sophos were due to macro viruses, 9% were parasitic viruses and only 3% were boot sector viruses. Note

  16. Understanding virus filtration membrane performance

    Microsoft Academic Search

    S. Ranil Wickramasinghe; Emily D. Stump; David L. Grzenia; Scott M. Husson; John Pellegrino

    2010-01-01

    Virus filtration membranes are used to obtain virus clearance during the purification of biopharmaceutical products. These direct flow (also referred to as dead end or normal flow) filtration membranes are designed to reject virus particles and yield >98% product recovery for proteins less than 170kDa. Virus filtration feed streams generally have high purity and high product concentrations. Decrease in permeate

  17. Realms of the Viruses Online

    ERIC Educational Resources Information Center

    Liu, Dennis

    2007-01-01

    Viruses have evolved strategies for infecting all taxa, but most viruses are highly specific about their cellular host. In humans, viruses cause diverse diseases, from chronic but benign warts, to acute and deadly hemorrhagic fever. Viruses have entertaining names like Zucchini Yellow Mosaic, Semliki Forest, Coxsackie, and the original terminator,…

  18. Citrus Virus Symptoms in Sardinia

    Microsoft Academic Search

    A. Bruno

    1964-01-01

    SARDINIA was believed to be a virus-free citrus region until Boselli1 first noted a disorder showing symptoms commonly referred to as the psorosis virus complex. Following this, the main citrus areas of the Island have been surveyed with the view of recognizing and recording virus or virus-like manifestations.

  19. Virus-PEDOT Biocomposite Films

    PubMed Central

    Donavan, Keith C.; Arter, Jessica A.

    2012-01-01

    Virus-poly(3,4-ethylenedioxythiophene) (virus-PEDOT) biocomposite films are prepared by electropolymerizing 3,4-ethylenedioxythiophene (EDOT) in aqueous electrolytes containing 12 mM LiClO4 and the bacteriophage M13. The concentration of virus in these solutions, [virus]soln, is varied from 3 nM to 15 nM. A quartz crystal microbalance is used to directly measure the total mass of the biocomposite film during its electrodeposition. In combination with a measurement of the electrodeposition charge, the mass of the virus incorporated into the film is calculated. These data show that concentration of the M13 within the electropolymerized film, [virus]film, increases linearly with [virus]soln. The incorporation of virus particles into the PEDOT film from solution is efficient, resulting in a concentration ratio: [virus]film:[virus]soln ?450. Virus incorporation into the PEDOT causes roughening of the film topography that is observed using scanning electron microscopy and atomic force microscopy (AFM). The electrical conductivity of the virus-PEDOT film, measured perpendicular to the plane of the film using conductive tip AFM, decreases linearly with virus loading, from 270 ?S/cm for pure PE-DOT films to 50 ?S/cm for films containing 100 ?M virus. The presence on the virus surface of displayed affinity peptides did not significantly influence the efficiency of incorporation into virus-PEDOT biocomposite films. PMID:22856875

  20. Viruses isolated from Panamanian sloths.

    PubMed

    Seymour, C; Peralta, P H; Montgomery, G G

    1983-11-01

    Seven virus strains were isolated in Vero cells from whole blood samples from 80 wild-caught sloths, Bradypus variegatus and Choloepus hoffmanni, from Central Panamá. Four strains of at least two different serotypes are related to Changuinola virus; two of these were associated with prolonged or recrudescent viremias. One strain is an antigenic subtype of Punta Toro virus, and another, described here as Bradypus-4 virus, is a new, antigenically ungrouped virus. A second new virus from sloths, Utive virus, forms an antigenic complex within the Simbu serogroup with Utinga and Pintupo viruses. Tests on sequential plasma samples from radio-marked free-ranging sloths and from recently captured animals maintained in captivity showed that both species develop neutralizing antibodies following naturally acquired virus infections. Antibodies against the Changuinola and Simbu serogroup viruses are widespread in both sloth species and are especially prevalent in Choloepus, but are virtually absent in all other wild vertebrate species tested. PMID:6316795

  1. Towards synthetic viruses.

    PubMed

    Zuber, G; Dauty, E; Nothisen, M; Belguise, P; Behr, J P

    2001-11-19

    Gene delivery is too complex to be performed with a single carrier molecule. Synthetic multicomponent vectors are being designed that mimic key properties of viruses. Some solutions, such as diverting cell-anchoring molecules or the endogenous nuclear import machinery from their normal function, are directly copied from bacteria and viruses. Some other solutions are original ones: monomolecular genome condensation via detergent dimerization or endosome disruption by the proton sponge effect are not exploited by natural cell invaders. All these components, however, still have to be assembled into a unique supramolecular system, an 'artificial virus'. PMID:11718949

  2. [Grapevine viruses in Tunisia].

    PubMed

    Acheche, H; Fattouch, S; M'Hirsi, S; Marzouki, N; Marrakchi, M

    1998-01-01

    Tunisian grapevine culture is affected by many viruses caused by some phytovirus belonging to nepovirus, closterovirus and trichovirus groups. The present work deal with the economically important viroses identified in tunisian grapevines. We present here the development methods to detect these viruses in propagating material. The important viruses biologically, biochemically, serologically and using molecular techniques, characterised are: GFLV, GLRaV3 and GVB. The genetic polymorphism analysis was also carried and tunisian isolates were compared to previously described ones in literature. PMID:14666749

  3. Rapid Detection and Quantification of RNA of Ebola and Marburg Viruses, Lassa Virus, Crimean-Congo Hemorrhagic Fever Virus, Rift Valley Fever Virus, Dengue Virus, and Yellow Fever Virus by Real-Time Reverse Transcription-PCR

    Microsoft Academic Search

    Christian Drosten; Stephan Göttig; Stefan Schilling; Marcel Asper; Marcus Panning; Herbert Schmitz; Stephan Günther

    2002-01-01

    Viral hemorrhagic fevers (VHFs) are acute infections with high case fatality rates. Important VHF agents are Ebola and Marburg viruses (MBGV\\/EBOV), Lassa virus (LASV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), dengue virus (DENV), and yellow fever virus (YFV). VHFs are clinically difficult to diagnose and to distinguish; a rapid and reliable laboratory diagnosis is required in

  4. Virus Chapter: Iflaviridae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The iflaviruses comprise viruses isolated from arthropod species of agricultural importance. All members of iflaviruses have a genome arrangement similar to the picornaviruses, ootyviruses, and secoviruses. However, phylogenetic analysis using the RNA-dependent RNA polymerase region showed that th...

  5. What's West Nile Virus?

    MedlinePLUS

    ... discovered all the way back in 1937 in Africa, the West Nile virus probably didn't make ... Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com

  6. The dengue viruses.

    PubMed Central

    Henchal, E A; Putnak, J R

    1990-01-01

    Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration, rash, lymphadenopathy, and leukopenia. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Four distinct serotypes of the dengue virus (dengue-1, dengue-2, dengue-3, and dengue-4) exist, with numerous virus strains found worldwide. Molecular cloning methods have led to a greater understanding of the structure of the RNA genome and definition of virus-specific structural and nonstructural proteins. Progress towards producing safe, effective dengue virus vaccines, a goal for over 45 years, has been made. Images PMID:2224837

  7. Avoiding Computer Viruses.

    ERIC Educational Resources Information Center

    Rowe, Joyce; And Others

    1989-01-01

    The threat of computer sabotage is a real concern to business teachers and others responsible for academic computer facilities. Teachers can minimize the possibility. Eight suggestions for avoiding computer viruses are given. (JOW)

  8. Sexually transmitted viruses.

    PubMed Central

    Rapp, F.

    1989-01-01

    Human viruses known to be spread by sexual contact include herpes simplex viruses (HSV), papillomaviruses (HPV), human immunodeficiency virus (HIV), hepatitis B virus, and cytomegalovirus. Infections with the first three (HSV, HPV, and HIV) have reached epidemic proportions and pose global health concerns. Most of what we know about these human pathogens has been learned only recently, owing to the advent of DNA technologies and advances in culture techniques. In fact, our awareness of one virally transmitted venereal disease, acquired immunodeficiency syndrome, dates to the early 1980s. This paper touches on various aspects of the biology, pathogenesis, clinical manifestations, and, where applicable, oncogenicity of these agents, as well as current treatments and vaccine initiatives. PMID:2549736

  9. VIRUS instrument enclosures

    NASA Astrophysics Data System (ADS)

    Prochaska, T.; Allen, R.; Mondrik, N.; Rheault, J. P.; Sauseda, M.; Boster, E.; James, M.; Rodriguez-Patino, M.; Torres, G.; Ham, J.; Cook, E.; Baker, D.; DePoy, Darren L.; Marshall, Jennifer L.; Hill, G. J.; Perry, D.; Savage, R. D.; Good, J. M.; Vattiat, Brian L.

    2014-08-01

    The Visible Integral-Field Replicable Unit Spectrograph (VIRUS) instrument will be installed at the Hobby-Eberly Telescope† in the near future. The instrument will be housed in two enclosures that are mounted adjacent to the telescope, via the VIRUS Support Structure (VSS). We have designed the enclosures to support and protect the instrument, to enable servicing of the instrument, and to cool the instrument appropriately while not adversely affecting the dome environment. The system uses simple HVAC air handling techniques in conjunction with thermoelectric and standard glycol heat exchangers to provide efficient heat removal. The enclosures also provide power and data transfer to and from each VIRUS unit, liquid nitrogen cooling to the detectors, and environmental monitoring of the instrument and dome environments. In this paper, we describe the design and fabrication of the VIRUS enclosures and their subsystems.

  10. Powassan (POW) Virus Basics

    MedlinePLUS

    ... attachment time needed to transmit the virus. When spending time in wooded or brushy habitat in north ... and woods, and doing thorough tick checks after spending time in the woods. These precautions are most ...

  11. West Nile Virus

    MedlinePLUS

    ... for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q&A School & Jobs Drugs & Alcohol Staying Safe Recipes En Español ... Image West Nile Virus KidsHealth > Teens > Infections > Bacterial & ...

  12. Wheat Streak Mosaic Virus

    E-print Network

    Morgan, Gaylon

    2005-01-26

    Virus First discovered in Nebraska in 1922, wheat streak mosaic virus (WSMV) remains a threat today across most of the U.S. Central Plains. WSMV affects spring wheat, barley, corn, triticale, rye and numerous other annual and perennial grasses... have tre- mendous reproductive capability, enabling large populations to build. The mite is most active during warm weather, with temperatures of 75-80 degrees F optimum for reproduction. Mites require a living grass host to survive the summer; sum...

  13. Dengue Virus Diagnostics

    Microsoft Academic Search

    Evgeni Eltzov; Danit Atias; Levi Gheber; Robert S. Marks

    \\u000a Dengue fever (DF) is an emerging arborviral disease caused by infection with dengue virus (DENV) which has emerged as the\\u000a most important vector-borne viral disease in tropical areas and it continues to expand geographically. The four serotypes\\u000a of DENV that cause human disease are transmitted by Aedes mosquitoes. Expansion in geographic distribution of both viruses\\u000a and mosquito vectors, has led

  14. Origins of Viruses

    NSDL National Science Digital Library

    Ed Rybicki

    This page is part of a site created as a supplement for an introduction to virology course for second year microbiology students. It includes discussions on the origins of viruses as well as how they might have evolved. There are several links to pertinent conceptial matter such as basics on the different types of viruses as well as a link to the course home page.

  15. Hepatitis B virus infection.

    PubMed

    Trépo, Christian; Chan, Henry L Y; Lok, Anna

    2014-12-01

    Hepatitis B virus infection is a major public health problem worldwide; roughly 30% of the world's population show serological evidence of current or past infection. Hepatitis B virus is a partly double-stranded DNA virus with several serological markers: HBsAg and anti-HBs, HBeAg and anti-HBe, and anti-HBc IgM and IgG. It is transmitted through contact with infected blood and semen. A safe and effective vaccine has been available since 1981, and, although variable, the implementation of universal vaccination in infants has resulted in a sharp decline in prevalence. Hepatitis B virus is not cytopathic; both liver damage and viral control--and therefore clinical outcome--depend on the complex interplay between virus replication and host immune response. Overall, as much as 40% of men and 15% of women with perinatally acquired hepatitis B virus infection will die of liver cirrhosis or hepatocellular carcinoma. In addition to decreasing hepatic inflammation, long-term antiviral treatment can reverse cirrhosis and reduce hepatocellular carcinoma. Development of new therapies that can improve HBsAg clearance and virological cure is warranted. PMID:24954675

  16. Tick-borne viruses*

    PubMed Central

    Work, Telford H.

    1963-01-01

    More than 150 arthropod-borne viruses are now recognized, and over 50 of these are known to produce human infections and disease. Among these viruses are those of the tick-borne Russian spring-summer complex, which is etiologically involved in a wide variety of human diseases of varying severity. The eight antigenically different members of this complex so far known are Russian spring-summer encephalitis, louping-ill, Central European encephalitis, Omsk haemorrhagic fever, Kyasanur Forest disease, Langat, Negishi and Powassan viruses. In his review of the problems posed by these viruses and of research on them, the author points out that, while this complex is distributed around the globe in the temperate zone of the northern hemisphere, the only serious tick-borne virus disease known in the tropics is Kyasanur Forest disease. It is probable, however, that there are other, unrecognized tick-borne viruses in the tropical areas of Asia, Africa and America of importance to human health, and that these will be brought to light as virological studies of diseases of now obscure etiology are pursued. PMID:14043753

  17. Multiple virus infections in the honey bee and genome divergence of honey bee viruses

    Microsoft Academic Search

    Yanping Chen; Yan Zhao; John Hammond; Hei-ti Hsu; Jay Evans; Mark Feldlaufer

    2004-01-01

    Using uniplex RT-PCR we screened honey bee colonies for the presence of several bee viruses, including black queen cell virus (BQCV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood virus (SBV), and described the detection of mixed virus infections in bees from these colonies. We report for the first time that individual bees can harbor four viruses simultaneously.

  18. Immunology of hepatitis B virus and hepatitis C virus infection

    Microsoft Academic Search

    Michelina Nascimbeni; Barbara Rehermann

    2005-01-01

    More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and\\/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and

  19. Glycyrrhizic acid inhibits virus growth and inactivates virus particles.

    PubMed

    Pompei, R; Flore, O; Marccialis, M A; Pani, A; Loddo, B

    1979-10-25

    Screening investigations in antiviral action of plant extracts have revealed that a component of Glycyrrhiza glabra roots, found to be glycyrrhizie acid, is active against viruses. We report here that this drug inhibits growth and cytopathology of several unrelated DNA and RNA viruses, while not affecting cell activity and ability to replicate. In addition, glycyrrhizic acid inactivates herpes simplex virus particles irreversibly. PMID:233133

  20. Chicken anemia virus.

    PubMed

    Schat, K A

    2009-01-01

    Chicken anemia virus (CAV), the only member of the genus Gyrovirus of the Circoviridae, is a ubiquitous pathogen of chickens and has a worldwide distribution. CAV shares some similarities with Torque teno virus (TTV) and Torque teno mini virus (TTMV) such as coding for a protein inducing apoptosis and a protein with a dual-specificity phosphatase. In contrast to TTV, the genome of CAV is highly conserved. Another important difference is that CAV can be isolated in cell culture. CAV produces a single polycistronic messenger RNA (mRNA), which is translated into three proteins. The promoter-enhancer region has four direct repeats resembling estrogen response elements. Transcription is enhanced by estrogen and repressed by at least two other transcription factors, one of which is COUP-TF1. A remarkable feature of CAV is that the virus can remain latent in gonadal tissues in the presence or absence of virus-neutralizing antibodies. In contrast to TTV, CAV can cause clinical disease and subclinical immunosuppression especially affecting CD8+ T lymphocytes. Clinical disease is associated with infection in newly hatched chicks lacking maternal antibodies or older chickens with a compromised humoral immune response. PMID:19230563

  1. Research on computer virus database management system

    NASA Astrophysics Data System (ADS)

    Qi, Guoquan

    2011-12-01

    The growing proliferation of computer viruses becomes the lethal threat and research focus of the security of network information. While new virus is emerging, the number of viruses is growing, virus classification increasing complex. Virus naming because of agencies' capture time differences can not be unified. Although each agency has its own virus database, the communication between each other lacks, or virus information is incomplete, or a small number of sample information. This paper introduces the current construction status of the virus database at home and abroad, analyzes how to standardize and complete description of virus characteristics, and then gives the information integrity, storage security and manageable computer virus database design scheme.

  2. Mosquitoborne Viruses, Czech Republic, 2002

    PubMed Central

    Zeman, Petr; Halouzka, Ji?í; Ju?icová, Zina; Š?oví?ková, Eva; Bálková, Helena; Šikutová, Silvie; Rudolf, Ivo

    2005-01-01

    Specimens from residents (n = 497) of an area affected by the 2002 flood were examined serologically for mosquitoborne viruses. Antibodies were detected against Tahyna (16%), Sindbis (1%), and Batai (0.2%) viruses, but not West Nile virus. An examination of paired serum samples showed 1 Tahyna bunyavirus (California group) infection. PMID:15705333

  3. CAN CRYPTOGRAPHY PREVENT COMPUTER VIRUSES?

    Microsoft Academic Search

    John F Morar; David M Chess

    2000-01-01

    The relationship between cryptography and virus prevention is anything but simple. Since the beginning of the computer virus problem, people have proposed solutions involving some form of cryptography; but cryptography plays only a minor role in the solutions we actually use today. Encryption can also make virus prevention more difficult, by providing viral hiding places inside the objects that it

  4. An introduction to computer viruses

    SciTech Connect

    Brown, D.R.

    1992-03-01

    This report on computer viruses is based upon a thesis written for the Master of Science degree in Computer Science from the University of Tennessee in December 1989 by David R. Brown. This thesis is entitled An Analysis of Computer Virus Construction, Proliferation, and Control and is available through the University of Tennessee Library. This paper contains an overview of the computer virus arena that can help the reader to evaluate the threat that computer viruses pose. The extent of this threat can only be determined by evaluating many different factors. These factors include the relative ease with which a computer virus can be written, the motivation involved in writing a computer virus, the damage and overhead incurred by infected systems, and the legal implications of computer viruses, among others. Based upon the research, the development of a computer virus seems to require more persistence than technical expertise. This is a frightening proclamation to the computing community. The education of computer professionals to the dangers that viruses pose to the welfare of the computing industry as a whole is stressed as a means of inhibiting the current proliferation of computer virus programs. Recommendations are made to assist computer users in preventing infection by computer viruses. These recommendations support solid general computer security practices as a means of combating computer viruses.

  5. Viruses and viral proteins

    PubMed Central

    Verdaguer, Nuria; Ferrero, Diego; Murthy, Mathur R. N.

    2014-01-01

    For more than 30 years X-ray crystallography has been by far the most powerful approach for determining the structures of viruses and viral proteins at atomic resolution. The information provided by these structures, which covers many important aspects of the viral life cycle such as cell-receptor recognition, viral entry, nucleic acid transfer and genome replication, has extensively enriched our vision of the virus world. Many of the structures available correspond to potential targets for antiviral drugs against important human pathogens. This article provides an overview of the current knowledge of different structural aspects of the above-mentioned processes. PMID:25485129

  6. Soilborne viruses: advances in virus movement, virus induced gene silencing, and engineered resistance

    Microsoft Academic Search

    Jeanmarie Verchot-Lubicz

    2003-01-01

    Until recently soilborne plant viruses were considered important only because they are causative agents for agricultural diseases. In recent years, soilborne plant viruses have played a significant role in advancing research into mechanisms of plasmodesmata transport, gene silencing, and engineered resistance to plant pathogens. Three different mechanisms by which viruses move through plasmodesmata have been identified using dianthoviruses, nepoviruses, and

  7. Bat flight and zoonotic viruses

    USGS Publications Warehouse

    O'Shea, Thomas; Cryan, Paul M.; Cunningham, Andrew A.; Fooks, Anthony R.; Hayman, David T.S.; Luis, Angela D.; Peel, Alison J.; Plowright, Raina K.; Wood, James L.N.

    2014-01-01

    Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the subject of speculation. We hypothesize that flight, a factor common to all bats but to no other mammals, provides an intensive selective force for coexistence with viral parasites through a daily cycle that elevates metabolism and body temperature analogous to the febrile response in other mammals. On an evolutionary scale, this host–virus interaction might have resulted in the large diversity of zoonotic viruses in bats, possibly through bat viruses adapting to be more tolerant of the fever response and less virulent to their natural hosts.

  8. Toscana Virus in Spain

    Microsoft Academic Search

    Sara Sanbonmatsu-Gámez; Mercedes Pérez-Ruiz; Ximena Collao; María Paz Sánchez-Seco; Francisco Morillas-Márquez; Manuel de la Rosa-Fraile; José María Navarro-Marí; Antonio Tenorio

    2005-01-01

    Toscana virus (TOSV, Phlebovirus, family Bunya- viridae) infection is one of the most prevalent arboviruses in Spain. Within the objectives of a multidisciplinary network, a study on the epidemiology of TOSV was conducted in Granada, in southern Spain. The overall seroprevalence rate was 24.9%, significantly increasing with age. TOSV was detected in 3 of 103 sandfly pools by viral culture

  9. From Shakespeare to Viruses

    ScienceCinema

    Sung-Hou Kim

    2010-01-08

    Berkeley Lab scientists have created a unique new tool for analyzing and comparing long sets of data, be it the genomes of mammals or viruses, or the works of Shakespeare. The results of the Shakespeare analysis surprised scholars with their accuracy

  10. Virus Chapter: Dicistrovidae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dicistroviridae family comprises viruses infecting both beneficial arthropods such as honey bees and shrimp and insect pests of medical and agricultural importance. During the last five years, advances in sequencing and phylogenetic analysis have led to the discovery and identification of sever...

  11. Cache Valley virus.

    PubMed

    Edwards, J F

    1994-11-01

    Cache Valley Virus (CVV) is a causative agent of a mosquito-borne disease syndrome of sheep and, possibly, of all ruminants, characterized by embryonic and fetal death, stillbirths, and multiple congenital malformations. CVV is endemic in Canada, Mexico, and the United States. Several related Bunyaviruses also may play a role in syndromes of congenital malformations and embryonic losses in North America. PMID:7728634

  12. Human Viruses and Cancer

    PubMed Central

    Morales-Sánchez, Abigail; Fuentes-Pananá, Ezequiel M.

    2014-01-01

    The first human tumor virus was discovered in the middle of the last century by Anthony Epstein, Bert Achong and Yvonne Barr in African pediatric patients with Burkitt’s lymphoma. To date, seven viruses -EBV, KSHV, high-risk HPV, MCPV, HBV, HCV and HTLV1- have been consistently linked to different types of human cancer, and infections are estimated to account for up to 20% of all cancer cases worldwide. Viral oncogenic mechanisms generally include: generation of genomic instability, increase in the rate of cell proliferation, resistance to apoptosis, alterations in DNA repair mechanisms and cell polarity changes, which often coexist with evasion mechanisms of the antiviral immune response. Viral agents also indirectly contribute to the development of cancer mainly through immunosuppression or chronic inflammation, but also through chronic antigenic stimulation. There is also evidence that viruses can modulate the malignant properties of an established tumor. In the present work, causation criteria for viruses and cancer will be described, as well as the viral agents that comply with these criteria in human tumors, their epidemiological and biological characteristics, the molecular mechanisms by which they induce cellular transformation and their associated cancers. PMID:25341666

  13. Viruses and autophagy

    PubMed Central

    Kudchodkar, Sagar B.; Levine, Beth

    2010-01-01

    SUMMARY Autophagy is an evolutionarily conserved intracellular process by which bulk cytoplasm is enveloped inside a double-membraned vesicle and shuttled to lysosomes for degradation. Within the last 15 years, the genes necessary for the execution of autophagy have been identified and the number of tools for studying this process has grown. Autophagy is essential for tissue homeostasis and development and defective autophagy is associated with a number of diseases. As intracellular parasites, during the course of an infection, viruses encounter autophagy and interact with the proteins that execute this process. Autophagy and/or autophagy genes likely play both anti-viral and proviral roles in the life cycles and pathogenesis of many different virus families. With respect to anti-viral roles, the autophagy proteins function in targeting viral components or virions for lysosomal degradation in a process termed xenophagy, and they also play a role in the initiation of innate and adaptive immune system responses to viral infections. Consistent with this anti-viral role of host autophagy, some viruses encode virulence factors that interact with the host autophagy machinery and block the execution of autophagy. In contrast, other viruses appear to utilise components of the autophagic machinery to foster their own intracellular growth or non-lytic cellular egress. As the details of the role(s) of autophagy in viral pathogenesis become clearer, new anti-viral therapies could be developed to inhibit the beneficial and enhance the destructive aspects of autophagy on the viral life cycle. PMID:19750559

  14. VIRUS PERSISTENCE IN GROUNDWATER

    EPA Science Inventory

    The purpose of the study was to determine whether measurable chemical and physical factors correlate with virus survival in groundwater. Groundwater samples were obtained from 11 sites throughout the United States. Water temperature was measured at the time of collection. Several...

  15. Molecular epidemiology of respiratory viruses in virus-induced asthma

    PubMed Central

    Ishioka, Taisei; Noda, Masahiro; Kozawa, Kunihisa; Kimura, Hirokazu

    2013-01-01

    Acute respiratory illness (ARI) due to various viruses is not only the most common cause of upper respiratory infection in humans but is also a major cause of morbidity and mortality, leading to diseases such as bronchiolitis and pneumonia. Previous studies have shown that respiratory syncytial virus (RSV), human rhinovirus (HRV), human metapneumovirus (HMPV), human parainfluenza virus (HPIV), and human enterovirus infections may be associated with virus-induced asthma. For example, it has been suggested that HRV infection is detected in the acute exacerbation of asthma and infection is prolonged. Thus it is believed that the main etiological cause of asthma is ARI viruses. Furthermore, the number of asthma patients in most industrial countries has greatly increased, resulting in a morbidity rate of around 10-15% of the population. However, the relationships between viral infections, host immune response, and host factors in the pathophysiology of asthma remain unclear. To gain a better understanding of the epidemiology of virus-induced asthma, it is important to assess both the characteristics of the viruses and the host defense mechanisms. Molecular epidemiology enables us to understand the pathogenesis of microorganisms by identifying specific pathways, molecules, and genes that influence the risk of developing a disease. However, the epidemiology of various respiratory viruses associated with virus-induced asthma is not fully understood. Therefore, in this article, we review molecular epidemiological studies of RSV, HRV, HPIV, and HMPV infection associated with virus-induced asthma. PMID:24062735

  16. Gestión del riesgo del cambio (segunda parte)

    Microsoft Academic Search

    Juan Pablo Zorrilla Salgador

    1970-01-01

    Segunda parte del artículo acerca del uso de futuros sobre el tipo de cambio. Esta continuación abarca estrategias, definiciones, metodología y explicaciones sobre todo lo relacionado con el Ratio de cobertura de los futuros y la aparición del riesgo base.

  17. Polyadenylic acid in Visna virus RNA.

    PubMed

    Gillespie, D; Takemoto, K; Robert, M; Gallo, R C

    1973-03-30

    Visna virus 70S RNA contains long stretches of polyadenylic acid [poly(A)]. The homogeneity in length of poly(4) regions is observed in 70S RNA from visna virus and all RNA tumor viruses tested, and not with other types of RNA. By this criterion visna virus resembles RNA tumor viruses. PMID:4631425

  18. GB virus-C infection in patients infected with the human immunodeficiency virus

    Microsoft Academic Search

    Hans L Tillmann; Michael P Manns

    2001-01-01

    Hepatitis virus infections are frequent in patients suffering from HIV infection due to similar transmission routes of these viruses. In addition, hepatitis virus infections lead to impaired survival in HIV positive patients. The recently discovered flavivirus GB virus C (alias Hepatitis G Virus) was initially believed to be another hepatitis virus. While there is still some minor discussion whether GB

  19. Heparan Sulfate-Mediated Binding of Infectious Dengue Virus Type 2 and Yellow Fever Virus

    Microsoft Academic Search

    Raphaële Germi; Jean-Marc Crance; Daniel Garin; Josette Guimet; Hugues Lortat-Jacob; Rob W. H. Ruigrok; Jean-Pierre Zarski; Emmanuel Drouet

    2002-01-01

    Dengue virus type 2 and Yellow fever virus are arthropod-borne flaviviruses causing hemorrhagic fever in humans. Identification of virus receptors is important in understanding flavivirus pathogenesis. The aim of this work was to study the role of cellular heparan sulfate in the adsorption of infectious Yellow fever and Dengue type 2 viruses. Virus attachment was assessed by adsorbing virus to

  20. Detection of sweet potato viruses in Yunnan and genetic diversity analysis of the common viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two hundred seventy-nine samples with virus-like symptoms collected from 16 regions in Yunnan Province were tested by RT-PCR/PCR using virus-specific primers for 8 sweet potato viruses. Six viruses, Sweet potato chlorotic fleck virus (SPCFV), Sweet Potato feathery mottle virus (SPFMV), Sweet potato ...

  1. Virus diseases of Solanum laciniatum Ait. in New Zealand

    Microsoft Academic Search

    A. D. Thomson

    1976-01-01

    Cucumber mosaic virus, potato virus Y, potato virus X, tobacco mosaic virus, and tomato spotted wilt virus were identified in Solatium laciniatum Ait. Cucumber mosaic virus induced the most severe symptoms, including mottle and narrowing of the leaf lamina. Infection of crops with cucumber mosaic virus varied from 0–70% (mean of seven crops 25%), and potato virus Y from 0–48%

  2. PREVALENCE AND TRANSMISSION ROUTES OF HONEY BEE VIRUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transmission mechanisms of six viruses including acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood bee virus (SBV) in honey bee colonies were investigated by RT-PCR methods. The virus...

  3. Phage Displayed Peptides to Avian H5N1 Virus Distinguished the Virus from Other Viruses

    PubMed Central

    Qin, Chengfeng; Ren, Xiaofeng

    2011-01-01

    The purpose of the current study was to identify potential ligands and develop a novel diagnostic test to highly pathogenic avian influenza A virus (HPAI), subtype H5N1 viruses using phage display technology. The H5N1 viruses were used as an immobilized target in a biopanning process using a 12-mer phage display random peptide library. After five rounds of panning, three phages expressing peptides HAWDPIPARDPF, AAWHLIVALAPN or ATSHLHVRLPSK had a specific binding activity to H5N1 viruses were isolated. Putative binding motifs to H5N1 viruses were identified by DNA sequencing. In terms of the minimum quantity of viruses, the phage-based ELISA was better than antiserum-based ELISA and a manual, semi-quantitative endpoint RT-PCR for detecting H5N1 viruses. More importantly, the selected phages bearing the specific peptides to H5N1 viruses were capable of differentiating this virus from other avian viruses in enzyme-linked immunosorbent assays. PMID:21887228

  4. Frequently Asked Questions on Ebola Virus Disease

    MedlinePLUS

    ... Response Network Biorisk Reduction Frequently asked questions on Ebola virus disease May 2015 FAQs from August 2014 ... based on recent evidence. For more information on Ebola virus disease Fact sheet on Ebola virus disease ...

  5. Virus-encoded superantigens.

    PubMed Central

    Huber, B T; Hsu, P N; Sutkowski, N

    1996-01-01

    Superantigens are microbial agents that have a strong effect on the immune response of the host. Their initial target is the T lymphocyte, but a whole cascade of immunological reactions ensues. It is thought that the microbe engages the immune system of the host to its own advantage, to facilitate persistent infection and/or transmission. In this review, we discuss in detail the structure and function of the superantigen encoded by the murine mammary tumor virus, a B-type retrovirus which is the causative agent of mammary carcinoma. We will also outline what has more recently become known about superantigen activity associated with two human herpesviruses, cytomegalovirus and Epstein-Barr virus. It is likely that we have only uncovered the tip of the iceberg in our discovery of microbial superantigens, and we predict a flood of new information on this topic shortly. PMID:8840782

  6. Mechanisms of Virus Assembly

    NASA Astrophysics Data System (ADS)

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-04-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid and in some cases are surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assemble within their host cells and in vitro. We describe the thermodynamics and kinetics for the assembly of protein subunits into icosahedral capsid shells and how these are modified in cases in which the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques used to characterize capsid assembly, and we highlight aspects of virus assembly that are likely to receive significant attention in the near future.

  7. Canine respiratory viruses.

    PubMed

    Buonavoglia, Canio; Martella, Vito

    2007-01-01

    Acute contagious respiratory disease (kennel cough) is commonly described in dogs worldwide. The disease appears to be multifactorial and a number of viral and bacterial pathogens have been reported as potential aetiological agents, including canine parainfluenza virus, canine adenovirus and Bordetella bronchiseptica, as well as mycoplasmas, Streptococcus equi subsp. zooepidemicus, canine herpesvirus and reovirus-1,-2 and -3. Enhancement of pathogenicity by multiple infections can result in more severe clinical forms. In addition, acute respiratory diseases associated with infection by influenza A virus, and group I and II coronaviruses, have been described recently in dogs. Host species shifts and tropism changes are likely responsible for the onset of these new pathogens. The importance of the viral agents in the kennel cough complex is discussed. PMID:17296161

  8. The encephalomyocarditis virus

    PubMed Central

    Carocci, Margot; Bakkali-Kassimi, Labib

    2012-01-01

    The encephalomyocarditis virus (EMCV) is a small non-enveloped single-strand RNA virus, the causative agent of not only myocarditis and encephalitis, but also neurological diseases, reproductive disorders and diabetes in many mammalian species. EMCV pathogenesis appears to be viral strain- and host-specific, and a better understanding of EMCV virulence factors is increasingly required. Indeed, EMCV is often used as a model for diabetes and viral myocarditis, and is also widely used in immunology as a double-stranded RNA stimulus in the study of Toll-like as well as cytosolic receptors. However, EMCV virulence and properties have often been neglected. Moreover, EMCV is able to infect humans albeit with a low morbidity. Progress on xenografts, such as pig heart transplantation in humans, has raised safety concerns that need to be explored. In this review we will highlight the biology of EMCV and all known and potential virulence factors. PMID:22722247

  9. Measles Virus Receptors

    Microsoft Academic Search

    Y. Yanagi; M. Takeda; S. Ohno; T. Hashiguchi

    Measles virus (MV) has two envelope glycoproteins, the hemagglutinin (H) and fusion protein, which are responsible for attachment\\u000a and membrane fusion, respectively. Signaling lymphocyte activation molecule (SLAM, also called CD150), a membrane glycoprotein\\u000a expressed on immune cells, acts as the principal cellular receptor for MV, accounting for its lymphotropism and immunosuppressive\\u000a nature. MV also infects polarized epithelial cells via an

  10. Chikungunya Virus Infection

    Microsoft Academic Search

    Fabrice Simon; Emilie Javelle; Manuela Oliver; Isabelle Leparc-Goffart; Catherine Marimoutou

    2011-01-01

    Chikungunya virus (CHIKV) is an alphavirus transmitted by mosquitoes, mostly Aedes aegypti and Aedes albopictus. After half a century of focal outbreaks of acute febrile polyarthralgia in Africa and Asia, the disease unexpectedly spread\\u000a in the past decade with large outbreaks in Africa and around the Indian Ocean and rare autochthonous transmission in temperate\\u000a areas. This emergence brought new insights

  11. Molecular studies of avian leukosis virus 

    E-print Network

    Mozisek, Blayne Myron

    2007-04-25

    leukosis virus (ALV), Rous sarcoma virus (RSV), mouse mammary tumor virus (MMTV), and murine leukemia virus (MLV). These viruses were the subject of intense study due to their propensity to form neoplastic disease in their host organisms. Investigations... into the mechanisms by which these viruses were able to cause tumors eventually led to the discovery and development of the oncogene theory of tumorigenesis: the elucidation of oncogenes within their viral genomes or their interaction with host oncogenes following...

  12. Nuclear entry of DNA viruses

    PubMed Central

    Fay, Nikta; Panté, Nelly

    2015-01-01

    DNA viruses undertake their replication within the cell nucleus, and therefore they must first deliver their genome into the nucleus of their host cells. Thus, trafficking across the nuclear envelope is at the basis of DNA virus infections. Nuclear transport of molecules with diameters up to 39 nm is a tightly regulated process that occurs through the nuclear pore complex (NPC). Due to the enormous diversity of virus size and structure, each virus has developed its own strategy for entering the nucleus of their host cells, with no two strategies alike. For example, baculoviruses target their DNA-containing capsid to the NPC and subsequently enter the nucleus intact, while the hepatitis B virus capsid crosses the NPC but disassembles at the nuclear side of the NPC. For other viruses such as herpes simplex virus and adenovirus, although both dock at the NPC, they have each developed a distinct mechanism for the subsequent delivery of their genome into the nucleus. Remarkably, other DNA viruses, such as parvoviruses and human papillomaviruses, access the nucleus through an NPC-independent mechanism. This review discusses our current understanding of the mechanisms used by DNA viruses to deliver their genome into the nucleus, and further presents the experimental evidence for such mechanisms.

  13. Nuclear entry of DNA viruses.

    PubMed

    Fay, Nikta; Panté, Nelly

    2015-01-01

    DNA viruses undertake their replication within the cell nucleus, and therefore they must first deliver their genome into the nucleus of their host cells. Thus, trafficking across the nuclear envelope is at the basis of DNA virus infections. Nuclear transport of molecules with diameters up to 39 nm is a tightly regulated process that occurs through the nuclear pore complex (NPC). Due to the enormous diversity of virus size and structure, each virus has developed its own strategy for entering the nucleus of their host cells, with no two strategies alike. For example, baculoviruses target their DNA-containing capsid to the NPC and subsequently enter the nucleus intact, while the hepatitis B virus capsid crosses the NPC but disassembles at the nuclear side of the NPC. For other viruses such as herpes simplex virus and adenovirus, although both dock at the NPC, they have each developed a distinct mechanism for the subsequent delivery of their genome into the nucleus. Remarkably, other DNA viruses, such as parvoviruses and human papillomaviruses, access the nucleus through an NPC-independent mechanism. This review discusses our current understanding of the mechanisms used by DNA viruses to deliver their genome into the nucleus, and further presents the experimental evidence for such mechanisms. PMID:26029198

  14. Limits in virus filtration capability? Impact of virus quality and spike level on virus removal with xenotropic murine leukemia virus.

    PubMed

    Roush, David J; Myrold, Adam; Burnham, Michael S; And, Joseph V; Hughes, Joseph V

    2015-01-01

    Virus filtration (VF) is a key step in an overall viral clearance process since it has been demonstrated to effectively clear a wide range of mammalian viruses with a log reduction value (LRV)?>?4. The potential to achieve higher LRV from virus retentive filters has historically been examined using bacteriophage surrogates, which commonly demonstrated a potential of?>?9 LRV when using high titer spikes (e.g. 10(10) PFU/mL). However, as the filter loading increases, one typically experiences significant decreases in performance and LRV. The 9 LRV value is markedly higher than the current expected range of 4-5 LRV when utilizing mammalian retroviruses on virus removal filters (Miesegaes et al., Dev Biol (Basel) 2010;133:3-101). Recent values have been reported in the literature (Stuckey et al., Biotech Progr 2014;30:79-85) of LRV in excess of 6 for PPV and XMuLV although this result appears to be atypical. LRV for VF with therapeutic proteins could be limited by several factors including process limits (flux decay, load matrix), virus spike level and the analytical methods used for virus detection (i.e. the Limits of Quantitation), as well as the virus spike quality. Research was conducted using the Xenotropic-Murine Leukemia Virus (XMuLV) for its direct relevance to the most commonly cited document, the International Conference of Harmonization (ICH) Q5A (International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, Geneva, Switzerland, 1999) for viral safety evaluations. A unique aspect of this work is the independent evaluation of the impact of retrovirus quality and virus spike level on VF performance and LRV. The VF studies used XMuLV preparations purified by either ultracentrifugation (Ultra 1) or by chromatographic processes that yielded a more highly purified virus stock (Ultra 2). Two monoclonal antibodies (Mabs) with markedly different filtration characteristics and with similar levels of aggregate (<1.5%) were evaluated with the Ultra 1 and Ultra 2 virus preparations utilizing the Planova 20 N, a small virus removal filter. Impurities in the virus preparation ultimately limited filter loading as measured by determining the volumetric loading condition where 75% flux decay is observed versus initial conditions (V75). This observation occurred with both Mabs with the difference in virus purity more pronounced when very high spike levels were used (>5 vol/vol %). Significant differences were seen for the process performance over a number of lots of the less-pure Ultra 1 virus preparations. Experiments utilizing a developmental lot of the chromatographic purified XMuLV (Ultra 2 Development lot) that had elevated levels of host cell residuals (vs. the final Ultra 2 preparations) suggest that these contaminant residuals can impact virus filter fouling, even if the virus prep is essentially monodisperse. Process studies utilizing an Ultra 2 virus with substantially less host cell residuals and highly monodispersed virus particles demonstrated superior performance and an LRV in excess of 7.7 log10 . A model was constructed demonstrating the linear dependence of filtration flux versus filter loading which can be used to predict the V75 for a range of virus spike levels conditions using this highly purified virus. Fine tuning the virus spike level with this model can ultimately maximize the LRV for the virus filter step, essentially adding the LRV equivalent of another process step (i.e. protein A or CEX chromatography). PMID:25395156

  15. Computer virus information update CIAC-2301

    SciTech Connect

    Orvis, W.J.

    1994-01-15

    While CIAC periodically issues bulletins about specific computer viruses, these bulletins do not cover all the computer viruses that affect desktop computers. The purpose of this document is to identify most of the known viruses for the MS-DOS and Macintosh platforms and give an overview of the effects of each virus. The authors also include information on some windows, Atari, and Amiga viruses. This document is revised periodically as new virus information becomes available. This document replaces all earlier versions of the CIAC Computer virus Information Update. The date on the front cover indicates date on which the information in this document was extracted from CIAC`s Virus database.

  16. Tomato chlorosis virus and Tomato infectious chlorosis virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation will help consultants, growers, and other practitioners in the Southern and Western Regions of the US, as well as Mexico and the Caribbean identify and manage Tomato infectious chlorosis virus (TICV) and Tomato chlorosis virus (ToCV) in tomato. Information will directly benefit cr...

  17. Lactate dehydrogenase-elevating virus: an ideal persistent virus?

    Microsoft Academic Search

    Peter G. W. Plagemann; Raymond R. R. Rowland; Chen Even; Kay S. Faaberg

    1995-01-01

    LDV contradicts all commonly held views about mechanisms of virus persistence, namely that persistence is primarily associated with noncytopathic viruses, or the selection of immune escape variants or other mutants, or a decrease in expression of certain viral proteins by infected cells, or replication in “immune-privileged sites”, or a general suppression of the host immune system, etc. [1, 2, 5,

  18. Bovine virus diarrhoea virus - strategic decisions for diagnosis and control

    Microsoft Academic Search

    Joe Brownlie; Ian Thompson; Andrew Curwen

    2000-01-01

    IN the 15 years since the last In Practice article on bovine virus diarrhoea virus (BVDV) (Brownlie 1985), there has been an explosion in the understanding of the molecular mechanisms of viral replication and mutation, especially those related to biotypic variation. Hand in hand has come a greater understanding of the importance of BVDV as a primary pathogen of cattle,

  19. Molecular characterization and experimental host range of an isolate of Wissadula golden mosaic St. Thomas virus.

    PubMed

    Collins, A M; Mujaddad-ur-Rehman, Malik; Brown, J K; Reddy, C; Wang, A; Fondong, V; Roye, M E

    2009-12-01

    Partial genome segments of a begomovirus were previously amplified from Wissadula amplissima exhibiting yellow-mosaic and leaf-curl symptoms in the parish of St. Thomas, Jamaica and this isolate assigned to a tentative begomovirus species, Wissadula golden mosaic St. Thomas virus. To clone the complete genome of this isolate of Wissadula golden mosaic St. Thomas virus, abutting primers were designed to PCR amplify its full-length DNA-A and DNA-B components. Sequence analysis of the complete begomovirus genome obtained, confirmed that it belongs to a distinct begomovirus species and this isolate was named Wissadula golden mosaic St. Thomas virus-[Jamaica:Albion:2005] (WGMSTV-[JM:Alb:05]). The genome of WGMSTV-[JM:Alb:05] is organized similar to that of other bipartite Western Hemisphere begomoviruses. Phylogenetic analyses placed the genome components of WGMSTV-[JM:Alb:05] in the Abutilon mosaic virus clade and showed that the DNA-A component is most closely related to four begomovirus species from Cuba, Tobacco leaf curl Cuba virus, Tobacco leaf rugose virus, Tobacco mottle leaf curl virus, and Tomato yellow distortion leaf virus. The putative Rep-binding-site motif in the common region of WGMSTV-[JM:Alb:05] was observed to be identical to that of Chino del tomate virus-Tomato [Mexico:Sinaloa:1983], Sida yellow mosaic Yucatan virus-[Mexico:Yucatan:2005], and Tomato leaf curl Sinaloa virus-[Nicaragua:Santa Lucia], suggesting that WGMSTV-[JM:Alb:05] is capable of forming viable pseudo-recombinants with these begomoviruses, but not with other members of the Abutilon mosaic virus clade. Biolistic inoculation of test plant species with partial dimers of the WGMSTV-[JM:Alb:05] DNA-A and DNA-B components showed that the virus was infectious to Nicotiana benthamiana and W. amplissima and the cultivated species Phaseolus vulgaris (kidney bean) and Lycopersicon esculentum (tomato). Infected W. amplissima plants developed symptoms similar to symptoms observed under field conditions, confirming that this virus is a causal agent of Wissadula yellow mosaic disease in W. amplissima. PMID:19768650

  20. Group 2 Vaccinia Virus, Brazil

    PubMed Central

    Assis, Felipe Lopes; Borges, Iara Apolinario; Ferreira, Paulo César Peregrino; Bonjardim, Cláudio Antônio; Trindade, Giliane de Souza; Lobato, Zélia Inês Portela; Guedes, Maria Isabel Maldonado; Mesquita, Vaz; Kroon, Erna Geessien

    2012-01-01

    In 2011, vaccinia virus caused an outbreak of bovine vaccinia, affecting dairy cattle and dairy workers in Brazil. Genetic and phenotypic analyses identified this isolate as distinct from others recently identified, thereby reinforcing the hypothesis that different vaccinia virus strains co-circulate in Brazil. PMID:23171598

  1. INTERACTIONS OF VIRUS AND HOST

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine viral diarrhea virus (BVDV) is an ubiquitous pathogen of ruminants, found worldwide that is often associated with severe economic losses. Understanding these viruses, particularly at the cellular and molecular levels, is important to develop new vaccination and treatment strategies for produc...

  2. West Nile Virus and Wildlife

    Microsoft Academic Search

    Peter P. Marra; Sean Griffing; Carolee Caffrey; A. Marm Kilpatrick; Robert McLean; Christopher Brand; Emi Saito; Alan P. Dupuis; Laura Kramer; Robert Novak

    2004-01-01

    West Nile virus (WNV) has spread rapidly across North America, resulting in human deaths and in the deaths of untold numbers of birds, mammals, and reptiles. The virus has reached Central America and the Caribbean and may spread to Hawaii and South America. Although tens of thousands of birds have died, and studies of some bird species show local declines,

  3. Hepatitis C Virus and Cardiomyopathy

    Microsoft Academic Search

    Akira Matsumori

    2000-01-01

    The importance of hepatitis C virus infection has been recently noted in patients with hypertrophic cardiomyopathy or dilated cardiomyopathy. In a collaborative research project of the Committees for the Study of Idiopathic Cardiomyopathy, hepatitis C virus antibody was found in 74 of 697 patients (10.65) with hypertrophic cardiomyopathy and in 42 of 663 patients (6.3%) with dilated cardiomyopathy; these prevalences

  4. Human viruses: discovery and emergence

    PubMed Central

    Woolhouse, Mark; Scott, Fiona; Hudson, Zoe; Howey, Richard; Chase-Topping, Margo

    2012-01-01

    There are 219 virus species that are known to be able to infect humans. The first of these to be discovered was yellow fever virus in 1901, and three to four new species are still being found every year. Extrapolation of the discovery curve suggests that there is still a substantial pool of undiscovered human virus species, although an apparent slow-down in the rate of discovery of species from different families may indicate bounds to the potential range of diversity. More than two-thirds of human viruses can also infect non-human hosts, mainly mammals, and sometimes birds. Many specialist human viruses also have mammalian or avian origins. Indeed, a substantial proportion of mammalian viruses may be capable of crossing the species barrier into humans, although only around half of these are capable of being transmitted by humans and around half again of transmitting well enough to cause major outbreaks. A few possible predictors of species jumps can be identified, including the use of phylogenetically conserved cell receptors. It seems almost inevitable that new human viruses will continue to emerge, mainly from other mammals and birds, for the foreseeable future. For this reason, an effective global surveillance system for novel viruses is needed. PMID:22966141

  5. TOTAL CULTURABLE VIRUS QUANTAL ASSAY

    EPA Science Inventory

    This chapter describes a quantal method for assaying culturable human enteric viruses from water matrices. The assay differs from the plaque assay described in Chapter 10 (December 1987 Revision) in that it is based upon the direct microscopic viewing of cells for virus-induced ...

  6. Swine Influenza Virus: Emerging Understandings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: In March-April 2009, a novel pandemic H1N1 emerged in the human population in North America [1]. The gene constellation of the emerging virus was demonstrated to be a combination of genes from swine influenza A viruses (SIV) of North American and Eurasian lineages that had never before...

  7. Dynamic models for computer viruses

    Microsoft Academic Search

    Jose R. C. Piqueira; Adolfo A. De Vasconcelos; Carlos E. C. J. Gabriel; Vanessa O. Araujo

    2008-01-01

    Computer viruses are an important risk to computational systems endangering either corporations of all sizes or personal computers used for domestic applications. Here, classical epidemiological models for disease propagation are adapted to computer networks and, by using simple systems identification techniques a model called SAIC (Susceptible, Antidotal, Infectious, Contaminated) is developed. Real data about computer viruses are used to validate

  8. Computer viruses: a quantitative analysis

    Microsoft Academic Search

    A. Coulthard; T. A. Vuori

    2002-01-01

    This paper provides interesting insights for anti-virus research, as it reflects a period of rapid uptake in the application of the Internet and the use of e-mail for business purposes. The purpose of the research is to provide independent justification of the growing prevalence of computer virus incidents over the past five years, and identify patterns in the frequency and

  9. Mathematical models on computer viruses

    Microsoft Academic Search

    Bimal Kumar Mishra; Dinesh Saini

    2007-01-01

    An attempt has been made to develop mathematical models on computer viruses infecting the system under different conditions. Mathematical model 1 discusses the situation to find the probability that at any time t how many software components are infected by virus, assuming the recovery rate and proportion of un-infected population receiving infection per unit time does not change with time.

  10. Computer Viruses as Artificial Life

    Microsoft Academic Search

    Eugene H. Spafford

    1994-01-01

    There has been considerable interest in computer viruses since they first appeared in 1981, and especially in the past few years as they have reached epidemic numbers in many per- sonal computer environments. Viruses have been written about as a security problem, as a social problem, and as a possible means of performing useful tasks in a distributed computing environment.

  11. Oropouche Virus Isolation, Southeast Brazil

    PubMed Central

    Martins, Lívia Carício; Rodrigues, Sueli Guerreiro; Chiang, Jannifer Oliveira; Azevedo, Raimunda do Socorro da Silva; Travassos da Rosa, Amelia P.A.; Vasconcelos, Pedro Fernando da Costa

    2005-01-01

    An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription–polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama. PMID:16318707

  12. Defining Life: The Virus Viewpoint

    NASA Astrophysics Data System (ADS)

    Forterre, Patrick

    2010-04-01

    Are viruses alive? Until very recently, answering this question was often negative and viruses were not considered in discussions on the origin and definition of life. This situation is rapidly changing, following several discoveries that have modified our vision of viruses. It has been recognized that viruses have played (and still play) a major innovative role in the evolution of cellular organisms. New definitions of viruses have been proposed and their position in the universal tree of life is actively discussed. Viruses are no more confused with their virions, but can be viewed as complex living entities that transform the infected cell into a novel organism—the virus—producing virions. I suggest here to define life (an historical process) as the mode of existence of ribosome encoding organisms (cells) and capsid encoding organisms (viruses) and their ancestors. I propose to define an organism as an ensemble of integrated organs (molecular or cellular) producing individuals evolving through natural selection. The origin of life on our planet would correspond to the establishment of the first organism corresponding to this definition.

  13. Pathogenic pseudorabies virus, China, 2012.

    PubMed

    Yu, Xiuling; Zhou, Zhi; Hu, Dongmei; Zhang, Qian; Han, Tao; Li, Xiaoxia; Gu, Xiaoxue; Yuan, Lin; Zhang, Shuo; Wang, Baoyue; Qu, Ping; Liu, Jinhua; Zhai, Xinyan; Tian, Kegong

    2014-01-01

    In 2012, an unprecedented large-scale outbreak of disease in pigs in China caused great economic losses to the swine industry. Isolates from pseudorabies virus epidemics in swine herds were characterized. Evidence confirmed that the pathogenic pseudorabies virus was the etiologic agent of this epidemic. PMID:24377462

  14. Pathogenic Pseudorabies Virus, China, 2012

    PubMed Central

    Yu, Xiuling; Zhou, Zhi; Hu, Dongmei; Zhang, Qian; Han, Tao; Li, Xiaoxia; Gu, Xiaoxue; Yuan, Lin; Zhang, Shuo; Wang, Baoyue; Qu, Ping; Liu, Jinhua; Zhai, Xinyan

    2014-01-01

    In 2012, an unprecedented large-scale outbreak of disease in pigs in China caused great economic losses to the swine industry. Isolates from pseudorabies virus epidemics in swine herds were characterized. Evidence confirmed that the pathogenic pseudorabies virus was the etiologic agent of this epidemic. PMID:24377462

  15. How Viruses Enter Animal Cells

    Microsoft Academic Search

    Alicia E. Smith; Ari Helenius

    2004-01-01

    Viruses replicate within living cells and use the cellular machinery for the synthesis of their genome and other components. To gain access, they have evolved a variety of elegant mechanisms to deliver their genes and accessory proteins into the host cell. Many animal viruses take advantage of endocytic pathways and rely on the cell to guide them through a complex

  16. Marine Viruses: Truth or Dare

    NASA Astrophysics Data System (ADS)

    Breitbart, Mya

    2012-01-01

    Over the past two decades, marine virology has progressed from a curiosity to an intensely studied topic of critical importance to oceanography. At concentrations of approximately 10 million viruses per milliliter of surface seawater, viruses are the most abundant biological entities in the oceans. The majority of these viruses are phages (viruses that infect bacteria). Through lysing their bacterial hosts, marine phages control bacterial abundance, affect community composition, and impact global biogeochemical cycles. In addition, phages influence their hosts through selection for resistance, horizontal gene transfer, and manipulation of bacterial metabolism. Recent work has also demonstrated that marine phages are extremely diverse and can carry a variety of auxiliary metabolic genes encoding critical ecological functions. This review is structured as a scientific "truth or dare," revealing several well-established "truths" about marine viruses and presenting a few "dares" for the research community to undertake in future studies.

  17. Vaccinia virus in postvaccinal encephalitis.

    PubMed

    Gurvich, E B; Vilesova, I S

    1983-03-01

    Results of virological examination of 239 samples taken from 84 children with neurological complications after smallpox vaccination are described. In postvaccinal encephalitis, vaccinia virus was isolated from blood, cerebrospinal fluid and pharyngeal secretions of 23 out of 40 children (57.5%) as well as from autopsy specimens sampled between 10-35 days after vaccination. During the acute period of disease, virus was detected in 17 out of 31 (54.2%) cerebrospinal fluid specimens. In 3 postvaccinal encephalitis cases the virus was present in brain and in a case of encephalomyelitis--in the spinal cord. These results confirmed the participation of vaccinia virus in the pathogenesis of postvaccinal encephalitis. The pathogenicity of vaccinia virus may be manifested only under a changed reactivity of the vaccinated host. PMID:6135334

  18. Co-infections with Chikungunya Virus and Dengue Virus in Delhi, India

    PubMed Central

    Chahar, Harendra S.; Bharaj, Preeti; Dar, Lalit; Guleria, Randeep; Kabra, Sushil K.

    2009-01-01

    Aedes aegypti mosquitoes are common vectors for dengue virus and chikungunya virus. In areas where both viruses cocirculate, they can be transmitted together. During a dengue outbreak in Delhi in 2006, 17 of 69 serum samples were positive for chikungunya virus by reverse transcription–PCR; 6 samples were positive for both viruses. PMID:19624923

  19. Genome Sequence of Bivens Arm Virus, a Tibrovirus Belonging to the Species Tibrogargan virus (Mononegavirales: Rhabdoviridae)

    PubMed Central

    Hensley, Lisa E.

    2015-01-01

    The new rhabdoviral genus Tibrovirus currently has two members, Coastal Plains virus and Tibrogargan virus. Here, we report the coding-complete genome sequence of a putative member of this genus, Bivens Arm virus. A genomic comparison reveals Bivens Arm virus to be closely related to, but distinct from, Tibrogargan virus. PMID:25792044

  20. IInoculate your computer with Symantec AntiVirus, for free! Welchia virus? Blaster

    E-print Network

    IInoculate your computer with Symantec AntiVirus, for free! Welchia virus? Blaster virus? PC all students, faculty and staff can get a free copy. Computer viruses on campus are no laughing matter. Last Symantec AntiVirus managed version from the "Computing Essentials 2004" CD or download it from http

  1. Infectious vaccinia virus recombinants that express hepatitis B virus surface antigen

    NASA Astrophysics Data System (ADS)

    Smith, Geoffrey L.; Mackett, Michael; Moss, Bernard

    1983-04-01

    Potential live vaccines against hepatitis B virus have been produced. The coding sequence for hepatitis B virus surface antigen (HBsAg) has been inserted into the vaccinia virus genome under control of vaccinia virus early promoters. Cells infected with these vaccinia virus recombinants synthesize and excrete HBsAg and vaccinated rabbits rapidly produce antibodies to HBsAg.

  2. A single vertebrate DNA virus protein disarms invertebrate immunity to RNA virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. While investigating virus-invertebrate host interactions we found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), were unable to infect certain Lepido...

  3. Immunogenicity of combination DNA vaccines for Rift Valley fever virus, tick-borne encephalitis virus, Hantaan virus, and Crimean Congo hemorrhagic fever virus

    Microsoft Academic Search

    Kristin Spik; Amy Shurtleff; Anita K. McElroy; Mary C. Guttieri; Jay W. Hooper; Connie Schmaljohn

    2006-01-01

    DNA vaccines for Rift Valley fever virus (RVFV), Crimean Congo hemorrhagic fever virus (CCHFV), tick-borne encephalitis virus (TBEV), and Hantaan virus (HTNV), were tested in mice alone or in various combinations. The bunyavirus vaccines (RVFV, CCHFV, and HTNV) expressed Gn and Gc genes, and the flavivirus vaccine (TBEV) expressed the preM and E genes. All vaccines were delivered by gene

  4. Biologically Inspired Defenses Against Computer Viruses

    Microsoft Academic Search

    Jeffrey O. Kephart; Gregory B. Sorkin; William C. Arnold; David M. Chess; Gerald Tesauro; Steve R. White

    1995-01-01

    Today's anti-virus technology, based largely on analysis of existing viruses by human experts, is just barely able to keep pace with the more than three new computer viruses that are writ­ ten daily. In a few years, intelligent agents nav­ igating through highly connected networks are likely to form an extremely fertile medium for a new breed of viruses. At

  5. Modeling Computer Viruses MSc Thesis (Afstudeerscriptie)

    E-print Network

    Amsterdam, University of

    Modeling Computer Viruses MSc Thesis (Afstudeerscriptie) written by Luite Menno Pieter van Zelst About half a year ago, Alban Ponse, my thesis supervisor, suggested that the topic of `computer viruses indus- try and the creators of computer viruses. After all, the anti-virus industry stands to lose a lot

  6. Hepatitis E Virus Infection

    PubMed Central

    Dalton, Harry R.; Abravanel, Florence; Izopet, Jacques

    2014-01-01

    SUMMARY Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries. PMID:24396139

  7. CARACTERSTICAS Y ARTICULACIN DEL ESPACIO DEL MUNDO TERRENAL Y DEL ESPACIO DEL MS ALL

    E-print Network

    Paris-Sud XI, Université de

    1 12/03/2009 CARACTERÍSTICAS Y ARTICULACI�N DEL ESPACIO DEL MUNDO TERRENAL Y DEL ESPACIO DEL MÁS "El tiempo y el espacio en Gonzalo de Berceo"1. El estudio concierne toda la obra, y se centra en la las "herramientas mentales" que son la concepción del tiempo y del espacio. En lo que toca al segundo

  8. Virus interactions with human signal transduction pathways.

    PubMed

    Zhao, Zhongming; Xia, Junfeng; Tastan, Oznur; Singh, Irtisha; Kshirsagar, Meghana; Carbonell, Jaime; Klein-Seetharaman, Judith

    2011-01-01

    Viruses depend on their hosts at every stage of their life cycles and must therefore communicate with them via Protein-Protein Interactions (PPIs). To investigate the mechanisms of communication by different viruses, we overlay reported pairwise human-virus PPIs on human signalling pathways. Of 671 pathways obtained from NCI and Reactome databases, 355 are potentially targeted by at least one virus. The majority of pathways are linked to more than one virus. We find evidence supporting the hypothesis that viruses often interact with different proteins depending on the targeted pathway. Pathway analysis indicates overrepresentation of some pathways targeted by viruses. The merged network of the most statistically significant pathways shows several centrally located proteins, which are also hub proteins. Generally, hub proteins are targeted more frequently by viruses. Numerous proteins in virus-targeted pathways are known drug targets, suggesting that these might be exploited as potential new approaches to treatments against multiple viruses. PMID:21330695

  9. Modelling the evolution of the influenza virus

    E-print Network

    Burke, David

    2008-06-27

    CamGrid: High Throughput Computing in Science dfb21@cam.ac.uk Dr David Burke Antigenic Cartography Group Department of Zoology University of Cambridge 25th June 2008 Modelling the evolution of the influenza virus Antigenic variation of viruses... Antigenically Stable Pathogens Antigenically Variable Pathogens Smallpox Measles Tuberculosis Mumps Tetanus Influenza Virus Malaria HIV Dengue The Influenza Virus Annually, 'flu infects 7-14% of the population (400-800 million people globally ) Virus...

  10. SARS and West Nile Virus

    Microsoft Academic Search

    Mark B. Loeb

    Clinical presentation of SARS is nonspecific; the important clinical findings in West Nile virus infection are those associated\\u000a with neurological complications.\\u000a \\u000a Rapid and accurate diagnosis of SARS and West Nile virus infection remains an important clinical challenge.\\u000a \\u000a \\u000a Older adults are at higher risk of complications, including death from SARS and West Nile virus.\\u000a \\u000a \\u000a At present, there is no effective therapy

  11. Respiratory Viruses Other than Influenza Virus: Impact and Therapeutic Advances

    PubMed Central

    Nichols, W. Garrett; Peck Campbell, Angela J.; Boeckh, Michael

    2008-01-01

    Summary: Though several antivirals have been developed and marketed to treat influenza virus infections, the development of antiviral agents with clinical activity against other respiratory viruses has been more problematic. Here we review the epidemiology of respiratory viral infections in immunocompetent and immunocompromised hosts, examine the evidence surrounding the currently available antivirals for respiratory viral infections other than influenza, highlight those that are in the pipeline, and discuss the hurdles for development of such agents. PMID:18400797

  12. Gene homology between orf virus and smallpox variola virus.

    PubMed

    Mercer, A A; Fraser, K M; Esposito, J J

    1996-01-01

    About 47% identity was observed between the deduced amino acid sequences of a protein encoded by a gene of the parapoxvirus orf virus (OV) strain NZ2 and a 6 kDa protein of unknown function reported to be produced by an open reading frame expressed early after infection by the orthopoxvirus Western Reserve vaccinia virus (VAC); the open reading frame is absent from VAC strain Copenhagen. Examination of sequences reported for variola virus (VAR) strains Bangladesh, India, Congo- 1970, Somalia- 1977 and Garcia- 1966 revealed each encoded a correlate 58 amino acid protein. The open reading frame was not reported in the original analyses of these sequences because a lower limit of 60 amino acids was used to identify potential encoded proteins. Inspection of partial reading frames reported for cowpox virus (CWV) and ectromelia virus (EMV) suggested that these viruses might also code for a correlate of the VAC WR protein. DNA sequencing of cloned fragments of CWV and EMV confirmed that both these orthopoxviruses encode closely related, full length variants of the VAC and VAR open reading frames. The OV homologue is coded in the OV strain NZ2 BamHI-E fragment E2L open reading frame, which we reported is transcribed early postinfection; moreover, analysis of an NZ2 variant showed E2L was absent, indicating that E2L, like the VAC cognate, is nonessential for virus replication in cell culture. The parapoxvirus and orthopoxvirus correlates have about 20% amino acid sequence resemblance to African swine fever virus DNA binding protein p10, suggesting an ancestral relation of genes. PMID:8972571

  13. Oncolytic virus therapy using genetically engineered herpes simplex viruses

    Microsoft Academic Search

    Tomoki Todo

    2002-01-01

    An increasing number of oncolytic virus vectors has been developed lately for cancer therapy. Herpes simplex virus type 1\\u000a (HSV-1) vectors are particularly useful, because they can be genetically engineered to replicate and spread highly selectively\\u000a in tumor cells and can also express multiple foreign transgenes. These vectors can manifest cytopathic effect in a wide variety\\u000a of tumor types without

  14. Rice Yellow Mottle Virus, an RNA Plant Virus, Evolves as Rapidly as Most RNA Animal Viruses? †

    PubMed Central

    Fargette, D.; Pinel, A.; Rakotomalala, M.; Sangu, E.; Traoré, O.; Sérémé, D.; Sorho, F.; Issaka, S.; Hébrard, E.; Séré, Y.; Kanyeka, Z.; Konaté, G.

    2008-01-01

    The rate of evolution of an RNA plant virus has never been estimated using temporally spaced sequence data, by contrast to the information available on an increasing range of animal viruses. Accordingly, the evolution rate of Rice yellow mottle virus (RYMV) was calculated from sequences of the coat protein gene of isolates collected from rice over a 40-year period in different parts of Africa. The evolution rate of RYMV was estimated by pairwise distance linear regression on five phylogeographically defined groups comprising a total of 135 isolates. It was further assessed from 253 isolates collected all over Africa by Bayesian coalescent methods under strict and relaxed molecular clock models and under constant size and skyline population genetic models. Consistent estimates of the evolution rate between 4 × 10?4 and 8 × 10?4 nucleotides (nt)/site/year were obtained whatever method and model were applied. The synonymous evolution rate was between 8 × 10?4 and 11 × 10?4 nt/site/year. The overall and synonymous evolution rates of RYMV were within the range of the rates of 50 RNA animal viruses, below the average but above the distribution median. Experimentally, in host change studies, substitutions accumulated at an even higher rate. The results show that an RNA plant virus such as RYMV evolves as rapidly as most RNA animal viruses. Knowledge of the molecular clock of plant viruses provides methods for testing a wide range of biological hypotheses. PMID:18199644

  15. Adeno-associated virus: from defective virus to effective vector

    PubMed Central

    Gonçalves, Manuel AFV

    2005-01-01

    The initial discovery of adeno-associated virus (AAV) mixed with adenovirus particles was not a fortuitous one but rather an expression of AAV biology. Indeed, as it came to be known, in addition to the unavoidable host cell, AAV typically needs a so-called helper virus such as adenovirus to replicate. Since the AAV life cycle revolves around another unrelated virus it was dubbed a satellite virus. However, the structural simplicity plus the defective and non-pathogenic character of this satellite virus caused recombinant forms to acquire centre-stage prominence in the current constellation of vectors for human gene therapy. In the present review, issues related to the development of recombinant AAV (rAAV) vectors, from the general principle to production methods, tropism modifications and other emerging technologies are discussed. In addition, the accumulating knowledge regarding the mechanisms of rAAV genome transduction and persistence is reviewed. The topics on rAAV vectorology are supplemented with information on the parental virus biology with an emphasis on aspects that directly impact on vector design and performance such as genome replication, genetic structure, and host cell entry. PMID:15877812

  16. Role of murine leukemia virus nucleocapsid protein in virus assembly.

    PubMed

    Muriaux, Delphine; Costes, Sylvain; Nagashima, Kunio; Mirro, Jane; Cho, Ed; Lockett, Stephen; Rein, Alan

    2004-11-01

    The retroviral nucleocapsid protein (NC) originates by cleavage of the Gag polyprotein. It is highly basic and contains one or two zinc fingers. Mutations in either the basic residues or the zinc fingers can affect several events of the virus life cycle. They frequently prevent the specific packaging of the viral RNA, affect reverse transcription, and impair virion assembly. In this work, we explore the role of NC in murine leukemia virus (MLV) particle assembly and release. A panel of NC mutants, including mutants of the zinc finger and of a basic region, as well as truncations of the NC domain of Gag, were studied. Several of these mutations dramatically reduce the release of virus particles. A mutant completely lacking the NC domain is apparently incapable of assembling into particles, although its Gag protein is still targeted to the plasma membrane. By electron microscopy on thin sections of virus-producing cells, we observed that some NC mutants exhibit various stages of budding defects at the plasma membrane and have aberrant particle morphology; electron micrographs of cells expressing some of these mutants are strikingly similar to those of cells expressing "late-domain" mutants. However, the defects of NC mutants with respect to virus release and infectivity could be complemented by an MLV lacking the p12 domain. Therefore, the functions of NC in virus budding and infectivity are completely distinct from viral late-domain function. PMID:15507624

  17. Role of Murine Leukemia Virus Nucleocapsid Protein in Virus Assembly

    PubMed Central

    Muriaux, Delphine; Costes, Sylvain; Nagashima, Kunio; Mirro, Jane; Cho, Ed; Lockett, Stephen; Rein, Alan

    2004-01-01

    The retroviral nucleocapsid protein (NC) originates by cleavage of the Gag polyprotein. It is highly basic and contains one or two zinc fingers. Mutations in either the basic residues or the zinc fingers can affect several events of the virus life cycle. They frequently prevent the specific packaging of the viral RNA, affect reverse transcription, and impair virion assembly. In this work, we explore the role of NC in murine leukemia virus (MLV) particle assembly and release. A panel of NC mutants, including mutants of the zinc finger and of a basic region, as well as truncations of the NC domain of Gag, were studied. Several of these mutations dramatically reduce the release of virus particles. A mutant completely lacking the NC domain is apparently incapable of assembling into particles, although its Gag protein is still targeted to the plasma membrane. By electron microscopy on thin sections of virus-producing cells, we observed that some NC mutants exhibit various stages of budding defects at the plasma membrane and have aberrant particle morphology; electron micrographs of cells expressing some of these mutants are strikingly similar to those of cells expressing “late-domain” mutants. However, the defects of NC mutants with respect to virus release and infectivity could be complemented by an MLV lacking the p12 domain. Therefore, the functions of NC in virus budding and infectivity are completely distinct from viral late-domain function. PMID:15507624

  18. Human immunodeficiency virus endocrinopathy

    PubMed Central

    Sinha, Uma; Sengupta, Nilanjan; Mukhopadhyay, Prasanta; Roy, Keshab Sinha

    2011-01-01

    Human immunodeficiency virus (HIV) endocrinopathy encompasses a broad spectrum of disorders. Almost all the endocrine organs are virtually affected by HIV infection. HIV can directly alter glandular function. More commonly secondary endocrine dysfunction occurs due to opportunistic infections and neoplasms in immunocompromised state. The complex interaction between HIV infection and endocrine system may be manifested as subtle biochemical and hormonal perturbation to overt glandular failure. Antiretroviral therapy as well as other essential medications often result in adverse endocrinal consequences. Apart from adrenal insufficiency, hypogonadism, diabetes and bone loss, AIDS wasting syndrome and HIV lipodystrophy need special reference. Endocrinal evaluation should proceed as in other patients with suspected endocrine dysfunction. Available treatment options have been shown to improve quality of life and long-term mortality in AIDS patients. PMID:22028995

  19. Ebola virus disease.

    PubMed

    Richardson, Kathleen J

    2015-01-01

    Ebola is an unfamiliar disease with a high mortality rate. Until recently, it occurred only in rural tropical regions and most health care providers had only read about it in epidemiology classes. With globalization, international travel, and foreign medical missions, it is possible that a patient with Ebola exposure and/or symptoms may present in any emergency department. All health care providers must be familiar with identifying the signs and symptoms of Ebola and capable of initiating an appropriate response. This article presents an overview of Ebola virus disease for health care providers, covering pathophysiology, identification, treatment, and general considerations for hospitals and providers to consider when developing policies and procedures. PMID:25929221

  20. Lactate dehydrogenase-elevating virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter describes the taxonomic classification of Lactate dehydrogenase-elevating virus (LDV). Included are: host, genome, classification, morphology, physicochemical and physical properties, nucleic acid, proteins, lipids, carbohydrates, geographic range, phylogenetic properties, biologic...

  1. Arthropod viruses and small RNAs.

    PubMed

    Vijayendran, Diveena; Airs, Paul M; Dolezal, Kelly; Bonning, Bryony C

    2013-10-01

    The recently characterized small RNAs provide a new paradigm for physiological studies. These molecules have been shown to be integral players in processes as diverse as development and innate immunity against bacteria and viruses in eukaryotes. Several of the well-characterized small RNAs including small interfering RNAs, microRNAs and PIWI-interacting RNAs are emerging as important players in mediating arthropod host-virus interactions. Understanding the role of small RNAs in arthropod host-virus molecular interactions will facilitate manipulation of these pathways for both management of arthropod pests of agricultural and medical importance, and for protection of beneficial arthropods such as honey bees and shrimp. This review highlights recent research on the role of small RNAs in arthropod host-virus interactions with reference to other host-pathogen systems. PMID:23932976

  2. Mapping overlapping functional elements embedded within the protein-coding regions of RNA viruses

    E-print Network

    Firth, Andrew E.

    2014-10-17

    with the potential to cause acute fatal disease in healthy adult humans are RNA viruses. Such viruses include influenza A virus (IAV), Ebola virus, ra- bies virus, SARS virus, MERS virus, Japanese encephali- tis virus, yellow fever virus, dengue virus, eastern equine...

  3. Cellular Sequences in Stealth Viruses

    Microsoft Academic Search

    W. John Martin

    1998-01-01

    Cloned DNA obtained from the culture of an African green monkey simian cytomegalovirus-derived stealth virus contains multiple discrete regions of significant sequence homology (p values ranging from 4 × 10–3to 1 × 10–20) to portions of known human cellular genes. The stealth virus was cultured from a patient with chronic fatigue syndrome (CFS). Earlier studies had revealed considerable sequence heterogeneity

  4. Coronavirus avian infectious bronchitis virus

    Microsoft Academic Search

    Dave Cavanagh

    2007-01-01

    Infectious bronchitis virus (IBV), the coronavirus of the chicken (Gallus gallus), is one of the foremost causes of economic loss within the poultry industry, affecting the performance of both meat-type and egg-laying birds. The virus replicates not only in the epithelium of upper and lower respiratory tract tissues, but also in many tissues along the alimentary tract and elsewhere e.g.

  5. Simian virus 40 in humans

    Microsoft Academic Search

    Fernanda Martini; Alfredo Corallini; Veronica Balatti; Silvia Sabbioni; Cecilia Pancaldi; Mauro Tognon

    2007-01-01

    Simian virus 40 (SV40) is a monkey virus that was administered to human populations by contaminated vaccines which were produced in SV40 naturally infected monkey cells. Recent molecular biology and epidemiological studies suggest that SV40 may be contagiously transmitted in humans by horizontal infection, independently from the earlier administration of SV40-contaminated vaccines. SV40 footprints in humans have been found associated

  6. Foodborne viruses: an emerging problem

    Microsoft Academic Search

    Marion Koopmans; Erwin Duizer

    2004-01-01

    Several groups of viruses may infect persons after ingestion and then are shed via stool. Of these, the norovirus (NoV) and hepatitis A virus (HAV) are currently recognised as the most important human foodborne pathogens with regard to the number of outbreaks and people affected in the Western world.NoV and HAV are highly infectious and may lead to widespread outbreaks.

  7. Human Enteric Viruses in Groundwater

    Microsoft Academic Search

    S. H. Park; E. J. Kim; T. H. Yun; J. H. Lee; C. K. Kim; Y. H. Seo; S. A. Oh; S. S. Choi; S. J. Cho; M. S. Kim; G. Y. Han; M. Y. Kim; H. S. Jeong; D. S. Cheon; H. S. Kim

    2010-01-01

    Waterborne outbreaks of enteric viruses are a major public health concern. The present study has been carried out to assess\\u000a the presence of enteric viruses responsible for human acute gastroenteritis (AGE) in groundwater intended for drinking and\\u000a produce washing. In total, 62 samples from groundwater for drinking and produce washing collected from Dec 2007 to Dec 2008\\u000a in Seoul were

  8. Lily symptomless virus in tulip

    Microsoft Academic Search

    A. F. L. M. Derks; C. J. Asjes

    1975-01-01

    Lily symptomless virus (LSV) was transmitted mechanically to only two out of 53 plant species (18 families) tested, i.e.Lilium formosanum and tulip ‘Rose Copland’ (Liliaceae). The aphid speciesMacrosiphum euphorbiae, Myzus persicae, andAphis gossypii transmitted LSV in a non-persistent manner fromLilium Mid-century hybrid ‘Enchantment’ to tulip ‘Rose Copland’.M. euphorbiae transmitted the virus more efficiently thanM. persicae andA. gossypii. The yield of

  9. Another Really, Really Big Virus

    PubMed Central

    Van Etten, James L.

    2011-01-01

    Viruses with genomes larger than 300 kb and up to 1.2 Mb, which encode hundreds of proteins, are being discovered and characterized with increasing frequency. Most, but not all, of these large viruses (often referred to as giruses) infect protists that live in aqueous environments. Bioinformatic analyses of metagenomes of aqueous samples indicate that large DNA viruses are quite common in nature and await discovery. One issue that is perhaps not appreciated by the virology community is that large viruses, even those classified in the same family, can differ significantly in morphology, lifestyle, and gene complement. This brief commentary, which will mention some of these unique properties, was stimulated by the characterization of the newest member of this club, virus CroV (Fischer, M.G.; Allen, M.J.; Wilson, W.H.; Suttle, C.A. Giant virus with a remarkable complement of genes infects marine zooplankton. Proc. Natl. Acad. Sci. USA 2010, 107, 19508–19513 [1]). CroV has a 730 kb genome (with ?544 protein-encoding genes) and infects the marine microzooplankton Cafeteria roenbergensis producing a lytic infection. PMID:21994725

  10. A DNA Virus of Drosophila

    PubMed Central

    Unckless, Robert L.

    2011-01-01

    Little is known about the viruses infecting most species. Even in groups as well-studied as Drosophila, only a handful of viruses have been well-characterized. A viral metagenomic approach was used to explore viral diversity in 83 wild-caught Drosophila innubila, a mushroom feeding member of the quinaria group. A single fly that was injected with, and died from, Drosophila C Virus (DCV) was added to the sample as a control. Two-thirds of reads in the infected sample had DCV as the best BLAST hit, suggesting that the protocol developed is highly sensitive. In addition to the DCV hits, several sequences had Oryctes rhinoceros Nudivirus, a double-stranded DNA virus, as a best BLAST hit. The virus associated with these sequences was termed Drosophila innubila Nudivirus (DiNV). PCR screens of natural populations showed that DiNV was both common and widespread taxonomically and geographically. Electron microscopy confirms the presence of virions in fly fecal material similar in structure to other described Nudiviruses. In 2 species, D. innubila and D. falleni, the virus is associated with a severe (?80–90%) loss of fecundity and significantly decreased lifespan. PMID:22053195

  11. ENZYMATIC VARIANTS OF INFLUENZA VIRUS

    PubMed Central

    Padgett, Billie L.; Walker, Duard L.

    1958-01-01

    The rate of elution of the variant virus from chicken RBC is progressively decreased as the temperature of incubation is increased above 25°C. The activity of the parent virus, on the other hand, is increased as the temperature is increased up to 40°C. The major cause of the decreased activity of the variant at temperatures above 2S°C. is an inhibition of the variant enzyme rather than its inactivation. The activity of the variant enzyme is stimulated in the presence of strontium, calcium, and barium ions. Manganese has only a slight effect, and magnesium has no stimulatory effect on the elution of the variant virus. Elution of the variant at 37°C. is progressively inhibited at pH values above 7, while the parent virus is still active at pH 8. In the absence of calcium the variant enzyme, hemagglutinin, and infectivity are more heat labile than those of the parent virus. The addition of calcium increases the heat stability of all three properties of the variant, and in the presence of calcium the infectivity of the variant is as stable as that of the parent virus. PMID:13587849

  12. PC viruses: How do they do that

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They've been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  13. PC viruses: How do they do that?

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They`ve been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  14. Genomic sequencing of deer tick virus and phylogeny of powassan-related viruses of North America.

    PubMed

    Kuno, G; Artsob, H; Karabatsos, N; Tsuchiya, K R; Chang, G J

    2001-11-01

    Powassan (POW) virus is responsible for central nervous system infection in humans in North America and the eastern parts of Russia. Recently, a new flavivirus, deer tick (DT) virus, related to POW virus was isolated in the United States, but neither its pathogenic potential in human nor the taxonomic relationship with POW virus has been elucidated. In this study, we obtained the near-full-length genomic sequence of the DT virus and complete sequences of 3 genomic regions of 15 strains of POW-related virus strains. The phylogeny revealed 2 lineages, one of which had the prototype POW virus and the other DT virus. Both lineages can cause central nervous system infection in humans. By use of the combination of molecular definition of virus species within the genus Flavivirus and serological distinction in a 2-way cross-neutralization test, the lineage of DT virus is classified as a distinct genotype of POW virus. PMID:11716135

  15. Foodborne viruses: an emerging problem.

    PubMed

    Koopmans, Marion; Duizer, Erwin

    2004-01-01

    Several groups of viruses may infect persons after ingestion and then are shed via stool. Of these, the norovirus (NoV) and hepatitis A virus (HAV) are currently recognised as the most important human foodborne pathogens with regard to the number of outbreaks and people affected in the Western world. NoV and HAV are highly infectious and may lead to widespread outbreaks. The clinical manifestation of NoV infection, however, is relatively mild. Asymptomatic infections are common and may contribute to the spread of the infection. Introduction of NoV in a community or population (a seeding event) may be followed by additional spread because of the highly infectious nature of NoV, resulting in a great number of secondary infections (50% of contacts). Hepatitis A is an increasing problem because of the decrease in immunity of populations in countries with high standards of hygiene. Molecular-based methods can detect viruses in shellfish but are not yet available for other foods. The applicability of the methods currently available for monitoring foods for viral contamination is unknown. No consistent correlation has been found between the presence of indicator microorganisms (i.e. bacteriophages, E. coli) and viruses. NoV and HAV are highly infectious and exhibit variable levels of resistance to heat and disinfection agents. However, they are both inactivated at 100 degrees C. No validated model virus or model system is available for studies of inactivation of NoV, although investigations could make use of structurally similar viruses (i.e. canine and feline caliciviruses). In the absence of a model virus or model system, food safety guidelines need to be based on studies that have been performed with the most resistant enteric RNA viruses (i.e. HAV, for which a model system does exist) and also with bacteriophages (for water). Most documented foodborne viral outbreaks can be traced to food that has been manually handled by an infected foodhandler, rather than to industrially processed foods. The viral contamination of food can occur anywhere in the process from farm to fork, but most foodborne viral infections can be traced back to infected persons who handle food that is not heated or otherwise treated afterwards. Therefore, emphasis should be on stringent personal hygiene during preparation. If viruses are present in food preprocessing, residual viral infectivity may be present after some industrial processes. Therefore, it is key that sufficient attention be given to good agriculture practice (GAP) and good manufacturing practice (GMP) to avoid introduction of viruses onto the raw material and into the food-manufacturing environment, and to HACCP to assure adequate management of (control over) viruses present during the manufacturing process. If viruses are present in foods after processing, they remain infectious in most circumstances and in most foods for several days or weeks, especially if kept cooled (at 4 degrees C). Therefore, emphasis should be on stringent personal hygiene during preparation. For the control of foodborne viral infections, it is necessary to: Heighten awareness about the presence and spread of these viruses by foodhandlers; Optimise and standardise methods for the detection of foodborne viruses; Develop laboratory-based surveillance to detect large, common-source outbreaks at an early stage; and Emphasise consideration of viruses in setting up food safety quality control and management systems (GHP, GMP, HACCP). PMID:14672828

  16. Comparison of cowpox-like viruses isolated from European zoos

    Microsoft Academic Search

    D. Baxby; W. B. Shackleton; Jean Wheeler; A. Turner

    1979-01-01

    Summary Poxviruses isolated from captive carnivores in Russia (Moscow virus) and elephants in Germany (elephant virus) were very closely-related to cowpox virus. Immunological analysis with absorbed sera separated elephant virus but not cowpox and Moscow virus, whereas polypeptide analysis separated cowpox but not elephant and Moscow virus. A combination of biological tests separated all three. The epidemiological implications are briefly

  17. Stochastic analysis of virus transport in aquifers

    USGS Publications Warehouse

    Campbell, Rehmann L.L.; Welty, C.; Harvey, R.W.

    1999-01-01

    A large-scale model of virus transport in aquifers is derived using spectral perturbation analysis. The effects of spatial variability in aquifer hydraulic conductivity and virus transport (attachment, detachment, and inactivation) parameters on large-scale virus transport are evaluated. A stochastic mean model of virus transport is developed by linking a simple system of local-scale free-virus transport and attached-virus conservation equations from the current literature with a random-field representation of aquifer and virus transport properties. The resultant mean equations for free and attached viruses are found to differ considerably from the local-scale equations on which they are based and include effects such as a free-virus effective velocity that is a function of aquifer heterogeneity as well as virus transport parameters. Stochastic mean free-virus breakthrough curves are compared with local model output in order to observe the effects of spatial variability on mean one-dimensional virus transport in three-dimensionally heterogeneous porous media. Significant findings from this theoretical analysis include the following: (1) Stochastic model breakthrough occurs earlier than local model breakthrough, and this effect is most pronounced for the least conductive aquifers studied. (2) A high degree of aquifer heterogeneity can lead to virus breakthrough actually preceding that of a conservative tracer. (3) As the mean hydraulic conductivity is increased, the mean model shows less sensitivity to the variance of the natural-logarithm hydraulic conductivity and mean virus diameter. (4) Incorporation of a heterogeneous colloid filtration term results in higher predicted concentrations than a simple first-order adsorption term for a given mean attachment rate. (5) Incorporation of aquifer heterogeneity leads to a greater range of virus diameters for which significant breakthrough occurs. (6) The mean model is more sensitive to the inactivation rate of viruses associated with solid surfaces than to the inactivation rate of viruses in solution.

  18. Emerging and re-emerging swine viruses.

    PubMed

    Meng, X J

    2012-03-01

    In the past two decades or so, a number of viruses have emerged in the global swine population. Some, such as porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2), cause economically important diseases in pigs, whereas others such as porcine torque teno virus (TTV), now known as Torque teno sus virus (TTSuV), porcine bocavirus (PBoV) and related novel parvoviruses, porcine kobuvirus, porcine toroviruses (PToV) and porcine lymphotropic herpesviruses (PLHV), are mostly subclinical in swine herds. Although some emerging swine viruses such as swine hepatitis E virus (swine HEV), porcine endogenous retrovirus (PERV) and porcine sapovirus (porcine SaV) may have a limited clinical implication in swine health, they do pose a potential public health concern in humans due to zoonotic (swine HEV) or potential zoonotic (porcine SaV) and xenozoonotic (PERV, PLHV) risks. Other emerging viruses such as Nipah virus, Bungowannah virus and Menangle virus not only cause diseases in pigs but some also pose important zoonotic threat to humans. This article focuses on emerging and re-emerging swine viruses that have a limited or uncertain clinical and economic impact on pig health. The transmission, epidemiology and pathogenic potential of these viruses are discussed. In addition, the two economically important emerging viruses, PRRSV and PCV2, are also briefly discussed to identify important knowledge gaps. PMID:22225855

  19. Plasmodesmata: channels for viruses on the move.

    PubMed

    Heinlein, Manfred

    2015-01-01

    The symplastic communication network established by plasmodesmata (PD) and connected phloem provides an essential pathway for spatiotemporal intercellular signaling in plant development but is also exploited by viruses for moving their genomes between cells in order to infect plants systemically. Virus movement depends on virus-encoded movement proteins (MPs) that target PD and therefore represent important keys to the cellular mechanisms underlying the intercellular trafficking of viruses and other macromolecules. Viruses and their MPs have evolved different mechanisms for intracellular transport and interaction with PD. Some viruses move from cell to cell by interacting with cellular mechanisms that control the size exclusion limit of PD whereas other viruses alter the PD architecture through assembly of specialized transport structures within the channel. Some viruses move between cells in the form of assembled virus particles whereas other viruses may interact with nucleic acid transport mechanisms to move their genomes in a non-encapsidated form. Moreover, whereas several viruses rely on the secretory pathway to target PD, other viruses interact with the cortical endoplasmic reticulum and associated cytoskeleton to spread infection. This chapter provides an introduction into viruses and their role in studying the diverse cellular mechanisms involved in intercellular PD-mediated macromolecular trafficking. PMID:25287194

  20. Phylogenetic Properties of RNA Viruses

    PubMed Central

    Pompei, Simone; Loreto, Vittorio; Tria, Francesca

    2012-01-01

    A new word, phylodynamics, was coined to emphasize the interconnection between phylogenetic properties, as observed for instance in a phylogenetic tree, and the epidemic dynamics of viruses, where selection, mediated by the host immune response, and transmission play a crucial role. The challenges faced when investigating the evolution of RNA viruses call for a virtuous loop of data collection, data analysis and modeling. This already resulted both in the collection of massive sequences databases and in the formulation of hypotheses on the main mechanisms driving qualitative differences observed in the (reconstructed) evolutionary patterns of different RNA viruses. Qualitatively, it has been observed that selection driven by the host immune response induces an uneven survival ability among co-existing strains. As a consequence, the imbalance level of the phylogenetic tree is manifestly more pronounced if compared to the case when the interaction with the host immune system does not play a central role in the evolutive dynamics. While many imbalance metrics have been introduced, reliable methods to discriminate in a quantitative way different level of imbalance are still lacking. In our work, we reconstruct and analyze the phylogenetic trees of six RNA viruses, with a special emphasis on the human Influenza A virus, due to its relevance for vaccine preparation as well as for the theoretical challenges it poses due to its peculiar evolutionary dynamics. We focus in particular on topological properties. We point out the limitation featured by standard imbalance metrics, and we introduce a new methodology with which we assign the correct imbalance level of the phylogenetic trees, in agreement with the phylodynamics of the viruses. Our thorough quantitative analysis allows for a deeper understanding of the evolutionary dynamics of the considered RNA viruses, which is crucial in order to provide a valuable framework for a quantitative assessment of theoretical predictions. PMID:23028645

  1. Gestión del riesgo del cambio (primera parte)

    Microsoft Academic Search

    Juan Pablo Zorrilla Salgador

    1970-01-01

    A partir de la desaparición del sistema Bretton-Woods, y la libre flotación del\\u000atipo de cambio, el mundo se volvió más susceptible a todo tipo de riesgos.\\u000aEl presente artículo pretende explicar a los gestores financieros o empresarios interesados en el tema de instrumentos financieros derivados, a conocer lo\\u000amás relevante y necesario acerca del uso de futuros sobre el

  2. Virus Population Dynamics and Acquired Virus Resistance in Natural Microbial Communities

    Microsoft Academic Search

    Anders F. Andersson; Jillian F. Banfield

    2008-01-01

    Viruses shape microbial community structure and function by altering the fitness of their hosts and by promoting genetic exchange. The complexity of most natural ecosystems has precluded detailed studies of virus-host interactions. We reconstructed virus and host bacterial and archaeal genome sequences from community genomic data from two natural acidophilic biofilms. Viruses were matched to their hosts by analyzing spacer

  3. Nyamanini and Midway Viruses Define a Novel Taxon of RNA Viruses in the Order Mononegavirales

    Microsoft Academic Search

    Kathie A. Mihindukulasuriya; Nang L. Nguyen; Guang Wu; Henry V. Huang; Vsevolod L. Popov; Robert B. Tesh; David Wang

    2009-01-01

    Here, we report the sequencing and classification of Nyamanini virus (NYMV) and Midway virus (MIDWV), two antigenically related viruses that were first isolated in 1957 and 1966, respectively. Although these viruses have been cultured multiple times from cattle egrets, seabirds, and their ticks, efforts to classify them taxonomically using conventional serological and electron microscopic approaches have failed completely. We used

  4. Differential diagnosis and genetic analysis of the antigenically related swine vesicular disease virus and Coxsackie viruses

    Microsoft Academic Search

    Otfried Marquardt; Volker F. Ohlinger

    1995-01-01

    Monoclonal antibodies directed against an isolate of swine vesicular disease virus (SVDV), characterized by virus neutralization tests and competition assays, were used to compare SVDV isolates and isolates of the antigenically related Coxsackie viruses by ELISA. Four SVDV-specific reaction patterns and one specific for Coxsackie viruses were observed. This provided a method for distinguishing between these enteroviruses. In addition, RT-PCRs

  5. A comparative electrophoretic examination of swine vesicular disease virus and Coxsackie B5 virus

    Microsoft Academic Search

    1977-01-01

    Summary Purified suspensions of Coxsackie B5 virus and swine vesicular disease virus (SVDV) were prepared by harvesting and purifying cell pack virus. Crossed immunoelectrophoresis was carried out with purified N and H antigen fractions (full and empty particles). Relative migration velocity (RMV) was calculated for the N antigen fraction of 3 SVD viruses (UKG72, HK71 and Italy66) and 2 Coxsackie

  6. A Fusion-Inhibiting Peptide against Rift Valley Fever Virus Inhibits Multiple, Diverse Viruses

    E-print Network

    A Fusion-Inhibiting Peptide against Rift Valley Fever Virus Inhibits Multiple, Diverse Viruses (Class I, II, and III) based on the protein sequence and structure. For Rift Valley fever virus (RVFV KW, Taylor SL, et al. (2013) A Fusion-Inhibiting Peptide against Rift Valley Fever Virus Inhibits

  7. Functional Features of Hepatitis C Virus Glycoproteins for Pseudotype Virus Entry into Mammalian Cells

    Microsoft Academic Search

    Keith Meyer; Arnab Basu; Ranjit Ray

    2000-01-01

    We have previously reported the generation of pseudotype virus from chimeric gene constructs encoding the ectodomain of the E1 or E2 glycoprotein of hepatitis C virus (HCV) genotype 1a appended to the trans membrane domain and cytoplasmic tail of the vesicular stomatitis virus (VSV) G protein. Sera derived from chimpanzees immunized with homologous HCV glycoproteins neutralized pseudotype virus infectivity (L.

  8. Research Projects in Ly's & Liang's Labs How virus-host interactions affect Lassa and Influenza virus

    E-print Network

    Blanchette, Robert A.

    Guanarito (BSL4) Sabia (BSL4) Chapare (BSL4) Lujo (BSL4) Rift Valley Fever (BSL3) (BSL4) Yellow Fever (BSL and Influenza virus replication, virulence and pathogenesis? I fl iLassa fever virus Influenza virus #12;Lassa Virus Causes Lethal Hemorrhagic Fever · Severe multisystem syndrome · Damage to overall vascular system

  9. Structure of the hepatitis E virus-like particle suggests mechanisms for virus assembly

    E-print Network

    Tao, Yizhi Jane

    Structure of the hepatitis E virus-like particle suggests mechanisms for virus assembly (received for review May 1, 2009) Hepatitis E virus (HEV), a small, non-enveloped RNA virus in the family Hepeviridae, is associated with endemic and epidemic acute viral hepatitis in developing countries. Our 3.5-Å

  10. GENOMIC SEQUENCING OF DEER TICK VIRUS AND PHYLOGENY OF POWASSAN-RELATED VIRUSES OF NORTH AMERICA

    Microsoft Academic Search

    G. KUNO; H. ARTSOB; N. KARABATSOS; K. R. TSUCHIYA; G. J. J. CHANG

    2001-01-01

    Powassan (POW) virus is responsible for central nervous system infection in humans in North America and the eastern parts of Russia. Recently, a new flavivirus, deer tick (DT) virus, related to POW virus was isolated in the United States, but neither its pathogenic potential in human nor the taxonomic relationship with POW virus has been elucidated. In this study, we

  11. Full Genome Sequencing and Genetic Characterization of Eubenangee Viruses Identify Pata Virus as a Distinct Species within the Genus Orbivirus

    Microsoft Academic Search

    Manjunatha N. Belaganahalli; Sushila Maan; Narender S. Maan; Kyriaki Nomikou; Ian Pritchard; Ross Lunt; Peter D. Kirkland; Houssam Attoui; Joe Brownlie; Peter P. C. Mertens

    2012-01-01

    Eubenangee virus has previously been identified as the cause of Tammar sudden death syndrome (TSDS). Eubenangee virus (EUBV), Tilligery virus (TILV), Pata virus (PATAV) and Ngoupe virus (NGOV) are currently all classified within the Eubenangee virus species of the genus Orbivirus, family Reoviridae. Full genome sequencing confirmed that EUBV and TILV (both of which are from Australia) show high levels

  12. Nucleocytoplasmic Shuttling of Influenza A Virus Proteins

    PubMed Central

    Li, Jing; Yu, Meng; Zheng, Weinan; Liu, Wenjun

    2015-01-01

    Influenza viruses transcribe and replicate their genomes in the nuclei of infected host cells. The viral ribonucleoprotein (vRNP) complex of influenza virus is the essential genetic unit of the virus. The viral proteins play important roles in multiple processes, including virus structural maintenance, mediating nucleocytoplasmic shuttling of the vRNP complex, virus particle assembly, and budding. Nucleocytoplasmic shuttling of viral proteins occurs throughout the entire virus life cycle. This review mainly focuses on matrix protein (M1), nucleoprotein (NP), nonstructural protein (NS1), and nuclear export protein (NEP), summarizing the mechanisms of their nucleocytoplasmic shuttling and the regulation of virus replication through their phosphorylation to further understand the regulation of nucleocytoplasmic shuttling in host adaptation of the viruses. PMID:26008706

  13. Testing for the Hepatitis C Virus

    MedlinePLUS

    ... C Virus" /> Consumer Summary – Sept. 13, 2013 Testing for the Hepatitis C Virus Formats View PDF ( ... longer for bleeding to stop Understanding Hepatitis C Testing How do I know if I have the ...

  14. The Origins of the AIDS Virus.

    ERIC Educational Resources Information Center

    Essex, Max; Kanki, Phyllis J.

    1988-01-01

    States that the virus is not unique since it has been discovered in other primates as well as in man. Relates studies of viruses that indicate some have evolved disease-free coexistence with their animal hosts. (RT)

  15. Recombination Promoted by DNA Viruses: Phage ? to Herpes Simplex Virus

    PubMed Central

    Weller, Sandra K.; Sawitzke, James A.

    2015-01-01

    The purpose of this review is to explore recombination strategies in DNA viruses. Homologous recombination is a universal genetic process that plays multiple roles in the biology of all organisms, including viruses. Recombination and DNA replication are interconnected, with recombination being essential for repairing DNA damage and supporting replication of the viral genome. Recombination also creates genetic diversity, and viral recombination mechanisms have important implications for understanding viral origins as well as the dynamic nature of viral-host interactions. Both bacteriophage ? and herpes simplex virus (HSV) display high rates of recombination, both utilizing their own proteins and commandeering cellular proteins to promote recombination reactions. We focus primarily on ? and HSV, as they have proven amenable to both genetic and biochemical analysis and have recently been shown to exhibit some surprising similarities that will guide future studies. PMID:25002096

  16. Autophagic machinery activated by dengue virus enhances virus replication

    SciTech Connect

    Lee, Y.-R. [Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Lei, H.-Y. [Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Liu, M.-T. [Tainan Hospital, Department of Health, Executive Yuan, Tainan, Taiwan (China); Wang, J.-R. [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Chen, S.-H. [Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Jiang-Shieh, Y.-F. [Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Lin, Y.-S. [Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Yeh, T.-M. [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Liu, C.-C. [Department of Pediatrics, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Liu, H.-S. [Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China)], E-mail: a713@mail.ncku.edu.tw

    2008-05-10

    Autophagy is a cellular response against stresses which include the infection of viruses and bacteria. We unravel that Dengue virus-2 (DV2) can trigger autophagic process in various infected cell lines demonstrated by GFP-LC3 dot formation and increased LC3-II formation. Autophagosome formation was also observed under the transmission electron microscope. DV2-induced autophagy further enhances the titers of extracellular and intracellular viruses indicating that autophagy can promote viral replication in the infected cells. Moreover, our data show that ATG5 protein is required to execute DV2-induced autophagy. All together, we are the first to demonstrate that DV can activate autophagic machinery that is favorable for viral replication.

  17. Evolution of Computer Virus Concealment and Anti-Virus Techniques: A Short Survey

    E-print Network

    Rad, Babak Bashari; Ibrahim, Suhaimi

    2011-01-01

    This paper presents a general overview on evolution of concealment methods in computer viruses and defensive techniques employed by anti-virus products. In order to stay far from the anti-virus scanners, computer viruses gradually improve their codes to make them invisible. On the other hand, anti-virus technologies continually follow the virus tricks and methodologies to overcome their threats. In this process, anti-virus experts design and develop new methodologies to make them stronger, more and more, every day. The purpose of this paper is to review these methodologies and outline their strengths and weaknesses to encourage those are interested in more investigation on these areas.

  18. Inoculación del virus de la enfermedad del ojo azul en verracos de la raza Pelón Mexicano

    Microsoft Academic Search

    Humberto Ramírez Mendoza; Roberto martínez Gamba; Oscar Trinidad; Vizuet Arriaga; Juan Monrroy Basilio

    Five Mexican Hairless boars were inoculated with Blue Eye Disease Rubulavirus in order to study clinical signs and pathologic findings in this breed. After inoculation by both intranasal and intramuscular routes clinical signs were observed in each boar daily. Subsequently, animals were slaugthered at 5, 10, 20, 30 and 45 days after inoculation. Samples were taken from tonsils, liver, lung,

  19. El estado del arte en las infecciones producidas por el virus del papiloma humano (VPH)

    Microsoft Academic Search

    R EINA; NUBIA M UÑOZ

    SUMMARY Anogenital human papillomavirus infection is the most frequent sexually transmitted disease. Around one hundred genotypes have been identified in humans, and 40 infect the genitalia and anal regions. Fifteen genotypes, classified as high- risk HPVs, are the necessary cause of cervical cancer and have been involved as carcinogenic agents for cancer of the vulva, vagina, anus, penis, and oropharyngeal

  20. A Mediterranean arbovirus: The Toscana virus

    Microsoft Academic Search

    Marcello Valassina; Maria Grazia Cusi; Pier Egisto Valensin

    2003-01-01

    Toscana virus (Bunyaviridae family, Phlebovirus genus) is a sandfly fever virus responsible for human neurological infections.\\u000a Sandfly viruses are transmitted by insect vectors (Phlebotomus species) and the infection is present in climatic areas that\\u000a allow the life cycle of the vector. The arthropode-borne Toscana virus is the etiologic agent of meningitis, meningoencephalitis,\\u000a and encephalitis. The frequency of this neuropathic infection

  1. SURVEY OF GRAPEVINE VIRUSES IN CHILE

    Microsoft Academic Search

    N. Fiore; S. Prodan; J. Montealegre; E. Aballay; A. M. Pino; A. Zamorano

    SUMMARY Grapevines from six Chilean regions were surveyed for virus diseases and tested for the presence of the most important viruses. ELISA testing of 2535 samples and confirmatory RT-PCR of some ELISA-negative samples from symptomatic and symptomless vines gave the fol- lowing infection rates: 6.36% for Grapevine fanleaf virus (GFLV); 4.67% for Grapevine leafroll associated virus 1 (GLRaV-1); 16.05% for

  2. Metamorphic Viruses Detection Using Artificial Immune System

    Microsoft Academic Search

    Essam Al Daoud

    2009-01-01

    This paper introduces a new artificial immune system for metamorphic viruses detection, the suggested system uses components and techniques found in the biological immune system such as multilayer, self, nonself , skin,skeleton, B-cell and receptors. In this study; metamorphic viruses are generated by two tools: Next Generation Virus Creation Kit (NGVCK0.30) and Virus Creation Lab for Windows 32 (VCL32). The

  3. Recent advances in oncolytic virus design

    Microsoft Academic Search

    Rubén Hernández-Alcoceba

    2011-01-01

    The cytolytic properties of viruses can be used to treat cancer. Replication of certain viruses is favoured in cancer cells,\\u000a whereas others can be modified to obtain tumour specificity. This approach has evolved to become a new discipline called virotherapy.\\u000a In addition, these replication-competent (oncolytic) viruses can be adapted as vectors for cancer gene therapy. The “armed”\\u000a viruses show a

  4. Virus-membrane interactions: spectroscopic studies

    Microsoft Academic Search

    K. P. Datema

    1987-01-01

    In this thesis some new aspects of the infection process of nonenveloped viruses are reported. The interaction of a rod-shaped (TMV) and three spherical (CCMV, BMV, SBMV) plant viruses, of the filamentous bacteriophage M13, and of their coat proteins with membranes have been investigated. A comparison is made between the infection mechanisms of these non-enveloped viruses.1 EFFECT OF PLANT VIRUSES

  5. Characteristics of Filoviridae: Marburg and Ebola Viruses

    NASA Astrophysics Data System (ADS)

    Beer, Brigitte; Kurth, Reinhard; Bukreyev, Alexander

    Filoviruses are enveloped, nonsegmented negative-stranded RNA viruses. The two species, Marburg and Ebola virus, are serologically, biochemically, and genetically distinct. Marburg virus was first isolated during an outbreak in Europe in 1967, and Ebola virus emerged in 1976 as the causative agent of two simultaneous outbreaks in southern Sudan and northern Zaire. Although the main route of infection is known to be person-to-person transmission by intimate contact, the natural reservoir for filoviruses still remains a mystery.

  6. Fatal Case of Deer Tick Virus Encephalitis

    Microsoft Academic Search

    Norma P. Tavakoli; Heng Wang; Michelle Dupuis; Rene Hull; Gregory D. Ebel; Emily J. Gilmore; Phyllis L. Faust

    2010-01-01

    Summary Deer tick virus is related to Powassan virus, a tickborne encephalitis virus. A 62-year- old man presented with a meningoencephalitis syndrome and eventually died. Analy- ses of tissue samples obtained during surgery and at autopsy revealed a widespread necrotizing meningoencephalitis. Nucleic acid was extracted from formalin-fixed tissue, and the presence of deer tick virus was verified on a flavivirus-specific

  7. Cooperation between the Hemagglutinin of Avian Viruses and the Matrix Protein of Human Influenza A Viruses

    Microsoft Academic Search

    Christoph Scholtissek; Jürgen Stech; Scott Krauss; Robert G. Webster

    2002-01-01

    To analyze the compatibility of avian influenza A virus hemagglutinins (HAs) and human influenza A virus matrix (M) proteins M1 and M2, we doubly infected Madin-Darby canine kidney cells with amantadine (1-aminoadamantane hydrochloride)-resistant human viruses and amantadine-sensitive avian strains. By using antisera against the human virus HAs and amantadine, we selected reassortants containing the human virus M gene and the

  8. Class II virus membrane fusion proteins

    Microsoft Academic Search

    Margaret Kielian

    2006-01-01

    Enveloped animal viruses fuse their membrane with a host cell membrane, thus delivering the virus genetic material into the cytoplasm and initiating infection. This critical membrane fusion reaction is mediated by a virus transmembrane protein known as the fusion protein, which inserts its hydrophobic fusion peptide into the cell membrane and refolds to drive the fusion reaction. This review describes

  9. Citrus tristeza virus-host interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus tristeza virus (CTV) is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or s...

  10. Immunotherapy for chronic hepatitis B virus infections

    Microsoft Academic Search

    Xian-Jie Yu; Gui-Qiang Wang

    2007-01-01

    The immune system functions to control and clear virus infections. Viral persistence has been closely associated with dysfunctional specific immunity, especially cellular immunity. Current antiviral therapies have been disappointing. Immunotherapies with strategies to boost or restore the virus-specific immune response of patients with chronic hepatitis B virus infection have been proposed for curing persistent i n f e c t

  11. killed-virus influenza vaccine Polio vaccine

    E-print Network

    Shyy, Wei

    killed-virus influenza vaccine Polio vaccine FluMist Thomas Francis, Jr. National Institutes of Health live-virus influenza vaccine Hunein Maassab Jonas Salk Type-A virus trivalent cold that Maassab's innovative, trivalent, cold- adapted influenza vaccine, FluMist, which uses live but weakened

  12. Inhibition of Interferons by Ectromelia Virus

    Microsoft Academic Search

    Vincent P. Smith; Antonio Alcami

    2002-01-01

    Ectromelia virus (EV) is an orthopoxvirus (OPV) that causes mousepox, a severe disease of laboratory mice. Mousepox is a useful model of OPV infection because EV is likely to be a natural mouse pathogen, unlike its close relatives vaccinia virus (VV) and variola virus. Several studies have highlighted the importance of mouse interferons (IFNs) in resistance to and recovery from

  13. Report on potato virus diseases in 1939

    Microsoft Academic Search

    T. P. Dykstra

    1940-01-01

    This report gives a review of some of the papers on potato virus diseases published during 1939 and the latter part of I938. Not all these papers were read, and in some cases only the abstracts found in the Review of Applied Mycology were used. Dennis (8) conducted studies to determine the properties of Solanum virus 4 (= virus B)

  14. Review article Pathobiology of bovine leukemia virus

    E-print Network

    Boyer, Edmond

    Review article Pathobiology of bovine leukemia virus I Schwartz D Lévy URA-INRA d-Alfort cedex, France (Received 16 March 1994; accepted 25 July 1994) Summary ― Bovine leukemia virus (BLV) is a retrovirus similar to the human T-cell leukemia virus (HTLV). Most BLV infected animals (70

  15. ENTOMOPATHOGENIC VIRUS FROM GLASSY-WINGED SHARPSHOOTER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The glassy-winged sharpshooter, GWSS, has been shown to be susceptible to insect virus infections. A new virus was isolated from field caught GWSS and partially sequenced. Sequence identity showed that this was a new sharpshooter virus separate from those already reported by Hunter et. al. 2004, and...

  16. GENETIC VARIABILITY IN MAIZE CHLOROTIC DWARF VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize chlorotic dwarf virus (MCDV) (genus Waikavirus; family Sequiviridae) is a picorna-like virus transmitted by the black-faced leafhopper, Graminella nigrifrons, in a semi-persistent manner using a virus-encoded helper protein. The MCDV genome contains one large open reading frame encoding a poly...

  17. Ubiquitous Reassortments in influenza a viruses

    Microsoft Academic Search

    Xiu-feng Wan; Mufit Ozden; Guohui Lin

    2008-01-01

    Influenza A virus is a negative stranded RNA virus, composed of eight segmented RNA molecules, including polymerases (PB2, PB1, PA), haemaglutin (HA), nucleoprotein (NP), neuraminidase (NA), matrix protein (MP), and nonstructure gene (NS). The influenza A viruses are notorious for rapid mutations, frequent genomic reassortments, and possible recombinations. Among these evolutionary events, genetic reassortments refer to exchanges of internal fragments

  18. Taxonomic Classification of Hepatitis A Virus

    Microsoft Academic Search

    Ian D. Gust; Anthony G. Coulepis; Stephen M. Feinstone; Stephen A. Locarnini; Yasuo Moritsugu; Raphael Najera; Gunter Siegl

    1983-01-01

    Summary Sufficient data have accumulated to permit the ICTV Ad Hoc Study Group on the Taxonomy of Hepatitis Viruses to recognize hepatitis A virus as a picornavirus. Within the family Picornaviridae, hepatitis A virus closely resembles members of the genus Enterovirus.Copyright © 1983 S. Karger AG, Basel

  19. Email Virus Propagation Modeling and Analysis

    Microsoft Academic Search

    Cliff C. Zou; Don Towsley; Weibo Gong

    2003-01-01

    Email viruses constitute one of the major Internet security problems. In this paper we present an email virus model that accounts for the behaviors of email users, such as email checking frequency and the probability of opening an email attachment. Email viruses spread over a logical network defined by email address books. The topology of email network plays an important

  20. A modified epidemiological model for computer viruses

    Microsoft Academic Search

    José Roberto C. Piqueira; Vanessa O. Araujo

    2009-01-01

    Since the computer viruses pose a serious problem to individual and corporative computer systems, a lot of effort has been dedicated to study how to avoid their deleterious actions, trying to create anti-virus programs acting as vaccines in personal computers or in strategic network nodes. Another way to combat viruses propagation is to establish preventive policies based on the whole

  1. A history of computer viruses - Introduction

    Microsoft Academic Search

    Harold Joseph Highland

    1997-01-01

    The following series of articles are taken from Harold's Computer Virus Handbook, published by Elsevier Advanced Technology in 1990. Viruses have moved on a long way since then, but the extracts published here provide a useful background in virus development, and contain much information that is still relevant today. It is also interesting to note that Harold introduces the Macro

  2. Current best practice against computer viruses

    Microsoft Academic Search

    Fred Cohen

    1991-01-01

    Summarizes research on viruses and defenses. The author examines the state-of-the-art in virus defense today and describes how normal computing activities can proceed without undue risk of substantial viral harm. He then describes a set of redundant integrity protection mechanisms used in defending against computer viruses in untrusted computing environments. They include applications of coding theory, cryptography, operating system modifications,

  3. An Abstract Theory of Computer Viruses

    Microsoft Academic Search

    Leonard M. Adleman

    1988-01-01

    In recent years the detection of computer viruses has become common place. It appears that for the most part these viruses\\u000a have been ‘benign’ or only mildly destructive. However, whether or not computer viruses have the potential to cause major\\u000a and prolonged disruptions of computing environments is an open question.

  4. Pairwise Alignment of Metamorphic Computer Viruses

    Microsoft Academic Search

    Scott McGhee

    2007-01-01

    Computer viruses and other forms of malware pose a threat to virtually any software system (with only a few exceptions). A computer virus is a piece of software which takes advantage of known weaknesses in a software system, and usually has the ability to deliver a malicious payload. A common technique that virus writers use to avoid detection is to

  5. On the time complexity of computer viruses

    Microsoft Academic Search

    Zhi-hong Zuo; Qing-xin Zhu; Ming-tian Zhou

    2005-01-01

    Computer viruses can disable computer systems not only by destroying data or modifying a system's configuration, but also by consuming most of the computing resources such as CPU time and storage. The latter effects are related to the computational complexity of computer viruses. In this correspondence, we investigate some issues concerning the time complexity of computer viruses, and prove some

  6. Semester Thesis Virus Inoculation on Social Graphs -

    E-print Network

    Schmid, Stefan

    led to a huge number of computer-viruses, acting in many different manners and aiming at diverse. A contaminated computer hence serves as a source for the virus to infect every other directly linked computer of the virus, every computer that eventually is infected has also to face a drawback in terms of e.g. lost data

  7. Virus detection and quantification using electrical parameters

    NASA Astrophysics Data System (ADS)

    Ahmad, Mahmoud Al; Mustafa, Farah; Ali, Lizna M.; Rizvi, Tahir A.

    2014-10-01

    Here we identify and quantitate two similar viruses, human and feline immunodeficiency viruses (HIV and FIV), suspended in a liquid medium without labeling, using a semiconductor technique. The virus count was estimated by calculating the impurities inside a defined volume by observing the change in electrical parameters. Empirically, the virus count was similar to the absolute value of the ratio of the change of the virus suspension dopant concentration relative to the mock dopant over the change in virus suspension Debye volume relative to mock Debye volume. The virus type was identified by constructing a concentration-mobility relationship which is unique for each kind of virus, allowing for a fast (within minutes) and label-free virus quantification and identification. For validation, the HIV and FIV virus preparations were further quantified by a biochemical technique and the results obtained by both approaches corroborated well. We further demonstrate that the electrical technique could be applied to accurately measure and characterize silica nanoparticles that resemble the virus particles in size. Based on these results, we anticipate our present approach to be a starting point towards establishing the foundation for label-free electrical-based identification and quantification of an unlimited number of viruses and other nano-sized particles.

  8. Open Problems in Computer Virus Research

    Microsoft Academic Search

    Steve R. White

    1998-01-01

    Over a decade of work on the computer virus problem has resulted in a number of useful scientific and technological achievements. The study of biological epidemiology has been extended to help us understand when and why computer viruses spread. Techniques have been developed to help us estimate the safety and effectiveness of anti-virus technology before it is deployed. Technology for

  9. Assembly and budding of influenza virus

    Microsoft Academic Search

    Debi P. Nayak; Eric Ka-Wai Hui; Subrata Barman

    2004-01-01

    Influenza viruses are causative agents of an acute febrile respiratory disease called influenza (commonly known as “flu”) and belong to the Orthomyxoviridae family. These viruses possess segmented, negative stranded RNA genomes (vRNA) and are enveloped, usually spherical and bud from the plasma membrane (more specifically, the apical plasma membrane of polarized epithelial cells). Complete virus particles, therefore, are not found

  10. VIRUS TRANSPORT EXPERIMENTS IN A SANDY AQUIFER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The occurrence of human enteric viruses in ground water has been well documented in the literature. Bacteriophages, such as MS-2 and PRD1, have properties similar to pathogenic human viruses, suggesting that bacteriophages can be used as proxies for virus transport. The objective of this study is to...

  11. G to A hypermutation of TT virus

    Microsoft Academic Search

    Masataka Tsuge; Chiemi Noguchi; Rie Akiyama; Miyuki Matsushita; Kana Kunihiro; Sachi Tanaka; Hiromi Abe; Fukiko Mitsui; Shosuke Kitamura; Tsuyoshi Hatakeyama; Takashi Kimura; Daiki Miki; Nobuhiko Hiraga; Michio Imamura; Shoichi Takahashi; C. Nelson Hayses; Kazuaki Chayama

    2010-01-01

    APOBEC3 proteins function as part of innate antiviral immunity and induce G to A hypermutation in retroviruses and hepatitis B virus (HBV) genomes. Whether APOBEC3 proteins affect viruses that replicate without a reverse transcription step is unknown. TT virus (TTV), known to present in serum of healthy individuals and HBV carriers, has a single-stranded circular DNA genome and replicates without

  12. Emerging intracellular receptors for hemorrhagic fever viruses.

    PubMed

    Jae, Lucas T; Brummelkamp, Thijn R

    2015-07-01

    Ebola virus and Lassa virus belong to different virus families that can cause viral hemorrhagic fever, a life-threatening disease in humans with limited treatment options. To infect a target cell, Ebola and Lassa viruses engage receptors at the cell surface and are subsequently shuttled into the endosomal compartment. Upon arrival in late endosomes/lysosomes, the viruses trigger membrane fusion to release their genome into the cytoplasm. Although contact sites at the cell surface were recognized for Ebola virus and Lassa virus, it was postulated that Ebola virus requires a critical receptor inside the cell. Recent screens for host factors identified such internal receptors for both viruses: Niemann-Pick disease type C1 protein (NPC1) for Ebola virus and lysosome-associated membrane protein 1 (LAMP1) for Lassa virus. A cellular trigger is needed to permit binding of the viral envelope protein to these intracellular receptors. This 'receptor switch' represents a previously unnoticed step in virus entry with implications for host-pathogen interactions and viral tropism. PMID:26004032

  13. Phylogeny of North American Powassan virus

    Microsoft Academic Search

    Gregory D. Ebel; Andrew Spielman; Sam R. Telford

    2001-01-01

    To determine whether Powassan virus (POW) and deer tick virus (DTV) constitute distinct flaviviral populations transmitted by ixodid ticks in North America, we analysed diverse nucleotide sequences from 16 strains of these viruses. Two distinct genetic lineages are evident, which may be defined by geographical and host associations. The nucleotide and amino acid sequences of lineage one (comprising New York

  14. VideoLab:Virus Spreads Fourfold Faster

    NSDL National Science Digital Library

    Virginie Doceul (Imperial College London, St Maryâ??s Campus; Department of Virology, Faculty of Medicine)

    2010-02-12

    Viruses are thought to infect cells cyclically: infect, replicate, release, repeat. However, the vaccinia virus can spread four times faster than this iterative process allows (first movie clip). To explain this incredible speed, Doceul et al. found that as soon as this virus infects a cell, it directs the cell to make two crucial surface proteins.

  15. A pesar del escepticismo inicial, las vacunas contra el VPH demuestran ser eficaces

    Cancer.gov

    Los virus del papiloma humano responsables de prácticamente todos los casos de cáncer de cuello uterino poseen características que los hacen particularmente susceptibles para la creación de vacunas. Este artículo describe las investigaciones realizadas para la creación de las dos vacunas aprobadas por la FDA.

  16. Estadísticas del cáncer

    Cancer.gov

    Información básica sobre las estadísticas del cáncer, las cuales describen las tendencias en grupos grandes de personas y ofrecen una imagen a través del tiempo de la carga que representa el cáncer en la sociedad.

  17. HIV-1 Pathogenesis: The Virus

    PubMed Central

    Swanstrom, Ronald; Coffin, John

    2012-01-01

    Transmission of HIV-1 results in the establishment of a new infection, typically starting from a single virus particle. That virion replicates to generate viremia and persistent infection in all of the lymphoid tissue in the body. HIV-1 preferentially infects T cells with high levels of CD4 and those subsets of T cells that express CCR5, particularly memory T cells. Most of the replicating virus is in the lymphoid tissue, yet most of samples studied are from blood. For the most part the tissue and blood viruses represent a well-mixed population. With the onset of immunodeficiency, the virus evolves to infect new cell types. The tropism switch involves switching from using CCR5 to CXCR4 and corresponds to an expansion of infected cells to include naïve CD4+ T cells. Similarly, the virus evolves the ability to enter cells with low levels of CD4 on the surface and this potentiates the ability to infect macrophages, although the scope of sites where infection of macrophages occurs and the link to pathogenesis is only partly known and is clear only for infection of the central nervous system. A model linking viral evolution to these two pathways has been proposed. Finally, other disease states related to immunodeficiency may be the result of viral infection of additional tissues, although the evidence for a direct role for the virus is less strong. Advancing immunodeficiency creates an environment in which viral evolution results in viral variants that can target new cell types to generate yet another class of opportunistic infections (i.e., HIV-1 with altered tropism). PMID:23143844

  18. Dominant resistance against plant viruses

    PubMed Central

    de Ronde, Dryas; Butterbach, Patrick; Kormelink, Richard

    2014-01-01

    To establish a successful infection plant viruses have to overcome a defense system composed of several layers. This review will overview the various strategies plants employ to combat viral infections with main emphasis on the current status of single dominant resistance (R) genes identified against plant viruses and the corresponding avirulence (Avr) genes identified so far. The most common models to explain the mode of action of dominant R genes will be presented. Finally, in brief the hypersensitive response (HR) and extreme resistance (ER), and the functional and structural similarity of R genes to sensors of innate immunity in mammalian cell systems will be described. PMID:25018765

  19. Bovine viral diarrhea virus: characteristics of the virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reviews the history of research on bovine viral diarrhea viruses (BVDV) from their discovery in the 1940's to the design of current BVDV eradication programs. The physiochemical characteristics of BVDV are discussed and well as classification of BVDV into biotypes and genotypes. The trans...

  20. Halting viruses in scale-free networks

    NASA Astrophysics Data System (ADS)

    Dezs?, Zoltán; Barabási, Albert-László

    2002-05-01

    The vanishing epidemic threshold for viruses spreading on scale-free networks indicate that traditional methods, aiming to decrease a virus' spreading rate cannot succeed in eradicating an epidemic. We demonstrate that policies that discriminate between the nodes, curing mostly the highly connected nodes, can restore a finite epidemic threshold and potentially eradicate a virus. We find that the more biased a policy is towards the hubs, the more chance it has to bring the epidemic threshold above the virus' spreading rate. Furthermore, such biased policies are more cost effective, requiring less cures to eradicate the virus.

  1. Divergent Roles of Autophagy in Virus Infection

    PubMed Central

    Chiramel, Abhilash I.; Brady, Nathan R.; Bartenschlager, Ralf

    2013-01-01

    Viruses have played an important role in human evolution and have evolved diverse strategies to co-exist with their hosts. As obligate intracellular pathogens, viruses exploit and manipulate different host cell processes, including cellular trafficking, metabolism and immunity-related functions, for their own survival. In this article, we review evidence for how autophagy, a highly conserved cellular degradative pathway, serves either as an antiviral defense mechanism or, alternatively, as a pro-viral process during virus infection. Furthermore, we highlight recent reports concerning the role of selective autophagy in virus infection and how viruses manipulate autophagy to evade lysosomal capture and degradation. PMID:24709646

  2. Comparative analysis of chrysanthemum transcriptome in response to three RNA viruses: Cucumber mosaic virus, Tomato spotted wilt virus and Potato virus X.

    PubMed

    Choi, Hoseong; Jo, Yeonhwa; Lian, Sen; Jo, Kyoung-Min; Chu, Hyosub; Yoon, Ju-Yeon; Choi, Seung-Kook; Kim, Kook-Hyung; Cho, Won Kyong

    2015-06-01

    The chrysanthemum is one of popular flowers in the world and a host for several viruses. So far, molecular interaction studies between the chrysanthemum and viruses are limited. In this study, we carried out a transcriptome analysis of chrysanthemum in response to three different viruses including Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV) and Potato virus X (PVX). A chrysanthemum 135K microarray derived from expressed sequence tags was successfully applied for the expression profiles of the chrysanthemum at early stage of virus infection. Finally, we identified a total of 125, 70 and 124 differentially expressed genes (DEGs) for CMV, TSWV and PVX, respectively. Many DEGs were virus specific; however, 33 DEGs were commonly regulated by three viruses. Gene ontology (GO) enrichment analysis identified a total of 132 GO terms, and of them, six GO terms related stress response and MCM complex were commonly identified for three viruses. Several genes functioning in stress response such as chitin response and ethylene mediated signaling pathway were up-regulated indicating their involvement in establishment of host immune system. In particular, TSWV infection significantly down-regulated genes related to DNA metabolic process including DNA replication, chromatin organization, histone modification and cytokinesis, and they are mostly targeted to nucleosome and MCM complex. Taken together, our comparative transcriptome analysis revealed several genes related to hormone mediated viral stress response and DNA modification. The identified chrysanthemums genes could be good candidates for further functional study associated with resistant to various plant viruses. PMID:25904110

  3. La regulación del precio del etanol en Colombia. ¿Teoría del interés general o teoría del interés privado?

    Microsoft Academic Search

    Luz Marina Romero Alvarado

    2010-01-01

    El objetivo de este artículo es presentar los resultados del trabajo de investigación en el que la unidad de análisis se delimitó a la regulación del precio del etanol en Colombia, desde la perspectiva de la regulación económica, siguiendo los enfoques de la teoría del interés general versus teoría del interés privado. El desarrollo del trabajo consistió en hallar la

  4. Top 10 plant viruses in molecular plant pathology.

    PubMed

    Scholthof, Karen-Beth G; Adkins, Scott; Czosnek, Henryk; Palukaitis, Peter; Jacquot, Emmanuel; Hohn, Thomas; Hohn, Barbara; Saunders, Keith; Candresse, Thierry; Ahlquist, Paul; Hemenway, Cynthia; Foster, Gary D

    2011-12-01

    Many scientists, if not all, feel that their particular plant virus should appear in any list of the most important plant viruses. However, to our knowledge, no such list exists. The aim of this review was to survey all plant virologists with an association with Molecular Plant Pathology and ask them to nominate which plant viruses they would place in a 'Top 10' based on scientific/economic importance. The survey generated more than 250 votes from the international community, and allowed the generation of a Top 10 plant virus list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Tobacco mosaic virus, (2) Tomato spotted wilt virus, (3) Tomato yellow leaf curl virus, (4) Cucumber mosaic virus, (5) Potato virus Y, (6) Cauliflower mosaic virus, (7) African cassava mosaic virus, (8) Plum pox virus, (9) Brome mosaic virus and (10) Potato virus X, with honourable mentions for viruses just missing out on the Top 10, including Citrus tristeza virus, Barley yellow dwarf virus, Potato leafroll virus and Tomato bushy stunt virus. This review article presents a short review on each virus of the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant virology community, as well as laying down a benchmark, as it will be interesting to see in future years how perceptions change and which viruses enter and leave the Top 10. PMID:22017770

  5. Viruses and prions of Saccharomyces cerevisiae

    PubMed Central

    Wickner, Reed B.; Fujimura, Tsutomu; Esteban, Rosa

    2014-01-01

    Saccharomyces cerevisiae has been a key experimental organism for the study of infectious diseases, including dsRNA viruses, ssRNA viruses and prions. Studies of the mechanisms of virus and prion replication, virus structure and structure of the amyloid filaments that are the basis of yeast prions have been at the forefront of such studies in these classes of infectious entities. Yeast has been particularly useful in defining the interactions of the infectious elements with cellular components: chromosomally encoded proteins necessary for or blocking the propagation of the viruses and prions, and proteins involved in expression of viral components. Here we emphasize the L-A dsRNA virus and its killer-toxin-encoding satellites, the 20S and 23S ssRNA naked viruses, and the several infectious proteins (prions) of yeast. PMID:23498901

  6. Systems analysis of West Nile virus infection.

    PubMed

    Suthar, Mehul S; Pulendran, Bali

    2014-06-01

    Emerging and re-emerging mosquito-borne viruses continue to pose a significant threat to human health throughout the world. Over the past decade, West Nile virus (WNV), Dengue virus (DENV), and Chikungunya virus (CHIKV), have caused annual epidemics of virus-induced encephalitis, hemorrhagic fever\\shock syndromes, and arthritis, respectively. Currently, no specific antiviral therapies or vaccines exist for use in humans to combat or prevent these viral infections. Thus, there is a pressing need to define the virus-host interactions that govern immunity and infection outcome. Recent technological breakthroughs in 'omics' resources and high-throughput based assays are beginning to accelerate antiviral drug discovery and improve on current strategies for vaccine design. In this review, we highlight studies with WNV and discuss how traditional and systems biological approaches are being used to rapidly identify novel host targets for therapeutic intervention and develop a deeper conceptual understanding of the host response to virus infection. PMID:24851811

  7. West Nile virus in the Americas.

    PubMed

    Pollock, Christal G

    2008-06-01

    West Nile virus causes sporadic disease in the Eastern hemisphere that is often asymptomatic or mild, whereas in the Western hemisphere, West Nile virus has been associated with illness and profound mortality in many avian species. West Nile virus might have been transported to North America by an infected mosquito or the virus could have entered within a vertebrate host like a bird. Although the most important method of West Nile virus transmission is by Culex species mosquitoes, additional modes of transmission have been identified. West Nile virus has been isolated from almost 300 species of Western birds. The long-term effects on common species such as corvids, sparrows, grackles, finches, hawks, and robins are still being debated. However the potential effect of West Nile virus on small populations or species with limited geographic distribution, such as Hawaiian avifauna, could be much more catastrophic. PMID:18689077

  8. Virus-Induced Aggregates in Infected Cells

    PubMed Central

    Moshe, Adi; Gorovits, Rena

    2012-01-01

    During infection, many viruses induce cellular remodeling, resulting in the formation of insoluble aggregates/inclusions, usually containing viral structural proteins. Identification of aggregates has become a useful diagnostic tool for certain viral infections. There is wide variety of viral aggregates, which differ by their location, size, content and putative function. The role of aggregation in the context of a specific virus is often poorly understood, especially in the case of plant viruses. The aggregates are utilized by viruses to house a large complex of proteins of both viral and host origin to promote virus replication, translation, intra- and intercellular transportation. Aggregated structures may protect viral functional complexes from the cellular degradation machinery. Alternatively, the activation of host defense mechanisms may involve sequestration of virus components in aggregates, followed by their neutralization as toxic for the host cell. The diversity of virus-induced aggregates in mammalian and plant cells is the subject of this review. PMID:23202461

  9. Systems analysis of West Nile virus infection

    PubMed Central

    Suthar, Mehul S.; Pulendran, Bali

    2014-01-01

    Emerging and re-emerging mosquito-borne viruses continue to pose a significant threat to human health throughout the world. Over the past decade, West Nile virus (WNV), Dengue virus (DENV), and Chikungunya virus (CHIKV), have caused annual epidemics of virus-induced encephalitis, hemorrhagic fever\\shock syndromes, and arthritis, respectively. Currently, no specific antiviral therapies or vaccines exist for use in humans to combat or prevent these viral infections. Thus, there is a pressing need to define the virus-host interactions that govern immunity and infection outcome. Recent technological breakthroughs in ‘omics’ resources and high-throughput based assays are beginning to accelerate antiviral drug discovery and improve on current strategies for vaccine design. In this review, we highlight studies with WNV and discuss how traditional and systems based approaches are being used to rapidly identify novel host targets for therapeutic intervention and develop a deeper conceptual understanding of the host response to virus infection. PMID:24851811

  10. Xenotransplantation and Hepatitis E virus.

    PubMed

    Denner, Joachim

    2015-05-01

    Xenotransplantation using pig cells, tissues and organs may be associated with the transmission of porcine microorganisms to the human recipient. Some of these microorganisms may induce a zoonosis, that is an infectious disease induced by microorganisms transmitted from another species. With exception of the porcine endogenous retroviruses (PERVs), which are integrated in the genome of all pigs, the transmission of all other microorganisms can be prevented by specified or designated pathogen-free (spf or dpf, respectively) production of the animals. However, it is becoming clear in the last years that the hepatitis E virus (HEV) is one of the viruses which are difficult to eliminate. It is important to note that there are differences between HEV of genotypes (gt) 1 and gt2 on one hand and HEV of gt3 and gt4 on the other. HEV gt1 and gt2 are human viruses, and they induce hepatitis and in the worst case fatal infections in pregnant women. In contrast, HEV gt3 and gt4 are viruses of pigs, and they may infect humans, induce commonly only mild diseases, if any, and are harmless for pregnant women. The goal of this review was to evaluate the risk posed by HEV gt3 and gt4 for xenotransplantation and to indicate ways of their elimination from pigs in order to prevent transmission to the human recipient. PMID:25676629

  11. A virus-based biocatalyst

    NASA Astrophysics Data System (ADS)

    Carette, Noëlle; Engelkamp, Hans; Akpa, Eric; Pierre, Sebastien J.; Cameron, Neil R.; Christianen, Peter C. M.; Maan, Jan C.; Thies, Jens C.; Weberskirch, Ralf; Rowan, Alan E.; Nolte, Roeland J. M.; Michon, Thierry; van Hest, Jan C. M.

    2007-04-01

    Virus particles are probably the most precisely defined nanometre-sized objects that can be formed by protein self-assembly. Although their natural function is the storage and transport of genetic material, they have more recently been applied as scaffolds for mineralization and as containers for the encapsulation of inorganic compounds. The reproductive power of viruses has been used to develop versatile analytical methods, such as phage display, for the selection and identification of (bio)active compounds. To date, the combined use of self-assembly and reproduction has not been used for the construction of catalytic systems. Here we describe a self-assembled system based on a plant virus that has its coat protein genetically modified to provide it with a lipase enzyme. Using single-object and bulk catalytic studies, we prove that the virus-anchored lipase molecules are catalytically active. This anchored biocatalyst, unlike man-made supported catalysts, has the capability to reproduce itself in vivo, generating many independent catalytically active copies.

  12. Who Let the Virus In?

    NSDL National Science Digital Library

    2011-11-01

    Fifty-second monthly installment of our "What A Year!" website project, introducing life science breakthroughs to middle and high school students and their teachers. Respiratory syncytial virus, RSV for short, is so common that almost every child in the United States under two years of age has been infected once, and that half of children under three have been infected at least twice.

  13. West Nile Virus Problem Space

    NSDL National Science Digital Library

    Ethel Stanley (Beloit College; )

    2005-12-13

    As an emerging disease in the public eye, WNV continues to generate scientific interest as well. Researchers are exploring questions about its origin, evolution, transmission by multiple vectors and host tissues, replication in multiple hosts, viremic period, viral loads, seroconversion and antibody production, detection, vaccine potential, etc. Central to these investigations are the use of molecular data including nucleic acid sequences and the use of bioinformatics. There are multiple ways this data can be used in courses. Other instructors have used West Nile Virus to: * Help students become familiar with Biology Workbench, including the use of Nucleic Acid Tools such as ClustalW and SixFrame as well as Alignment Tools such as DrawGram, BoxShade, and MView, etc. * Locate and download sequence data on line using Biology WorkBench, NCBI, and more. Edit the sequences for comparing sequence data obtained from multiple sources and/or for making shorter labels. * Learn more about the West Nile Virus, including structure of the virus, transmission cycle, replication cycle, viremia, blood titers and the disease in reservoir and incidental hosts, vectors for virus, natural history in the US and around the world, and testing for WNV.

  14. Characterization of Reemerging Chikungunya Virus

    Microsoft Academic Search

    Marion Sourisseau; Clémentine Schilte; Nicoletta Casartelli; Céline Trouillet; Florence Guivel-Benhassine; Dominika Rudnicka; Nathalie Sol-Foulon; Karin Le Roux; Marie-Christine Prevost; Hafida Fsihi; Marie-Pascale Frenkiel; Fabien Blanchet; Philippe V. Afonso; Pierre-Emmanuel Ceccaldi; Simona Ozden; Antoine Gessain; Isabelle Schuffenecker; Bruno Verhasselt; Alessia Zamborlini; Ali Saïb; Felix A. Rey; Fernando Arenzana-Seisdedos; Philippe Desprès; Alain Michault; Matthew L. Albert; Olivier Schwartz

    2007-01-01

    An unprecedented epidemic of chikungunya virus (CHIKV) infection recently started in countries of the Indian Ocean area, causing an acute and painful syndrome with strong fever, asthenia, skin rash, polyarthritis, and lethal cases of encephalitis. The basis for chikungunya disease and the tropism of CHIKV remain unknown. Here, we describe the replication characteristics of recent clinical CHIKV strains. Human epithelial

  15. Oncolytic Viruses as Anticancer Vaccines

    PubMed Central

    Woller, Norman; Gürlevik, Engin; Ureche, Cristina-Ileana; Schumacher, Anja; Kühnel, Florian

    2014-01-01

    Oncolytic virotherapy has shown impressive results in preclinical studies and first promising therapeutic outcomes in clinical trials as well. Since viruses are known for a long time as excellent vaccination agents, oncolytic viruses are now designed as novel anticancer agents combining the aspect of lysis-dependent cytoreductive activity with concomitant induction of antitumoral immune responses. Antitumoral immune activation by oncolytic virus infection of tumor tissue comprises both, immediate effects of innate immunity and also adaptive responses for long lasting antitumoral activity, which is regarded as the most prominent challenge in clinical oncology. To date, the complex effects of a viral tumor infection on the tumor microenvironment and the consequences for the tumor-infiltrating immune cell compartment are poorly understood. However, there is more and more evidence that a tumor infection by an oncolytic virus opens up a number of options for further immunomodulating interventions such as systemic chemotherapy, generic immunostimulating strategies, dendritic cell-based vaccines, and antigenic libraries to further support clinical efficacy of oncolytic virotherapy. PMID:25101244

  16. New vaccines against influenza virus

    PubMed Central

    Lee, Young-Tae; Kim, Ki-Hye; Ko, Eun-Ju; Lee, Yu-Na; Kim, Min-Chul; Kwon, Young-Man; Tang, Yinghua; Cho, Min-Kyoung; Lee, Youn-Jeong

    2014-01-01

    Vaccination is one of the most effective and cost-benefit interventions that prevent the mortality and reduce morbidity from infectious pathogens. However, the licensed influenza vaccine induces strain-specific immunity and must be updated annually based on predicted strains that will circulate in the upcoming season. Influenza virus still causes significant health problems worldwide due to the low vaccine efficacy from unexpected outbreaks of next epidemic strains or the emergence of pandemic viruses. Current influenza vaccines are based on immunity to the hemagglutinin antigen that is highly variable among different influenza viruses circulating in humans and animals. Several scientific advances have been endeavored to develop universal vaccines that will induce broad protection. Universal vaccines have been focused on regions of viral proteins that are highly conserved across different virus subtypes. The strategies of universal vaccines include the matrix 2 protein, the hemagglutinin HA2 stalk domain, and T cell-based multivalent antigens. Supplemented and/or adjuvanted vaccination in combination with universal target antigenic vaccines would have much promise. This review summarizes encouraging scientific advances in the field with a focus on novel vaccine designs. PMID:24427759

  17. Schmallenberg Virus Recurrence, Germany, 2014

    PubMed Central

    Wernike, Kerstin; Hoffmann, Bernd; Conraths, Franz J.

    2015-01-01

    Schmallenberg virus (SBV) emerged in Germany in 2011, spread rapidly across Europe, and almost disappeared in 2013. However, since late summer 2014, new cases have occurred in adult cattle. Full-genome analysis revealed some amino acid substitution differences from the first SBV sample. Viremia developed in experimentally infected sheep and cattle for 4–6 days. PMID:26079975

  18. Powassan virus encephalitis, Minnesota, USA.

    PubMed

    Birge, Justin; Sonnesyn, Steven

    2012-10-01

    Powassan virus (POWV) is a rare tick-borne agent of encephalitis in North America. Historically, confirmed cases occurred mainly in the northeastern United States. Since 2008, confirmed cases in Minnesota and Wisconsin have increased. We report a fatal case of POWV encephalitis in Minnesota. POWV infection should be suspected in tick-exposed patients with viral encephalitis. PMID:23017222

  19. Powassan Virus Encephalitis, Minnesota, USA

    PubMed Central

    Sonnesyn, Steven

    2012-01-01

    Powassan virus (POWV) is a rare tick-borne agent of encephalitis in North America. Historically, confirmed cases occurred mainly in the northeastern United States. Since 2008, confirmed cases in Minnesota and Wisconsin have increased. We report a fatal case of POWV encephalitis in Minnesota. POWV infection should be suspected in tick-exposed patients with viral encephalitis. PMID:23017222

  20. Molecular Characteristic-Based Epidemiology of Hepatitis B, C, and E Viruses and GB Virus C\\/Hepatitis G Virus in Myanmar

    Microsoft Academic Search

    KAZUHIKO NAKAI; KHIN MAUNG WIN; SAN SAN OO; YASUYUKI ARAKAWA; KENJI ABE

    2001-01-01

    We carried out a molecular characteristic-based epidemiological survey of various hepatitis viruses, includ- ing hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis E virus (HEV), and GB virus C (GBV-C)\\/hepatitis G virus (HGV), in Myanmar. The study population of 403 subjects consisted of 213 healthy individuals residing in the city of Yangon, Myanmar, and the surrounding suburbs and 190

  1. Clarification and guidance on the proper usage of virus and virus species names

    PubMed Central

    Jahrling, Peter B.

    2010-01-01

    A pivotal step in the development of a consistent nomenclature for virus classification was the introduction of the virus species concept by the International Committee on Taxonomy of Viruses (ICTV) in 1991. Yet, almost two decades later, many virologists still are unable to differentiate between virus species and actual viruses. Here we attempt to explain the origin of this confusion, clarify the difference between taxa and physical entities, and suggest simple measures that could be implemented by ICTV Study Groups to make virus taxonomy and nomenclature more accessible to laboratory virologists. PMID:20204430

  2. Pathogenic Interactions Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum. 

    E-print Network

    Theu, M.P.K.J; Toler, R.W.

    1992-01-01

    Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum M.P.K.J. Theu and R. W. Toler1 Abstract A pathogenic interaction between sorghum yel low banding virus (SYBV) and maize dwarf mosaic (MDMV-A) virus was proved. Inoculation... of MDMV A 3 days before inoculation with SYBV resulted in a more severe disease and the resultant disease symp toms were different from those caused by either virus alone. Both viruses were serologically detected in a treatment in which MDMV...

  3. What contemporary viruses tell us about evolution: a personal view.

    PubMed

    Moelling, Karin

    2013-09-01

    Recent advances in information about viruses have revealed novel and surprising properties such as viral sequences in the genomes of various organisms, unexpected amounts of viruses and phages in the biosphere, and the existence of giant viruses mimicking bacteria. Viruses helped in building genomes and are driving evolution. Viruses and bacteria belong to the human body and our environment as a well-balanced ecosystem. Only in unbalanced situations do viruses cause infectious diseases or cancer. In this article, I speculate about the role of viruses during evolution based on knowledge of contemporary viruses. Are viruses our oldest ancestors? PMID:23568292

  4. Electronic Parameters of Mesoporous Silicon Upon Adsorption of Plant Viruses

    Microsoft Academic Search

    Yuriy Vashpanov; Jung-Young Son; Kae-Dal Kwack; Seung-Jung Shin

    2008-01-01

    Changes in the electronic parameters of mesoporous silicon upon adsorption of nematodetransmitted polyhedral (NEPO) viruses of plant [tomato ringspot virus (TORSV), grapevine virus A (GVA), and grapevine fan leaf virus (GFLV)] measured at room temperature are investigated. The adsorption of these viruses affected essentially on the electronic characteristic of the porous material. The measurement of the electronic characteristics of porous

  5. SURVEY FOR VIRUSES OF GRAPEVINE IN OREGON AND WASHINGTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevines in Washington and Oregon were surveyed for the prevalence of key grapevine viruses. Samples collected from 1522 vines in Washington were tested for Rupestris stem pitting associated virus (RSPaV), Grapevine fanleaf virus (GFLV), Arabis mosaic virus (ArMV), Tomato ringspot virus (ToRSV), ...

  6. Flow cytometry assay for intracellular rabies virus detection

    Microsoft Academic Search

    Juliano Bordignon; Silvia Cordoba Pires Ferreira; Graciane Maria Medeiros Caporale; Maria Luiza Carrieri; Ivanete Kotait; Hermênio Cavalcante Lima; Carlos Roberto Zanetti

    2002-01-01

    Following previous studies reporting microbiological diagnosis by flow cytometry, the possibility of using this method was examined to monitor infection of susceptible cell lines by a fixed rabies virus strain (Pasteur Virus strain—PV) or a wild rabies virus strain (WRS). Suspensions of BHK-21 and C6 cells were infected with viruses and a time course of virus infection was established. Sequentially,

  7. Genetic mechanisms of Maize dwarf mosaic virus resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize resistance to viruses has been well-characterized at the genetic level, and loci responsible for resistance to potyviruses including Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), and Johnsongrass mosaic virus (JGMV), have been mapped in several ge...

  8. A Dynamic Immunity-Based Model for Computer Virus Detection

    Microsoft Academic Search

    Yu Zhang; Tao Li; Renchao Qin

    2008-01-01

    Internet provides a fertile medium for new breeds of computer viruses. Many people who have access to a wealth of information via Internet are attacked by more computer viruses than they can effectively process. We present a dynamic computer virus detection model that can detect known viruses and previously unknown viruses to prevent information systems from damage. This model is

  9. Canine distemper virus in Lake Baikal seals (Phoca sibirica)

    Microsoft Academic Search

    L. V. Mamaev; I. K. G. Visser; S. I. Belikov; N. N. Denikina; T. C. Harder; L. Goatley; B. Rima; B. Edginton; A. D. M. E. Osterhaus; T. Barrett

    1996-01-01

    The virus epizootic which resulted in significant mortality in Siberian seals (Phoca sibirica) in Lake Baikal during 1987\\/88 was caused by canine distemper virus. Sequence analysis of the virus glycoprotein genes revealed that it was most closely related to recent European field isolates of canine distemper virus. This paper presents evidence that the same virus continued to circulate in seals

  10. Determinants of the Host Range of Feline Leukaemia Viruses

    Microsoft Academic Search

    O. Jarrett; HELEN M. LAIRD; D. Hay

    1973-01-01

    SUMMARY Feline leukaemia viruses of subgroups B and C multiply in human and canine cells, while subgroup A viruses do not. This host range restriction is determined by the virus envelope and operates at the level of virus entry into the cell. Subgroup A virus genomes are expressed and replicated when they are introduced within B subgroup envelopes into human

  11. Managing diseases caused by viruses, viroids, and phytoplasmas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant viruses and virus-like pathogens are of considerable economic importance in potato production. The plant viruses and viroids are small, noncellular pathogens. In contrast, phytoplasmas are cellular organisms. In this chapter, information is presented on a number of virus and virus-like pat...

  12. Intrahost Dynamics of Influenza Virus Reassortment

    PubMed Central

    Tao, Hui; Steel, John

    2014-01-01

    ABSTRACT The segmented nature of the influenza virus genome allows reassortment between coinfecting viruses. This process of genetic exchange vastly increases the diversity of circulating influenza viruses. The importance of reassortment to public health is clear from its role in the emergence of a number of epidemiologically important viruses, including novel pandemic and epidemic strains. To gauge its impact on within-host genomic variation, we tracked reassortment in coinfected guinea pigs over time and given matched or discordant doses of coinfecting viruses. To ensure unbiased detection of reassortants, we used parental viruses of equivalent fitness that differ only by noncoding nucleotide changes. These viruses were based on the isolate A/Panama/2007/1999 (H3N2). At a dose of 2 × 102 PFU, one parental virus was absent from each guinea pig throughout the time course, indicating the presence of a bottleneck. With an intermediate dose of 2 × 103 PFU, genomic diversity present in nasal lavage samples increased from 1 to 3 days postinfection (dpi) and then declined by 6 dpi. With a high dose of 2 × 106 PFU, however, reassortment levels were high (avg. 59%) at 1 dpi and remained stable. Even late in the course of infection, parental viruses were not eclipsed by reassortants, suggesting that a uniformly high multiplicity of infection was not achieved in vivo. Inoculation with ?10-fold discordant doses did not reduce reassortment relative to equivalent inputs but markedly changed the spectrum of genotypes produced. Our data reveal the potential for reassortment to contribute to intrahost diversity in mixed influenza virus infection. IMPORTANCE Influenza virus reassortment is prevalent in nature and is a major contributor to the diversity of influenza viruses circulating in avian, swine, human and other host species. This diversity, in turn, increases the potential for influenza viruses to evade selective pressures or adapt to new host environments. As examples, reassortment was key to the emergence of the 1957, 1968, and 2009 pandemics; the unusually severe influenza epidemics of 2003, 1951, and 1947; and the rise in adamantane resistance among currently circulating human H3N2 viruses. We reveal here the diversity of viral genotypes generated over time in a host coinfected with two influenza viruses. We found that intrahost diversity driven by reassortment is dynamic and dependent on the amount of each virus initiating infection. Our results demonstrate the readiness with which reassortant influenza viruses arise, offering new insight into this important mechanism of influenza virus evolution. PMID:24741099

  13. Detection of Multiple Potato Viruses in the Field Suggests Synergistic Interactions among Potato Viruses in Pakistan

    PubMed Central

    Hameed, Amir; Iqbal, Zafar; Asad, Shaheen; Mansoor, Shahid

    2014-01-01

    Viral diseases have been a major limiting factor threating sustainable potato (Solanum tuberosum L.) production in Pakistan. Surveys were conducted to serologically quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato virus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50% in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for systemic infections and symptomology studies. The results obtained conclude that multiple viral infections dramatically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save potato crop. PMID:25506305

  14. Pharmacological Inhibition of Feline Immunodeficiency Virus (FIV)

    PubMed Central

    Mohammadi, Hakimeh; Bienzle, Dorothee

    2012-01-01

    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. PMID:22754645

  15. Sumoylation of Influenza A Virus Nucleoprotein Is Essential for Intracellular Trafficking and Virus Growth

    PubMed Central

    Han, Qinglin; Chang, Chong; Li, Li; Klenk, Christoph; Cheng, Jinke; Chen, Yixin; Xia, Ningshao; Shu, Yuelong; Chen, Ze; Gabriel, Gülsah

    2014-01-01

    ABSTRACT Viruses take advantage of host posttranslational modifications for their own benefit. It was recently reported that influenza A virus proteins interact extensively with the host sumoylation system. Thereby, several viral proteins, including NS1 and M1, are sumoylated to facilitate viral replication. However, to what extent sumoylation is exploited by influenza A virus is not fully understood. In this study, we found that influenza A virus nucleoprotein (NP) is a bona fide target of sumoylation in both NP-transfected cells and virus-infected cells. We further found that NP is sumoylated at the two most N-terminal residues, lysines 4 and 7, and that sumoylation at lysine 7 of NP is highly conserved across different influenza A virus subtypes and strains, including the recently emerged human H7N9 virus. While NP stability and polymerase activity are little affected by sumoylation, the NP sumoylation-defective WSN-NPK4,7R virus exhibited early cytoplasmic localization of NP. The growth of the WSN-NPK4,7R virus was highly attenuated compared to that of the wild-type WSN virus, and the lysine residue at position 7 is indispensable for the virus's survival, as illustrated by the rapid emergence of revertant viruses. Thus, sumoylation of influenza A virus NP is essential for intracellular trafficking of NP and for virus growth, illustrating sumoylation as a crucial strategy extensively exploited by influenza A virus for survival in its host. IMPORTANCE Host posttranslational modifications are heavily targeted by viruses for their own benefit. We and others previously reported that influenza A virus interacts extensively with the host sumoylation system. However, the functional outcomes of viral sumoylation are not fully understood. Here we found that influenza A virus nucleoprotein (NP), an essential component for virus replication, is a new target of SUMO. This is the first study to find that NP from different influenza A viruses, including recently emerged H7N9, is sumoylated at conserved lysine 7. Our data further illustrated that sumoylation of influenza A virus NP is essential for intracellular trafficking of NP and virus growth, indicating that influenza A virus relies deeply on sumoylation to survive in host cells. Strategies to downregulate viral sumoylation could thus be a potential antiviral treatment. PMID:24920808

  16. Comparison of Swine Vesicular Disease Virus and Coxsackie B5 Virus by Serological and RNA Hybridization Methods

    Microsoft Academic Search

    F. Brown; T. F. Wild; L. W. Rowe; B. O. Underwood; T. J. R. Harris

    1976-01-01

    SUMMARY The relatedness of swine vesicular disease virus (SVDV) and Coxsackie B5 virus has been studied by virus neutralization and immunodiffusion tests and by hybridization of the virus RNAs. Clearly defined differences between the two viruses were found by the three methods. Isolates of SVDV from several countries were very closely related but could be differentiated. Recent isolates of Coxsackie

  17. Molecular Epidemiology of Hepatitis Viruses and Genotypic Distribution of Hepatitis B and C Viruses in Harbin, China

    Microsoft Academic Search

    Xin Ding; Hongxi Gu; Zhao-Hua Zhong; Xu Zilong; Huy Thien-Tuan Tran; Yohko Iwaki; Tian-Cheng Li; Tetsutaro Sata; Kenji Abe

    2003-01-01

    SUMMARY: We carried out a molecular-based epidemiological survey of hepatitis viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis E virus (HEV), in Harbin, China. The study population of 358 subjects consisted of 132 healthy blood donors and 226 liver disease patients residing in Harbin City and surrounding suburbs. The infection rate of each virus among healthy

  18. Chemical Modification of Viruses and Virus-Like Particles

    Microsoft Academic Search

    E. Strable; M. G. Finn

    Protein capsids derived from viruses may be modified by methods, generated, isolated, and purified on large scales with relative\\u000a ease. In recent years, methods for their chemical derivatization have been employed to broaden the properties and functions\\u000a accessible to investigators desiring monodisperse, atomic-resolution structures on the nanometer scale. Here we review the\\u000a reactions and methods used in these endeavors, including

  19. Malsoor Virus, a Novel Bat Phlebovirus, Is Closely Related to Severe Fever with Thrombocytopenia Syndrome Virus and Heartland Virus

    PubMed Central

    Yadav, P. D.; Basu, A.; Shete, A.; Patil, D. Y.; Zawar, D.; Majumdar, T. D.; Kokate, P.; Sarkale, P.; Raut, C. G.; Jadhav, S. M.

    2014-01-01

    During a survey in the year 2010, a novel phlebovirus was isolated from the Rousettus leschenaultii species of bats in western India. The virus was identified by electron microscopy from infected Vero E6 cells. Phylogenic analysis of the complete genome showed its close relation to severe fever with thrombocytopenia syndrome (SFTS) and Heartland viruses, which makes it imperative to further study its natural ecology and potential as a novel emerging zoonotic virus. PMID:24390329

  20. Host range and some properties of Physalis mosaic virus, a new virus of the turnip yellow mosaic virus group

    Microsoft Academic Search

    D. Peters; A. F. L. M. Derks

    1974-01-01

    An apparently undescribed virus was isolated fromPhysalis subglabrata in Illinois, USA, and its properties were studied. The virus was namedPhysalis mosaic virus (PMV). It was readily transmitted by sap inoculation to 23 out of 34 Solanaceae tested, toChenopodium foetidum andSonchus oleraceus but not to 28 other non-solanaceous species inoculated. Purified preparations of PMV contained isometric particles of 27 nm in

  1. Malsoor virus, a novel bat phlebovirus, is closely related to severe fever with thrombocytopenia syndrome virus and heartland virus.

    PubMed

    Mourya, D T; Yadav, P D; Basu, A; Shete, A; Patil, D Y; Zawar, D; Majumdar, T D; Kokate, P; Sarkale, P; Raut, C G; Jadhav, S M

    2014-03-01

    During a survey in the year 2010, a novel phlebovirus was isolated from the Rousettus leschenaultii species of bats in western India. The virus was identified by electron microscopy from infected Vero E6 cells. Phylogenic analysis of the complete genome showed its close relation to severe fever with thrombocytopenia syndrome (SFTS) and Heartland viruses, which makes it imperative to further study its natural ecology and potential as a novel emerging zoonotic virus. PMID:24390329

  2. Powassan virus: persistence of virus activity during 1966.

    PubMed

    McLean, D M; Cobb, C; Gooderham, S E; Smart, C A; Wilson, A G; Wilson, W E

    1967-03-18

    Powassan virus isolations were achieved from three of 60 pools of Ixodes cookei ticks removed from 286 groundhogs (Marmota monax) which were collected some 200 miles north of Toronto between May 5 and September 5, 1966. Virus yields per pool of one to 11 ticks ranged from 10(2.5) to 10(6.0) TCD(50) for primary swine kidney tissue cultures, and positive pools were collected on June 24, July 15 and August 10. Powassan neutralizing antibodies were detected by mouse inoculation tests in 143 of 362 animals including 127 of 286 groundhogs, 14 of 45 red squirrels (Tamiasciurus hudsonicus) and two of 31 other forest mammals. The monthly prevalence of antibody in the current season's groundhogs increased from 0 to 25% with the progression of summer, but in older animals the incidence remained between 38 and 62% throughout the season. These results substantiate earlier findings which pointed towards the maintenance of Powassan virus in nature by a cycle involving groundhogs and squirrels as reservoirs, with ticks as vectors, from which human infections occurred tangentially. PMID:6019677

  3. Powassan Virus: Persistence of Virus Activity During 1966

    PubMed Central

    McLean, Donald M.; Cobb, Cathron; Gooderham, Susan E.; Smart, Carol A.; Wilson, A. G.; Wilson, W. E.

    1967-01-01

    Powassan virus isolations were achieved from three of 60 pools of Ixodes cookei ticks removed from 286 groundhogs (Marmota monax) which were collected some 200 miles north of Toronto between May 5 and September 5, 1966. Virus yields per pool of one to 11 ticks ranged from 102.5 to 106.0 TCD50 for primary swine kidney tissue cultures, and positive pools were collected on June 24, July 15 and August 10. Powassan neutralizing antibodies were detected by mouse inoculation tests in 143 of 362 animals including 127 of 286 groundhogs, 14 of 45 red squirrels (Tamiasciurus hudsonicus) and two of 31 other forest mammals. The monthly prevalence of antibody in the current season's groundhogs increased from 0 to 25% with the progression of summer, but in older animals the incidence remained between 38 and 62% throughout the season. These results substantiate earlier findings which pointed towards the maintenance of Powassan virus in nature by a cycle involving groundhogs and squirrels as reservoirs, with ticks as vectors, from which human infections occurred tangentially. PMID:6019677

  4. Kunjin Virus Replicon Vectors for Human Immunodeficiency Virus Vaccine Development†

    PubMed Central

    Harvey, Tracey J.; Anraku, Itaru; Linedale, Richard; Harrich, David; Mackenzie, Jason; Suhrbier, Andreas; Khromykh, Alexander A.

    2003-01-01

    We have previously demonstrated the ability of the vaccine vectors based on replicon RNA of the Australian flavivirus Kunjin (KUN) to induce protective antiviral and anticancer CD8+ T-cell responses using murine polyepitope as a model immunogen (I. Anraku, T. J. Harvey, R. Linedale, J. Gardner, D. Harrich, A. Suhrbier, and A. A. Khromykh, J. Virol. 76:3791-3799, 2002). Here we showed that immunization of BALB/c mice with KUN replicons encoding HIV-1 Gag antigen resulted in induction of both Gag-specific antibody and protective Gag-specific CD8+ T-cell responses. Two immunizations with KUNgag replicons in the form of virus-like particles (VLPs) induced anti-Gag antibodies with titers of ?1:10,000. Immunization with KUNgag replicons delivered as plasmid DNA, naked RNA, or VLPs induced potent Gag-specific CD8+ T-cell responses, with one immunization of KUNgag VLPs inducing 4.5-fold-more CD8+ T cells than the number induced after immunization with recombinant vaccinia virus carrying the gag gene (rVVgag). Two immunizations with KUNgag VLPs also provided significant protection against challenge with rVVgag. Importantly, KUN replicon VLP vaccinations induced long-lasting immune responses with CD8+ T cells able to secrete gamma interferon and to mediate protection 6 to 10 months after immunization. These results illustrate the potential value of the KUN replicon vectors for human immunodeficiency virus vaccine design. PMID:12829819

  5. Identification of Novel Viruses Using VirusHunter -- an Automated Data Analysis Pipeline

    PubMed Central

    Zhao, Guoyan; Krishnamurthy, Siddharth; Cai, Zhengqiu; Popov, Vsevolod L.; Travassos da Rosa, Amelia P.; Guzman, Hilda; Cao, Song; Virgin, Herbert W.; Tesh, Robert B.; Wang, David

    2013-01-01

    Quick and accurate identification of microbial pathogens is essential for both diagnosis and response to emerging infectious diseases. The advent of next-generation sequencing technology offers an unprecedented platform for rapid sequencing-based identification of novel viruses. We have developed a customized bioinformatics data analysis pipeline, VirusHunter, for the analysis of Roche/454 and other long read Next generation sequencing platform data. To illustrate the utility of VirusHunter, we performed Roche/454 GS FLX titanium sequencing on two unclassified virus isolates from the World Reference Center for Emerging Viruses and Arboviruses (WRCEVA). VirusHunter identified sequences derived from a novel bunyavirus and a novel reovirus in the two samples respectively. Further sequence analysis demonstrated that the viruses were novel members of the Phlebovirus and Orbivirus genera. Both Phlebovirus and Orbivirus genera include many economic important viruses or serious human pathogens. PMID:24167629

  6. Virus population dynamics and acquired virus resistance in natural microbial communities.

    PubMed

    Andersson, Anders F; Banfield, Jillian F

    2008-05-23

    Viruses shape microbial community structure and function by altering the fitness of their hosts and by promoting genetic exchange. The complexity of most natural ecosystems has precluded detailed studies of virus-host interactions. We reconstructed virus and host bacterial and archaeal genome sequences from community genomic data from two natural acidophilic biofilms. Viruses were matched to their hosts by analyzing spacer sequences that occur among clustered regularly interspaced short palindromic repeats (CRISPRs) that are a hallmark of virus resistance. Virus population genomic analyses provided evidence that extensive recombination shuffles sequence motifs sufficiently to evade CRISPR spacers. Only the most recently acquired spacers match coexisting viruses, which suggests that community stability is achieved by rapid but compensatory shifts in host resistance levels and virus population structure. PMID:18497291

  7. Virus vector gene inserts are stabilized in the presence of satellite panicum mosaic virus coat protein 

    E-print Network

    Everett, Anthany Laurence

    2009-05-15

    The coat protein of satellite panicum mosaic virus (SPMV) was used to stabilize viral vector gene inserts in planta. A Potato virus X (PVX) vector carrying the SPMV capsid protein (CP) gene was successfully stabilized through three serial passages...

  8. The role of feline syncytium forming virus in feline immunodeficiency virus-mediated acquired immunodeficiency 

    E-print Network

    Zenger, Elizabeth

    1991-01-01

    THE ROLE OF FELINE SYNCYTIUM FORMING VIRUS IN FELINE IMMUNODEFICIENCY VIRUS-MEDIATED ACQUIRED IMMUNODEFICIENCY A Thesis by ELIZABETH ZENGER Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1991 Major Subject: Veterinary Medicine and Surgery THE ROLE OF FELINE SYNCYTIUM FORMING VIRUS IN FELINE IMMUNODEFICIENCY VIRUS-MEDIATED ACQUIRED IMMUNODEFICIENCY A Thesis by ELIZABETH ZENGER...

  9. Human and Animal Viruses in Food (Including Taxonomy of Enteric Viruses)

    Microsoft Academic Search

    Gail E. Greening

    1.0. INTRODUCTION In recent years, there has been an increase in the incidence of food-borne diseases worldwide, with viruses now recognized as a major cause of these illnesses. The viruses implicated in food-borne disease are the enteric viruses, which are found in the human gut, excreted in human feces, and transmitted by the fecal-oral route. Many different viruses are found

  10. Molecular Detection of Cucumber Mosaic Virus and Other RNA Viruses Based on New Techniques

    Microsoft Academic Search

    Jishuang Chen

    \\u000a Plant diseases caused by viruses and related pathogenic agents bring about substantial losses in agricultural and horticultural\\u000a crops. And the study of plant viruses has contributed quite a lot to the agricultural progress and basic understanding of\\u000a plant development as a molecular standard. For example, based on a virus’s diagnosis, the omission of plant viruses from potato\\u000a and many vegetative

  11. Virus Neutralising Antibodies Against 22 Bovine Viral Diarrhoea Virus Isolates in Vaccinated Calves

    Microsoft Academic Search

    C. Hamers; E. Di valentin; C. Lecomte; M. Lambot; E. Joris; B. Genicot; P. Pastoret

    2002-01-01

    Seven of nine colostrum deprived calves, free from bovine viral diarrhoea virus (BVDV), were vaccinated with a commercially available vaccine containing two inactivated strains of BVDV, an inactivated strain of bovine herpesvirus-1 and modified-live strains of bovine respiratory syncytial virus and para-influenza-3 virus. The two other calves were kept as controls. The virus neutralising (VN) antibodies induced by vaccination were

  12. Systemic vaccination with inactivated bovine virus diarrhoea virus protects against respiratory challenge

    Microsoft Academic Search

    C. J. Howard; M. C. Clarke; P. Sopp; J. Brownlie

    1994-01-01

    Inactivated bovine virus diarrhoea virus, strain 11249nc, inoculated subcutaneously three times with Quil-A into calves protected against intranasal challenge with the same strain. Virus was isolated from nasopharyngeal swabs taken 4 to 8 days post challenge and blood taken 4 to 6 days post challenge from control calves but not from vaccinated calves. A second strain of virus, Kyl203nc, was

  13. Yellow fever vector live-virus vaccines: West Nile virus vaccine development

    Microsoft Academic Search

    Juan Arroyo; Charles A Miller; John Catalan; Thomas P Monath

    2001-01-01

    By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World

  14. Satsuma Dwarf and Related Viruses Belong to a New Lineage of Plant Picorna-like Viruses

    Microsoft Academic Search

    Alexander V. Karasev; Sang Sub Han; Toru Iwanami

    2001-01-01

    Satsuma dwarf virus (SDV) and two closely related viruses, Citrus mosaic (CiMV), and Naval orange infectious mottling (NIMV), seriously affect citrus varieties grown in Japan and East Asia. All three viruses have icosahedral particles built of two proteins encapsidating two single-stranded genomic RNAs. The natural mode of transmission of these SDV-like viruses is unknown, and they were previously placed among

  15. Satellite RNAs and Satellite Viruses of Plants

    PubMed Central

    Hu, Chung-Chi; Hsu, Yau-Heiu; Lin, Na-Sheng

    2009-01-01

    The view that satellite RNAs (satRNAs) and satellite viruses are purely molecular parasites of their cognate helper viruses has changed. The molecular mechanisms underlying the synergistic and/or antagonistic interactions among satRNAs/satellite viruses, helper viruses, and host plants are beginning to be comprehended. This review aims to summarize the recent achievements in basic and practical research, with special emphasis on the involvement of RNA silencing mechanisms in the pathogenicity, population dynamics, and, possibly, the origin(s) of these subviral agents. With further research following current trends, the comprehensive understanding of satRNAs and satellite viruses could lead to new insights into the trilateral interactions among host plants, viruses, and satellites. PMID:21994595

  16. Determination of Time Dependent Virus Inactivation Rates

    NASA Astrophysics Data System (ADS)

    Chrysikopoulos, C. V.; Vogler, E. T.

    2003-12-01

    A methodology is developed for estimating temporally variable virus inactivation rate coefficients from experimental virus inactivation data. The methodology consists of a technique for slope estimation of normalized virus inactivation data in conjunction with a resampling parameter estimation procedure. The slope estimation technique is based on a relatively flexible geostatistical method known as universal kriging. Drift coefficients are obtained by nonlinear fitting of bootstrap samples and the corresponding confidence intervals are obtained by bootstrap percentiles. The proposed methodology yields more accurate time dependent virus inactivation rate coefficients than those estimated by fitting virus inactivation data to a first-order inactivation model. The methodology is successfully applied to a set of poliovirus batch inactivation data. Furthermore, the importance of accurate inactivation rate coefficient determination on virus transport in water saturated porous media is demonstrated with model simulations.

  17. Fatal case of deer tick virus encephalitis.

    PubMed

    Tavakoli, Norma P; Wang, Heng; Dupuis, Michelle; Hull, Rene; Ebel, Gregory D; Gilmore, Emily J; Faust, Phyllis L

    2009-05-14

    Deer tick virus is related to Powassan virus, a tickborne encephalitis virus. A 62-year-old man presented with a meningoencephalitis syndrome and eventually died. Analyses of tissue samples obtained during surgery and at autopsy revealed a widespread necrotizing meningoencephalitis. Nucleic acid was extracted from formalin-fixed tissue, and the presence of deer tick virus was verified on a flavivirus-specific polymerase-chain-reaction (PCR) assay, followed by sequence confirmation. Immunohistochemical analysis with antisera specific for deer tick virus identified numerous immunoreactive neurons, with prominent involvement of large neurons in the brain stem, cerebellum, basal ganglia, thalamus, and spinal cord. This case demonstrates that deer tick virus can be a cause of fatal encephalitis. PMID:19439744

  18. 21 CFR 866.3330 - Influenza virus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Influenza virus serological reagents. 866...Serological Reagents § 866.3330 Influenza virus serological reagents. (a) Identification. Influenza virus serological reagents are...

  19. 21 CFR 866.3330 - Influenza virus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Influenza virus serological reagents. 866...Serological Reagents § 866.3330 Influenza virus serological reagents. (a) Identification. Influenza virus serological reagents are...

  20. 21 CFR 866.3330 - Influenza virus serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Influenza virus serological reagents. 866...Serological Reagents § 866.3330 Influenza virus serological reagents. (a) Identification. Influenza virus serological reagents are...

  1. 21 CFR 866.3330 - Influenza virus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Influenza virus serological reagents. 866...Serological Reagents § 866.3330 Influenza virus serological reagents. (a) Identification. Influenza virus serological reagents are...

  2. Virus Mutation Explains Poor Performance of Last Season's Flu Shot

    MedlinePLUS

    ... html Virus Mutation Explains Poor Performance of Last Season's Flu Shot: Study Strain of H3N2 virus that ... the virus that circulated during the last flu season. The findings were published June 25 in the ...

  3. 21 CFR 866.3305 - Herpes simplex virus serological assays.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Herpes simplex virus serological assays. 866... Serological Reagents § 866.3305 Herpes simplex virus serological assays. (a) Identification . Herpes simplex virus serological assays...

  4. 21 CFR 866.3305 - Herpes simplex virus serological assays.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Herpes simplex virus serological assays. 866... Serological Reagents § 866.3305 Herpes simplex virus serological assays. (a) Identification . Herpes simplex virus serological assays...

  5. Foot-and-mouth disease virus L peptidase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease virus (FMDV), equine rhinitis A virus (ERAV) and bovine rhinitis B virus (BRBV) comprise the genus Aphthovirus of the Picornaviridae family. Seven genera within this family, Aphthoviruses, Cardioviruses, Erboviruses (ERBV), Kobuviruses, Senecaviruses, Sapeloviruses, and Tescho...

  6. Respiratory Syncytial Virus Vaccine Development

    PubMed Central

    Murata, Yoshihiko

    2009-01-01

    Respiratory syncytial virus (RSV) is a clinically significant cause of respiratory tract disease, especially among high-risk infants and immunocompromised and elderly adults. Despite the burden of disease, there is no licensed prophylactic RSV vaccine. The initial efforts to develop an RSV vaccine involved formalin-inactivated virus preparations that unexpectedly caused vaccine-enhanced disease in clinical trials in RSV-naïve children. Over the last four decades, cautious and deliberate progress has been made towards RSV vaccine development using a variety of experimental approaches (Table 1), including live attenuated strains, vector-based, and viral protein subunit/DNA-based candidates. The scientific rationale, preclinical testing, and clinical development of each of these approaches are reviewed. PMID:19892231

  7. Seasonal Inactivated Influenza Virus Vaccines

    PubMed Central

    Couch, Robert B.

    2008-01-01

    Inactivated influenza virus vaccines are the primary modality used for prevention of influenza. A system of annual identification of new strains causing illnesses, selections for vaccines, chick embryo growth, inactivation, processing, packaging, distribution and usage has been in place for decades. Current vaccines contain 15 µg of the HA of an A/H1N1, A/H3N2 and B strain and are given parenterally to induce serum anti-HA antibody for prevention of subsequent infection and illness from natural influenza. Reactogenicity is low and protection among healthy older children and adults is good; protection levels are generally lower in young children and the elderly. Needs include ensuring antigenic matches of vaccine and epidemic viruses each season, enhancing immunization rates, and providing new and improved vaccines and immunization approaches for the varied populations and circumstances globally. PMID:18602728

  8. [Characterization of Marburg virus morphology].

    PubMed

    Song, Jing-Dong; Qu, Jian-Guo; Hong, Tao

    2014-05-01

    Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae. Filoviruses cause severe filovirus hemorrhagic fever (FHF) in humans, with high case fatality rates, and represent potential agents for bioterrorism and biological weapons. It is necessary to keep surveillance of filoviruses, even though there is no report of their isolation and patients in China so far. To characterize MARV morphology, the Lake Victoria marburgvirus--Leiden was stained negatively and observed under a transmission electron microscope which is one of important detection methods for filoviruses in emergencies and bioterrorism. MARV showed pleomorphism, with filamentous, rod-shaped, cobra-like, spherical, and branch-shaped particles of uniform diameter but different lengths. Pleomorphism of negatively stained MARV is summarized in this article, so as to provide useful information for possible electron microscopic identification of filoviruses in China. PMID:25118385

  9. Respiratory syncytial virus vaccine development

    PubMed Central

    Hurwitz, Julia L

    2011-01-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract viral disease in infants and young children. Presently, there are no explicit recommendations for RSV treatment apart from supportive care. The virus is therefore responsible for an estimated 160,000 deaths per year worldwide. Despite half a century of dedicated research, there remains no licensed vaccine product. Herein are described past and current efforts to harness innate and adaptive immune potentials to combat RSV. A plethora of candidate vaccine products and strategies are reviewed. The development of a successful RSV vaccine may ultimately stem from attention to historical lessons, in concert with an integral partnering of immunology and virology research fields. PMID:21988307

  10. Eradicating Computer Viruses on Networks

    E-print Network

    Huang, Jinyu

    2012-01-01

    Spread of computer viruses can be modeled as the SIS (susceptible-infected-susceptible) epidemic propagation. We show that in order to ensure the random immunization or the targeted immunization effectively prevent computer viruses propagation on homogeneous networks, we should install antivirus programs in every computer node and frequently update those programs. This may produce large work and cost to install and update antivirus programs. Then we propose a new policy called "network monitors" to tackle this problem. In this policy, we only install and update antivirus programs for small number of computer nodes, namely the "network monitors". Further, the "network monitors" can monitor their neighboring nodes' behavior. This mechanism incur relative small cost to install and update antivirus programs.We also indicate that the policy of the "network monitors" is efficient to protect the network's safety. Numerical simulations confirm our analysis.

  11. West Nile Virus Maps - 2002

    NSDL National Science Digital Library

    The US Geological Survey Center for Integration of Natural Disaster Information has provided these maps of reported occurrences of West Nile Virus (WNV). "The West Nile Virus Surveillance System is intended to monitor the geographic and temporal spread of WNV over the contiguous United States." Maps include 2002 surveillance data for birds, humans, mosquitoes, sentinel chicken flocks, and data submitted by veterinarians. Maps from previous years are available, including comprehensive maps through 2000, and maps of 2001 data. It is unclear whether the 2002 maps are based on 2002 data alone, or include all data through June of 2002. Brief background on WNV and surveillance activities help make this site appealing to a broader audience.

  12. Influenza virus and neurological diseases.

    PubMed

    Hayase, Y; Tobita, K

    1997-08-01

    Influenza viruses rarely cause acute encephalopathy. Post-influenzal encephalitis, which occurs a few weeks after recovery from influenza is thought to be an autoimmune process associated with demyelination and vasculopathy. It has been suggested that Economo lethargic encephalitis followed by postencephalitic Parkinsonism was associated with the influenza A epidemic of 1918 (Spanish flu). The incidence of Reye's syndrome has markedly decreased due to the avoidance of salicylates in the treatment of influenza or varicella. One inactivated flu vaccine is thought to have caused Guillain Barre syndrome due to molecular mimicry between viral protein and myelin, which triggered autoimmune responses. The persistence of influenza virus genes in neural cells as one of the causes of chronic degenerative diseases of the central nervous system by inducing apoptosis of the host cells is yet to be proven. PMID:9316161

  13. Replication of avian influenza viruses in humans

    Microsoft Academic Search

    A. S. Beare; R. G. Webster

    1991-01-01

    Summary Volunteers inoculated with avian influenza viruses belonging to subtypes currently circulating in humans (H1N1 and H3N2) were largely refractory to infection. However 11 out of 40 volunteers inoculated with the avian subtypes, H4N8, H6N1, and H10N7, shed virus and had mild clinical symptoms: they did not produce a detectable antibody response. This was presumably because virus multiplication was limited

  14. Inactivation of Viruses by Benzalkonium Chloride

    PubMed Central

    Armstrong, J. A.; Froelich, E. J.

    1964-01-01

    Benzalkonium chloride (as Roccal or Zephiran) was found to inactivate influenza, measles, canine distemper, rabies, fowl laryngotracheitis, vaccinia, Semliki Forest, feline pneumonitis, meningopneumonitis, and herpes simplex viruses after 10 min of exposure at 30 C or at room temperature. Poliovirus and encephalomyocarditis virus were not inactivated under the same conditions. It was concluded that all viruses tested were sensitive except members of the picorna group. The literature was reviewed. PMID:4288740

  15. Biomedical Nanotechnology Using Virus-Based Nanoparticles

    Microsoft Academic Search

    G. Destito; A. Schneemann; M. Manchester

    A great challenge in biomedicine is the ability to target therapeutics to specific locations in the body in order to increase\\u000a therapeutic benefit and minimize adverse effects. Virus-based nanotechnology takes advantage of the natural circulatory and\\u000a targeting properties of viruses, in order to design therapeutics and vaccines that specifically target tissues of interest\\u000a in vivo. Cowpea mosaic virus (CPMV) and

  16. Newly discovered viruses of flying foxes.

    PubMed

    Halpin, K; Young, P L; Field, H; Mackenzie, J S

    1999-08-16

    Flying foxes have been the focus of research into three newly described viruses from the order Mononegavirales, namely Hendra virus (HeV), Menangle virus and Australian Bat Lyssavirus (ABL). Early investigations indicate that flying foxes are the reservoir host for these viruses. In 1994, two outbreaks of a new zoonotic disease affecting horses and humans occurred in Queensland. The virus which was found to be responsible was called equine morbillivirus (EMV) and has since been renamed HeV. Investigation into the reservoir of HeV has produced evidence that antibodies capable of neutralising HeV have only been detected in flying foxes. Over 20% of flying foxes in eastern Australia have been identified as being seropositive. Additionally six species of flying foxes in Papua New Guinea have tested positive for antibodies to HeV. In 1996 a virus from the family Paramyxoviridae was isolated from the uterine fluid of a female flying fox. Sequencing of 10000 of the 18000 base pairs (bp) has shown that the sequence is identical to the HeV sequence. As part of investigations into HeV, a virus was isolated from a juvenile flying fox which presented with neurological signs in 1996. This virus was characterised as belonging to the family Rhabdoviridae, and was named ABL. Since then four flying fox species and one insectivorous species have tested positive for ABL. The third virus to be detected in flying foxes is Menangle virus, belonging to the family Paramyxoviridae. This virus was responsible for a zoonotic disease affecting pigs and humans in New South Wales in 1997. Antibodies capable of neutralising Menangle virus, were detected in flying foxes. PMID:10501164

  17. Dose-Response Model for Lassa Virus

    Microsoft Academic Search

    Sushil B. Tamrakar; Charles N. Haas

    2008-01-01

    This article develops dose-response models for Lassa fever virus using data sets found in the open literature. Dose-response data were drawn from two studies in which guinea pigs were given subcutaneous and aerosol exposure to Lassa virus. In one study, six groups of inbred guinea pigs were inoculated subcutaneously with doses of Lassa virus and five groups of out-bred guinea

  18. Influenza virus propagation in embryonated chicken eggs.

    PubMed

    Brauer, Rena; Chen, Peter

    2015-01-01

    Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 °C and 55-60% humidity for 10-11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 °C, the eggs are chilled for at least 4 hr at 4 °C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 °C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed. PMID:25867050

  19. RNA Virus Reverse Genetics and Vaccine Design

    PubMed Central

    Stobart, Christopher C.; Moore, Martin L.

    2014-01-01

    RNA viruses are capable of rapid spread and severe or potentially lethal disease in both animals and humans. The development of reverse genetics systems for manipulation and study of RNA virus genomes has provided platforms for designing and optimizing viral mutants for vaccine development. Here, we review the impact of RNA virus reverse genetics systems on past and current efforts to design effective and safe viral therapeutics and vaccines. PMID:24967693

  20. Detecting Unknown Computer Viruses - A New Approach

    Microsoft Academic Search

    Akira Mori

    2003-01-01

    \\u000a We give an overview of the tools to detect computer viruses without relying on “pattern files” that contain “signatures” of\\u000a previously captured viruses. The system combines static code analysis with code simulation to identify malicious behaviors\\u000a commonly found in computer viruses such as mass mailing, file infection, and registry overwrite. These prohibited behaviors\\u000a are defined separately as security policies at

  1. Nucleotide sequence of cassava latent virus DNA

    Microsoft Academic Search

    John Stanley; Michael R. Gay

    1983-01-01

    Only two groups of plant viruses, the caulimoviruses1,2 and the geminiviruses3, are known to contain a genome of DNA. Unlike that of the caulimoviruses, the genome of the geminivinises is composed of single-stranded, covalently-closed circles of DNA. There is evidence that the geminiviruses, specifically bean golden mosaic virus4 and tomato golden mosaic virus5, have a genome composed of two similar-sized

  2. Tubule-Guided Movement of Plant Viruses

    Microsoft Academic Search

    Christophe Ritzenthaler; Christina Hofmann

    Plant viruses move from cell to cell through plasmodesmata, which are complex gatable pores in the\\u000a cell wall. While plasmodesmata normally allow the diffusion of only small molecules, they can be biochemically\\u000a or structurally modified by virus-encoded movement proteins to enable the passage of either infectious ribonucleoprotein\\u000a complexes or entire virus particles. In the latter case, the movement protein forms

  3. NK Cells and Virus-Related Cancers

    PubMed Central

    Mishra, Rabinarayan; Welsh, Raymond M.; Szomolanyi-Tsuda, Eva

    2014-01-01

    Natural killer (NK) cells become activated during viral infections and can play roles in such infections by attacking virus-infected cells or by regulating adaptive immune responses. Experimental models suggest that NK cells may also have the capacity to restrain virus-induced cancers. Here, we discuss the seven viruses linked to human cancers and the evidence of NK cell involvement in these systems. PMID:24941377

  4. Transgenic gene silencing strategies for virus control

    Microsoft Academic Search

    R. G. Dietzgen; N. Mitter

    2006-01-01

    Co-suppression of transgenes and their homologous viral sequences by RNA silencing is a powerful strategy for achieving high-level\\u000a virus resistance in plants. This review provides a brief overview of RNA silencing mechanisms in plants and discusses important\\u000a transgene construct design features underpinning successful RNA silencing-mediated transgenic virus control. Application of\\u000a those strategies to protect horticultural and field crops from virus

  5. Virus Transmission—Getting Out and In

    Microsoft Academic Search

    Stéphane Blanc

    Logically, most plant viruses being vector-transmitted, the majority of viral transport mechanisms\\u000a associated to the transmission step have been approached through the study of virus-vector relationships.\\u000a However, in the case of non-vector vertical transmission through the seeds, some viruses have evolved specific\\u000a patterns to colonize either the gametes or the embryo, thereby connecting viral transport within the plant\\u000a to that

  6. Maize rayado fino virus capsid proteins assemble into virus-like particles in Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize rayado fino virus (MRFV; genus Marafivirus; family Tymoviridae) is a small spherical plant virus that contains two components: empty shells and complete virus particles (encapsidating the 6.3 kb genomic RNA). Virions are approximately 30 nm in diameter and composed of two serologically related...

  7. Incorporation of High Levels of Chimeric Human Immunodeficiency Virus Envelope Glycoproteins into Virus-Like Particles

    Microsoft Academic Search

    Bao-Zhong Wang; Weimin Liu; Sang-Moo Kang; Munir Alam; Chunzi Huang; Ling Ye; Yuliang Sun; Yingying Li; Denise L. Kothe; Peter Pushko; Terje Dokland; Barton F. Haynes; Gale Smith; Beatrice H. Hahn; Richard W. Compans

    2007-01-01

    The human immunodeficiency virus (HIV) envelope (Env) protein is incorporated into HIV virions or virus-like particles (VLPs) at very low levels compared to the glycoproteins of most other enveloped viruses. To test factors that influence HIV Env particle incorporation, we generated a series of chimeric gene constructs in which the coding sequences for the signal peptide (SP), transmembrane (TM), and

  8. Cell Type Mediated Resistance of Vesicular Stomatitis Virus and Sendai Virus to Ribavirin

    Microsoft Academic Search

    Nirav R. Shah; Amanda Sunderland; Valery Z. Grdzelishvili; Ron A. M. Fouchier

    2010-01-01

    Ribavirin (RBV) is a synthetic nucleoside analog with broad spectrum antiviral activity. Although RBV is approved for the treatment of hepatitis C virus, respiratory syncytial virus, and Lassa fever virus infections, its mechanism of action and therapeutic efficacy remains highly controversial. Recent reports show that the development of cell-based resistance after continuous RBV treatment via decreased RBV uptake can greatly

  9. Multiplex Real Time PCR For Detection of Wheat Streak Mosaic Virus and Triticum Mosaic Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TRIMV) are widespread throughout the southwestern Great Plains states. Using conventional diagnostics such as Enzyme-Linked Immunosorbent Assays (ELISA), these two viruses are commonly found together in infected wheat samples. Methods for m...

  10. New perspectives on virus detection in shellfish: hemocytes as a source of concentrated virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USDA ARS research indicates that circulating phagocytic cells (hemocytes) within oysters retain virus particles. We find that persistence of hepatitis A virus (HAV) within oyster hemocytes correlates with the presence of virus within whole oysters. Since bivalve shellfish have no self-nonself immun...

  11. Human Immunodeficiency Virus-Like Particles Produced by a Vaccinia Virus Expression Vector

    Microsoft Academic Search

    Velissarios Karacostas; Kunio Nagashima; Matthew A. Gonda; Bernard Moss

    1989-01-01

    Infectious retrovirus particles consist of a core structure containing RNA and gag-pol polypeptides surrounded by a lipid membrane studded with env proteins. A recombinant vaccinia virus was designed to express the entire gag-pol precursor protein of the human immunodeficiency virus type 1. Synthesis and processing of gag proteins occurred in mammalian cells infected with this live recombinant virus, and reverse

  12. Vesicular Stomatitis Virus–Based Vaccines against Lassa and Ebola Viruses

    PubMed Central

    Marzi, Andrea; Feldmann, Friederike; Geisbert, Thomas W.; Feldmann, Heinz

    2015-01-01

    We demonstrated that previous vaccination with a vesicular stomatitis virus (VSV)–based Lassa virus vaccine does not alter protective efficacy of subsequent vaccination with a VSV-based Ebola virus vaccine. These findings demonstrate the utility of VSV-based vaccines against divergent viral pathogens, even when preexisting immunity to the vaccine vector is present. PMID:25625358

  13. 72 FR 4467 - Viruses, Serums, Toxins, and Analogous Products; Detection of Avian Lymphoid Leukosis Virus

    Federal Register 2010, 2011, 2012, 2013, 2014

    2007-01-31

    We are proposing to amend the Virus-Serum-Toxin Act regulations concerning testing for avian lymphoid leukosis in veterinary biologics to specify that the test is for the detection of extraneous replicating avian leukosis virus; require such testing to be conducted using a procedure that will detect extraneous replicating avian leukosis virus and that is acceptable to the Animal and Plant Health......

  14. Targeting CTCF to Control Virus Gene Expression: A Common Theme amongst Diverse DNA Viruses.

    PubMed

    Pentland, Ieisha; Parish, Joanna L

    2015-01-01

    All viruses target host cell factors for successful life cycle completion. Transcriptional control of DNA viruses by host cell factors is important in the temporal and spatial regulation of virus gene expression. Many of these factors are recruited to enhance virus gene expression and thereby increase virus production, but host cell factors can also restrict virus gene expression and productivity of infection. CCCTC binding factor (CTCF) is a host cell DNA binding protein important for the regulation of genomic chromatin boundaries, transcriptional control and enhancer element usage. CTCF also functions in RNA polymerase II regulation and in doing so can influence co-transcriptional splicing events. Several DNA viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV), Epstein-Barr virus (EBV) and human papillomavirus (HPV) utilize CTCF to control virus gene expression and many studies have highlighted a role for CTCF in the persistence of these diverse oncogenic viruses. CTCF can both enhance and repress virus gene expression and in some cases CTCF increases the complexity of alternatively spliced transcripts. This review article will discuss the function of CTCF in the life cycle of DNA viruses in the context of known host cell CTCF functions. PMID:26154016

  15. Salivary gland hypertrophy viruses (SGHVs): a novel group of insect pathogenic viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salivary gland hypertrophy viruses (SGHVs) are a unique, unclassified group of entomopathogenic, double-stranded DNA viruses that have been reported from three genera of Diptera. These viruses replicate in nuclei of salivary gland cells in adult flies, inducing gland enlargement with little obvious ...

  16. A comparative study of O'nyong nyong virus with Chikungunya virus and plaque variants

    Microsoft Academic Search

    A. C. Chanas; Z. Hubalek; B. K. Johnson; D. I. H. Simpson

    1979-01-01

    Summary Two plaque variants of Chikungunya (CHIK) virus were serologically compared with O'nyong nyong (ONN) virus in order to elucidate the reported one way antigenic relationships between the two viruses. Three different hypotheses are examined and evidence is shown to support one of them.

  17. Marburg virus-like particles protect guinea pigs from lethal Marburg virus infection

    Microsoft Academic Search

    Kelly L Warfield; Dana L Swenson; Diane L Negley; Alan L Schmaljohn; M. Javad Aman; Sina Bavari

    2004-01-01

    Ongoing outbreaks of filoviruses in Africa and concerns about their use in bioterrorism attacks have led to intense efforts to find safe and effective vaccines to prevent the high mortality associated with these viruses. We previously reported the generation of virus-like particles (VLPs) for the filoviruses, Marburg (MARV) and Ebola (EBOV) virus, and that vaccinating mice with Ebola VLPs (eVLPs)

  18. Origin of giant viruses from smaller DNA viruses not from a fourth domain of cellular life.

    PubMed

    Yutin, Natalya; Wolf, Yuri I; Koonin, Eugene V

    2014-10-01

    The numerous and diverse eukaryotic viruses with large double-stranded DNA genomes that at least partially reproduce in the cytoplasm of infected cells apparently evolved from a single virus ancestor. This major group of viruses is known as Nucleocytoplasmic Large DNA Viruses (NCLDV) or the proposed order Megavirales. Among the "Megavirales", there are three groups of giant viruses with genomes exceeding 500kb, namely Mimiviruses, Pithoviruses, and Pandoraviruses that hold the current record of viral genome size, about 2.5Mb. Phylogenetic analysis of conserved, ancestral NLCDV genes clearly shows that these three groups of giant viruses have three distinct origins within the "Megavirales". The Mimiviruses constitute a distinct family that is distantly related to Phycodnaviridae, Pandoraviruses originate from a common ancestor with Coccolithoviruses within the Phycodnaviridae family, and Pithoviruses are related to Iridoviridae and Marseilleviridae. Maximum likelihood reconstruction of gene gain and loss events during the evolution of the "Megavirales" indicates that each group of giant viruses evolved from viruses with substantially smaller and simpler gene repertoires. Initial phylogenetic analysis of universal genes, such as translation system components, encoded by some giant viruses, in particular Mimiviruses, has led to the hypothesis that giant viruses descend from a fourth, probably extinct domain of cellular life. The results of our comprehensive phylogenomic analysis of giant viruses refute the fourth domain hypothesis and instead indicate that the universal genes have been independently acquired by different giant viruses from their eukaryotic hosts. PMID:25042053

  19. Emergence of Groundnut ringspot virus and Tomato chlorotic spot virus in U.S. vegetable production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host and geographic ranges, genetic diversity and thrips transmission of Groundnut ringspot virus and Tomato chlorotic spot virus isolates from the U.S. were characterized. This report provides an overview of these viruses for growers, extension workers, crop consultants and research and regulatory...

  20. Subterranean clover red leaf virus and bean yellow mosaic virus in alsike clover

    Microsoft Academic Search

    J. W. Ashby

    1976-01-01

    Subterranean clover red leaf virus (SCRLV) and bean yellow mosaic virus (BYMV) were isolated from alsike clover (Trifolium hybridum L.) grown in experimental plots on the Canterbury Plains. SCRLV caused reddening of older leaves, and BYMV caused yellowing and streaking of the leaves of infected plants. Some plants were infected by both viruses. A survey in the mid-altitude zone (50D-1000

  1. Treatment of ebola virus disease.

    PubMed

    Kilgore, Paul E; Grabenstein, John D; Salim, Abdulbaset M; Rybak, Michael

    2015-01-01

    In March 2014, the largest Ebola outbreak in history exploded across West Africa. As of November 14, 2014, the World Health Organization has reported a total of 21,296 Ebola virus disease (EVD) cases, including 13,427 laboratory-confirmed EVD cases reported from the three most affected countries (Guinea, Liberia, and Sierra Leone). As the outbreak of EVD has spread, clinical disease severity and national EVD case-fatality rates have remained high (21.2-60.8%). Prior to 2013, several EVD outbreaks were controlled by using routine public health interventions; however, the widespread nature of the current EVD outbreak as well as cultural practices in the affected countries have challenged even the most active case identification efforts. In addition, although treatment centers provide supportive care, no effective therapeutic agents are available for EVD-endemic countries. The ongoing EVD outbreak has stimulated investigation of several different therapeutic strategies that target specific viral structures and mechanisms of Ebola viruses. Six to eight putative pharmacotherapies or immunologically based treatments have demonstrated promising results in animal studies. In addition, agents composed of small interfering RNAs targeting specific proteins of Ebola viruses, traditional hyperimmune globulin isolated from Ebola animal models, monoclonal antibodies, and morpholino oligomers (small molecules used to block viral gene expression). A number of EVD therapeutic agents are now entering accelerated human trials in EVD-endemic countries. The goal of therapeutic agent development includes postexposure prevention and EVD cure. As knowledge of Ebola virus virology and pathogenesis grows, it is likely that new therapeutic tools will be developed. Deployment of novel Ebola therapies will require unprecedented cooperation as well as investment to ensure that therapeutic tools become available to populations at greatest risk for EVD and its complications. In this article, we review several agents and strategies that are now under active development. PMID:25630412

  2. West Nile Virus Neuroinvasive Disease

    Microsoft Academic Search

    Roberta L. DeBiasi

    2011-01-01

    West Nile virus (WNV), first recognized in North America in 1999, was responsible for the largest arboviral epidemic of human\\u000a encephalitis in history and continues to be the most frequent cause of epidemic meningoencephalitis in North America. WNV\\u000a neuroinvasive disease (WNND) occurs in fewer than 1% of infected individuals, with presentations including aseptic meningitis,\\u000a encephalitis, and poliomyelitis. Between 1999 and

  3. Giant virus in the sea

    PubMed Central

    Claverie, Jean-Michel

    2013-01-01

    The viral nature of the first “giant virus,” Mimivirus, was realized in 2003, 10 y after its initial isolation from the water of a cooling tower in Bradford, UK. Soon after its genome was sequenced, the mining of the Global Ocean Sampling environmental sequence database revealed that the closest relatives of Mimivirus, only known to infect Acanthamoeba, were to be found in the sea. These predicted marine Mimivirus relatives remained elusive until 2010, with the first genomic characterization of a virus infecting a heterotrophic unicellular eukaryote, the microflagellate grazer Cafeteria roenbergensis. The genome analysis of a virus (PgV) infecting the common unicellular algae Phaeocystis globosa now shows that it is a bona fide member of the Mimivirus family (i.e., the Megaviridae), extending the realm of these giant viruses to abundant blooming phytoplankton species. Despite its smaller genome size (460 kb encoding 434 proteins), PgV exhibits the most intriguing feature of the previously characterized Megaviridae: an associated virophage. However, the 19-kb virophage genome, devoid of a capsid gene, is packaged in the PgV particle and propagated as a “viral plasmid,” the first ever described. The PgV genome also exhibits the duplication of “core genes,” normally present as single copies and a putative new type of mobile element. In a DNA polymerase phylogeny including representatives of the three cellular domains, PgV and the other Megaviridae cluster into their own clade deeply branching between domains Archaea and Eukarya domains, thus exhibiting the topology of a fourth domain in the Tree of Life. PMID:24563700

  4. Metamorphic Viruses with Built-In Buffer Overflow

    Microsoft Academic Search

    Ronak Shah

    2010-01-01

    Metamorphic computer viruses change their structure—and thereby their signature—each time they infect a system. Metamorphic viruses are potentially one of the most dangerous types of computer viruses because they are difficult to detect using signature-based methods. Most anti-virus software today is based on signature detection techniques. In this project, we create and analyze a metamorphic virus toolkit which creates viruses

  5. Reversible Inactivation and Desiccation Tolerance of Silicified Viruses

    PubMed Central

    Laidler, James R.; Shugart, Jessica A.; Cady, Sherry L.; Bahjat, Keith S.

    2013-01-01

    Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus Sulfolobus spindle-shaped virus Kamchatka, and vaccinia virus are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot springs. In contrast, bacteriophage PRD1 is not silicified. Moreover, silicification provides viruses with remarkable desiccation resistance, which could allow extensive aerial dispersal. PMID:24109222

  6. Reversible inactivation and desiccation tolerance of silicified viruses.

    PubMed

    Laidler, James R; Shugart, Jessica A; Cady, Sherry L; Bahjat, Keith S; Stedman, Kenneth M

    2013-12-01

    Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus Sulfolobus spindle-shaped virus Kamchatka, and vaccinia virus are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot springs. In contrast, bacteriophage PRD1 is not silicified. Moreover, silicification provides viruses with remarkable desiccation resistance, which could allow extensive aerial dispersal. PMID:24109222

  7. Electronic Parameters of Mesoporous Silicon Upon Adsorption of Plant Viruses

    NASA Astrophysics Data System (ADS)

    Vashpanov, Yuriy; Son, Jung-Young; Kwack, Kae-Dal; Shin, Seung-Jung

    2008-06-01

    Changes in the electronic parameters of mesoporous silicon upon adsorption of nematodetransmitted polyhedral (NEPO) viruses of plant [tomato ringspot virus (TORSV), grapevine virus A (GVA), and grapevine fan leaf virus (GFLV)] measured at room temperature are investigated. The adsorption of these viruses affected essentially on the electronic characteristic of the porous material. The measurement of the electronic characteristics of porous silicon can be applied to the creation of detectors for the presence of viruses in a given environment.

  8. Quantitation of Grapevine leafroll associated virus-1 and -3, Grapevine virus A, Grapevine fanleaf virus and Grapevine fleck virus in field-collected Vitis vinifera L. ‘Nebbiolo’ by real-time reverse transcription-PCR

    Microsoft Academic Search

    Davide Pacifico; Piero Caciagli; Sabrina Palmano; Franco Mannini; Cristina Marzachì

    2011-01-01

    TaqMan one-step real-time qRT-PCR assays were developed for the quantitation of Grapevine leafroll associated virus-1 and -3 (GLRaV-1 and -3), Grapevine virus A (GVA), Grapevine fanleaf virus (GFLV) and Grapevine fleck virus (GFkV) in Vitis vinifera L. Virus load in the progenies of three ‘Nebbiolo’ clones planted in two experimental vineyards in Piemonte (northwestern Italy), and carrying the viruses in

  9. Infectious laryngotracheitis virus in chickens

    PubMed Central

    Ou, Shan-Chia; Giambrone, Joseph J

    2012-01-01

    Infectious laryngotracheitis (ILT) is an important respiratory disease of chickens and annually causes significant economic losses in the poultry industry world-wide. ILT virus (ILTV) belongs to alphaherpesvirinae and the Gallid herpesvirus 1 species. The transmission of ILTV is via respiratory and ocular routes. Clinical and post-mortem signs of ILT can be separated into two forms according to its virulence. The characteristic of the severe form is bloody mucus in the trachea with high mortality. The mild form causes nasal discharge, conjunctivitis, and reduced weight gain and egg production. Conventional polymerase chain reaction (PCR), nested PCR, real-time PCR, and loop-mediated isothermal amplification were developed to detect ILTV samples from natural or experimentally infected birds. The PCR combined with restriction fragment length polymorphism (RFLP) can separate ILTVs into several genetic groups. These groups can separate vaccine from wild type field viruses. Vaccination is a common method to prevent ILT. However, field isolates and vaccine viruses can establish latent infected carriers. According to PCR-RFLP results, virulent field ILTVs can be derived from modified-live vaccines. Therefore, modified-live vaccine reversion provides a source for ILT outbreaks on chicken farms. Two recently licensed commercial recombinant ILT vaccines are also in use. Other recombinant and gene-deficient vaccine candidates are in the developmental stages. They offer additional hope for the control of this disease. However, in ILT endemic regions, improved biosecurity and management practices are critical for improved ILT control. PMID:24175219

  10. Infectious laryngotracheitis virus in chickens.

    PubMed

    Ou, Shan-Chia; Giambrone, Joseph J

    2012-10-12

    Infectious laryngotracheitis (ILT) is an important respiratory disease of chickens and annually causes significant economic losses in the poultry industry world-wide. ILT virus (ILTV) belongs to alphaherpesvirinae and the Gallid herpesvirus 1 species. The transmission of ILTV is via respiratory and ocular routes. Clinical and post-mortem signs of ILT can be separated into two forms according to its virulence. The characteristic of the severe form is bloody mucus in the trachea with high mortality. The mild form causes nasal discharge, conjunctivitis, and reduced weight gain and egg production. Conventional polymerase chain reaction (PCR), nested PCR, real-time PCR, and loop-mediated isothermal amplification were developed to detect ILTV samples from natural or experimentally infected birds. The PCR combined with restriction fragment length polymorphism (RFLP) can separate ILTVs into several genetic groups. These groups can separate vaccine from wild type field viruses. Vaccination is a common method to prevent ILT. However, field isolates and vaccine viruses can establish latent infected carriers. According to PCR-RFLP results, virulent field ILTVs can be derived from modified-live vaccines. Therefore, modified-live vaccine reversion provides a source for ILT outbreaks on chicken farms. Two recently licensed commercial recombinant ILT vaccines are also in use. Other recombinant and gene-deficient vaccine candidates are in the developmental stages. They offer additional hope for the control of this disease. However, in ILT endemic regions, improved biosecurity and management practices are critical for improved ILT control. PMID:24175219

  11. Structural studies of Hantaan virus.

    PubMed

    Battisti, Anthony J; Chu, Yong-Kyu; Chipman, Paul R; Kaufmann, Bärbel; Jonsson, Colleen B; Rossmann, Michael G

    2011-01-01

    Hantaan virus is the prototypic member of the Hantavirus genus within the family Bunyaviridae and is a causative agent of the potentially fatal hemorrhagic fever with renal syndrome. The Bunyaviridae are a family of negative-sense RNA viruses with three-part segmented genomes. Virions are enveloped and decorated with spikes derived from a pair of glycoproteins (Gn and Gc). Here, we present cryo-electron tomography and single-particle cryo-electron microscopy studies of Hantaan virus virions. We have determined the structure of the tetrameric Gn-Gc spike complex to a resolution of 2.5 nm and show that spikes are ordered in lattices on the virion surface. Large cytoplasmic extensions associated with each Gn-Gc spike also form a lattice on the inner surface of the viral membrane. Rod-shaped ribonucleoprotein complexes are arranged into nearly parallel pairs and triplets within virions. Our results differ from the T=12 icosahedral organization found for some bunyaviruses. However, a comparison of our results with the previous tomographic studies of the nonpathogenic Tula hantavirus indicates a common structural organization for hantaviruses. PMID:21068243

  12. West Nile Virus Drug Discovery

    PubMed Central

    Lim, Siew Pheng; Shi, Pei-Yong

    2013-01-01

    The outbreak of West Nile virus (WNV) in 1999 in the USA, and its continued spread throughout the Americas, parts of Europe, the Middle East and Africa, underscored the need for WNV antiviral development. Here, we review the current status of WNV drug discovery. A number of approaches have been used to search for inhibitors of WNV, including viral infection-based screening, enzyme-based screening, structure-based virtual screening, structure-based rationale design, and antibody-based therapy. These efforts have yielded inhibitors of viral or cellular factors that are critical for viral replication. For small molecule inhibitors, no promising preclinical candidate has been developed; most of the inhibitors could not even be advanced to the stage of hit-to-lead optimization due to their poor drug-like properties. However, several inhibitors developed for related members of the family Flaviviridae, such as dengue virus and hepatitis C virus, exhibited cross-inhibition of WNV, suggesting the possibility to re-purpose these antivirals for WNV treatment. Most promisingly, therapeutic antibodies have shown excellent efficacy in mouse model; one of such antibodies has been advanced into clinical trial. The knowledge accumulated during the past fifteen years has provided better rationale for the ongoing WNV and other flavivirus antiviral development. PMID:24300672

  13. Inhibition of enveloped viruses infectivity by curcumin.

    PubMed

    Chen, Tzu-Yen; Chen, Da-Yuan; Wen, Hsiao-Wei; Ou, Jun-Lin; Chiou, Shyan-Song; Chen, Jo-Mei; Wong, Min-Liang; Hsu, Wei-Li

    2013-01-01

    Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA) activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB)-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter) than for the pseudorabies virus (approximately 180 nm) and the vaccinia virus (roughly 335 × 200 × 200 nm). These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses. PMID:23658730

  14. Structural and Functional Studies of Archaeal Viruses*

    PubMed Central

    Lawrence, C. Martin; Menon, Smita; Eilers, Brian J.; Bothner, Brian; Khayat, Reza; Douglas, Trevor; Young, Mark J.

    2009-01-01

    Viruses populate virtually every ecosystem on the planet, including the extreme acidic, thermal, and saline environments where archaeal organisms can dominate. For example, recent studies have identified crenarchaeal viruses in the hot springs of Yellowstone National Park and other high temperature environments worldwide. These viruses are often morphologically and genetically unique, with genomes that show little similarity to genes of known function, complicating efforts to understand their viral life cycles. Here, we review progress in understanding these fascinating viruses at the molecular level and the evolutionary insights coming from these studies. PMID:19158076

  15. Viruses: Making Friends with Old Foes

    NSDL National Science Digital Library

    Trevor Douglas (Montana State University; Center for Bio-Inspired Nanomaterials)

    2006-05-12

    Access to the article is free, however registration and sign-in are required: The study of viruses has traditionally focused on their roles as infectious agents and as tools for understanding cell biology. Viruses are now finding a new expanded role as nanoplatforms with applications in materials science and medicine. Viruses form highly symmetrical monodisperse architectures and are ideal templates for engineering multifunctionality, including multivalent display of surface ligands and encapsulation of inorganic and organic materials. These developments assure that viruses will find applications as versatile nanoscale materials.

  16. Flexible filamentous virus structure from fiber diffraction

    SciTech Connect

    Stubbs, Gerald; Kendall, Amy; McDonald, Michele; Bian, Wen; Bowles, Timothy; Baumgarten, Sarah; McCullough, Ian; Shi, Jian; Stewart, Phoebe; Bullitt, Esther; Gore, David; Ghabrial, Said (IIT); (BU-M); (Vanderbilt); (Kentucky)

    2008-10-24

    Fiber diffraction data have been obtained from Narcissus mosaic virus, a potexvirus from the family Flexiviridae, and soybean mosaic virus (SMV), a potyvirus from the family Potyviridae. Analysis of the data in conjunction with cryo-electron microscopy data allowed us to determine the symmetry of the viruses and to make reconstructions of SMV at 19 {angstrom} resolution and of another potexvirus, papaya mosaic virus, at 18 {angstrom} resolution. These data include the first well-ordered data ever obtained for the potyviruses and the best-ordered data from the potexviruses, and offer the promise of eventual high resolution structure determinations.

  17. Neutralizing Antibody Response to Hepatitis C Virus

    PubMed Central

    Wang, Yong; Keck, Zhen-Yong; Foung, Steven K. H.

    2011-01-01

    A critical first step in a “rational vaccine design” approach for hepatitis C virus (HCV) is to identify the most relevant mechanisms of immune protection. Emerging evidence provides support for a protective role of virus neutralizing antibodies, and the ability of the B cell response to modify the course of acute HCV infection. This has been made possible by the development of in vitro cell culture models, based on HCV retroviral pseudotype particles expressing E1E2 and infectious cell culture-derived HCV virions, and small animal models that are robust tools in studies of antibody-mediated virus neutralization. This review is focused on the immunogenic determinants on the E2 glycoprotein mediating virus neutralization and the pathways in which the virus is able to escape from immune containment. Encouraging findings from recent studies provide support for the existence of broadly neutralization antibodies that are not associated with virus escape. The identification of conserved epitopes mediating virus neutralization that are not associated with virus escape will facilitate the design of a vaccine immunogen capable of eliciting broadly neutralizing antibodies against this highly diverse virus. PMID:22163337

  18. [Rift Valley fever virus: evolution in progress].

    PubMed

    Tolou, H; Plumet, S; Leparc-Goffart, I; Couissinier-Paris, P

    2009-06-01

    Several viruses now circulating in tropical zones around the globe are potential threats for ever-increasing human populations even in temperate zones that have long remained unaffected. The mechanisms underlying transport and transmission, which can be enhanced by human activity, can be even stronger in zones where factors needed to support development of these viruses, i.e., hosts, reservoirs and vectors, are already present. This possibility has been illustrated by dengue virus, and now by the rapid spread of the Chikungunya virus on Reunion Island in 2005 and then in Italy in 2007. The spreading of Chikungunya virus despite its mild reputation had a major unexpected impact. It showed that the evolution of the virus, whether a cause or consequence of observed events, could be determinant. The risk of extension of more pathogenic viruses due to similar mechanisms must be considered as a possibility. In this regard the Rift Valley fever virus, that already involves a large area and has a major reservoir, is one of the viruses that deserves close surveillance. PMID:19702138

  19. Control of sweet potato virus diseases.

    PubMed

    Loebenstein, Gad

    2015-01-01

    Sweet potato (Ipomoea batatas) is ranked seventh in global food crop production and is the third most important root crop after potato and cassava. Sweet potatoes are vegetative propagated from vines, root slips (sprouts), or tubers. Therefore, virus diseases can be a major constrain, reducing yields markedly, often more than 50%. The main viruses worldwide are Sweet potato feathery mottle virus (SPFMV) and Sweet potato chlorotic stunt virus (SPCSV). Effects on yields by SPFMV or SPCSV alone are minor, or but in complex infection by the two or other viruses yield losses of 50%. The orthodox way of controlling viruses in vegetative propagated crops is by supplying the growers with virus-tested planting material. High-yielding plants are tested for freedom of viruses by PCR, serology, and grafting to sweet potato virus indicator plants. After this, meristem tips are taken from those plants that reacted negative. The meristems were grown into plants which were kept under insect-proof conditions and away from other sweet potato material for distribution to farmers after another cycle of reproduction. PMID:25591876

  20. The nucleolar interface of RNA viruses.

    PubMed

    Rawlinson, Stephen M; Moseley, Gregory W

    2015-08-01

    In recent years, understanding of the nucleolus has undergone a renaissance. Once considered primarily as the sites of ribosome biogenesis, nucleoli are now understood to be highly dynamic, multifunctional structures that participate in a plethora of cellular functions including regulation of the cell cycle, signal recognition particle assembly, apoptosis and stress responses. Although the molecular/mechanistic details of many of these functions remain only partially resolved, it is becoming increasingly apparent that nucleoli are also common targets of almost all types of viruses, potentially allowing viruses to manipulate cellular responses and the intracellular environment to facilitate replication and propagation. Importantly, a number of recent studies have moved beyond early descriptive observations to identify key roles for nucleolar interactions in the viral life cycle and pathogenesis. While it is perhaps unsurprising that many viruses that replicate within the nucleus also form interactions with nucleoli, the roles of nucleoli in the biology of cytoplasmic viruses is less intuitive. Nevertheless, a number of positive-stranded RNA viruses that replicate exclusively in the cytoplasm are known to express proteins that enter the nucleus and target nucleoli, and recent data have indicated similar processes in several cytoplasmic negative-sense RNA viruses. Here, we review this emerging aspect of the virus-host interface with a focus on examples where virus-nucleolus interactions have been linked to specific functional outcomes/mechanistic processes in infection and on the nucleolar interfaces formed by viruses that replicate exclusively in the cytoplasm. PMID:26041433

  1. Viruses as Modulators of Mitochondrial Functions

    PubMed Central

    Anand, Sanjeev K.; Tikoo, Suresh K.

    2013-01-01

    Mitochondria are multifunctional organelles with diverse roles including energy production and distribution, apoptosis, eliciting host immune response, and causing diseases and aging. Mitochondria-mediated immune responses might be an evolutionary adaptation by which mitochondria might have prevented the entry of invading microorganisms thus establishing them as an integral part of the cell. This makes them a target for all the invading pathogens including viruses. Viruses either induce or inhibit various mitochondrial processes in a highly specific manner so that they can replicate and produce progeny. Some viruses encode the Bcl2 homologues to counter the proapoptotic functions of the cellular and mitochondrial proteins. Others modulate the permeability transition pore and either prevent or induce the release of the apoptotic proteins from the mitochondria. Viruses like Herpes simplex virus 1 deplete the host mitochondrial DNA and some, like human immunodeficiency virus, hijack the host mitochondrial proteins to function fully inside the host cell. All these processes involve the participation of cellular proteins, mitochondrial proteins, and virus specific proteins. This review will summarize the strategies employed by viruses to utilize cellular mitochondria for successful multiplication and production of progeny virus. PMID:24260034

  2. RNA Viruses: ROS-Mediated Cell Death

    PubMed Central

    Reshi, Mohammad Latif; Su, Yi-Che; Hong, Jiann-Ruey

    2014-01-01

    Reactive oxygen species (ROS) are well known for being both beneficial and deleterious. The main thrust of this review is to investigate the role of ROS in ribonucleic acid (RNA) virus pathogenesis. Much evidences has accumulated over the past decade, suggesting that patients infected with RNA viruses are under chronic oxidative stress. Changes to the body's antioxidant defense system, in relation to SOD, ascorbic acid, selenium, carotenoids, and glutathione, have been reported in various tissues of RNA-virus infected patients. This review focuses on RNA viruses and retroviruses, giving particular attention to the human influenza virus, Hepatitis c virus (HCV), human immunodeficiency virus (HIV), and the aquatic Betanodavirus. Oxidative stress via RNA virus infections can contribute to several aspects of viral disease pathogenesis including apoptosis, loss of immune function, viral replication, inflammatory response, and loss of body weight. We focus on how ROS production is correlated with host cell death. Moreover, ROS may play an important role as a signal molecule in the regulation of viral replication and organelle function, potentially providing new insights in the prevention and treatment of RNA viruses and retrovirus infections. PMID:24899897

  3. Infectivity of rabies virus-exposed macrophages.

    PubMed

    Nazé, Florence; Suin, Vanessa; Lamoral, Sophie; Francart, Aurélie; Brochier, Bernard; Roels, Stefan; Mast, Jan; Kalai, Michael; Van Gucht, Steven

    2013-02-01

    Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophages. The infection characteristics in murine macrophages and the infectivity of virus-exposed macrophages were examined upon inoculation in mice. In vitro, Mf4/4 spleen macrophages supported mild virus production (10(4)-fold less than neuroblastoma), with formation of typical virions. Bone marrow-derived macrophages (BMM) were most efficient to capture virus, but new virus production was not detected. Virus-induced cell death was significantly stronger in BMM, which might have eliminated BMM with productive infection. Still, viral RNA remained detectable in the remaining BMM for at least 4 weeks. Injection of in vitro-infected Mf4/4 in the nose or brain proved efficient to propagate infection in mice, even when cells were pre-incubated with neutralizing antibodies. Surprisingly, injection of ex-vivo-infected BMM in the brain also led to lethal infection in 8 out of 12 mice. Injection of infected Mf4/4 in the muscle mostly favoured a protective antibody response. Despite that macrophages are less fit to support virus production, they can still act as a source of infectious virus upon transfer in mice. This may be relevant for screening donor organs/cells, for which RT-PCR should be preferred over the traditional antigen or virus isolation assays. PMID:23159243

  4. Museo Universitario del Chopo Datos del plan de estudio

    E-print Network

    Islas, León

    periodismo cultural para producir información en los diferentes géneros informativos, para su publicación características del fenómeno informativo, delimitando el campo de acción del periodista cultural. Utilizar los elementos del lenguaje periodístico. Distinguir la estructura de los diferentes géneros informativos

  5. Isolation of influenza viruses in MDCK 33016PF cells and clearance of contaminating respiratory viruses.

    PubMed

    Roth, Bernhard; Mohr, Hannah; Enders, Martin; Garten, Wolfgang; Gregersen, Jens-Peter

    2012-01-11

    This paper summarizes results obtained by multiplex PCR screening of human clinical samples for respiratory viruses and corresponding data obtained after passaging of virus-positive samples in MDCK 33016PF cells. Using the ResPlexII v2.0 (Qiagen) multiplex PCR, 393 positive results were obtained in 468 clinical samples collected during an influenza season in Germany. The overall distribution of positive results was influenza A 42.0%, influenza B 38.7%, adenovirus 1.5%, bocavirus 0.5%, coronavirus 3.3%, enterovirus 5.6%, metapneumovirus 1.0%, parainfluenza virus 0.8%, rhinovirus 4.1%, and respiratory syncytial virus (RSV) 2.5%. Double infections of influenza virus together with another virus were found for adenovirus B and E, bocavirus, coronavirus, enterovirus and for rhinovirus. These other viruses were rapidly lost upon passages in MDCK 33016PF cells and under conditions as applied to influenza virus passaging. Clinical samples, in which no influenza virus but other viruses were found, were also subject to passages in MDCK 33016PF cells. Using lower inoculum dilutions than those normally applied for preparations containing influenza virus (total dilution of the original sample of ?10(4)), the positive results for the different viruses turned negative already after 2 or 3 passages in MDCK 33016PF cells. These results demonstrate that, under practical conditions as applied to grow influenza viruses, contaminating viruses can be effectively removed by passages in MDCK cells. In combination with their superior isolation efficiency, MDCK cells appear highly suitable to be used as an alternative to embryonated eggs to isolate and propagate influenza vaccine candidate viruses. PMID:22119922

  6. Upolu virus and Aransas Bay virus, Two Presumptive Bunyaviruses, Are Novel Members of the Family Orthomyxoviridae

    PubMed Central

    Chowdhary, Rashmi; Travassos da Rosa, Amelia; Hutchison, Stephen K.; Popov, Vsevolod; Street, Craig; Tesh, Robert B.; Lipkin, W. Ian

    2014-01-01

    ABSTRACT Emerging and zoonotic pathogens pose continuing threats to human health and ongoing challenges to diagnostics. As nucleic acid tests are playing increasingly prominent roles in diagnostics, the genetic characterization of molecularly uncharacterized agents is expected to significantly enhance detection and surveillance capabilities. We report the identification of two previously unrecognized members of the family Orthomyxoviridae, which includes the influenza viruses and the tick-transmitted Thogoto and Dhori viruses. We provide morphological, serologic, and genetic evidence that Upolu virus (UPOV) from Australia and Aransas Bay virus (ABV) from North America, both previously considered potential bunyaviruses based on electron microscopy and physicochemical features, are orthomyxoviruses instead. Their genomes show up to 68% nucleotide sequence identity to Thogoto virus (segment 2; ?74% at the amino acid level) and a more distant relationship to Dhori virus, the two prototype viruses of the recognized species of the genus Thogotovirus. Despite sequence similarity, the coding potentials of UPOV and ABV differed from that of Thogoto virus, instead being like that of Dhori virus. Our findings suggest that the tick-transmitted viruses UPOV and ABV represent geographically distinct viruses in the genus Thogotovirus of the family Orthomyxoviridae that do not fit in the two currently recognized species of this genus. IMPORTANCE Upolu virus (UPOV) and Aransas Bay virus (ABV) are shown to be orthomyxoviruses instead of bunyaviruses, as previously thought. Genetic characterization and adequate classification of agents are paramount in this molecular age to devise appropriate surveillance and diagnostics. Although more closely related to Thogoto virus by sequence, UPOV and ABV differ in their coding potentials by lacking a proposed pathogenicity factor. In this respect, they are similar to Dhori virus, which, despite the lack of a pathogenicity factor, can cause disease. These findings enable further studies into the evolution and pathogenicity of orthomyxoviruses. PMID:24574415

  7. Characterization of uncultivable bat influenza virus using a replicative synthetic virus.

    PubMed

    Zhou, Bin; Ma, Jingjiao; Liu, Qinfang; Bawa, Bhupinder; Wang, Wei; Shabman, Reed S; Duff, Michael; Lee, Jinhwa; Lang, Yuekun; Cao, Nan; Nagy, Abdou; Lin, Xudong; Stockwell, Timothy B; Richt, Juergen A; Wentworth, David E; Ma, Wenjun

    2014-10-01

    Bats harbor many viruses, which are periodically transmitted to humans resulting in outbreaks of disease (e.g., Ebola, SARS-CoV). Recently, influenza virus-like sequences were identified in bats; however, the viruses could not be cultured. This discovery aroused great interest in understanding the evolutionary history and pandemic potential of bat-influenza. Using synthetic genomics, we were unable to rescue the wild type bat virus, but could rescue a modified bat-influenza virus that had the HA and NA coding regions replaced with those of A/PR/8/1934 (H1N1). This modified bat-influenza virus replicated efficiently in vitro and in mice, resulting in severe disease. Additional studies using a bat-influenza virus that had the HA and NA of A/swine/Texas/4199-2/1998 (H3N2) showed that the PR8 HA and NA contributed to the pathogenicity in mice. Unlike other influenza viruses, engineering truncations hypothesized to reduce interferon antagonism into the NS1 protein didn't attenuate bat-influenza. In contrast, substitution of a putative virulence mutation from the bat-influenza PB2 significantly attenuated the virus in mice and introduction of a putative virulence mutation increased its pathogenicity. Mini-genome replication studies and virus reassortment experiments demonstrated that bat-influenza has very limited genetic and protein compatibility with Type A or Type B influenza viruses, yet it readily reassorts with another divergent bat-influenza virus, suggesting that the bat-influenza lineage may represent a new Genus/Species within the Orthomyxoviridae family. Collectively, our data indicate that the bat-influenza viruses recently identified are authentic viruses that pose little, if any, pandemic threat to humans; however, they provide new insights into the evolution and basic biology of influenza viruses. PMID:25275541

  8. Ácaros del mango

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Los ácaros constituyen un grupo abundante y diverso que ocupa diferentes hábitats en árboles frutales y la estructura y disposición del follaje y ramas del mango, contribuyen significativamente a que se presente gran diversidad de ácaros benéficos y dañinos asociados a esta especie frutal. En Colomb...

  9. en Fisioterapia del Deporte

    E-print Network

    Rey Juan Carlos, Universidad

    Experto en Fisioterapia del Deporte III Edición RESERVA DE PLAZAY MATRÍCULA Título: Experto en Fisioterapia del Deporte Precio de título: 1.800 Plazo de preinscripción: hasta 15 de Octubre 2014 Nº de que se encuentra matriculado en cuarto curso de grado en fisioterapia (en caso de alumnos

  10. Pathogenic Interactions Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum.

    E-print Network

    Theu, M.P.K.J; Toler, R.W.

    1992-01-01

    Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum M.P.K.J. Theu and R. W. Toler1 Abstract A pathogenic interaction between sorghum yel low banding virus (SYBV) and maize dwarf mosaic (MDMV-A) virus was proved. Inoculation..., MDMV-A was the only virus that was serologically detected. SYBV infected root tissue revealed the presence of SYBV particles in the mitochondria and not in the nucleus. Maize dwarf mosaic strain 0 also produced a patho genic synergistic interaction...

  11. Detection of Vaccinia Virus DNA, but not Infectious Virus, in the Blood of Smallpox Vaccine Recipients

    PubMed Central

    Cohen, Jeffrey I.; Hohman, Patricia; Preuss, Jeanne C.; Li, Li; Fischer, Steven H.; Fedorko, Daniel P.

    2007-01-01

    The authors of a recent study suggested that the duration of deferral for blood donations by smallpox vaccinees should be extended, based on detection of vaccinia virus DNA in 5 blood samples by PCR and the potential for viremia. We found that 4 of 202 blood specimens (from 3 of 27 smallpox vaccinees) were positive for vaccinia virus DNA by PCR; none were positive for virus by culture. Throat swabs were negative by PCR and culture. Thus, while some blood specimens contained vaccinia virus DNA, infectious virus was not detected. Current guidelines for deferral of blood donation in vaccinees seem appropriate. PMID:17493714

  12. Citrus tristeza virus (CTV) resistance in transgenic citrus based on virus challenge of protoplasts

    Microsoft Academic Search

    O. Olivares-Fuster; G. H. Fleming; M. R. Albiach-Marti; S. Gowda; W. O. Dawson; J. W. Crosser

    2003-01-01

    Summary  A strategy for the sereening of candidate virus-derived sequences to provide RNA-mediated citrus tristeza virus (CTV) resistance\\u000a and early selection of virus-resistant citrus is presented. The system is based on the polyethylene glycol-(PEG) mediated\\u000a cotransformation of protoplasts using virus-derived sequences and green fluorescent protein as a single selectable marker,\\u000a followed by an in vitro assay of virus inoculation into transgenic

  13. Characterization of the Early Steps of Hepatitis C Virus Infection by Using Luciferase Reporter Viruses

    PubMed Central

    Koutsoudakis, George; Kaul, Artur; Steinmann, Eike; Kallis, Stephanie; Lohmann, Volker; Pietschmann, Thomas; Bartenschlager, Ralf

    2006-01-01

    The lack of an efficient system to produce hepatitis C virus (HCV) particles has impeded the analysis of the HCV life cycle. Recently, we along with others demonstrated that transfection of Huh7 hepatoma cells with a novel HCV isolate (JFH1) yields infectious viruses. To facilitate studies of HCV replication, we generated JFH1-based bicistronic luciferase reporter virus genomes. We found that RNA replication of the reporter construct was only slightly attenuated and that virus titers produced were only three- to fivefold lower compared to the parental virus, making these reporter viruses an ideal tool for quantitative analyses of HCV infections. To expand the scope of the system, we created two chimeric JFH1 luciferase reporter viruses with structural proteins from the Con1 (genotype 1b) and J6CF (genotype 2a) strains. Using these and the authentic JFH1 reporter viruses, we analyzed the early steps of the HCV life cycle. Our data show that the mode of virus entry is conserved between these isolates and involves CD81 as a key receptor for pH-dependent virus entry. Competition studies and time course experiments suggest that interactions of HCV with cell surface-resident glycosaminoglycans aid in efficient infection of Huh7 cells and that CD81 acts during a postattachment step. The reporter viruses described here should be instrumental for investigating the viral life cycle and for the development of HCV inhibitors. PMID:16699011

  14. Animal Viruses Probe dataset (AVPDS) for microarray-based diagnosis and identification of viruses.

    PubMed

    Yadav, Brijesh S; Pokhriyal, Mayank; Vasishtha, Dinesh P; Sharma, Bhaskar

    2014-03-01

    AVPDS (Animal Viruses Probe dataset) is a dataset of virus-specific and conserve oligonucleotides for identification and diagnosis of viruses infecting animals. The current dataset contain 20,619 virus specific probes for 833 viruses and their subtypes and 3,988 conserved probes for 146 viral genera. Dataset of virus specific probe has been divided into two fields namely virus name and probe sequence. Similarly conserved probes for virus genera table have genus, and subgroup within genus name and probe sequence. The subgroup within genus is artificially divided subgroups with no taxonomic significance and contains probes which identifies viruses in that specific subgroup of the genus. Using this dataset we have successfully diagnosed the first case of Newcastle disease virus in sheep and reported a mixed infection of Bovine viral diarrhea and Bovine herpesvirus in cattle. These dataset also contains probes which cross reacts across species experimentally though computationally they meet specifications. These probes have been marked. We hope that this dataset will be useful in microarray-based detection of viruses. The dataset can be accessed through the link https://dl.dropboxusercontent.com/u/94060831/avpds/HOME.html. PMID:24129840

  15. Virus Enrichment for Single Virus Infection by Using 3D Insulator Based Dielectrophoresis

    PubMed Central

    Masuda, Taisuke; Maruyama, Hisataka; Honda, Ayae; Arai, Fumihito

    2014-01-01

    We developed an active virus filter (AVF) that enables virus enrichment for single virus infection, by using insulator-based dielectrophoresis (iDEP). A 3D-constricted flow channel design enabled the production of an iDEP force in the microfluidic chip. iDEP using a chip with multiple active virus filters (AVFs) was more accurate and faster than using a chip with a single AVF, and improved the efficiency of virus trapping. We utilized maskless photolithography to achieve the precise 3D gray-scale exposure required for fabrication of constricted flow channel. Influenza virus (A PR/8) was enriched by a negative DEP force when sinusoidal wave was applied to the electrodes within an amplitude range of 20 Vp-p and a frequency of 10 MHz. AVF-mediated virus enrichment can be repeated simply by turning the current ON or OFF. Furthermore, the negative AVF can inhibit virus adhesion onto the glass substrate. We then trapped and transported one of the enriched viruses by using optical tweezers. This microfluidic chip facilitated the effective transport of a single virus from AVFs towards the cell-containing chamber without crossing an electrode. We successfully transported the virus to the cell chamber (v?=?10 µm/s) and brought it infected with a selected single H292 cell. PMID:24918921

  16. Virus enrichment for single virus infection by using 3D insulator based dielectrophoresis.

    PubMed

    Masuda, Taisuke; Maruyama, Hisataka; Honda, Ayae; Arai, Fumihito

    2014-01-01

    We developed an active virus filter (AVF) that enables virus enrichment for single virus infection, by using insulator-based dielectrophoresis (iDEP). A 3D-constricted flow channel design enabled the production of an iDEP force in the microfluidic chip. iDEP using a chip with multiple active virus filters (AVFs) was more accurate and faster than using a chip with a single AVF, and improved the efficiency of virus trapping. We utilized maskless photolithography to achieve the precise 3D gray-scale exposure required for fabrication of constricted flow channel. Influenza virus (A PR/8) was enriched by a negative DEP force when sinusoidal wave was applied to the electrodes within an amplitude range of 20 Vp-p and a frequency of 10 MHz. AVF-mediated virus enrichment can be repeated simply by turning the current ON or OFF. Furthermore, the negative AVF can inhibit virus adhesion onto the glass substrate. We then trapped and transported one of the enriched viruses by using optical tweezers. This microfluidic chip facilitated the effective transport of a single virus from AVFs towards the cell-containing chamber without crossing an electrode. We successfully transported the virus to the cell chamber (v = 10 µm/s) and brought it infected with a selected single H292 cell. PMID:24918921

  17. Label-Free Capacitance-Based Identification of Viruses

    PubMed Central

    Ahmad, Mahmoud Al; Mustafa, Farah; Ali, Lizna M.; Karakkat, Jimsheena V.; Rizvi, Tahir A.

    2015-01-01

    This study was undertaken to quantitate a single virus suspension in culture medium without any pre-processing. The electrical capacitance per virus particle was used to identify the kind of virus present by measuring the suspension (virus plus medium) capacitance, de-embedding the medium contribution, and dividing by the virus count. The proposed technique is based on finding the single virus effective dielectric constant which is directly related to the virus composition. This value was used to identify the virus type accordingly. Two types of viruses thus tested were further quantified by a biochemical technique to validate the results. Furthermore, non-organic nanoparticles with known concentration and capacitance per particle were identified using the proposed method. The selectivity of the method was demonstrated by performing electrical measurements on a third virus, revealing that the proposed technique is specific and sensitive enough to permit detection of a few hundred virus particles per milliliter within a few minutes. PMID:25966875

  18. Hepatitis B virus and hepatitis C virus co-infection: a therapeutic challenge.

    PubMed

    Hamzaoui, Lamine; El Bouchtili, Souheil; Siai, Karima; Mahmoudi, Moufida; Azzouz, Mohamed Msaddak

    2013-02-01

    Hepatitis B virus and hepatitis C virus are the two most common causes of chronic liver disease in the world. Dual infection with hepatitis B virus and hepatitis C virus, whose prevalence is underestimated, is characterized by a more severe liver injury, a higher probability of liver cirrhosis and a higher incidence of hepatocellular carcinoma. Treatment of these patients represents a therapeutic challenge. We report the case of an hepatitis B virus-hepatitis C virus co-infected patient, which particularly illustrates the interactions between these two viruses and therapeutic problems caused by the dual infection. HCV was initially dominant, which indicated a combination therapy by pegylated interferon and ribavirin. This treatment was associated with an early virological response of the HCV but an increase of HBV DNA occurred, requiring the use of a nucleoside analogue. A good response was obtained for the HBV but a relapse of HCV was noted, posing a problem for therapeutic decision. PMID:22959099

  19. Expression of the Hantaan virus M genome segment by using a vaccinia virus recombinant.

    PubMed

    Pensiero, M N; Jennings, G B; Schmaljohn, C S; Hay, J

    1988-03-01

    A cDNA containing the complete open reading frame of the Hantaan virus (HTN) M genome segment has been cloned into vaccinia virus. This recombinant virus expresses two glycoproteins which are similar to the HTN structural glycoproteins, G1 and G2, in molecular weight, cleavage pattern, and cellular distribution. Both HTN and recombinant vaccinia virus glycoproteins are exclusively associated with the Golgi apparatus of the cell. Despite this intracellular restriction, mice inoculated with the recombinant vaccinia virus raised neutralizing antibodies against HTN. The specificity of virus neutralization appears to reside in the HTN glycoproteins, since a vaccinia virus recombinant expressing the HTN nucleocapsid protein was unable to elicit a neutralizing antibody response. PMID:3123711

  20. Evidence of rabies virus exposure among humans in the Peruvian Amazon.

    PubMed

    Gilbert, Amy T; Petersen, Brett W; Recuenco, Sergio; Niezgoda, Michael; Gómez, Jorge; Laguna-Torres, V Alberto; Rupprecht, Charles

    2012-08-01

    In May of 2010, two communities (Truenococha and Santa Marta) reported to be at risk of vampire bat depredation were surveyed in the Province Datem del Marañón in the Loreto Department of Perú. Risk factors for bat exposure included age less than or equal to 25 years and owning animals that had been bitten by bats. Rabies virus neutralizing antibodies (rVNAs) were detected in 11% (7 of 63) of human sera tested. Rabies virus ribonucleoprotein (RNP) immunoglobulin G (IgG) antibodies were detected in the sera of three individuals, two of whom were also seropositive for rVNA. Rabies virus RNP IgM antibodies were detected in one respondent with no evidence of rVNA or RNP IgG antibodies. Because one respondent with positive rVNA results reported prior vaccination and 86% (six of seven) of rVNA-positive respondents reported being bitten by bats, these data suggest nonfatal exposure of persons to rabies virus, which is likely associated with vampire bat depredation. PMID:22855749

  1. Determinación del perfil instrumental del EBASIM

    NASA Astrophysics Data System (ADS)

    Nieva, M. F.; Rodriguez, M. V.; Pintado, O. I.

    Se calcula el perfil instrumental para el telescopio de 2,15m del CASLEO con EBASIM. Para ello se usaron flats de cielo y el espectro solar FTS de Kurucz. El método, que se puede utilizar para otras configuraciones instrumentales, es convolucionar ambos espectros para obtener los coeficientes de corrección.

  2. Satsuma dwarf and related viruses belong to a new lineage of plant picorna-like viruses.

    PubMed

    Karasev, A V; Han, S S; Iwanami, T

    2001-01-01

    Satsuma dwarf virus (SDV) and two closely related viruses, Citrus mosaic (CiMV), and Naval orange infectious mottling (NIMV), seriously affect citrus varieties grown in Japan and East Asia. All three viruses have icosahedral particles built of two proteins encapsidating two single-stranded genomic RNAs. The natural mode of transmission of these SDV-like viruses is unknown, and they were previously placed among tentative members of the family Comoviridae. Recently, a complete genome of SDV was sequenced, and its replication-related proteins were found only distantly related to those of viruses from the family Comoviridae (Iwanami T., Kondo Y., and Karasev A.V. J Gen Virol 80, 793-797, 1999). Here we present a partial genome sequence for another SDV-like virus, NIMV, and a thorough phylogenetic analysis of the gene products encoded by SDV, CiMV, and NIMV to assess their relationships with picorna-like viruses infecting plants, insects, and vertebrates. The RdRp's of SDV-like viruses form a new lineage, separate from members of Como- and Sequiviridae families. Phylogenetic analysis suggests that SDV-like viruses may represent a new family of plant picorna-like viruses. Sequence analysis of the capsid proteins (CPs) encoded by the SDV-like viruses revealed a region of similarity to CPs of animal calici- and picornaviruses that encompasses the structural core of the eight-strand beta-barrel characteristic of picornaviral CPs. These data suggest that SDV and related bipartite viruses evolved separately from the viruses in the family Comoviridae and that the split of an ancestor, monopartite picorna-like virus genome might have occurred more than once. PMID:11556400

  3. GRAPEVINE RUPESTRIS STEM PITTING-ASSOCIATED VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevine rupestris stem pitting-associated virus (GRSPaV) is a recently identified virus and belongs to the Foveavirus genus within the Flexiviridae family. Its single–stranded RNA genome contains five open reading frames that potentially encode the replication related proteins, a triple gene bloc...

  4. Immunopathogenesis of hepatitis C virus infection

    Microsoft Academic Search

    Anthony J Freeman; George Marinos; Rosemary A Ffrench; Andrew R Lloyd

    2001-01-01

    Hepatitis C virus, a recently identified member of the family Flaviviridae, is an important cause of chronic viral hepatitis and cirrhosis. There are similarities in the nature of the immune response to this pathogen with immunity in other flavivirus and hepatotropic virus infections, such as hepatitis B. However, the high rate of viral persistence after primary hepatitis C infection, and

  5. Swine influenza virus: epidemiology and vaccine concerns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. Swine influenza virus (SIV) is a primary cause of respiratory disease in swine and a component of the porcine respiratory disease complex (PRDC). Influenza viruses are an important health and economic concern for swine producers throughout the world. Swine operations may be affected by...

  6. Influenza A virus infections in Chinese landbirds

    E-print Network

    Peterson, A. Townsend; Bush, Sarah E.; Spackman, Erica; Swayne, David E.; Ip, Hon S.

    2009-10-01

    occurrence of infl uenza viruses in diverse taxa of Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 10, October 2008 1645 Table. Prevalence of influenza A virus in avian orders and families at 5 sites, People’s Republic of China Location, no...

  7. Influenza A Virus Infections in Land

    E-print Network

    Clayton, Dale H.

    Influenza A Virus Infections in Land Birds, People's Republic of China A. Townsend Peterson, Sarah­PCR testing of 939 Asian land birds of 153 species. Influenza A infection was found, particularly among influenza virus ecology has long regarded water- birds as a primary reservoir. Although the benchmark study

  8. The Genomes of Sheeppox and Goatpox Viruses

    Microsoft Academic Search

    E. R. Tulman; C. L. Afonso; Z. Lu; L. Zsak; J.-H. Sur; N. T. Sandybaev; U. Z. Kerembekova; V. L. Zaitsev; G. F. Kutish; D. L. Rock

    2002-01-01

    Sheeppox virus (SPPV) and goatpox virus (GTPV), members of the Capripoxvirus genus of the Poxviridae, are etiologic agents of important diseases of sheep and goats in northern and central Africa, southwest and central Asia, and the Indian subcontinent. Here we report the genomic sequence and comparative analysis of five SPPV and GTPV isolates, including three pathogenic field isolates and two

  9. Epidemiology of Blackberry yellow vein associated virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blackberry yellow vein disease is one of the most important diseases of blackberry in the United States. Several viruses are found associated with the symptomology but Blackberry yellow vein associated virus (BYVaV) appears to be the most prevalent of all, leading to the need for a better understand...

  10. Original article Bovine respiratory syncytial virus

    E-print Network

    Boyer, Edmond

    antibodies and suggest a widespread BRSV infection in the cattle population of Uruguay. respiratory syncytial. INTRODUCTION Bovine Respiratory Syncytial Virus (BRSV) is the major cause of acute respi- ratory diseaseOriginal article Bovine respiratory syncytial virus: first serological evidence in Uruguay Mauro

  11. Pseudorabies virus infection in Oklahoma hunting dogs.

    PubMed

    Cramer, Sarah D; Campbell, Gregory A; Njaa, Bradley L; Morgan, Sandra E; Smith, Stephen K; McLin, William R; Brodersen, Bruce W; Wise, Annabel G; Scherba, Gail; Langohr, Ingeborg M; Maes, Roger K

    2011-09-01

    Pseudorabies is caused by Suid herpesvirus 1, a member of the Alphaherpesvirinae subfamily. Although pigs are the natural host of Pseudorabies virus (PRV), the virus has a broad host range and may cause fatal encephalitis in many species. The United States obtained PRV-free status in 2004 after the virus was eradicated from domestic swineherds, but the virus is still present in feral swine populations. The current report describes PRV infection in 3 dogs that were used to hunt feral swine. The dogs developed clinical signs including facial pruritus with facial abrasions, dyspnea, vomiting, diarrhea, ataxia, muscle stiffness, and death. Two were euthanized, and 1 died within approximately 48 hr after onset of clinical signs. The salient histologic changes consisted of neutrophilic trigeminal ganglioneuritis with neuronophagia and equivocal intranuclear inclusion bodies. Pseudorabies virus was isolated from fresh tissues from 2 of the dogs, and immunohistochemistry detected the virus in the third dog. Virus sequencing and phylogeny, based upon available GenBank sequences, revealed that the virus was likely a field strain that was closely related to a cluster of PRV strains previously identified in Illinois. Though eradicated from domestic swine in the United States, PRV is present in populations of feral swine, and should therefore continue to be considered a possible cause of disease in dogs and other domestic animals with compatible clinical history and signs. Continued surveillance is necessary to prevent reintroduction of PRV into domestic swine. PMID:21908347

  12. Lettuce necrotic yellows virus in New Zealand

    Microsoft Academic Search

    P. R. Fry; R. C. Close; C. H. Procter; R. Sunde

    1973-01-01

    Lettuce necrotic yellows virus, found in lettuce (Lactuca saliva L.) and sowthistle (Sonchus oleraceus L.) near Blenheim in 1965 caused severe losses in an Auckland lettuce crop in 1969. The virus was transmitted between S. oleraceus plants by the aphid Hyperomyzus lactucae L., which occurs throughout the year but is least plentiful during winter. Most infectivity in sap extracts was

  13. Immune System for Virus Detection and Elimination

    E-print Network

    Immune System for Virus Detection and Elimination Rune Schmidt Jensen IMM-THESIS-2002-08-31 IMM #12 consider the aspects of designing a computer immune system for virus detection and elimination using components and techniques found in the biological immune system. Already published proposals for constructing

  14. Transmission and pathogenesis of vesicular stomatitis viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vesicular Stomatitis (VS) is caused by the Vesicular Stomatitis Virus (VSV), a negative single stranded RNA arthropod-borne virus member of the Family Rhabdoviridae. The virion is composed of the host derived plasma membrane, the envelope, and an internal ribonucleoprotein core. The envelope contain...

  15. Control of virus diseases of berry crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus control in berry crops starts with the development of plants free of targeted pathogens, usually viruses, viroids, phytoplasmas and systemic bacteria, through a combination of testing and therapy. These then become the top tier plants in certification programs and are the source from which all...

  16. VIRUS-MEMBRANE INTERACTIONS spectroscopic studies

    E-print Network

    Hemminga, Marcus A.

    #12;#12;VIRUS-MEMBRANE INTERACTIONS spectroscopic studies #12;Promotor: dr. T.J. Schaafsma VIRUS-MEMB NE INTERACTIONS spectroscopic studies PROEFSCHRIFT ter verkrijging van de graad van doctor. Dr. T.J. Schaafsma was mijn promotor. Het onderzoek is uitgevoerd binnen de "virusgroep", waarvan

  17. Bovine Viral Diarrhea Virus: Global Status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the success of regional bovine viral diarrhea viruses (BVDV) eradication programs, infections with this diverse group of viruses remain a source of economic loss for producers worldwide. There is a wide range of variation among BVDV results in differences in genotype (BVDV1 and BVDV2), biot...

  18. The Molecular Biology of the AIDS Virus.

    ERIC Educational Resources Information Center

    Haseltine, William A.; Wong-Staal, Flossie

    1988-01-01

    Describes the initial site, and symptoms of the human immunodeficiency virus. Explains the diverse behavior and destructive consequences of the disease through discussion, diagrams, and pictures of the life cycle of the virus and the genetic material that controls it. (RT)

  19. Viruses infecting Passiflora species in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report documents multiple viruses in Passiflora spp. in Florida. It also reiterates the risk of movement of vegetatively-propagated plant material. This report provides an overview of this virus for growers, extension workers, crop consultants and research and regulatory scientists....

  20. "Illustrating the Machinery of Life": Viruses

    ERIC Educational Resources Information Center

    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…

  1. SOIL-BORNE WHEAT MOSAIC VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-borne wheat mosaic virus is widely distributed in most temperate wheat growing regions of the world. It can cause significant yield loss although due to the transient symptoms that disappear as temperatures increase, the disease is often mistaken for a nutrient deficiency. The virus has many ...

  2. Virology: Independent virus development outside a host

    Microsoft Academic Search

    Monika Häring; Gisle Vestergaard; Reinhard Rachel; Lanming Chen; Roger A. Garrett; David Prangishvili

    2005-01-01

    Viruses are thought to be functionally inactive once they are outside and independent of their host cell. Here we describe an exceptional property of a newly discovered virus that infects a hyperthermophilic archaeon growing in acidic hot springs: the lemon-shaped viral particle develops a very long tail at each of its pointed ends after being released from its host cell.

  3. Molecular biology of avian infectious laryngotracheitis virus

    Microsoft Academic Search

    Walter Fuchs; Jutta Veits; Dorothee Helferich; Harald Granzow; Jens P. Teifke; Thomas C. Mettenleiter

    2007-01-01

    Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes an econom- ically important chicken disease, which results in delayed growth, reduced egg production, and also frequently in death of the animals. After acute infection of the upper respiratory tract, the virus can establish latency in the central nervous system, and subsequent reactivations can lead to infec- tion of naive chickens.

  4. Viruses of the Archaea: a unifying view

    Microsoft Academic Search

    Patrick Forterre; Roger A. Garrett; David Prangishvili

    2006-01-01

    DNA viruses of the Archaea have highly diverse and often exceptionally complex morphotypes. Many have been isolated from geothermally heated hot environments, raising intriguing questions about their origins, and contradicting the widespread notion of limited biodiversity in extreme environments. Here, we provide a unifying view on archaeal viruses, and present them as a particular assemblage that is fundamentally different in

  5. Molecular evolution of swine vesicular disease virus

    Microsoft Academic Search

    Gang Zhang; Daniel T. Haydon; Nick J. Knowles; John W. McCauley

    1999-01-01

    Phylogenetic analysis was used to examine the evolutionary relationships within a group of coxsackie B viruses that contained representatives of the major serotypes of this group and 45 isolates of swine vesicular disease virus (SVDV) from Asia and Europe. Separate analyses of sequence data from two regions of the viral genomes encoding the VP1 and 3BC genes both revealed that

  6. Virus dissemination via the lymphomyeloid complex.

    PubMed

    Yoffey, J M

    1990-06-01

    In the previous AIDS symposium organized by the Society, Witte and Witte (1) made a number of predictions, one of which was that in AIDS patients, "Lymph from the thoracic duct should be strongly positive for HIV." Though direct evidence for this is lacking, some early experiments of ours with vaccinia virus (2) are fully in accord with this prediction, to which they lend indirect support. In rabbits, nasally instilled vaccinia virus spreads via the lymphatic pathway (afferent peripheral lymph--deep cervical gland--efferent lymph--thoracic duct) in as short a time as nine hours. Virus is transported mainly in cells, for when the efferent lymph is centrifuged virus is found only in the cell sediment. It seems reasonable to assume that other viruses, including HIV, are similarly disseminated. Paradoxically, the lymphomyeloid complex both greatly facilitates the spread of virus, and at the same time, mounts the immunological defenses against the virus which it so effectively helps to disseminate. Whatever the portal of entry of the virus, its transport by migrating cells ensures its dissemination throughout the lymphomyeloid complex, including the bone marrow. The bone marrow is an integral part of the complex, as the prime source of B lymphocytes, T lymphocyte precursors, and many of the antigen-presenting cells as well as the granulocytes. There is some evidence concerning possible ways in which the bone marrow can contribute to the development of immune deficiency in AIDS patients. The bone marrow merits further study in this context. PMID:2214864

  7. Reemergence of Chikungunya Virus in Cambodia

    PubMed Central

    Duong, Veasna; Andries, Anne-Claire; Ngan, Chantha; Sok, Touch; Richner, Beat; Asgari-Jirhandeh, Nima; Bjorge, Steve; Huy, Rekol; Ly, Sovann; Laurent, Denis; Hok, Bunheng; Roces, Maria Concepcion; Ong, Sivuth; Char, Meng Chuor; Deubel, Vincent; Tarantola, Arnaud

    2012-01-01

    Chikungunya virus (CHIKV), probably Asian genotype, was first detected in Cambodia in 1961. Despite no evidence of acute or recent CHIKV infections since 2000, real-time reverse transcription PCR of serum collected in 2011 detected CHIKV, East Central South African genotype. Spatiotemporal patterns and phylogenetic clustering indicate that the virus probably originated in Thailand. PMID:23171736

  8. Reemergence of Chikungunya virus in Cambodia.

    PubMed

    Duong, Veasna; Andries, Anne-Claire; Ngan, Chantha; Sok, Touch; Richner, Beat; Asgari-Jirhandeh, Nima; Bjorge, Steve; Huy, Rekol; Ly, Sovann; Laurent, Denis; Hok, Bunheng; Roces, Maria Concepcion; Ong, Sivuth; Char, Meng Chuor; Deubel, Vincent; Tarantola, Arnaud; Buchy, Philippe

    2012-12-01

    Chikungunya virus (CHIKV), probably Asian genotype, was first detected in Cambodia in 1961. Despite no evidence of acute or recent CHIKV infections since 2000, real-time reverse transcription PCR of serum collected in 2011 detected CHIKV, East Central South African genotype. Spatiotemporal patterns and phylogenetic clustering indicate that the virus probably originated in Thailand. PMID:23171736

  9. Propagation of Viruses on Micropatterned Host Cells

    E-print Network

    Prentiss, Mara

    Propagation of Viruses on Micropatterned Host Cells Elizabeth E. Endler,1 Karen A. Duca,1,2 Paul F-mail: yin@engr.wisc.edu 2 Department of Electrical Engineering and Computer Science, Tufts University developed a technique to characterize the in vitro propagation of viruses. Microcontact printing was used

  10. Computer Viruses: An Assessment of Student Perceptions

    Microsoft Academic Search

    Mary C. Jones; Kirk P. Arnett

    1992-01-01

    Virtually every computer installation is susceptible to the damage that computer viruses may cause. Without appropriate precautionary measures, it is difficult to contain\\/prevent the spread of these unwanted interlopers. The key to such precautionary measures is education about viruses and the damage they can cause. This article presents the findings of a study undertaken to assess what business college students

  11. Computer Viruses - A Form of Artificial Life?

    Microsoft Academic Search

    Eugene H. Spafford

    1991-01-01

    There has been considerable interest in computer viruses since they first appeared in 1981, and especially in the past few years as they have reached epidemic numbers in many personal computer environments. Viruses have been written about as a security problem, as a social problem, and as a possible means of performing useful tasks in a distributed manner. However, only

  12. A fault tolerance approach to computer viruses

    Microsoft Academic Search

    Mark K. Joseph; Algirdas AviZienis

    1988-01-01

    Extensions of program flow monitors and n-version programming can be combined to provide a solution to the detection and containment of computer viruses. The consequence is that a computer can tolerate both deliberate faults and random physical faults by one common mechanism. Specifically, the technique detects control flow errors due to physical faults as well as the presence of viruses

  13. Accuracy estimation of foamy virus genome copying

    Microsoft Academic Search

    Kathleen Gärtner; Tatiana Wiktorowicz; Ayalew Mergia; Axel Rethwilm; Carsten Scheller

    2009-01-01

    BACKGROUND: Foamy viruses (FVs) are the most genetically stable viruses of the retrovirus family. This is in contrast to the in vitro error rate found for recombinant FV reverse transcriptase (RT). To investigate the accuracy of FV genome copying in vivo we analyzed the occurrence of mutations in HEK 293T cell culture after a single round of reverse transcription using

  14. Genetics of seed transmission Soybean mosaic virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean mosaic virus (SMV) is an aphid- and seed-transmitted member of the Potyviridae that infects soybean plants and, in years when virus infections are widespread, can cause significant reductions in the quantity and quality of seed harvested. Because seed-borne infections are the primary sources...

  15. RNA viruses: hijacking the dynamic nucleolus

    Microsoft Academic Search

    Julian A. Hiscox

    2007-01-01

    The nucleolus is a dynamic subnuclear structure with roles in ribosome subunit biogenesis, mediation of cell-stress responses and regulation of cell growth. The proteome and structure of the nucleolus are constantly changing in response to metabolic conditions. RNA viruses interact with the nucleolus to usurp host-cell functions and recruit nucleolar proteins to facilitate virus replication. Investigating the interactions between RNA

  16. Detection of enteric viruses in shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Norovirus and hepatitis A virus contamination are significant threats to the safety of shellfish and other foods. Methods for the extraction and assay of these viruses from shellfish are complex, time consuming, and technically challenging. Here, we itemize some of the salient points in extracting...

  17. Evolutionary Genomics of Marek's Disease Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease virus (MDV) is one of the most oncogenic herpesviruses known and induces a rapid onset T-cell lymphoma and demyelinating disease in chickens. The virus is classified as a member of the genus Mardivirus in the Alphaherpesvirinae subfamily of Herpesviridae. The disease (Marek's Disease...

  18. Optimization of network protection against virus spread

    E-print Network

    Van Mieghem, Piet

    Optimization of network protection against virus spread Eric Gourdin Orange Labs, Issy Abstract--The effect of virus spreading in a telecommunication network, where a certain curing strategy and interdependent. As a consequence, the security of each host depends heavily on the level of protection of its

  19. Multipartite nature of potato virus X.

    PubMed Central

    Price, M

    1993-01-01

    Potato virus X (PVX) was among the first viruses to be purified. Nonetheless, properties of the purified virus remain contentious. The literature has been heavily influenced by the concept of a virus as a monopartite entity. Despite the fact that electron micrographs invariably show large proportions of shorter virus particles, the latter are universally ignored. Seven distinct classes of particle lengths were detected. Seven RNA species of approximate sizes 6.4, 3.6, 3.0, 2.1, 1.8, 1.4, and 0.9 kb were extracted from these purified virus preparations. This study shows clearly that shorter PVX particles are not breakage products and indicates that they may reflect fundamental properties of the genome strategy. Furthermore, other potexviruses have been found to contain many shorter particles, and the level of these particles is stable during purification. PVX is generally believed to consist of particles of single length even though the literature does not confirm this conclusion. The notion of a single particle length appears to reflect historical concepts of what a virus should be rather than what PVX is. This report considers whether shorter rods present in virus preparations of PVX are distinctive products of infection. The problem addressed is significant because if affects conclusions concerning the mechanisms of PVX biosynthesis and replication. Images PMID:8416388

  20. Human Immunodeficiency Virus and Carcinoma Cervix

    Microsoft Academic Search

    A. Jaisri; Shanta Bhaskaran; Prasanna Kumar

    2010-01-01

    Problem statement: Carcinoma of the cervix is the second leading cause of death in women in the world. Human Papilloma Virus (HPV) which plays a major role in the etiology of cervical cancer is said to have the same mode of transmission as the H uman Immunodeficiency Virus (HIV). Hence the curiosity to learn the prevalence, incidence and as sociation

  1. Citrus viruses in sub-Saharan Africa

    Microsoft Academic Search

    C. P. R. Cronjéa

    There are approximately 20 known citrus viruses. The most important ones in South Africa used to be CiTV (trizteza), exocortis, and porosis. Since the initiation of the Cultivar Improvement Programme (CIP), exocortis and psorosis were excluded from new planting material by the use of shoot tip grafting. The only virus which is still of major importance is trizteza, especially on

  2. Viruses in Water: The Problem, Some Solutions

    ERIC Educational Resources Information Center

    Gerba, Charles P.; And Others

    1975-01-01

    Increasing population and industrialization places heavy demands on water resources making recycling of wastewaters for domestic consumption inevitable. Eliminating human pathogenic viruses is a major problem of reclaiming wastewater. Present water treatment methods may not be sufficient to remove viruses. (MR)

  3. Common Respiratory Viruses and Pulmonary Mucosal Immunology

    Microsoft Academic Search

    David B. Huang

    tory epithelium. In most cases, viral infection is limited to the upper airways; however, infections of the lower airway regions occur in a significant number of infected individuals. Worldwide, approximately 90% of the cases of the “common cold” are caused by viruses and most are seen in the winter months. These viruses are spread from person to person and commonly

  4. A case of Ebola virus infection

    Microsoft Academic Search

    R T Emond; B Evans; Etw Bowen; G Lloyd

    1977-01-01

    In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness

  5. THE EBOLA VIRUS BY R. AARON ROBISON

    E-print Network

    Faraon, Andrei

    OUTBREAK: THE EBOLA VIRUS BY R. AARON ROBISON IN JULY OF 1976, A SUDANESE STOREKEEPER BECAME forests of central Africa. The virus that killed him eventually became known as Ebola, named after a river traveling from Africa started exhibiting Ebola-like symptoms, sparking a brief media bonanza before she

  6. Fruit bats as reservoirs of Ebola virus

    Microsoft Academic Search

    Eric M. Leroy; Brice Kumulungui; Xavier Pourrut; Pierre Rouquet; Alexandre Hassanin; Philippe Yaba; André Délicat; Janusz T. Paweska; Jean-Paul Gonzalez; Robert Swanepoel

    2005-01-01

    The first recorded human outbreak of Ebola virus was in 1976, but the wild reservoir of this virus is still unknown. Here we test for Ebola in more than a thousand small vertebrates that were collected during Ebola outbreaks in humans and great apes between 2001 and 2003 in Gabon and the Republic of the Congo. We find evidence of

  7. An adenosine nucleoside inhibitor of dengue virus.

    PubMed

    Yin, Zheng; Chen, Yen-Liang; Schul, Wouter; Wang, Qing-Yin; Gu, Feng; Duraiswamy, Jeyaraj; Kondreddi, Ravinder Reddy; Niyomrattanakit, Pornwaratt; Lakshminarayana, Suresh B; Goh, Anne; Xu, Hao Ying; Liu, Wei; Liu, Boping; Lim, Joanne Y H; Ng, Chuan Young; Qing, Min; Lim, Chin Chin; Yip, Andy; Wang, Gang; Chan, Wai Ling; Tan, Hui Pen; Lin, Kai; Zhang, Bo; Zou, Gang; Bernard, Kristen A; Garrett, Christine; Beltz, Karen; Dong, Min; Weaver, Margaret; He, Handan; Pichota, Arkadius; Dartois, Veronique; Keller, Thomas H; Shi, Pei-Yong

    2009-12-01

    Dengue virus (DENV), a mosquito-borne flavivirus, is a major public health threat. The virus poses risk to 2.5 billion people worldwide and causes 50 to 100 million human infections each year. Neither a vaccine nor an antiviral therapy is currently available for prevention and treatment of DENV infection. Here, we report a previously undescribed adenosine analog, NITD008, that potently inhibits DENV both in vitro and in vivo. In addition to the 4 serotypes of DENV, NITD008 inhibits other flaviviruses, including West Nile virus, yellow fever virus, and Powassan virus. The compound also suppresses hepatitis C virus, but it does not inhibit nonflaviviruses, such as Western equine encephalitis virus and vesicular stomatitis virus. A triphosphate form of NITD008 directly inhibits the RNA-dependent RNA polymerase activity of DENV, indicating that the compound functions as a chain terminator during viral RNA synthesis. NITD008 has good in vivo pharmacokinetic properties and is biologically available through oral administration. Treatment of DENV-infected mice with NITD008 suppressed peak viremia, reduced cytokine elevation, and completely prevented the infected mice from death. No observed adverse effect level (NOAEL) was achieved when rats were orally dosed with NITD008 at 50 mg/kg daily for 1 week. However, NOAEL could not be accomplished when rats and dogs were dosed daily for 2 weeks. Nevertheless, our results have proved the concept that a nucleoside inhibitor could be developed for potential treatment of flavivirus infections. PMID:19918064

  8. A multiplex polymerase chain reaction method for reliable, sensitive and simultaneous detection of multiple viruses in citrus trees

    Microsoft Academic Search

    Avijit Roy; Amer Fayad; G. Barthe; R. H. Brlansky

    2005-01-01

    A multiplex polymerase chain reaction (mPCR) assay was developed to detect six RNA and one DNA citrus virus: Citrus leaf rugose virus (CLRV), Citrus psorosis virus (CPsV), Citrus tatter leaf virus (CTLV), Citrus tristeza virus (CTV), Citrus variegation virus (CVV), Citrus yellow mosaic virus (CYMV), and Indian citrus ringspot virus (ICRSV) from citrus plants. These seven viruses are classified in

  9. An Automatic Unpacking Method for Computer Virus Effective in the Virus Filter Based on Paul Graham's Bayesian Theorem

    NASA Astrophysics Data System (ADS)

    Zhang, Dengfeng; Nakaya, Naoshi; Koui, Yuuji; Yoshida, Hitoaki

    Recently, the appearance frequency of computer virus variants has increased. Updates to virus information using the normal pattern matching method are increasingly unable to keep up with the speed at which viruses occur, since it takes time to extract the characteristic patterns for each virus. Therefore, a rapid, automatic virus detection algorithm using static code analysis is necessary. However, recent computer viruses are almost always compressed and obfuscated. It is difficult to determine the characteristics of the binary code from the obfuscated computer viruses. Therefore, this paper proposes a method that unpacks compressed computer viruses automatically independent of the compression format. The proposed method unpacks the common compression formats accurately 80% of the time, while unknown compression formats can also be unpacked. The proposed method is effective against unknown viruses by combining it with the existing known virus detection system like Paul Graham's Bayesian Virus Filter etc.

  10. Virus Budding and the ESCRT Pathway

    PubMed Central

    Votteler, Jörg; Sundquist, Wesley I.

    2013-01-01

    Enveloped viruses escape infected cells by budding through limiting membranes. In the decade since the discovery that the Human Immunodeficiency Virus (HIV) recruits cellular ESCRT (endosomal sorting complexes required for transport) machinery to facilitate viral budding, this pathway has emerged as the major escape route for enveloped viruses. In cells, the ESCRT pathway catalyzes the analogous membrane fission events required for the abscission stage of cytokinesis and for a series of “reverse topology” vesiculation events. Studies of enveloped virus budding are therefore providing insights into the complex cellular mechanisms of cell division and membrane protein trafficking (and vice versa). Here, we review how viruses mimic cellular recruiting signals to usurp the ESCRT pathway, discuss mechanistic models for ESCRT pathway functions, and highlight important research frontiers. PMID:24034610

  11. Immunology of avian influenza virus: a review.

    PubMed

    Suarez, D L; Schultz-Cherry, S

    2000-01-01

    Avian influenza virus can cause serious disease in a wide variety of birds and mammals, but its natural host range is in wild ducks, gulls, and shorebirds. Infections in poultry can be inapparent or cause respiratory disease, decreases in production, or a rapidly fatal systemic disease known as highly pathogenic avian influenza (HPAI). For the protection of poultry, neutralizing antibody to the hemagglutinin and neuraminidase proteins provide the primary protection against disease. A variety of vaccines elicit neutralizing antibody, including killed whole virus vaccines and fowl-pox recombinant vaccines. Antigenic drift of influenza viruses appears to be less important in causing vaccine failures in poultry as compared to humans. The cytotoxic T lymphocyte response can reduce viral shedding in mildly pathogenic avian influenza viruses, but provides questionable protection against HPAI. Influenza viruses can directly affect the immune response of infected birds, and the role of the Mx gene, interferons, and other cytokines in protection from disease remains unknown. PMID:10717293

  12. West Nile virus in livestock and wildlife

    USGS Publications Warehouse

    McLean, R.G.; Ubico, S.R.; Bourne, D.; Komar, N.

    2002-01-01

    WN virus is one of the most ubiquitous arboviruses occurring over a broad geographical range and in a wide diversity of vertebrate host and vector species. The virus appears to be maintained in endemic foci on the African continent and is transported annually to temperate climates to the north in Europe and to the south in South Africa. Reports of clinical disease due to natural WN virus infection in wild or domestic animals were much less common than reports of infection (virus isolation or antibody detection). Until recently, records of morbidity and mortality in wild birds were confined to a small number of cases and infections causing encephalitis, sometimes fatal, in horses were reported infrequently. In the period 1996-2001, there was an increase in outbreaks of illness due to WN virus in animals as well as humans. Within the traditional range of WN virus, encephalitis was reported in horses in Italy in 1998 and in France in 2000. The first report of disease and deaths caused by WN virus infection in domestic birds was reported in Israel in 1997-1999, involving hundreds of young geese. In 1999 WN virus reached North America and caused an outbreak of encephalitis in humans in the New York area at the same time as a number of cases of equine encephalitis and deaths in American crows and a variety of other bird species, both North American natives and exotics. Multi-state surveillance for WN virus has been in place since April 2000 and has resulted in the detection of WN virus in thousands of dead birds from an increasing number of species in North America, and also in several species of mammals. The surveillance system that has developed in North America because of the utility of testing dead birds for the rapid detection of WN virus presence has been a unique integration of public health and wildlife health agencies. It has been suggested that the recent upsurge in clinical WN virus infection in wild and domestic animals as well as in humans may be related to the emergence of one or more new strains of WN virus. Virus isolated in New York in 1999 was found to be identical to that from Israel. It was alarming for WN virus to so easily invade the United States and surprising that it became established so quickly in the temperature climate of New York. Its persistence and rapid expansion in the United States leave a number of unanswered questions. New disease characteristics and patterns have occurred and more are evolving as WN virus further invades the western hemisphere. Additional animal research is needed to answer these questions. Some of the research needs include bird migration as a mechanism of virus dispersal, vector and vertebrate host relationships, virus persistence mechanisms, laboratory diagnosis, viral pathogenesis, risk factor studies, vaccine development, and WN virus impact on wildlife (CDC 2001a). Determination of the primary reservoir host species that are involved in the epidemiology of WN virus and the suitable sentinel species for active surveillance are also important research areas.

  13. Biosensors for waterborne viruses: Detection and removal.

    PubMed

    Altintas, Zeynep; Gittens, Micah; Pocock, Jack; Tothill, Ibtisam E

    2015-08-01

    Detection of waterborne viruses is important to eliminate and control their harmful effect as pathogens. Hence, the use of rapid and sensitive detection technologies is critically important as they can aid in investigating outbreaks and help in developing prevention strategies. To date range of viruses can contaminate drinking water sources, causing illnesses such as diarrhoea, pneumonia and gastroenteritis which can result in death. Due to their small size (nm) their complete removal from water can be difficult with current water treatment processes while being resistant to disinfectants. Available techniques for virus detection include filtration technologies, enzyme-linked immunosorbent assays and polymerase chain reaction. Although each technique has limitations, the use of biosensor technology with smart affinity materials and nanomaterials can show great potential in sensing viruses in water samples. This review reports on the latest technologies used for waterborne virus removal and detection with focus on rapid detection using biosensors. PMID:26005094

  14. Microbial ecology in Hydra: why viruses matter.

    PubMed

    Bosch, Thomas C G; Grasis, Juris A; Lachnit, Tim

    2015-03-01

    While largely studied because of their harmful effects on human health, there is growing appreciation that viruses are also important members of the animal holobiont. This review highlights recent findings on viruses associated with Hydra and related Cnidaria. These early evolutionary diverging animals not only select their bacterial communities but also select for viral communities in a species-specific manner. The majority of the viruses associating with these animals are bacteriophages. We demonstrate that the animal host and its virome have evolved into a homeostatic, symbiotic relationship and propose that viruses are an important part of the Hydra holobiont by controlling the species-specific microbiome. We conclude that beneficial virus-bacterial-host interactions should be considered as an integral part of animal development and evolution. PMID:25732740

  15. The impact of bluetongue virus on reproduction.

    PubMed

    Osburn, B I

    1994-01-01

    Bluetongue virus has been recognized as an important noncontagious, arthropodborne infectious viral disease of ruminants. 24 different serotypes of virus have been recognized worldwide. The most severe clinical disease has been associated with severe clinical disease in sheep and some free ranging wild ruminants. A number of reports have implicated the viruses as causing reproductive disorders in both males and females. The bluetongue related reproductive disorders include early embryonic deaths, abortions, malformed fetal calves or lambs, transient infertility in bulls and rams, and shedding of virus in semen. Recently, bluetongue virus contamination of modified live commercial canine vaccine was associated with abortion and acute death of pregnant bitches. The pathogenesis of these various aspects of reproductive failure are discussed herein. PMID:8001344

  16. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    PubMed Central

    Costa, Liliana; Faustino, Maria Amparo F.; Neves, Maria Graça P. M. S.; Cunha, Ângela; Almeida, Adelaide

    2012-01-01

    Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process. PMID:22852040

  17. Persistence in herpes simplex virus infections.

    PubMed Central

    Longson, M.

    1978-01-01

    Diseases of man caused by the virus of herpes simplex fall into two broad categories. The primary disease occurs only once in any individual's life and is caused by transmission of virus from an already infected human. Thereafter, the individual may be subject to recurrent herpetic disease, the manifestations of which are different from the primary disease. Recurrent disease varies in severity from trivial, to incapacitating and frankly lethal (as in diseases resulting from the virus's neurotropic and oncogenic properties). The source of the virus in recurrent herpetic disease has never been conclusively resolved, but is almost certainly endogenous to the patient. Theories, case reports and experiments exist to show that endogenous virus may, in periods of clinical quiescence, be latent (or persistent) at the site of the recurrent lesions itself, or more remotely in nerve tissues related to the site of recurrence. Images Fig. 1 PMID:214773

  18. Mechanisms of plant resistance to viruses.

    PubMed

    Soosaar, Jennifer L M; Burch-Smith, Tessa M; Dinesh-Kumar, Savithramma P

    2005-10-01

    Plants have evolved in an environment rich with microorganisms that are eager to capitalize on the plants' biosynthetic and energy-producing capabilities. There are approximately 450 species of plant-pathogenic viruses, which cause a range of diseases. However, plants have not been passive in the face of these assaults, but have developed elaborate and effective defence mechanisms to prevent, or limit, damage owing to viral infection. Plant resistance genes confer resistance to various pathogens, including viruses. The defence response that is initiated after detection of a specific virus is stereotypical, and the cellular and physiological features associated with it have been well characterized. Recently, RNA silencing has gained prominence as an important cellular pathway for defence against foreign nucleic acids, including viruses. These pathways function in concert to result in effective protection against virus infection in plants. PMID:16132037

  19. Influenza A virus recycling revisited.

    PubMed Central

    Dowdle, W. R.

    1999-01-01

    Current textbooks link influenza pandemics to influenza A virus subtypes H2 (1889-91), H3 (1990), H1 (1918-20), H2 (1957-58) and H3 (1968), a pattern suggesting subtype recycling in humans. Since H1 reappeared in 1977, whatever its origin, some workers feel that H2 is the next pandemic candidate. This report reviews the publications on which the concept of influenza A virus subtype recycling is based and concludes that the data are inconsistent with the purported sequence of events. The three influenza pandemics prior to 1957-58 were linked with subtypes through retrospective studies of sera from the elderly, or through seroarchaeology. The pandemic seroarchaeological model for subtype H1 has been validated by the recent recovery of swine virus RNA fragments from persons who died from influenza in 1918. Application of the model to pre-existing H3 antibody among the elderly links the H3 subtype to the pandemic of 1889-91, not that of 1900 as popularly quoted. Application of the model to pre-existing H2 antibody among the elderly fails to confirm that this subtype caused a pandemic in the late 1800's, a finding which is consistent with age-related excess mortality patterns during the pandemics of 1957 (H2) and 1968 (H3). H2 variants should be included in pandemic planning for a number of reasons, but not because of evidence of recycling. It is not known when the next pandemic will occur or which of the 15 (or more) haemagglutinin subtypes will be involved. Effective global surveillance remains the key to influenza preparedness. PMID:10593030

  20. Inhibition of cowpox virus and monkeypox virus infection by mitoxantrone

    PubMed Central

    Altmann, Sharon E.; Smith, Alvin L.; Dyall, Julie; Johnson, Reed F.; Dodd, Lori E.; Jahrling, Peter B.; Paragas, Jason; Blaney, Joseph E.

    2012-01-01

    Summary Mitoxantrone, an FDA-approved therapeutic for the treatment of cancer and multiple sclerosis, was previously reported to exhibit antiviral activity against vaccinia virus. To determine whether this activity extends to other orthopoxviruses, mitoxantrone was tested against cowpox and monkeypox. Mitoxantrone demonstrated an EC50 of 0.25 ?M against cowpox and 0.8 ?M against monkeypox. Intraperitoneal treatment of cowpox virus-challenged C57Bl/6 mice with 0.5 mg/kg mitoxantrone resulted in 25% survival and a significant increase in survival time. In an effort to improve its efficacy, mitoxantrone was tested for synergistic activity with cidofovir. In vitro tests demonstrated significant synergy between the two drugs against cowpox; however, no synergistic effect on animal survival or median time-to-death was seen in intranasally-infected BALB/c mice. Significantly fewer animals survived when treated with a combination of 0.5 mg/kg mitoxantrone and 100 mg/kg cidofovir than with 100 mg/kg cidofovir alone. This is, to our knowledge, the first report of limited anti-orthopoxvirus activity by mitoxantrone in an animal model. PMID:22182595

  1. Tobacco mosaic virus, not just a single component virus anymore.

    PubMed

    Knapp, E; Lewandowski, D J

    2001-05-01

    Summary Taxonomy: Tobacco mosaic virus (TMV) is the type species of the Tobamovirus genus and a member of the alphavirus-like supergroup. Historically, many tobamoviruses are incorrectly called strains of TMV, although they can differ considerably in sequence similarities and host range from each other and from TMV. Physical properties: TMV virions are 300 x 18 nm rods with a central hollow cavity (Fig. 1) and are composed of 95% capsid protein (CP), and 5% RNA. Each CP subunit interacts with 3-nts in a helical arrangement around the RNA. Virions are stable for decades; infectivity in sap survives heating to 90 degrees C. Hosts: The natural host range of TMV is limited; however, a broad range of weed and crop species, mostly Solanaceae that includes tobacco, pepper and tomato can be infected experimentally [Holmes, F.O. (1946) A comparison of the experimental host ranges of tobacco etch and tobacco mosaic viruses. Phytopathology, 36, 643-657]. TMV distribution is worldwide. No biological vectors are known. Useful website: http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/71010001.htm. PMID:20572999

  2. Ebola virus disease: radiology preparedness.

    PubMed

    Bluemke, David A; Meltzer, Carolyn C

    2015-02-01

    At present, there is a major emphasis on Ebola virus disease (EVD) preparedness training at medical facilities throughout the United States. Failure to have proper EVD procedures in place was cited as a major reason for infection of medical personnel in the United States. Medical imaging does not provide diagnosis of EVD, but patient assessment in the emergency department and treatment isolation care unit is likely to require imaging services. The purpose of this article is to present an overview of relevant aspects of EVD disease and preparedness relevant to the radiologic community. PMID:25405643

  3. [Modern threat of Ebola virus].

    PubMed

    P?usa, Tadeusz

    2014-11-01

    Since the detection of Ebola virus in 1976. recorded 13 major epidemics in Africa. The current threat in Guinea, Liberia and Sierra Leone absorbs another victims and threatened pandemic. Picture of the disease is initially very non-characteristic (influenza-like symptoms) and quickly leads to dehydration, shock and disseminated intravascular coagulation syndrome, which is responsible for high mortality. Lack of effective antibiotic therapy and vaccine hampers the existing situation. For this reason, there is an absolute necessity to introduce regimes sanitation, quarantine at the suspects and maintain the highest safety measures for emergency responders. Developed procedures require absolute compliance. PMID:25546984

  4. Mathematical Model of Computer Viruses

    Microsoft Academic Search

    Ferenc Leitold

    2000-01-01

    Abstract In real computers,the operating system,organizes,the connection,between,the unique programs. In most operating systems,a program can modify other program,and\\/or data files. There are some special programs which utilize this facility of the operating system, for example,the computer,viruses. For the analysis of programs which modify other programs it is necessary,to define a new computation,model. Thenew,mathematical,model,- called Random,Access Stored Program Machine with Attached

  5. Replication of hepatitis C virus.

    PubMed

    Moradpour, Darius; Penin, François; Rice, Charles M

    2007-06-01

    Exciting progress has recently been made in understanding the replication of hepatitis C virus, a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. The development of complete cell-culture systems should now enable the systematic dissection of the entire viral lifecycle, providing insights into the hitherto difficult-to-study early and late steps. These efforts have already translated into the identification of novel antiviral targets and the development of new therapeutic strategies, some of which are currently undergoing clinical evaluation. PMID:17487147

  6. Plant Disease Note 2007 | First Report of Onion yellow dwarf virus, Leek yellow stripe virus, and Garlic common latent virus in Garlic in Oregon Overview Current Issue Past Issues Search PD Search APS Journals

    E-print Network

    Pappu, Hanu R.

    Plant Disease Note 2007 | First Report of Onion yellow dwarf virus, Leek yellow stripe virus-2007 The American Phytopathological Society First Report of Onion yellow dwarf virus, Leek yellow stripe virus. With recent findings of Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV), and Garlic common

  7. TEORÍAS DEL DESARROLLO A PRINCIPIOS DEL SIGLO XXI

    Microsoft Academic Search

    AMARTYA SEN

    1 La evolución de las ideas no sigue el curso de los siglos. Es más, en el transcurso del siglo XX hemos presenciado cambios radicales en lo que a teoría del desarrollo se refiere. Ni siquiera es indispensable definir los siglos de acuerdo con la clasificación del calendario, de cero a noventa y nueve. En su célebre discurso del 8

  8. Phylogeny of dengue virus type 3 circulating in Colombia between 2001 and 2007.

    PubMed

    Villabona-Arenas, Christian Julián; Miranda-Esquivel, Daniel Rafael; Jimenez, Raquel Elvira Ocazionez

    2009-10-01

    Dengue virus type 3 (DENV-3) re-appeared in Colombia in 2001 after 23 years of apparent absence, in the state of Santander in the North-eastern region near to Venezuelan border. In 2002, the virus was isolated in the state of Valle del Cauca in the South-east region near to Ecuadorian/Peruvian border, and in the state of Antioquia in the North-east region near to Panama border. To gain insight into the molecular epidemiology of DENV-3 in Colombia, we sequenced the complete E gene of 21 isolates sampled in the period 2001-2007. Phylogenetic analyses revealed that Colombian strains seem to have been introduced from Venezuela, Ecuador and Peru, but not from Brazil, Argentina, Paraguay or Central America countries. This study also confirms previous report showing that Colombian isolates is closely related to DENV-3 genotype III. PMID:19619216

  9. Characterization of Grapevine Algerian latent virus isolated from nipplefruit ( Solanum mammosum ) in Japan

    Microsoft Academic Search

    Takehiro Ohki; Seiji Uematsu; Yasuhiro Nakayama; Dietrich-Eckhardt Lesemann; Yohachiro Honda; Shinya Tsuda; Ichiro Fujisawa

    2006-01-01

    Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), Potato virus Y (PVY), Tomato bushy stunt virus nipplefruit strain (TBSV-Nf), and an unknown spherical virus were isolated from nipplefruit (Solanum mammosum) cultivated in Chiba Prefecture, Japan. The spherical virus was identified as Grapevine Algerian latent virus nipplefruit strain (GALV-Nf) from the genus Tombusvirus, based on its physical properties, serological relationships, and

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

    PubMed Central

    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

  11. Differential diagnosis and genetic analysis of the antigenically related swine vesicular disease virus and coxsackie viruses.

    PubMed

    Marquardt, O; Ohlinger, V F

    1995-06-01

    Monoclonal antibodies directed against an isolate of swine vesicular disease virus (SVDV), characterized by virus neutralization tests and competition assays, were used to compare SVDV isolates and isolates of the antigenically related Coxsackie viruses by ELISA. SVDV-specific reaction patterns and one specific for Coxsackie viruses were observed. This provided a method for distinguishing between these enteroviruses. In addition, RT-PCRs were undertaken with Coxsackie virus and SVDV genomes. Different product patterns were obtained which correlated with the genetic differences revealed by nucleotide sequence determination. RT-PCR distinguished between SVDV and Coxsackie viruses by pattern differences. Further SVDV-specific PCRs were carried out with clinical samples. Viral genomes were detected with a sensitivity equivalent to that of virus isolation in cell culture. Sequencing of the Coxsackie virus-derived 2A-coding PCR products resulted in a not previously described sequence of a B5 isolate and in SVDV-specific sequence of two Coxsackie virus A16 isolates. The differences of the isolates by ELISA and PCR reactivity, as well as the nucleotide sequence differences are consistent with the quasispecies concept of RNA viruses. PMID:7673387

  12. Characterization of the Reconstructed 1918 Spanish Influenza Pandemic Virus

    Microsoft Academic Search

    Terrence M. Tumpey; Christopher F. Basler; Patricia V. Aguilar; Hui Zeng; Alicia Solórzano; David E. Swayne; Nancy J. Cox; Jacqueline M. Katz; Jeffery K. Taubenberger; Peter Palese; Adolfo García-Sastre

    2005-01-01

    The pandemic influenza virus of 1918-1919 killed an estimated 20 to 50 million people worldwide. With the recent availability of the complete 1918 influenza virus coding sequence, we used reverse genetics to generate an influenza virus bearing all eight gene segments of the pandemic virus to study the properties associated with its extraordinary virulence. In stark contrast to contemporary human

  13. Efficient Filtration and Sizing of Viruses with Membrane Filters

    PubMed Central

    Ver, Binie A.; Melnick, Joseph L.; Wallis, Craig

    1968-01-01

    Untreated membrane filters retain viruses by adsorption, as well as by physical restriction which occurs when the pore diameter of the filter is smaller than that of the virus particle. As originally recommended by Elford, membranes had to be pretreated with proteinaceous material to preclude virus adsorption. However, coating materials that prevent adsorption of certain viruses do not necessarily prevent adsorption of other viruses. In contrast to proteins, salts enhance virus adsorption. Viruses treated with sodium lauryl sulfate to reduce the surface tension, or purified viruses in distilled water, are not adsorbed to membranes. A procedure is recommended by which viruses may be passed through membranes with a porosity twice the diameter of the virus. Such filtrates, which contain 50 to 100% of the initial virus concentration, should be used for sizing viruses by subsequent filtration through smaller pores. The determination of virus size would then be based on the major population of particles in the virus suspension. In the past, as little as 0.1 to 0.001% of the initial virus population was the basis for size determination, because more than 99.9% of the virus was often lost by adsorption to membranes during the clarifying procedures. Images PMID:4316012

  14. Two previously undescribed potato viruses from South America

    Microsoft Academic Search

    L. F. Salazar; B. D. Harrison

    1977-01-01

    THE proneness of potatoes (Solanum spp.) to virus diseases is well known, and about 20 viruses are recorded in naturally infected potatoes in Europe and North America1,2. Many of these viruses also occur in the Andean region of South America. For example, in Peru several well known viruses were detected3 in `basic seed' stocks by inoculating sap to a range

  15. Microneutralization assay for swine influenza virus in swine serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microneutralization (MN) assay is a modification of the serum virus neutralization assay and is a serological test to detect the presence of functional systemic antibodies that prevent infectivity of virus. When infectious virus is mixed with serum antibody, the virus infectivity can be "neutral...

  16. tchen@engr.smu.edu Viruses and Worms

    E-print Network

    Chen, Thomas M.

    attacks Prevalence % Organizations detected virus/worm attacks 82% 83% 90% 85% 94% *2003 CSI/FBI Computer/ worms ($K) $75K $55K $45K $180K $243K *2003 CSI/FBI Computer Crime and Security Survey $283K $200K #12 student at USC - "Virus" named after biological virus · Cohen wrote the first documented virus

  17. The efficacy of preservation methods to inactivate foodborne viruses

    Microsoft Academic Search

    L. Baert; J. Debevere; M. Uyttendaele

    2009-01-01

    During the last decade an increased incidence of infections and outbreaks attributed to foodborne viruses, in particular noroviruses (NoV), was observed world wide. The awareness of the presence of viruses on food emphasized the need to acquire knowledge regarding the effect of preservation methods upon viruses. Most foodborne viruses cannot be cultured in the laboratory, which hinders studies of their

  18. Explaining Usutu virus dynamics in Austria: Model development and calibration

    Microsoft Academic Search

    Franz Rubel; Katharina Brugger; Michael Hantel; Sonja Chvala-Mannsberger; Tamás Bakonyi; Herbert Weissenböck; Norbert Nowotny

    2008-01-01

    Usutu virus (USUV), a flavivirus of the Japanese encephalitis virus complex, was for the first time detected outside Africa in the region around Vienna (Austria) in 2001 by Weissenböck et al. [Weissenböck, H., Kolodziejek, J., Url, A., Lussy, H., Rebel-Bauder, B., Nowotny, N., 2002. Emergence of Usutu virus, an African mosquito-borne flavivirus of the Japanese encephalitis virus group, central Europe.

  19. RESCUE OF THE 1918 SPANISH INFLUENZA PANDEMIC VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pandemic influenza virus of 1918-1919 swept the globe and killed an estimated 20-40 million people. With the recent availability of the complete nucleotide sequence of the 1918 influenza virus, we generated by reverse genetics an influenza virus bearing all 8 genes of the pandemic virus to study...

  20. Virus Strains Causing Mosaic in Louisiana and Florida Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosaic caused by Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV), respectively, affects sugarcane in Louisiana and Florida. Between 2004 and 2007, surveys were conducted in both states to determine which virus and virus strains were causing mosaic of sugarcane. In Louisiana, leaf sam...

  1. A Hierarchical Artificial Immune Model for Virus Detection

    Microsoft Academic Search

    Wei Wang; Pengtao Zhang; Ying Tan; Xingui He

    2009-01-01

    As viruses become more complex, existing antivirus methods are inefficient to detect various forms of viruses, especially new variants and unknown viruses. Inspired by immune system, a hierarchical artificial immune system (AIS) model, which is based on matching in three layers, is proposed to detect a variety of forms of viruses. In the bottom layer, a non-stochastic but guided candidate

  2. Predators: good will mobile codes combat against computer viruses

    Microsoft Academic Search

    Hiroshi Toyoizumi; Atsuhi Kara

    2002-01-01

    We present a mathematical analysis of a new approach to fight against computer viruses through the use of their predators. Predators are good will mobile codes which, like viruses, travel over computer networks, and replicate and multipy themselves. The only difference is that predators are specifically designed to eliminate the viruses. We model the interaction between predators and viruses by

  3. TOWARDS AN UNDETECTABLE COMPUTER VIRUS A Project Report

    E-print Network

    Stamp, Mark

    TOWARDS AN UNDETECTABLE COMPUTER VIRUS A Project Report Presented to The Faculty of the Department COMPUTER VIRUS by Priti Desai APPROVED FOR THE DEPARTMENT OF COMPUTER SCIENCE Dr. Mark Stamp Department Date iii #12;ABSTRACT TOWARDS AN UNDETECTABLE COMPUTER VIRUS by Priti Desai Metamorphic viruses modify

  4. Formal Models of Reproduction: from Computer Viruses to Artificial Life

    E-print Network

    Atkinson, Katie

    Formal Models of Reproduction: from Computer Viruses to Artificial Life Thesis submitted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1.1 Motivations of Computer Virus Writers . . . . . . . . . . . . . . 2 1.1.2 A Short History of Computer Viruses . . . . . . . . . . . . . . . 3 1.1.3 Academic Study of Computer Viruses

  5. Original article In vivo replication of African swine fever virus

    E-print Network

    Paris-Sud XI, Université de

    Original article In vivo replication of African swine fever virus (Malawi '83) in neutrophils L pigs inoculated with a highly virulent strain of African swine fever virus is described for the first replication / African swine fever virus / neutrophil Résumé― Réplication in vivo du virus de la peste

  6. Development and evaluation of a Luminex multiplex serology assay to detect antibodies to bovine herpes virus 1, parainfluenza 3 virus, bovine viral diarrhoea virus, and bovine respiratory syncytial virus, with comparison to existing ELISA detection methods

    Microsoft Academic Search

    Steve Anderson; Phil Wakeley; Guy Wibberley; Kath Webster; Jason Sawyer

    2011-01-01

    Detection of circulating antibodies to bovine herpes virus 1 (BHV-1), parainfluenza 3 virus (PI3V), bovine viral diarrhoea virus (BVDV) and bovine respiratory syncytial virus (BRSV) using ELISA is widely used for veterinary diagnostics and surveillance. In this paper, the potential of a multiplex serology test based on Luminex technology, where all antibodies are simultaneously detected in a single assay was

  7. Mutation, purification and chemical studies on the tobacco necrosis virus

    E-print Network

    Hockaday, William Don

    1957-01-01

    extraction of precipitates ? . . . 36 Effect of ethanol and centrifugal combination treatments in precipitating infective virus ? . . ? 3& Electrophoretic studies . . . . ? ................... 39 Paper chromatography of proteins from healthy... ..................129 Re-precipitation of infective virus by ethanol . . ? 132 Precipitation of infective virus by various combination chemical treatments ? ? ? ? ? ? ? ? ? 132 Sedimentation of infective virus ? ? ? ? ? ? ? ? ? ? 135 Effect of repeated extraction...

  8. Complete nucleotide sequence of the new potexvirus “Alstroemeria virus

    Microsoft Academic Search

    S. Fuji; K. Shinoda; M. Ikeda; H. Furuya; H. Naito; F. Fukumoto

    2005-01-01

    A flexuous virus was isolated in Japan from an alstroemeria plant showing mosaic symptoms. The virus had a broad host range but had systemically latent infectivity in alstroemeria. The virus was assigned to the genus Potexvirus based on morphology and physical properties and on an analysis of the complete nucleotide sequence. The genomic RNA of the virus was 7,009 nucleotides

  9. Interference between Variants of Pseudorabies Virus demonstrable in Tissue Culture

    Microsoft Academic Search

    George Ivánovics; Helena Béládi; Ervin Szöllósy

    1955-01-01

    THE results of a series of investigations dealing with the cytopathogenic activity of pseudorabies virus have recently been reported from this Institute1. In these studies a strain of pseudorabies virus was serially transferred in tissue suspensions derived from chick embryos, and these served as a source of virus for the experiments. Destructive effects of the virus on tissue cultures made

  10. West Nile Virus: Biology, Transmission, and Human Infection

    PubMed Central

    Colpitts, Tonya M.; Conway, Michael J.; Montgomery, Ruth R.

    2012-01-01

    Summary: West Nile Virus was introduced into the Western Hemisphere during the late summer of 1999 and has been causing significant and sometimes severe human diseases since that time. This article briefly touches upon the biology of the virus and provides a comprehensive review regarding recent discoveries about virus transmission, virus acquisition, and human infection and disease. PMID:23034323

  11. DETECTION OF TOBACCO STREAK VIRUS FROM HIBISCUS IN FLORIDA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several viruses have recently been isolated from hibiscus (Hibiscus rosa-sinensis), which is often observed in Florida landscapes and garden centers with virus-like symptoms. An unknown virus was transmitted to Nicotiana tabacum from symptomatic hibiscus in Florida in 2003. This virus was propagated...

  12. Applications of pox virus vectors to vaccination: an update.

    PubMed

    Paoletti, E

    1996-10-15

    Recombinant pox viruses have been generated for vaccination against heterologous pathogens. Amongst these, the following are notable examples. (i) The engineering of the Copenhagen strain of vaccinia virus to express the rabies virus glycoprotein. When applied in baits, this recombinant has been shown to vaccinate the red fox in Europe and raccoons in the United States, stemming the spread of rabies virus infection in the wild. (ii) A fowlpox-based recombinant expressing the Newcastle disease virus fusion and hemagglutinin glycoproteins has been shown to protect commercial broiler chickens for their lifetime when the vaccine was administered at 1 day of age, even in the presence of maternal immunity against either the Newcastle disease virus or the pox vector. (iii) Recombinants of canarypox virus, which is restricted for replication to avian species, have provided protection against rabies virus challenge in cats and dogs, against canine distemper virus, feline leukemia virus, and equine influenza virus disease. In humans, canarypox virus-based recombinants expressing antigens from rabies virus, Japanese encephalitis virus, and HIV have been shown to be safe and immunogenic. (iv) A highly attenuated vaccinia derivative, NYVAC, has been engineered to express antigens from both animal and human pathogens. Safety and immunogenicity of NYVAC-based recombinants expressing the rabies virus glycoprotein, a polyprotein from Japanese encephalitis virus, and seven antigens from Plasmodium falciparum have been demonstrated to be safe and immunogenic in early human vaccine studies. PMID:8876138

  13. Recombinant Measles Virus Vaccine Expressing the Nipah Virus Glycoprotein Protects against Lethal Nipah Virus Challenge

    PubMed Central

    Yoneda, Misako; Georges-Courbot, Marie-Claude; Ikeda, Fusako; Ishii, Miho; Nagata, Noriyo; Jacquot, Frederic; Raoul, Hervé; Sato, Hiroki; Kai, Chieko

    2013-01-01

    Nipah virus (NiV) is a member of the genus Henipavirus, which emerged in Malaysia in 1998. In pigs, infection resulted in a predominantly non-lethal respiratory disease; however, infection in humans resulted in over 100 deaths. Nipah virus has continued to re-emerge in Bangladesh and India, and person-to-person transmission appeared in the outbreak. Although a number of NiV vaccine studies have been reported, there are currently no vaccines or treatments licensed for human use. In this study, we have developed a recombinant measles virus (rMV) vaccine expressing NiV envelope glycoproteins (rMV-HL-G and rMV-Ed-G). Vaccinated hamsters were completely protected against NiV challenge, while the mortality of unvaccinated control hamsters was 90%. We trialed our vaccine in a non-human primate model, African green monkeys. Upon intraperitoneal infection with NiV, monkeys showed several clinical signs of disease including severe depression, reduced ability to move and decreased food ingestion and died at 7 days post infection (dpi). Intranasal and oral inoculation induced similar clinical illness in monkeys, evident around 9 dpi, and resulted in a moribund stage around 14 dpi. Two monkeys immunized subcutaneously with rMV-Ed-G showed no clinical illness prior to euthanasia after challenge with NiV. Viral RNA was not detected in any organ samples collected from vaccinated monkeys, and no pathological changes were found upon histopathological examination. From our findings, we propose that rMV-NiV-G is an appropriate NiV vaccine candidate for use in humans. PMID:23516477

  14. Coronavirus avian infectious bronchitis virus.

    PubMed

    Cavanagh, Dave

    2007-01-01

    Infectious bronchitis virus (IBV), the coronavirus of the chicken (Gallus gallus), is one of the foremost causes of economic loss within the poultry industry, affecting the performance of both meat-type and egg-laying birds. The virus replicates not only in the epithelium of upper and lower respiratory tract tissues, but also in many tissues along the alimentary tract and elsewhere e.g. kidney, oviduct and testes. It can be detected in both respiratory and faecal material. There is increasing evidence that IBV can infect species of bird other than the chicken. Interestingly breeds of chicken vary with respect to the severity of infection with IBV, which may be related to the immune response. Probably the major reason for the high profile of IBV is the existence of a very large number of serotypes. Both live and inactivated IB vaccines are used extensively, the latter requiring priming by the former. Their effectiveness is diminished by poor cross-protection. The nature of the protective immune response to IBV is poorly understood. What is known is that the surface spike protein, indeed the amino-terminal S1 half, is sufficient to induce good protective immunity. There is increasing evidence that only a few amino acid differences amongst S proteins are sufficient to have a detrimental impact on cross-protection. Experimental vector IB vaccines and genetically manipulated IBVs--with heterologous spike protein genes--have produced promising results, including in the context of in ovo vaccination. PMID:17296157

  15. Surface structure of Uukuniemi virus.

    PubMed Central

    von Bonsdorff, C H; Pettersson, R

    1975-01-01

    Uukuniemi virus, grown in chicken embryo fibroblasts, has been studied by electron microscopy using negative staining, thin sectioning, and freeze-etching techniques. The spherical virus particle measures about 95 nm in diameter. Its envelope consists of a 5-nm thick membrane covered by 8- to 10-nm long surface projections. These are composed of two polypeptides species of about the same size. Both of them can be removed by digestion with the proteolytic enzyme thermolysin except for a small fragment. The enzyme-treated particles are smooth surfaced and extremely deformable. The glycopolypeptides are clustered to form hollow cylindrical morphological units, 10 to 12 nm in diameter, with a 5-nm central cavity. Both negative staining and freeze-etching suggest that these units are penton-hexon clusters arranged in a T = 12, P = 3, icosahedral surface lattice. The membrane to which the surface subunits are attached is probably a lipid bilayer as evidenced by its double-track appearance in thin sections and the tendency of the freeze fracturing to occur within it. The strand-like nucleoprotein appears from thin-sectioning results to be to a large part located in a zone underneath the membrane. Images PMID:52726

  16. Hepatitis C Virus in Pregnancy

    PubMed Central

    Prasad, Mona R; Honegger, Jonathan R.

    2013-01-01

    Despite recent advances in the pathogenesis, treatment, and public health response to hepatitis C virus (HCV), HCV as it specifically relates to pregnancy has been a neglected condition and a markedly improved public health response to these populations is needed. HCV-monoinfected pregnant women have a 2–8% risk of viral transmission to their infant, but the mechanism and timing of mother to child transmission (MTCT) are not fully understood, nor is the natural history of the illness in pregnant women and their offspring. Recognition of HCV is relevant to infected pregnant women because of their risk of the long-term complications of infection, potential effects of infection on pregnancy, and risk of transmission to their infants. Certain risk factors for mother to child transmission (MTCT) of HCV appear similar to those for human immunodeficiency virus (HIV), however, unlike HIV, effective methods of prevention of HCV vertical transmission have not been developed. It is possible that a better understanding of HCV pathogenesis in pregnancy and MTCT of HCV infection will lead to useful prevention strategies, particularly as we enter an era where interferon-free drug cocktails may emerge as viable treatment options for HCV PMID:23389935

  17. Inhibition of Hendra Virus Fusion

    PubMed Central

    Porotto, M.; Doctor, L.; Carta, P.; Fornabaio, M.; Greengard, O.; Kellogg, G. E.; Moscona, A.

    2006-01-01

    Hendra virus (HeV) is a recently identified paramyxovirus that is fatal in humans and could be used as an agent of bioterrorism. The HeV receptor-binding protein (G) is required in order for the fusion protein (F) to mediate fusion, and analysis of the triggering/activation of HeV F by G should lead to strategies for interfering with this key step in viral entry. HeV F, once triggered by the receptor-bound G, by analogy with other paramyxovirus F proteins, undergoes multistep conformational changes leading to a six-helix bundle (6HB) structure that accomplishes fusion of the viral and cellular membranes. The ectodomain of paramyxovirus F proteins contains two conserved heptad repeat regions (HRN and HRC) near the fusion peptide and the transmembrane domains, respectively. Peptides derived from the HRN and HRC regions of F are proposed to inhibit fusion by preventing F, after the initial triggering step, from forming the 6HB structure that is required for fusion. HeV peptides have previously been found to be effective at inhibiting HeV fusion. However, we found that a human parainfluenza virus 3 F-peptide is more effective at inhibiting HeV fusion than the comparable HeV-derived peptide. PMID:16973588

  18. Hepatitis C virus and lymphoma.

    PubMed

    Viswanatha, D S; Dogan, A

    2007-12-01

    Hepatitis C virus (HCV) is well known for its aetiological role in chronic non-A, non-B viral hepatitis, liver cirrhosis and hepatocellular carcinoma; in addition, the virus has also been implicated in a number of extra-hepatic "autoimmune" disease manifestations. A causative association between HCV and non-Hodgkin lymphoma (NHL) was postulated relatively recently and has been the subject of intense investigation, as well as some debate. On the strength of epidemiological data, emerging biological investigations and clinical observations, HCV appears to be involved in the pathogenesis of at least a proportion of patients with NHL. Morphologically, HCV-associated lymphomas represent a variety of histological subtypes including marginal zone lymphoma (splenic, nodal and extranodal), small lymphocytic lymphoma/chronic lymphocytic leukaemia, lymphoplasmacytic lymphoma and diffuse large B-cell lymphoma. Remarkably, some HCV-associated NHL appears to be highly responsive to antiviral therapy, providing some clinical evidence for this relationship, as well as the prospect for novel therapeutic intervention. PMID:18042694

  19. Quantification and Localization of Watermelon Chlorotic Stunt Virus and Tomato Yellow Leaf Curl Virus (Geminiviridae) in Populations of Bemisia tabaci (Hemiptera, Aleyrodidae) with Differential Virus Transmission Characteristics

    PubMed Central

    Kollenberg, Mario; Winter, Stephan; Götz, Monika

    2014-01-01

    Bemisia tabaci (Gennadius) is one of the economically most damaging insects to crops in tropical and subtropical regions. Severe damage is caused by feeding and more seriously by transmitting viruses. Those of the genus begomovirus (Geminiviridae) cause the most significant crop diseases and are transmitted by B. tabaci in a persistent circulative mode, a process which is largely unknown. To analyze the translocation and to identify critical determinants for transmission, two populations of B. tabaci MEAM1 were compared for transmitting Watermelon chlorotic stunt virus (WmCSV) and Tomato yellow leaf curl virus (TYLCV). Insect populations were chosen because of their high and respectively low virus transmission efficiency to compare uptake and translocation of virus through insects. Both populations harbored Rickettsia, Hamiltonella and Wolbachia in comparable ratios indicating that endosymbionts might not contribute to the different transmission rates. Quantification by qPCR revealed that WmCSV uptake and virus concentrations in midguts and primary salivary glands were generally higher than TYLCV due to higher virus contents of the source plants. Both viruses accumulated higher in insects from the efficiently compared to the poorly transmitting population. In the latter, virus translocation into the hemolymph was delayed and virus passage was impeded with limited numbers of viruses translocated. FISH analysis confirmed these results with similar virus distribution found in excised organs of both populations. No virus accumulation was found in the midgut lumen of the poor transmitter because of a restrained virus translocation. Results suggest that the poorly transmitting population comprised insects that lacked transmission competence. Those were selected to develop a population that lacks virus transmission. Investigations with insects lacking transmission showed that virus concentrations in midguts were reduced and only negligible virus amounts were found at the primary salivary glands indicating for a missing or modified receptor responsible for virus attachment or translocation. PMID:25365330

  20. Tick-borne virus diseases of human interest in Europe.

    PubMed

    Charrel, R N; Attoui, H; Butenko, A M; Clegg, J C; Deubel, V; Frolova, T V; Gould, E A; Gritsun, T S; Heinz, F X; Labuda, M; Lashkevich, V A; Loktev, V; Lundkvist, A; Lvov, D V; Mandl, C W; Niedrig, M; Papa, A; Petrov, V S; Plyusnin, A; Randolph, S; Süss, J; Zlobin, V I; de Lamballerie, X

    2004-12-01

    Several human diseases in Europe are caused by viruses transmitted by tick bite. These viruses belong to the genus Flavivirus, and include tick-borne encephalitis virus, Omsk haemorrhagic fever virus, louping ill virus, Powassan virus, Nairovirus (Crimean-Congo haemorrhagic fever virus) and Coltivirus (Eyach virus). All of these viruses cause more or less severe neurological diseases, and some are also responsible for haemorrhagic fever. The epidemiology, clinical picture and methods for diagnosis are detailed in this review. Most of these viral pathogens are classified as Biosafety Level 3 or 4 agents, and therefore some of them have been classified in Categories A-C of potential bioterrorism agents by the Centers for Disease Control and Prevention. Their ability to cause severe disease in man means that these viruses, as well as any clinical samples suspected of containing them, must be handled with specific and stringent precautions. PMID:15606630