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Sample records for con otros virus

  1. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires.

    PubMed

    Balán, Iván C; Carballo-Diéguez, Alex; Marone, Rubén O; Pando, María A; Barreda, Victoria; Avila, María M

    2011-03-01

    El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  2. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires

    PubMed Central

    Balán, Iván C.; Carballo-Diéguez, Alex; Marone, Rubén O.; Pando, María A.; Barreda, Victoria; Ávila, María M.

    2011-01-01

    Resumen El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  3. Pros and cons of liver transplantation in human immunodeficiency virus infected recipients

    PubMed Central

    Baccarani, Umberto; Righi, Elda; Adani, Gian Luigi; Lorenzin, Dario; Pasqualucci, Alberto; Bassetti, Matteo; Risaliti, Andrea

    2014-01-01

    Before the introduction of combined highly active antiretroviral therapy, a positive human immunodeficiency virus (HIV) serological status represented an absolute contraindication for solid organ transplant (SOT). The advent of highly effective combined antiretroviral therapy in 1996 largely contributed to the increased demand for SOT in HIV-positive individuals due to increased patients life expectancy associated with the increasing prevalence of end-stage liver disease (ESLD). Nowadays, liver failure represents a frequent cause of mortality in the HIV-infected population mainly due to coinfection with hepatitis viruses sharing the same way of transmission. Thus, liver transplantation (LT) represents a reasonable approach in HIV patients with stable infection and ESLD. Available data presently supports with good evidence the practice of LT in the HIV-positive population. Thus, the issue is no longer whether it is correct to transplant HIV-infected patients, but who are the patients who can be safely transplanted and when is the best time to perform LT. Indeed, the benefits of LT in HIV-infected patients, especially in terms of mid- and long-term patient and graft survivals, are strictly related to the patients selection and to the correct timing for transplantation, especially when hepatitis C virus coinfection is present. Aim of this article is to review the pros and cons of LT in the cohort of HIV infected recipients. PMID:24833865

  4. DUCHAS VAGINALES Y OTROS RIESGOS DE VAGINOSIS BACTERIANA

    PubMed Central

    Chávez, Natividad; Molina, Helfer; Sánchez, Jorge; Gelaye, Bizu; Sánchez, Sixto E.

    2010-01-01

    Vaginosis bacteriana (VB) es una infección caracterizada por el cambio en la microflora de la vagina, asociándose a resultados adversos del embarazo y a la adquisición de infecciones de transmisión sexual (ITS), incluyendo el VIH. En este estudio se buscó la asociación entre el uso de duchas vaginales y otros factores de riesgos con VB. Se usó un diseño observacional descriptivo transversal prospectivo, en 1,252 mujeres que asistieron al servicio de planificación familiar de tres hospitales nacionales (Dos de Mayo, Arzobispo Loayza, San Bartolomé) y el Instituto Materno Perinatal, durante el año 1997. Se utilizó un cuestionario estructurado donde se registraron variables socio demográficas y características del estilo de vida de las participantes. VB fue diagnosticada mediante el puntaje de Nugent. Se empleó análisis de regresión logística para calcular odds ratio (OR) e intervalos de confianza al 95%. La edad promedio de las participantes fue 25.1 ± 4,7 años, el 23.4% tenían más de 11 años de educación. La prevalencía de VB fue 20,1%. Las mujeres que practicaban duchas vaginales tuvieron 2.28 veces (OR = 2.28, IC 95% [1.0–5.0]) mayor probabilidad de tener VB comparado con aquellas que no lo practicaban. Tener dos o más parejas sexuales estuvo asociado con 2.0 veces (OR =2.0, IC 95% [1.2–3.5]) mayor probabilidad de adquirir VB comparado con aquellas que habían tenido solo una pareja sexual. Las participantes que iniciaron una relación sexual a una edad temprana tuvieron 1.4 veces (OR=1.4, IC 95% [1.0 –1.9]) mayor probabilidad de adquirir VB. El uso de duchas vaginales es un factor de riesgo de VB. Los programas destinados a la salud de la mujer deben abordar las repercusiones perjudiciales para la salud asociados con las duchas vaginales. PMID:21132048

  5. Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lytic bacteriophages, viruses which infect and lyse bacterial cells, can provide a natural method to reduce bacterial pathogens on produce commodities. The use of multi-phage cocktails is most likely to be effective against bacterial pathogens on produce commodities, and minimize the development of...

  6. Del sujeto que ha intentado suicidarse y el Otro: la Institución Psiquiátrica

    PubMed Central

    Liliana, Mondragón B.; Miguel Ángel, Caballero G.

    2009-01-01

    El hospital psiquiátrico se ha constituido como un lugar donde se posibilita legitimar la exclusión y la radicalidad de ese otro “que no es igual”, como es el caso del sujeto que atenta contra su propia vida. En consecuencia, el intento de suicidio desde el pensamiento foucaultiano, es una resistencia que desmantela la estructura de dominación a través de un acto de poder, el cual se ejerce sobre el propio cuerpo. Así, la intención de este texto es mostrar que la relación Otro-otro es un lugar en la estructura subjetiva, que se deposita en la institución psiquiátrica, la cual representa el poder, la ley, y es aquello a lo que se le quiere agredir, resistir, abatir con un intento de suicidio. Para demostrar como se materializan estos hechos, se exponen los testimonios de tres adolescentes atendidas en un hospital psiquiátrico por intentos suicidas, en los cuales se señalan los diferentes significados que le atribuyen a la institución psiquiátrica en tanto que representa un Otro en sus actos autoinfligidos. PMID:25400324

  7. Identification of duck plague virus by polymerase chain reaction

    USGS Publications Warehouse

    Hansen, W.R.; Brown, Sean E.; Nashold, S.W.; Knudson, D.L.

    1999-01-01

    A polymerase chain reaction (PCR) assay was developed for detecting duck plague virus. A 765-bp EcoRI fragment cloned from the genome of the duck plague vaccine (DP-VAC) virus was sequenced for PCR primer development. The fragment sequence was found by GenBank alignment searches to be similar to the 3a?? ends of an undefined open reading frame and the gene for DNA polymerase protein in other herpesviruses. Three of four primer sets were found to be specific for the DP-VAC virus and 100% (7/7) of field isolates but did not amplify DNA from inclusion body disease of cranes virus. The specificity of one primer set was tested with genome templates from other avian herpesviruses, including those from a golden eagle, bald eagle, great horned owl, snowy owl, peregrine falcon, prairie falcon, pigeon, psittacine, and chicken (infectious laryngotracheitis), but amplicons were not produced. Hence, this PCR test is highly specific for duck plague virus DNA. Two primer sets were able to detect 1 fg of DNA from the duck plague vaccine strain, equivalent to five genome copies. In addition, the ratio of tissue culture infectious doses to genome copies of duck plague vaccine virus from infected duck embryo cells was determined to be 1:100, making the PCR assay 20 times more sensitive than tissue culture for detecting duck plague virus. The speed, sensitivity, and specificity of this PCR provide a greatly improved diagnostic and research tool for studying the epizootiology of duck plague. /// Se desarroll?? una prueba de reacci??n en cadena por la polimerasa para detectar el virus de la peste del pato. Un fragmento EcoRI de 765 pares de bases clonado del genoma del virus vacunal de la peste del pato fue secuenciado para la obtenci??n de los iniciadores de la prueba de la reacci??n en cadena por la polimerasa. En investigaciones de alineaci??n en el banco de genes ('GenBank') se encontr?? que la secuencia del fragmento era similar a los extremos 3a?? de un marco de lectura abierto indefinido y al gen para la proteina de la DNA polimerasa en otros virus herpes. Se encontraron tres o cuatro grupos de iniciadores especificos para el virus vacunal y para el 100% (7/7) de los a??slamientos de campo, pero no amplificaron el DNA del virus de hepatitis por cuerpos de inclusi??n de grullas. Se analiz?? la especificidad de un primer juego de iniciadores con moldes del genoma de otros virus herpes aviares, incluyendo el ?!guila dorada, ?!guila de cabeza blanca, lechuza de cuernos grandes, lechuza blanca, halc??n peregrino, palomas, aves psit?!cidas y pollos (virus de laringotraqueitis infecciosa), pero no se produjeron los productos finales. Por lo tanto, esta prueba de reacci??n en cadena por la polimerasa es altamente especifica para el DNA del virus. Dos grupos de iniciadores fueron capaces de detectar un fragmento de DNA de la cepa vacunal equivalente a cinco copias del genoma. Adem?!s, se determin?? que la proporci??n de la dosis infecciosa en cultivo celular y copias del genoma del virus vacunal de c??lulas de embri??n de pato infectadas era de 10 a 100 respectivamente, haciendo la prueba de la reacci??n en cadena por la polimerasa 20 veces m?!s sensible que el cultivo celular para detectar el virus. La velocidad, sensibilidad y especificidad de la prueba de la reacci??n en cadena por la polimerasa suministra una herramienta de investigaci??n y de diagn??stico altamente mejorada para el estudio de la epizootiolog?-a del virus.

  8. Heartland Virus

    MedlinePLUS

    ... Vector-Borne Diseases (DVBD) NCEZID Share Compartir Heartland virus On this Page What is Heartland virus? How ... Do I Need to Know? What is Heartland virus? Heartland virus belongs to a family of viruses ...

  9. Zika Virus

    MedlinePLUS

    ... Skip Content Marketing Share this: Main Content Area Zika Virus Discovered in Uganda in 1947, Zika virus is ... eyes) and lasts several days to a week. Zika Virus Why NIAID is Researching Zika Virus Research Approach ...

  10. Pros and Cons: Usage of organs from donors infected with hepatitis C virus - Revision in the direct-acting antiviral era.

    PubMed

    Coilly, Audrey; Samuel, Didier

    2016-01-01

    Should organs from hepatitis C antibody positive donors (HCVD+) be used for transplantation? Organ shortage forces transplant teams to use donors with extended criteria. The decision to transplant a HCVD+ graft is a balance between the risk of transmission of a virus that could lead to end-stage liver diseases and the benefit of access to transplantation, specifically in patients with life-threatening disease. The other issue is the impact of HCV-related liver fibrosis in the donor graft on the long-term outcome in the recipient. Thus, the use of HCVD+ demonstrated a shorter meantime on the waiting list in kidney transplantation. When a HCVD+ graft is transplanted, the risk of HCV transmission depends on; 1) the quality of screening of the donor; 2) the presence of viral replication in the donor at the time of transplantation and the ability to detect it; and 3) the HCV status of the recipient but also the type of transplanted organ. In liver transplantation, the use of HCVD+ graft is usually restricted to recipients with a chronic HCV infection. Several reports showed some competition between HCV donor and recipient strain without deleterious impact on graft and patient survival. Controversies are still pending regarding the quality of the graft and the progression of fibrosis. The recent approval of direct-acting antiviral agents (DAA) dramatically changes the landscape of HCV infection treatment. After transplantation, combinations of DAA show high efficacy and good safety profile. In the near future, extensive use of DAA should reduce the number of HCVD+ with a positive HCV RNA, limiting the risk of transmission but also the number of patients on waiting lists for a disease related to HCV. PMID:26375245

  11. Zika Virus

    MedlinePLUS

    ... Search The CDC Cancel Submit Search The CDC Zika Virus Note: Javascript is disabled or is not supported ... Pregnant women About Zika Areas with Zika About Zika Virus Disease Zika virus disease is a caused by ...

  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. Inventing Viruses.

    PubMed

    Summers, William C

    2014-11-01

    In the nineteenth century, "virus" commonly meant an agent (usually unknown) that caused disease in inoculation experiments. By the 1890s, however, some disease-causing agents were found to pass through filters that retained the common bacteria. Such an agent was called "filterable virus," the best known being the virus that caused tobacco mosaic disease. By the 1920s there were many examples of filterable viruses, but no clear understanding of their nature. However, by the 1930s, the term "filterable virus" was being abandoned in favor of simply "virus," meaning an agent other than bacteria. Visualization of viruses by the electron microscope in the late 1930s finally settled their particulate nature. This article describes the ever-changing concept of "virus" and how virologists talked about viruses. These changes reflected their invention and reinvention of the concept of a virus as it was revised in light of new knowledge, new scientific values and interests, and new hegemonic technologies. PMID:26958713

  14. Viruses - from pathogens to vaccine carriers.

    PubMed

    Small, Juliana C; Ertl, Hildegund C J

    2011-10-01

    Vaccination is mankind's greatest public health success story. By now vaccines to many of the viruses that once caused fatal childhood diseases are routinely used throughout the world. Traditional methods of vaccine development through inactivation or attenuation of viruses have failed for some of the most deadly human pathogens, necessitating new approaches. Genetic modification of viruses not only allows for their attenuation but also for incorporation of sequences from other viruses, turning one pathogen into a vaccine carrier for another. Recombinant viruses have pros and cons as vaccine carriers, as discussed below using vectors based on adenovirus, herpesvirus, flavivirus, and rhabdovirus as examples. PMID:22003377

  15. Zika Virus

    MedlinePLUS

    ... and sexual contact. There have been outbreaks of Zika virus in Africa, Southeast Asia, the Pacific Islands, parts ... not travel to areas where there is a Zika virus outbreak. If you do decide to travel, first ...

  16. ECHO virus

    MedlinePLUS

    Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that lead to gastrointestinal infection and skin rashes. ... Echovirus is one of several families of viruses that affect the ... are common. In the United States, they are most common in ...

  17. Zika virus.

    PubMed

    2016-02-10

    Essential facts Zika virus disease is caused by a virus that is transmitted by the Aedes mosquito. While it generally causes a mild illness, there is increasing concern that it is harmful in pregnancy and can cause congenital abnormalities in infants born to women infected with the virus. There is no antiviral treatment or vaccine currently available. The best form of prevention is protection against mosquito bites. PMID:26860150

  18. CHLORELLA VIRUSES

    PubMed Central

    Yamada, Takashi; Onimatsu, Hideki; Van Etten, James L.

    2007-01-01

    Chlorella viruses or chloroviruses are large, icosahedral, plaque‐forming, double‐stranded‐DNA—containing viruses that replicate in certain strains of the unicellular green alga Chlorella. DNA sequence analysis of the 330‐kbp genome of Paramecium bursaria chlorella virus 1 (PBCV‐1), the prototype of this virus family (Phycodnaviridae), predict ∼366 protein‐encoding genes and 11 tRNA genes. The predicted gene products of ∼50% of these genes resemble proteins of known function, including many that are completely unexpected for a virus. In addition, the chlorella viruses have several features and encode many gene products that distinguish them from most viruses. These products include: (1) multiple DNA methyltransferases and DNA site‐specific endonucleases, (2) the enzymes required to glycosylate their proteins and synthesize polysaccharides such as hyaluronan and chitin, (3) a virus‐encoded K+ channel (called Kcv) located in the internal membrane of the virions, (4) a SET domain containing protein (referred to as vSET) that dimethylates Lys27 in histone 3, and (5) PBCV‐1 has three types of introns; a self‐splicing intron, a spliceosomal processed intron, and a small tRNA intron. Accumulating evidence indicates that the chlorella viruses have a very long evolutionary history. This review mainly deals with research on the virion structure, genome rearrangements, gene expression, cell wall degradation, polysaccharide synthesis, and evolution of PBCV‐1 as well as other related viruses. PMID:16877063

  19. 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

  20. 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,...

  1. The Dyslexia Handbook: Procedures Concerning Dyslexia and Related Disorders = Manual sobre la dislexia: Procedimientos relacionados con la dislexia y otros desordenes.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This handbook, available in English and Spanish, contains the Texas State Board of Education's approved procedures concerning dyslexia and related disorders and information regarding the state's dyslexia statutes and their relation to the federal Rehabilitation Act of 1973, Section 504, and the Individuals with Disabilities Education Act. Chapters

  2. Computer viruses

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    The worm, Trojan horse, bacterium, and virus are destructive programs that attack information stored in a computer's memory. Virus programs, which propagate by incorporating copies of themselves into other programs, are a growing menace in the late-1980s world of unprotected, networked workstations and personal computers. Limited immunity is offered by memory protection hardware, digitally authenticated object programs,and antibody programs that kill specific viruses. Additional immunity can be gained from the practice of digital hygiene, primarily the refusal to use software from untrusted sources. Full immunity requires attention in a social dimension, the accountability of programmers.

  3. Chikungunya Virus

    MedlinePLUS

    ... Symptoms & Treatment Geographic Distribution Chikungunya virus in the United States 2014 data 2015 data For Health Care Providers Clinical Evaluation & Disease Diagnostic Testing Resources for Healthcare Providers Nowcast for the Americas Fact Sheets and ...

  4. Chikungunya Virus.

    PubMed

    Phillips, Jennan A

    2015-06-01

    A mosquito-borne viral disease that is creating increased concern globally is Chikungunya virus (CHIKV). Occupational and environmental health nurses should educate workers about this emerging viral infection. PMID:26135602

  5. Computer Viruses. Technology Update.

    ERIC Educational Resources Information Center

    Ponder, Tim, Comp.; Ropog, Marty, Comp.; Keating, Joseph, Comp.

    This document provides general information on computer viruses, how to help protect a computer network from them, measures to take if a computer becomes infected. Highlights include the origins of computer viruses; virus contraction; a description of some common virus types (File Virus, Boot Sector/Partition Table Viruses, Trojan Horses, and…

  6. Foodborne viruses.

    PubMed

    Koopmans, Marion; von Bonsdorff, Carl Henrik; Vinjé, Jan; de Medici, Dario; Monroe, Steve

    2002-06-01

    Foodborne and waterborne viral infections are increasingly recognized as causes of illness in humans. This increase is partly explained by changes in food processing and consumption patterns that lead to the worldwide availability of high-risk food. As a result, vast outbreaks may occur due to contamination of food by a single foodhandler or at a single source. Although there are numerous fecal-orally transmitted viruses, most reports of foodborne transmission describe infections with Norwalk-like caliciviruses (NLV) and hepatitis A virus (HAV), suggesting that these viruses are associated with the greatest risk of foodborne transmission. NLV and HAV can be transmitted from person to person, or indirectly via food, water, or fomites contaminated with virus-containing feces or vomit. People can be infected without showing symptoms. The high frequency of secondary cases of NLV illness and - to a lesser extent - of hepatitis A following a foodborne outbreak results in amplification of the problem. The burden of illness is highest in the elderly, and therefore is likely to increase due to the aging population. For HAV, the burden of illness may increase following hygienic control measures, due to a decreasing population of naturally immune individuals and a concurrent increase in the population at risk. Recent advances in the research of NLV and HAV have led to the development of molecular methods which can be used for molecular tracing of virus strains. These methods can be and have been used for the detection of common source outbreaks. While traditionally certain foods have been implicated in virus outbreaks, it is clear that almost any food item can be involved, provided it has been handled by an infected person. There are no established methods for detection of viruses in foods other than shellfish. Little information is available on disinfection and preventive measures specifically for these viruses. Studies addressing this issue are hampered by the lack of culture systems. As currently available routine monitoring systems exclusively focus on bacterial pathogens, efforts should be made to combine epidemiological and virological information for a combined laboratory-based rapid detection system for foodborne viruses. With better surveillance, including typing information, outbreaks of foodborne infections could be reported faster to prevent further spread. PMID:12069883

  7. Parainfluenza Viruses

    PubMed Central

    Henrickson, Kelly J.

    2003-01-01

    Human parainfluenza viruses (HPIV) were first discovered in the late 1950s. Over the last decade, considerable knowledge about their molecular structure and function has been accumulated. This has led to significant changes in both the nomenclature and taxonomic relationships of these viruses. HPIV is genetically and antigenically divided into types 1 to 4. Further major subtypes of HPIV-4 (A and B) and subgroups/genotypes of HPIV-1 and HPIV-3 have been described. HPIV-1 to HPIV-3 are major causes of lower respiratory infections in infants, young children, the immunocompromised, the chronically ill, and the elderly. Each subtype can cause somewhat unique clinical diseases in different hosts. HPIV are enveloped and of medium size (150 to 250 nm), and their RNA genome is in the negative sense. These viruses belong to the Paramyxoviridae family, one of the largest and most rapidly growing groups of viruses causing significant human and veterinary disease. HPIV are closely related to recently discovered megamyxoviruses (Hendra and Nipah viruses) and metapneumovirus. PMID:12692097

  8. Hendra virus

    PubMed Central

    Middleton, Deborah

    2014-01-01

    Synopsis Hendra virus infection of horses occurred sporadically between 1994 and 2010 as a result of spill-over from the viral reservoir in Australian mainland flying-foxes, and occasional onward transmission to people also followed from exposure to affected horses. For reasons that are not well understood an unprecedented number of outbreaks were recorded in 2011, including the first recorded field infection of a dog, leading to heightened community concern. Increasingly, pressure mounted to instigate measures for control of flying-fox numbers, and equine health care workers started to leave the industry on account of risk and liability concerns. Release of an inactivated subunit vaccine for horses against Hendra virus represents the first commercially available product that is focused on mitigating the impact of a Biosafety Level 4 pathogen. Through preventing the development of acute Hendra virus disease in horses, vaccine use is also expected to reduce the risk of transmission of infection to people. This approach to emerging infectious disease management focuses on the role of horses as the proximal cause of human Hendra virus disease, and may assist in redirecting community concerns away from the flying-fox reservoirs, keystone species for the ongoing health of Australias native forests. PMID:25281398

  9. VIRUSES IN FINISHED WATER: THE OCCOQUAN EXPERIENCE

    EPA Science Inventory

    Low levels of poliovirus 1 were reported to have been isolated from 4 finished water samples collected by an EPA contractor from a water system that used conventional treatment including disinfection. The circumstances surrounding these virus isolations suggest that exogenous con...

  10. Vacunas contra los virus del papiloma humano

    Cancer.gov

    Una hoja informativa acerca de las vacunas contra los virus del papiloma humano (VPH) para prevenir infecciones con ciertos tipos de VPH, los cuales son la causa principal del cáncer de cuello del útero o cérvix.

  11. [Influenza virus].

    PubMed

    Juozapaitis, Mindaugas; Antoniukas, Linas

    2007-01-01

    Every year, especially during the cold season, many people catch an acute respiratory disease, namely flu. It is easy to catch this disease; therefore, it spreads very rapidly and often becomes an epidemic or a global pandemic. Airway inflammation and other body ailments, which form in a very short period, torment the patient several weeks. After that, the symptoms of the disease usually disappear as quickly as they emerged. The great epidemics of flu have rather unique characteristics; therefore, it is possible to identify descriptions of such epidemics in historic sources. Already in the 4th century bc, Hippocrates himself wrote about one of them. It is known now that flu epidemics emerge rather frequently, but there are no regular intervals between those events. The epidemics can differ in their consequences, but usually they cause an increased mortality of elderly people. The great flu epidemics of the last century took millions of human lives. In 1918-19, during "The Spanish" pandemic of flu, there were around 40-50 millions of deaths all over the world; "Pandemic of Asia" in 1957 took up to one million lives, etc. Influenza virus can cause various disorders of the respiratory system: from mild inflammations of upper airways to acute pneumonia that finally results in the patient's death. Scientist Richard E. Shope, who investigated swine flu in 1920, had a suspicion that the cause of this disease might be a virus. Already in 1933, scientists from the National Institute for Medical Research in London - Wilson Smith, Sir Christopher Andrewes, and Sir Patrick Laidlaw - for the first time isolated the virus, which caused human flu. Then scientific community started the exhaustive research of influenza virus, and the great interest in this virus and its unique features is still active even today. PMID:18182834

  12. The Geometry of Viruses.

    ERIC Educational Resources Information Center

    Case, Christine L.

    1991-01-01

    Presented is an activity in which students make models of viruses, which allows them to visualize the shape of these microorganisms. Included are some background on viruses, the biology and geometry of viruses, directions for building viruses, a comparison of cells and viruses, and questions for students. (KR)

  13. 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

  14. Measles virus

    PubMed Central

    Naim, Hussein Y

    2014-01-01

    Measles was an inevitable infection during the human development with substantial degree of morbidity and mortality. The severity of measles virus (MV) infection was largely contained by the development of a live attenuated vaccine that was introduced into the vaccination programs. However, all efforts to eradicate the disease failed and continued to annually result in significant deaths. The development of molecular biology techniques allowed the rescue of MV from cDNA that enabled important insights into a variety of aspects of the biology of the virus and its pathogenesis. Subsequently these technologies facilitated the development of novel vaccine candidates that induce immunity against measles and other pathogens. Based on the promising prospective, the use of MV as a recombinant vaccine and a therapeutic vector is addressed. PMID:25483511

  15. Zika Virus.

    PubMed

    Musso, Didier; Gubler, Duane J

    2016-07-01

    Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) in the genus Flavivirus and the family Flaviviridae. ZIKV was first isolated from a nonhuman primate in 1947 and from mosquitoes in 1948 in Africa, and ZIKV infections in humans were sporadic for half a century before emerging in the Pacific and the Americas. ZIKV is usually transmitted by the bite of infected mosquitoes. The clinical presentation of Zika fever is nonspecific and can be misdiagnosed as other infectious diseases, especially those due to arboviruses such as dengue and chikungunya. ZIKV infection was associated with only mild illness prior to the large French Polynesian outbreak in 2013 and 2014, when severe neurological complications were reported, and the emergence in Brazil of a dramatic increase in severe congenital malformations (microcephaly) suspected to be associated with ZIKV. Laboratory diagnosis of Zika fever relies on virus isolation or detection of ZIKV-specific RNA. Serological diagnosis is complicated by cross-reactivity among members of the Flavivirus genus. The adaptation of ZIKV to an urban cycle involving humans and domestic mosquito vectors in tropical areas where dengue is endemic suggests that the incidence of ZIKV infections may be underestimated. There is a high potential for ZIKV emergence in urban centers in the tropics that are infested with competent mosquito vectors such as Aedes aegypti and Aedes albopictus. PMID:27029595

  16. Ebola Virus Disease

    MedlinePLUS

    ... 2014 Fact sheets Features Commentaries 2014 Multimedia Contacts Ebola virus disease Fact sheet N°103 Updated January ... for survivors of Ebola virus disease Symptoms of Ebola virus disease The incubation period, that is, the ...

  17. Computer Viruses: An Overview.

    ERIC Educational Resources Information Center

    Marmion, Dan

    1990-01-01

    Discusses the early history and current proliferation of computer viruses that occur on Macintosh and DOS personal computers, mentions virus detection programs, and offers suggestions for how libraries can protect themselves and their users from damage by computer viruses. (LRW)

  18. What's West Nile Virus?

    MedlinePLUS

    ... Skating Crushes What's a Booger? What's West Nile Virus? KidsHealth > For Kids > What's West Nile Virus? Print A A A Text Size en espaol Qu es el Virus del Nilo Occidental? What exactly is the West ...

  19. West Nile Virus

    MedlinePLUS

    ... is a virus that can infect humans, birds, horses and mosquitoes. Infection from this virus is most ... Nile virus has been found in humans, birds, horses or mosquitoes are at risk for infection. You ...

  20. SAMPLING VIRUSES FROM SOIL

    EPA Science Inventory

    This chapter describes in detail methods for detecting viruses of bacteria and humans in soil. Methods also are presented for the assay of these viruses. Reference sources are provided for information on viruses of plants.

  1. 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.

  2. Virus movement maintains local virus population diversity.

    PubMed

    Snyder, Jamie C; Wiedenheft, Blake; Lavin, Matthew; Roberto, Francisco F; Spuhler, Josh; Ortmann, Alice C; Douglas, Trevor; Young, Mark

    2007-11-27

    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. PMID:18025457

  3. Shellfish-associated enteric virus illness: virus localization, disease outbreaks and prevention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous outbreaks of shellfish-borne enteric virus illness have been reported worldwide. Most notable among the outbreaks are those involving norovirus illness and hepatitis A. Lessons learned from outbreak investigations indicate that most outbreaks are preventable. Anthropogenic sources of con...

  4. The Tobacco Mosaic Virus.

    ERIC Educational Resources Information Center

    Sulzinski, Michael A.

    1992-01-01

    Explains how the tobacco mosaic virus can be used to study virology. Presents facts about the virus, procedures to handle the virus in the laboratory, and four laboratory exercises involving the viruses' survival under inactivating conditions, dilution end point, filterability, and microscopy. (MDH)

  5. Virophages or satellite viruses?

    PubMed

    Krupovic, Mart; Cvirkaite-Krupovic, Virginija

    2011-11-01

    It has been argued that the smaller viruses associated with giant DNA viruses are a new biological entity. However, Mart Krupovic and Virginija Cvirkaite-Krupovic argue here that these smaller viruses should be classified with the satellite viruses. PMID:22016897

  6. Junn Virus Pathogenesis and Virus Replication

    PubMed Central

    Grant, Ashley; Seregin, Alexey; Huang, Cheng; Kolokoltsova, Olga; Brasier, Allan; Peters, Clarence; Paessler, Slobodan

    2012-01-01

    Junn virus, the etiological agent of Argentine hemorrhagic fever, causes significant morbidity and mortality. The virus is spread through the aerosolization of host rodent excreta and endemic to the humid pampas of Argentina. Recently, significant progress has been achieved with the development of new technologies (e.g. reverse genetics) that have expanded knowledge about the pathogenesis and viral replication of Junn virus. We will review the pathogenesis of Junn virus in various animal models and the role of innate and adaptive immunity during infection. We will highlight current research regarding the role of molecular biology of Junn virus in elucidating virus attenuation. We will also summarize current knowledge on Junn virus pathogenesis focusing on the recent development of vaccines and potential therapeutics. PMID:23202466

  7. Understanding Ebola Virus Transmission

    PubMed Central

    Judson, Seth; Prescott, Joseph; Munster, Vincent

    2015-01-01

    An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus. PMID:25654239

  8. Virus-Vectored Influenza Virus Vaccines

    PubMed Central

    Tripp, Ralph A.; Tompkins, S. Mark

    2014-01-01

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

  9. Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina.

    PubMed

    Carballo-Diéguez, Alex; Avila, María M; Balán, Iván C; Marone, Rubén; Pando, María A; Barreda, Victoria

    2011-03-01

    Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  10. Presentación del estudio “Links” de hombres que tienes sexo con hombres en Buenos Aires, Argentina

    PubMed Central

    Carballo-Diéguez, Alex; Ávila, María M; Balán, Iván C.; Marone, Rubén; Pando, María A.; Barreda, Victoria

    2011-01-01

    Resumen Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos (“teteras”), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  11. Viruses Infecting Reptiles

    PubMed Central

    Marschang, Rachel E.

    2011-01-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions. PMID:22163336

  12. Testing for Human Immunodeficiency Virus

    MedlinePLUS

    ... education Fact Sheet PFS005: Testing for Human Immunodeficiency Virus AUGUST 2015 • Reasons for Getting Tested • Who Should ... For More Information • Glossary Testing for Human Immunodeficiency Virus Human immunodeficiency virus (HIV) is the virus that ...

  13. RNA replicons - a new approach for influenza virus immunoprophylaxis.

    PubMed

    Zimmer, Gert

    2010-02-01

    RNA replicons are derived from either positive- or negative-strand RNA viruses. They represent disabled virus vectors that are not only avirulent, but also unable to revert to virulence. Due to autonomous RNA replication, RNA replicons are able to drive high level, cytosolic expression of recombinant antigens stimulating both the humoral and the cellular branch of the immune system. This review provides an update on the available literature covering influenza virus vaccines based on RNA replicons. The pros and cons of these vaccine strategies will be discussed and future perspectives disclosed. PMID:21994644

  14. Viruses in the sea

    NASA Astrophysics Data System (ADS)

    Suttle, Curtis A.

    2005-09-01

    Viruses exist wherever life is found. They are a major cause of mortality, a driver of global geochemical cycles and a reservoir of the greatest genetic diversity on Earth. In the oceans, viruses probably infect all living things, from bacteria to whales. They affect the form of available nutrients and the termination of algal blooms. Viruses can move between marine and terrestrial reservoirs, raising the spectre of emerging pathogens. Our understanding of the effect of viruses on global systems and processes continues to unfold, overthrowing the idea that viruses and virus-mediated processes are sidebars to global processes.

  15. Oncolytic virus therapies.

    PubMed

    Buonaguro, Franco Maria; Tornesello, Maria Lina; Izzo, Francesco; Buonaguro, Luigi

    2012-11-01

    Oncolytic virus (OV) therapy currently represents one of the most promising approaches to cancer treatment for their dual anticancer mechanisms: direct lysis of cancer cells (oncolytic feature) and activation of the immunosystem (cancer vaccine aspect). The latter demonstrates the advantage of a multi-target approach against multiple tumor-associated antigens. Since the 2005 SFDA (the Chinese FDA) approval for the clinical use of Oncorine™, the first human OV-based cancer treatment, more than 200 patents have been filed worldwide and several Phase I/II studies have been conducted. This patent review analyzes patents and clinical studies of the most promising OV products to highlight the pros and cons of this innovative anticancer approach, which is currently being tested in several cancers (i.e., hepatocellular carcinoma, melanoma and glioblastoma) by systemic as well as intratumoral injection. Clinical results, although effective only for a limited period of time, are encouraging. Combined treatments with radio or chemotherapeutic protocols are also in progress. PMID:24236929

  16. Tumorigenic DNA viruses

    SciTech Connect

    Klein, G.

    1989-01-01

    The eighth volume of Advances in Viral Oncology focuses on the three major DNA virus groups with a postulated or proven tumorigenic potential: papillomaviruses, animal hepatitis viruses, and the Epstein-Bar virus. In the opening chapters, the contributors analyze the evidence that papillomaviruses and animal hepatitis viruses are involved in tumorigenesis and describe the mechanisms that trigger virus-host cell interactions. A detailed section on the Epstein-Barr virus (EBV) - comprising more than half the book - examines the transcription and mRNA processing patterns of the virus genome; the mechanisms by which EBV infects lymphoid and epithelial cells; the immunological aspects of the virus; the actions of EBV in hosts with Acquired Immune Deficiency Syndrome; and the involvement of EBV in the etiology of Burkitt's lymphoma.

  17. Viruses and Breast Cancer

    PubMed Central

    Lawson, James S.; Heng, Benjamin

    2010-01-01

    Viruses are the accepted cause of many important cancers including cancers of the cervix and anogenital area, the liver, some lymphomas, head and neck cancers and indirectly human immunodeficiency virus associated cancers. For over 50 years, there have been serious attempts to identify viruses which may have a role in breast cancer. Despite these efforts, the establishment of conclusive evidence for such a role has been elusive. However, the development of extremely sophisticated new experimental techniques has allowed the recent development of evidence that human papilloma virus, Epstein-Barr virus, mouse mammary tumor virus and bovine leukemia virus may each have a role in the causation of human breast cancers. This is potentially good news as effective vaccines are already available to prevent infections from carcinogenic strains of human papilloma virus, which causes cancer of the uterine cervix. PMID:24281093

  18. Human Parainfluenza Viruses

    MedlinePLUS

    ... HPIVs Are Not the Same as Influenza (Flu) Viruses People usually get HPIV infections more often in ... hands, and touching objects or surfaces with the viruses on them then touching your mouth, nose, or ...

  19. West Nile virus

    MedlinePLUS

    West Nile virus is a disease spread by mosquitoes. The condition ranges from mild to severe. ... West Nile virus was first identified in 1937 in Uganda in eastern Africa. It was first discovered in the U.S. in ...

  20. Respiratory Syncytial Virus Infections

    MedlinePLUS

    Respiratory syncytial virus (RSV) causes mild, cold-like symptoms in adults and older healthy children. It can cause serious problems in ... tests can tell if your child has the virus. There is no specific treatment. You should give ...

  1. Viruses and human cancer

    SciTech Connect

    Gallo, R.C.; Haseltine, W.; Klein, G.; Zur Hausen, H.

    1987-01-01

    This book contains papers on the following topics: Immunology and Epidemiology, Biology and Pathogenesis, Models of Pathogenesis and Treatment, Simian and Bovine Retroviruses, Human Papilloma Viruses, EBV and Herpesvirus, and Hepatitis B Virus.

  2. West Nile Virus

    MedlinePLUS

    ... West Nile virus has been found in animals, birds, and humans in all continental states in the ... picked up the virus after feeding on infected birds. Pets and other animals can also become infected ...

  3. Live Virus Smallpox Vaccine

    MedlinePLUS

    ... Ebola virus E. coli Food safety threats Glanders Lassa fever Marburg virus Melioidosis Plague Case Definitions and Report ... Investigation Infection Control Other Resources Typhoid fever Viral hemorrhagic fevers Treatment & Infection Control Specimen Submission & Lab Testing Education & ...

  4. Advances in virus research

    SciTech Connect

    Maramorosch, K. ); Murphy, F.A. ); Shatkin, A.J. )

    1988-01-01

    This book contains eight chapters. Some of the titles are: Initiation of viral DNA replication; Vaccinia: virus, vector, vaccine; The pre-S region of hepadnavirus envelope proteins; and Archaebacterial viruses.

  5. Zika Virus Fact Sheet

    MedlinePLUS

    ... 2014 Fact sheets Features Commentaries 2014 Multimedia Contacts Zika virus Fact sheet Updated 18 March 2016 Key facts ... last for 2-7 days. Potential complications of Zika virus disease During large outbreaks in French Polynesia and ...

  6. Zika Virus Infection

    MedlinePLUS

    ... Rare Diseases Information Center (GARD) Print friendly version Zika virus infection Table of Contents Overview Tests & Diagnosis Treatment ... Answered Other Names for this Disease Zika fever Zika virus disease About the GARD Information Center See Disclaimer ...

  7. Quasispecies of dengue virus

    PubMed Central

    Kurosu, Takeshi

    2011-01-01

    Pathogenic viruses have RNA genomes that cause acute and chronic infections. These viruses replicate with high mutation rates and exhibit significant genetic diversity, so-called viral quasispecies. Viral quasispecies play an important role in chronic infectious diseases, but little is known about their involvement in acute infectious diseases such as dengue virus (DENV) infection. DENV, the most important human arbovirus, is a causative agent of dengue fever (DF) and dengue hemorrhagic fever (DHF). Accumulating observations suggest that DENV exists as an extremely diverse virus population, but its biological significance is unclear. In other virus diseases, quasispecies affect the therapeutic strategies using drugs and vaccines. Here, I describe the quasispecies of DENV and discuss the possible role of quasispecies in the pathogenesis of and therapeutic strategy against DENV infection in comparison with other viruses such as Hepatitis C virus, human immunodeficiency virus type 1, and poliovirus. PMID:22500134

  8. Virus Assembly and Maturation

    NASA Astrophysics Data System (ADS)

    Johnson, John E.

    2004-03-01

    We use two techniques to look at three-dimensional virus structure: electron cryomicroscopy (cryoEM) and X-ray crystallography. Figure 1 is a gallery of virus particles whose structures Timothy Baker, one of my former colleagues at Purdue University, used cryoEM to determine. It illustrates the variety of sizes of icosahedral virus particles. The largest virus particle on this slide is the Herpes simplex virus, around 1200 in diameter; the smallest we examined was around 250 in diameter. Viruses bear their genomic information either as positive-sense DNA and RNA, double-strand DNA, double-strand RNA, or negative-strand RNA. Viruses utilize the various structure and function "tactics" seen throughout cell biology to replicate at high levels. Many of the biological principles that we consider general were in fact discovered in the context of viruses ...

  9. Computer Virus Protection

    ERIC Educational Resources Information Center

    Rajala, Judith B.

    2004-01-01

    A computer virus is a program--a piece of executable code--that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file, and are spread by replicating and being sent from one individual to another. Simply having

  10. West Nile Virus

    MedlinePLUS

    ... I Help a Friend Who Cuts? West Nile Virus KidsHealth > For Teens > West Nile Virus Print A A A Text Size What's in ... Basics Tips for Protecting Yourself en español El virus del Nilo Occidental West Nile Basics Most mosquitoes ...

  11. Respiratory Syncytial Virus

    MedlinePLUS

    ... Your Child All About Food Allergies Respiratory Syncytial Virus KidsHealth > For Parents > Respiratory Syncytial Virus Print A A A Text Size What's in ... RSV When to Call the Doctor en español Virus respiratorio sincitial About RSV Respiratory syncytial (sin-SISH- ...

  12. What's West Nile Virus?

    MedlinePLUS

    ... Skating Crushes What's a Booger? What's West Nile Virus? KidsHealth > For Kids > What's West Nile Virus? Print A A A Text Size en español ¿Qué es el Virus del Nilo Occidental? What exactly is the West ...

  13. Computer Virus Protection

    ERIC Educational Resources Information Center

    Rajala, Judith B.

    2004-01-01

    A computer virus is a program--a piece of executable code--that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file, and are spread by replicating and being sent from one individual to another. Simply having…

  14. Avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is caused by type A influenza virus, a member of the Orthomyxoviridae family. AI viruses are serologically categorized into 16 hemagglutinin (H1-H16) and 9 neuraminidase (N1-N9) subtypes. All subtypes have been identified in birds. Infections by AI viruses have been reported in ...

  15. 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...

  16. Respiratory Syncytial Virus

    MedlinePLUS

    ... Cerebral Palsy: Caring for Your Child Respiratory Syncytial Virus KidsHealth > For Parents > Respiratory Syncytial Virus Print A A A Text Size What's in ... RSV When to Call the Doctor en espaol Virus respiratorio sincitial About RSV Respiratory syncytial (sin-SISH- ...

  17. Avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is type A influenza, which is adapted to an avian host. Although avian influenza has been isolated from numerous avian species, the primary natural hosts for the virus are dabbling ducks, shorebirds, and gulls. The virus can be found world-wide in these species and in o...

  18. 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...

  19. Hanta virus (image)

    MedlinePLUS

    Hanta virus is a distant cousin of Ebola virus, but is found worldwide. The virus is spread by human contact with rodent waste. Dangerous respiratory illness develops. Effective treatment is not yet available and over 50% of cases end in fatality.

  20. 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...

  1. Avian influenza virus and Newcastle disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) severely impact poultry egg production. Decreased egg yield and hatchability, as well as misshapen eggs, are often observed during infection with AIV and NDV, even with low-virulence strains or in vaccinated flocks. Data suggest that in...

  2. Nairobi sheep disease virus/Ganjam virus.

    PubMed

    M D, Baron; B, Holzer

    2015-08-01

    Nairobi sheep disease virus (NSDV) is a tick-borne virus which causes a severe disease in sheep and goats, and has been responsible for several outbreaks of disease in East Africa. The virus is also found in the Indian subcontinent, where it is known as Ganjam virus. The virus only spreads through the feeding of competent infected ticks, and is therefore limited in its geographic distribution by the distribution of those ticks, Rhipicephalus appendiculata in Africa and Haemaphysalis intermedia in India. Animals bred in endemic areas do not normally develop disease, and the impact is therefore primarily on animals being moved for trade or breeding purposes. The disease caused by NSDV has similarities to several other ruminant diseases, and laboratory diagnosis is necessary for confirmation. There are published methods for diagnosis based on polymerase chain reaction, for virus growth in cell culture and for other simple diagnostic tests, though none has been commercialised. There is no established vaccine against NSDV, although cell-culture attenuated strains have been developed which show promise and could be put into field trials if it were deemed necessary. The virus is closely related to Crimean-Congo haemorrhagic fever virus, and studies on NSDV may therefore be useful in understanding this important human pathogen. PMID:26647464

  3. Haloarchaeal virus morphotypes.

    PubMed

    Atanasova, Nina S; Bamford, Dennis H; Oksanen, Hanna M

    2015-11-01

    Hypersaline waters and salt crystals are known to contain high numbers of haloarchaeal cells and their viruses. Both culture-dependent and culture-independent studies indicate that these viruses represent a world-wide distributed reservoir of orphan genes and possibly novel virion morphotypes. To date, 90 viruses have been described for halophilic archaeal hosts, all belonging to the Halobacteriaceae family. This number is higher than that described for the members of any other archaeal family, but still very low compared to the viruses of bacteria and eukaryotes. The known haloarchaeal viruses represent icosahedral tailed, icosahedral internal membrane-containing, pleomorphic, and spindle-shaped virion morphotypes. This morphotype distribution is low, especially when compared to the astronomical number (>10(31)) of viruses on Earth. This strongly suggests that only certain protein folds are capable of making a functional virion. Viruses infecting cells belonging to any of the three domains of life are known to share similar major capsid protein folds which can be used to classify viruses into structure-based lineages. The latest observation supporting this proposal comes from the studies of icosahedral tailed haloarchaeal viruses which are the most abundant virus isolates from hypersaline environments. These viruses were shown to have the same major capsid protein fold (HK97-fold) with tailed bacteriophages belonging to the order Caudovirales and with eukaryotic herpes viruses. This proposes that these viruses have a common origin dating back to ancient times. Here we summarize the current knowledge of haloarchaeal viruses from the perspective of virus morphotypes. PMID:26151345

  4. The Con Test

    ERIC Educational Resources Information Center

    Fletcher, Michael

    2009-01-01

    In this article, the author describes the format of the Con Test, an Australian television game show which followed the same general rules and game play as the UK show PokerFace. At the end of each round a contestant needs to decide whether or not he or she should fold. A contestant needs to know how likely it is that he or she is in last place.

  5. [Viruses as biological weapons].

    PubMed

    Akali, Alper

    2005-07-01

    The destruction made by nuclear, biological and chemical weapons used by governments and terrorist groups in the near history is posing anxiety and fear for human being. Rumour about the possible use of these agents leads to the development of serious negative effects on populations. Since there are no vaccine and therapy for most viral agents and cost of production as biological weapons is low, interest rate is rising for viruses. In this review, general characteristics, diagnosis, therapy and protective measures for viral agents such as variola virus, hemorrhagic fever viruses, encephalitis viruses, Hantaviruses and Nipah viruses, those can be used as biological weapon, have been summarized. PMID:16358499

  6. 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

  7. Multiple sclerosis and viruses.

    PubMed

    Brahic, Michel

    2010-07-01

    Discussing the problem of multiple sclerosis and viruses should not be limited to reviewing the epidemiological evidence in favor, or against, a particular candidate, such as Epstein-Barr virus or human herpes virus 6. In this text, I discuss the difficulty of going from association to causation in human epidemiology; the fact that viruses can trigger or prevent autoimmunity; the problem of our very limited knowledge of the viruses that we harbor as part of our metagenome; and the role of such viral flora in multifactorial diseases and also, possibly, in health. PMID:20582990

  8. Avian influenza virus.

    PubMed

    Lee, Chang-Won; Saif, Yehia M

    2009-07-01

    Avian influenza viruses do not typically replicate efficiently in humans, indicating direct transmission of avian influenza virus to humans is unlikely. However, since 1997, several cases of human infections with different subtypes (H5N1, H7N7, and H9N2) of avian influenza viruses have been identified and raised the pandemic potential of avian influenza virus in humans. Although circumstantial evidence of human to human transmission exists, the novel avian-origin influenza viruses isolated from humans lack the ability to transmit efficiently from person-to-person. However, the on-going human infection with avian-origin H5N1 viruses increases the likelihood of the generation of human-adapted avian influenza virus with pandemic potential. Thus, a better understanding of the biological and genetic basis of host restriction of influenza viruses is a critical factor in determining whether the introduction of a novel influenza virus into the human population will result in a pandemic. In this article, we review current knowledge of type A influenza virus in which all avian influenza viruses are categorized. PMID:18457876

  9. The quest of influenza A viruses for new hosts.

    PubMed

    Liu, M; Guan, Y; Peiris, M; He, S; Webby, R J; Perez, D; Webster, R G

    2003-01-01

    There is increasing evidence that stable lineages of influenza viruses are being established in chickens. H9N2 viruses are established in chickens in Eurasia, and there are increasing reports of H3N2, H6N1, and H6N2 influenza viruses in chickens both in Asia and North America. Surveillance in a live poultry market in Nanchang, South Central China, reveals that influenza viruses were isolated form 1% of fecal samples taken from healthy poultry over the course of 16 months. The highest isolation rates were from chickens (1.3%) and ducks (1.2%), followed by quail (0.8%), then pigeon (0.5%). H3N6, H9N2, H2N9, and H4N6 viruses were isolated from multiple samples, while single isolates of H1N1, H3N2, and H3N3 viruses were made. Representatives of each virus subtype were experimentally inoculated into both quail and chickens. All the viruses replicated in the trachea of quail, but efficient replication in chickens was confined to 25% of the tested isolates. In quail, these viruses were shed primarily by the aerosol route, raising the possibility that quail may be the "route modulator" that changes the route of transmission of influenza viruses from fecal-oral to aerosol transmission. Thus, quail may play an important role in the natural history of influenza viruses. The pros and cons of the use of inactivated and recombinant fowl pox-influenza vaccines to control the spread of avian influenza are also evaluated. PMID:14575076

  10. Estudio epidemiológico de sucesos traumáticos, trastorno de estrés post-traumático y otros trastornos psiquiátricos en una muestra representativa de Chile

    PubMed Central

    Pérez Benítez, Carlos I.; Vicente, Benjamin; Zlotnick, Caron; Kohn, Robert; Johnson, Jennifer; Valdivia, Sandra; Rioseco, Pedro

    2010-01-01

    RESUMEN Durante la década de 1990 en los Estados Unidos (EU), el conocimiento sobre el trastorno de estrés post-traumático (TEPT) evolucionó de estudios específicos en un principio, sobre veteranos de guerra y sobre víctimas de desastres, a estudios epidemiológicos más tarde, sin embargo, la epidemiología del TEPT en países en desarrollo ha sido un área poco estudiada hasta ahora. Los expertos en el área de trauma han propuesto que los sucesos traumáticos que ocurren en la niñez son más perjudiciales para la salud mental que aquellos que ocurren más tarde en la vida. Este trabajo revisa los resultados de un estudio epidemiológico llevado a cabo en Chile. Específicamente, se revisan los resultados sobre las tasas de prevalencia del TEPT, traumas asociados más frecuentemente con él, así como la comorbilidad de este trastorno con otros trastornos psiquiátricos a lo largo de la vida. Igualmente se analizaron las diferencias del TEPT en cada sexo, así como la exposición a traumas en una muestra representativa de chilenos. Además se comparó la prevalencia de trastornos psiquiátricos en personas que sufrieron su primer trauma durante la niñez, durante la edad adulta, o que no reportaron traumas durante su vida. En estos estudios epidemiológicos se usaron módulos del TEPT y trastorno de personalidad antisocial (TPA) de la entrevista diagnóstica siguiendo los criterios del DSM-III-R (DIS–III-R). Para evaluar el resto de los trastornos psiquiátricos se usó la Entrevista Diagnóstica Internacional Compuesta (CIDI). Estos instrumentos fueron administrados en tres ciudades chilenas a 2390 personas mayores de 15 años. Para estimar los errores estándares (EE) debido al diseño de la muestra y a la necesidad de ajuste se usó el método Taylor de linearización seriada. También se usó un análisis de regresión logística para examinar la relación entre el TEPT, los factores demográficos de riesgo y el tipo de trauma. Además se utilizó la regresión logística multivariada para evaluar si la relación entre el TEPT y el sexo pudiera ser explicada por medio de otros factores de riesgo, así como para calcular las tasas y la oportunidad relativa (razón de productos cruzados) de trastornos psiquiátricos a lo largo de la vida. El primer análisis arrojó que la prevalencia de TEPT a lo largo de la vida fue de 4.4% (2.5% para hombres y 6.2% para mujeres). De los hechos traumáticos reportados, la violación sexual tuvo una correlación más alta con el TEPT que los demás hechos traumáticos. Las mujeres tuvieron más probabilidades de experimentar TEPT que los hombres, después de controlar la variable asalto violento. El segundo análisis evidenció que los que habían sufrido traumas a lo largo de la vida tuvieron mayor probabilidad de tener un trastorno psiquiátrico en comparación con aquellos que no reportaron traumas. También se encontró que los que sufrieron su primer trauma durante la infancia tuvieron más probabilidad de desarrollar trastornos de pánico a lo largo de la vida que aquellos que sufrieron su primer trauma en la edad adulta, independientemente del número de traumas que sufrieron y de las diferencias demográficas. Aunque Chile tiene un contexto histórico-cultural y una economía diferente a otros países en los que se ha estudiado anteriormente la epidemiología del TEPT, el presente estudio reflejó tendencias similares a las reportadas en estudios previos. Los hallazgos expuestos enfatizan la importancia de investigar la prevalencia del TEPT, los patrones de comorbilidad del TEPT y las diferencias de sexo en la prevalencia del TEPT en diferentes países. También estos resultados sugieren que los sucesos traumáticos en la infancia (y no en la adultez) pueden estar relacionados con la ocurrencia de trastornos psiquiátricos específicos. PMID:21113425

  11. [The great virus comeback].

    PubMed

    Forterre, Patrick

    2013-01-01

    Viruses have been considered for a long time as by-products of biological evolution. This view is changing now as a result of several recent discoveries. Viral ecologists have shown that viral particles are the most abundant biological entities on our planet, whereas metagenomic analyses have revealed an unexpected abundance and diversity of viral genes in the biosphere. Comparative genomics have highlighted the uniqueness of viral sequences, in contradiction with the traditional view of viruses as pickpockets of cellular genes. On the contrary, cellular genomes, especially eukaryotic ones, turned out to be full of genes derived from viruses or related elements (plasmids, transposons, retroelements and so on). The discovery of unusual viruses infecting archaea has shown that the viral world is much more diverse than previously thought, ruining the traditional dichotomy between bacteriophages and viruses. Finally, the discovery of giant viruses has blurred the traditional image of viruses as small entities. Furthermore, essential clues on virus history have been obtained in the last ten years. In particular, structural analyses of capsid proteins have uncovered deeply rooted homologies between viruses infecting different cellular domains, suggesting that viruses originated before the last universal common ancestor (LUCA). These studies have shown that several lineages of viruses originated independently, i.e., viruses are polyphyletic. From the time of LUCA, viruses have coevolved with their hosts, and viral lineages can be viewed as lianas wrapping around the trunk, branches and leaves of the tree of life. Although viruses are very diverse, with genomes encoding from one to more than one thousand proteins, they can all be simply defined as organisms producing virions. Virions themselves can be defined as infectious particles made of at least one protein associated with the viral nucleic acid, endowed with the capability to protect the viral genome and ensure its delivery to the infected cell. These definitions, which clearly distinguish viruses from plasmids, suggest that infectious RNA molecules that only encode an RNA replicase presently classified among viruses by the ICTV (International Committee for the Taxonomy of Viruses) into families of Endornaviridae and Hypoviridae are in fact RNA plasmids. Since a viral genome should encode for at least one structural protein, these definitions also imply that viruses originated after the emergence of the ribosome in an RNA-protein cellular world. Although virions are the hallmarks of viruses, viruses and virions should not be confused. The infection transforms the ribocell (cell encoding ribosomes and dividing by binary fission) into a virocell (cell producing virions) or ribovirocell (cell that produces virions but can still divide by binary fission). In the ribovirocell, two different organisms, defined by their distinct evolutionary histories, coexist in symbiosis in the same cell. The virocells or ribovirocells are the living forms of the virus, which can be in fine considered to be a living organism. In the virocell, the metabolism is reorganized for the production of virions, while the ability to capture and store free energy is retained, as in other cellular organisms. In the virocell, viral genomes replicate, recombine and evolve, leading to the emergence of new viral proteins and potentially novel functions. Some of these new functions can be later on transferred to the cell, explaining how viruses can play a major (often underestimated) role in the evolution of cellular organisms. The virocell concept thus helps to understand recent hypotheses suggesting that viruses played a critical role in major evolutionary transitions, such as the origin of DNA genomes or else the origin of the eukaryotic nucleus. Finally, it is more and more recognized that viruses are the major source of variation and selection in living organisms (both viruses and cells), the two pillars of darwinism. One can thus conclude that the continuous interaction between viruses and cells, all along the history of life, has been, and still is, a major engine of biological evolution. PMID:24330969

  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. Lifestyles of plant viruses

    PubMed Central

    Roossinck, Marilyn J.

    2010-01-01

    The vast majority of well-characterized eukaryotic viruses are those that cause acute or chronic infections in humans and domestic plants and animals. However, asymptomatic persistent viruses have been described in animals, and are thought to be sources for emerging acute viruses. Although not previously described in these terms, there are also many viruses of plants that maintain a persistent lifestyle. They have been largely ignored because they do not generally cause disease. The persistent viruses in plants belong to the family Partitiviridae or the genus Endornavirus. These groups also have members that infect fungi. Phylogenetic analysis of the partitivirus RNA-dependent RNA polymerase genes suggests that these viruses have been transmitted between plants and fungi. Additional families of viruses traditionally thought to be fungal viruses are also found frequently in plants, and may represent a similar scenario of persistent lifestyles, and some acute or chronic viruses of crop plants may maintain a persistent lifestyle in wild plants. Persistent, chronic and acute lifestyles of plant viruses are contrasted from both a functional and evolutionary perspective, and the potential role of these lifestyles in host evolution is discussed. PMID:20478885

  14. Nam Con Son Basin

    SciTech Connect

    Tin, N.T.; Ty, N.D.; Hung, L.T.

    1994-07-01

    The Nam Con Son basin is the largest oil and gas bearing basin in Vietnam, and has a number of producing fields. The history of studies in the basin can be divided into four periods: Pre-1975, 1976-1980, 1981-1989, and 1990-present. A number of oil companies have carried out geological and geophysical studies and conducted drilling activities in the basin. These include ONGC, Enterprise Oil, BP, Shell, Petro-Canada, IPL, Lasmo, etc. Pre-Tertiary formations comprise quartz diorites, granodiorites, and metamorphic rocks of Mesozoic age. Cenozoic rocks include those of the Cau Formation (Oligocene and older), Dua Formation (lower Miocene), Thong-Mang Cau Formation (middle Miocene), Nam Con Son Formation (upper Miocene) and Bien Dong Formation (Pliocene-Quaternary). The basement is composed of pre-Cenozoic formations. Three fault systems are evident in the basin: north-south fault system, northeast-southwest fault system, and east-west fault system. Four tectonic zones can also be distinguished: western differentiated zone, northern differentiated zone, Dua-Natuna high zone, and eastern trough zone.

  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. Water system virus detection

    NASA Technical Reports Server (NTRS)

    Fraser, A. S.; Wells, A. F.; Tenoso, H. J. (Inventor)

    1978-01-01

    The performance of a waste water reclamation system is monitored by introducing a non-pathogenic marker virus, bacteriophage F2, into the waste-water prior to treatment and, thereafter, testing the reclaimed water for the presence of the marker virus. A test sample is first concentrated by absorbing any marker virus onto a cellulose acetate filter in the presence of a trivalent cation at low pH and then flushing the filter with a limited quantity of a glycine buffer solution to desorb any marker virus present on the filter. Photo-optical detection of indirect passive immune agglutination by polystyrene beads indicates the performance of the water reclamation system in removing the marker virus. A closed system provides for concentrating any marker virus, initiating and monitoring the passive immune agglutination reaction, and then flushing the system to prepare for another sample.

  17. Viruses of lower vertebrates.

    PubMed

    Essbauer, S; Ahne, W

    2001-08-01

    Viruses of lower vertebrates recently became a field of interest to the public due to increasing epizootics and economic losses of poikilothermic animals. These were reported worldwide from both wildlife and collections of aquatic poikilothermic animals. Several RNA and DNA viruses infecting fish, amphibians and reptiles have been studied intensively during the last 20 years. Many of these viruses induce diseases resulting in important economic losses of lower vertebrates, especially in fish aquaculture. In addition, some of the DNA viruses seem to be emerging pathogens involved in the worldwide decline in wildlife. Irido-, herpes- and polyomavirus infections may be involved in the reduction in the numbers of endangered amphibian and reptile species. In this context the knowledge of several important RNA viruses such as orthomyxo-, paramyxo-, rhabdo-, retro-, corona-, calici-, toga-, picorna-, noda-, reo- and birnaviruses, and DNA viruses such as parvo-, irido-, herpes-, adeno-, polyoma- and poxviruses, is described in this review. PMID:11550762

  18. DNA Virus Replication Compartments

    PubMed Central

    Schmid, Melanie; Speiseder, Thomas; Dobner, Thomas

    2014-01-01

    Viruses employ a variety of strategies to usurp and control cellular activities through the orchestrated recruitment of macromolecules to specific cytoplasmic or nuclear compartments. Formation of such specialized virus-induced cellular microenvironments, which have been termed viroplasms, virus factories, or virus replication centers, complexes, or compartments, depends on molecular interactions between viral and cellular factors that participate in viral genome expression and replication and are in some cases associated with sites of virion assembly. These virus-induced compartments function not only to recruit and concentrate factors required for essential steps of the viral replication cycle but also to control the cellular mechanisms of antiviral defense. In this review, we summarize characteristic features of viral replication compartments from different virus families and discuss similarities in the viral and cellular activities that are associated with their assembly and the functions they facilitate for viral replication. PMID:24257611

  19. Constructing computer virus phylogenies

    SciTech Connect

    Goldberg, L.A.; Goldberg, P.W.; Phillips, C.A.; Sorkin, G.B.

    1996-03-01

    There has been much recent algorithmic work on the problem of reconstructing the evolutionary history of biological species. Computer virus specialists are interested in finding the evolutionary history of computer viruses--a virus is often written using code fragments from one or more other viruses, which are its immediate ancestors. A phylogeny for a collection of computer viruses is a directed acyclic graph whose nodes are the viruses and whose edges map ancestors to descendants and satisfy the property that each code fragment is ``invented`` only once. To provide a simple explanation for the data, we consider the problem of constructing such a phylogeny with a minimal number of edges. In general, this optimization problem cannot be solved in quasi-polynomial time unless NQP=QP; we present positive and negative results for associated approximated problems. When tree solutions exist, they can be constructed and randomly sampled in polynomial time.

  20. The human oncogenic viruses

    SciTech Connect

    Luderer, A.A.; Weetall, H.H

    1986-01-01

    This book contains eight selections. The titles are: Cytogenetics of the Leukemias and Lymphomas; Cytogenetics of Solid Tumors: Renal Cell Carcinoma, Malignant Melanoma, Retinoblastoma, and Wilms' Tumor; Elucidation of a Normal Function for a Human Proto-Oncogene; Detection of HSV-2 Genes and Gene Products in Cervical Neoplasia; Papillomaviruses in Anogennital Neoplasms; Human Epstein-Barr Virus and Cancer; Hepatitis B Virus and Hepatocellular Carcinoma; and Kaposi's Sarcoma: Acquired Immunodeficiency Syndrome (AIDS) and Associated Viruses.

  1. 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.

  2. Virus Characterization by FFF-MALS Assay

    NASA Astrophysics Data System (ADS)

    Razinkov, Vladimer

    2009-03-01

    Adequate biophysical characterization of influenza virions is important for vaccine development. The influenza virus vaccines are produced from the allantoic fluid of developing chicken embryos. The process of viral replication produces a heterogeneous mixture of infectious and non-infectious viral particles with varying states of aggregation. The study of the relative distribution and behavior of different subpopulations and their inter-correlation can assist in the development of a robust process for a live virus vaccine. This report describes a field flow fractionation and multiangle light scattering (FFF-MALS) method optimized for the analysis of size distribution and total particle counts. A method using a combination of asymmetric flow field-flow fractionation (AFFFF) and multiangle light scattering (MALS) techniques has been shown to improve the estimation of virus particle counts and the amount of aggregated virus in laboratory samples. The FFF-MALS method was compared with several other methods such as transmission electron microscopy (TEM), atomic force microscopy (AFM), size exclusion chromatography followed by MALS (SEC-MALS), quantitative reverse transcription polymerase chain reaction (RT Q-PCR), median tissue culture dose (TCID(50)), and the fluorescent focus assay (FFA). The correlation between the various methods for determining total particle counts, infectivity and size distribution is reported. The pros and cons of each of the analytical methods are discussed.

  3. FAQ: General Questions about West Nile Virus

    MedlinePLUS

    ... Public Service Videos General Questions About West Nile Virus Recommend on Facebook Tweet Share Compartir On this ... West Nile virus cases? What is West Nile virus? West Nile virus is an arthropod-borne virus ( ...

  4. Asociación de XMRV con enfermedades humanas se debe a contaminación

    Cancer.gov

    Nuevas investigaciones muestran que una asociación, mencionada en numerosos estudios, entre el retrovirus conocido como XMRV y el cáncer de próstata así como el síndrome de fatiga crónica, se debe a contaminación de laboratorio con un virus que se originó en ratones.

  5. Respiratory Syncytial Virus (RSV): Treatment

    MedlinePLUS

    ... Research Topics Labs & Scientific Resources Funding About NIAID News & Events Volunteer NIAID > Health & Research Topics > Respiratory Syncytial Virus > Understanding Respiratory Syncytial Virus Understanding Quick Facts Cause Transmission ...

  6. 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....

  7. 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....

  8. Virus in Water

    PubMed Central

    Liu, O. C.; Brashear, D. A.; Seraichekas, H. R.; Barnick, J. A.; Metcalf, T. G.

    1971-01-01

    A preliminary study was carried out on evaluating a flow-through gauze sampler for its efficiency in recovering virus from both fresh and seawater. An attenuated type 1 poliovirus was used as the working model. When tap water was sampled, the amounts of virus adsorbed by the gauze pads were very small, about 2% of the total number of virus particles flowing through the device. The virus adsorption and recovery increased to 15 to 19% when seawater was sampled. Addition of NaCl to tap water produced a much better effect on virus adsorption and recovery by this device, i.e., 47% of the total virus particles in each sample. The best viral elution from the pads was obtained by using buffer solution of pH 8.0 to 9.0 containing a small amount of animal serum. Repeated elutions from the pads were necessary to recover the most virus although the first eluate contained approximately 50% of the adsorbed virus. Further development of this device appears warranted, because of (i) the simplicity of the procedure, (ii) its capability of sampling large volume of water, (iii) the low cost of collecting samples, and (iv) the feasibility of obtaining a rough quantitative assessment of viral pollutants in water examined. Images PMID:4324193

  9. Barley Yellow Dwarf Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley yellow dwarf (BYD) is the most widespread and economically important virus disease of cereals. The viruses causing BYD were initially grouped based on common biological properties, including persistent and often strain-specific transmission by aphids and induction of yellowing symptoms. The...

  10. 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 ...

  11. EPIDEMIOLOGY OF RETICULOENDOTHELIOSIS VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reticuloendotheliosis virus (REV) is an avian retrovirus unrelated to the leukosis/sarcoma group of viruses. REV infects chickens, turkeys, ducks, geese, pheasants, quail, and probably many other avian species . The most common clinical diseases induced by REV are chronic lymphomas and an immunosupp...

  12. Influenza A virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses are important veterinary and human health pathogens around the world. Avian influenza (AI) virus in poultry is unusual in that it can cause a range of disease symptoms from a subclinical infection to being highly virulent with 100% mortality. The difference between low pathogen...

  13. INFLUENZA VIRUS IN POULTRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is normally found in wild birds, particularly in ducks and shorebirds, where it does not cause any perceptible clinical disease. However, poultry, including chickens and turkeys, are not normal hosts for avian influenza, but if the virus is introduced it can result in mi...

  14. RYEGRASS MOSAIC VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A brief technical description of Ryegrass mosaic virus (RGMV) is presented. Described are biological properties, genome organization, and phylogenetic relationships among RGMV and other potyvirus species. RGMV is designated as a the type species of the genus Rymovirus within the plant virus family ...

  15. Bovine viral diarrhea viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infections with bovine viral diarrhea viruses (BVDV) result in significant economic losses for beef and dairy producers worldwide. BVDV is actually an umbrella term for two species of viruses, BVDV1 and BVDV2, within the Pestivirus genus of the Flavivirus family. While denoted as a bovine pathogen...

  16. Mayaro virus proteins.

    PubMed

    Mezencio, J M; Rebello, M A

    1993-01-01

    Mayaro virus was grown in BHK-21 cells and purified by centrifugation in a potassium-tartrate gradient (5-50%). The electron microscopy analyses of the purified virus showed an homogeneous population of enveloped particles with 69 +/- 2.3 nm in diameter. Three structural virus proteins were identified and designated p1, p2 and p3. Their average molecular weight were p1, 54 KDa; p2, 50 KDa and p3, 34 KDa. In Mayaro virus infected Aedes albopictus cells and in BHK-21 infected cells we detected six viral proteins, in which three of them are the structural virus proteins and the other three were products from processing of precursors of viral proteins, whose molecular weights are 62 KDa, 64 KDa and 110 KDa. The 34 KDa protein was the first viral protein synthesized at 5 hours post-infection in both cell lines studied. PMID:8107591

  17. Hepatitis B Virus Biology

    PubMed Central

    Seeger, Christoph; Mason, William S.

    2000-01-01

    Hepadnaviruses (hepatitis B viruses) cause transient and chronic infections of the liver. Transient infections run a course of several months, and chronic infections are often lifelong. Chronic infections can lead to liver failure with cirrhosis and hepatocellular carcinoma. The replication strategy of these viruses has been described in great detail, but virus-host interactions leading to acute and chronic disease are still poorly understood. Studies on how the virus evades the immune response to cause prolonged transient infections with high-titer viremia and lifelong infections with an ongoing inflammation of the liver are still at an early stage, and the role of the virus in liver cancer is still elusive. The state of knowledge in this very active field is therefore reviewed with an emphasis on past accomplishments as well as goals for the future. PMID:10704474

  18. Tembusu Virus in Ducks, China

    PubMed Central

    Cao, Zhenzhen; Zhang, Cun; Liu, Yuehuan; Ye, Weicheng; Han, Jingwen; Ma, Guoming; Zhang, Dongdong; Xu, Feng; Gao, Xuhui; Tang, Yi; Shi, Shaohua; Wan, Chunhe; Zhang, Chen; He, Bin; Yang, Mengjie; Lu, Xinhao; Huang, Yu; Diao, Youxiang; Ma, Xuejun

    2011-01-01

    In China in 2010, a disease outbreak in egg-laying ducks was associated with a flavivirus. The virus was isolated and partially sequenced. The isolate exhibited 87%91% identity with strains of Tembusu virus, a mosquito-borne flavivirus of the Ntaya virus group. These findings demonstrate emergence of Tembusu virus in ducks. PMID:22000358

  19. Pacui Virus, Rio Preto da Eva Virus, and Tapirape Virus, Three Distinct Viruses within the Family Bunyaviridae

    PubMed Central

    Medeiros, Daniele Barbosa de Almeida; Rodrigues, Sueli Guerreiro; Martins, Livia Caricio; de Lima, Clayton Pereira Silva; de Oliveira, Layanna Freitas; de Vasconcelos, Janaina Mota; Da Silva, Daisy Elaine; Cardoso, Jedson Ferreira; da Silva, Sandro Patroca; Vianez-Jnior, Joo Ldio da Silva Gonalves; Vasconcelos, Pedro Fernando da Costa

    2014-01-01

    Nearly complete genome sequences for three ungrouped viruses, Pacui virus (BEAN27326), Rio Preto da Eva virus (BEAR540870), and Tapirape virus (BEAN767592) isolated in the Amazon region are reported here. All three genomic segments (small, medium and large RNA) were recovered and were similar to members of the genus Orthobunyavirus. PMID:25395627

  20. A Virus in Turbo Pascal.

    ERIC Educational Resources Information Center

    Teleky, Heidi Ann; And Others

    1993-01-01

    Addresses why the authors feel it is not inappropriate to teach about viruses in the how-to, hands-on fashion. Identifies the special features of Turbo Pascal that have to be used for the creation of an effective virus. Defines virus, derives its structure, and from this structure is derived the implemented virus. (PR)

  1. Computer Viruses: Pathology and Detection.

    ERIC Educational Resources Information Center

    Maxwell, John R.; Lamon, William E.

    1992-01-01

    Explains how computer viruses were originally created, how a computer can become infected by a virus, how viruses operate, symptoms that indicate a computer is infected, how to detect and remove viruses, and how to prevent a reinfection. A sidebar lists eight antivirus resources. (four references) (LRW)

  2. 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,…

  3. Lipids and RNA virus replication

    PubMed Central

    Konan, Kouacou V.; Sanchez-Felipe, Lorena

    2014-01-01

    Most viruses rely heavily on their host machinery to successfully replicate their genome and produce new virus particles. Recently, the interaction of positive-strand RNA viruses with the lipid biosynthetic and transport machinery has been the subject of intense investigation. In this review, we will discuss the contribution of various host lipids and related proteins in RNA virus replication and maturation. PMID:25262061

  4. 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,

  5. Galaxias australes con ncleo doble

    NASA Astrophysics Data System (ADS)

    Gimeno, G.; Daz, R.; Carranza, G.

    Se estudia una muestra de galaxias australes con ncleo doble a partir de una bsqueda extensiva en la literatura. Se analizan las caractersticas morfolgicas, fotomtricas y espectroscpicas de la muestra. Para algunas galaxias se han realizado observaciones con el espectrgrafo multifuncin (EMF) de la Estacin Astrofsica de Bosque Alegre a partir de las cuales se determinaron parmetros cinemticos.

  6. Giant viruses infecting algae.

    PubMed

    Van Etten, J L; Meints, R H

    1999-01-01

    Paramecium bursaria chlorella virus (PBCV-1) is the prototype of a family of large, icosahedral, plaque-forming, double-stranded-DNA-containing viruses that replicate in certain unicellular, eukaryotic chlorella-like green algae. DNA sequence analysis of its 330, 742-bp genome leads to the prediction that this phycodnavirus has 376 protein-encoding genes and 10 transfer RNA genes. The predicted gene products of approximately 40% of these genes resemble proteins of known function. The chlorella viruses have other features that distinguish them from most viruses, in addition to their large genome size. These features include the following: (a) The viruses encode multiple DNA methyltransferases and DNA site-specific endonucleases; (b) PBCV-1 encodes at least part, if not the entire machinery to glycosylate its proteins; (c) PBCV-1 has at least two types of introns--a self-splicing intron in a transcription factor-like gene and a splicesomal processed type of intron in its DNA polymerase gene. Unlike the chlorella viruses, large double-stranded-DNA-containing viruses that infect marine, filamentous brown algae have a circular genome and a lysogenic phase in their life cycle. PMID:10547698

  7. Galactomannan thin films as supports for the immobilization of Concanavalin A and/or dengue viruses.

    PubMed

    Valenga, Francine; Petri, Denise F S; Lucyszyn, Neoli; J, Tatiane A; Sierakowski, Maria Rita

    2012-01-01

    The immobilization of the glucose/mannose-binding lectin from Concanavalia ensiformis seeds (ConA) onto a monolayer made of a galactomannan extracted from Leucaena leucocephala seeds (GML), which was adsorbed onto - amino-terminated surfaces, was investigated by means of ellipsometry and atomic force microscopy. The mean thickness of GML monolayer, which polysaccharide consists of linear 1?4-linked ?-D-mannopyranosil units partially substituted at C-6 by ?-D-galactopyranosyl units, amounted to (1.50.2) nm. ConA molecules adsorbed onto GML surfaces forming (2.00.5) nm thick layers. However, in the presence of mannose the adsorption failed, indicating that ConA binding sites were blocked by mannose and were no longer available for mannose units present in the GML backbone. The GML film was also used as support for the adsorption of three serotypes of dengue virus particles (DENV-1, DENV-2 and DENV-3), where DENV-2 formed the thickest film (42) nm. The adsorbed layer of DENV-2 onto ConA-covered GML surfaces presented mean thickness values similar to that determined for DENV-2 onto bare GML surfaces. The addition of free mannose units prevented DENV-2 adsorption onto ConA-covered GML films by ~50%, suggesting competition between virus and mannose for ConA binding sites. This finding suggests that if ConA is also adsorbed to GML surface and its binding site is blocked by free mannose, virus particles are able to recognized GML mannose unities substituted by galactose. Interactions between polysaccharides thin films, proteins, and viruses are of great relevance since they can provide basis for the development of biotechnological devices. These results indicate that GML is a potential polysaccharide for biomaterials development, as those could involve interactions between ConA in immune system and viruses. PMID:22020153

  8. Ocular Tropism of Respiratory Viruses

    PubMed Central

    Rota, Paul A.; Tumpey, Terrence M.

    2013-01-01

    SUMMARY Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism. PMID:23471620

  9. Ocular tropism of respiratory viruses.

    PubMed

    Belser, Jessica A; Rota, Paul A; Tumpey, Terrence M

    2013-03-01

    Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism. PMID:23471620

  10. Viruses in reptiles

    PubMed Central

    2011-01-01

    The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself. 1. Introduction 2. Methods for working with reptilian viruses 3. Reptilian viruses described by virus families 3.1. Herpesviridae 3.2. Iridoviridae 3.2.1 Ranavirus 3.2.2 Erythrocytic virus 3.2.3 Iridovirus 3.3. Poxviridae 3.4. Adenoviridae 3.5. Papillomaviridae 3.6. Parvoviridae 3.7. Reoviridae 3.8. Retroviridae and inclusion body disease of Boid snakes 3.9. Arboviruses 3.9.1. Flaviviridae 3.9.2. Togaviridae 3.10. Caliciviridae 3.11. Picornaviridae 3.12. Paramyxoviridae 4. Summary 5. Acknowledgements 6. Competing interests 7. References PMID:21933449

  11. Simian hemorrhagic fever virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter describes the taxonomic classification of Simian hemorrhagic fever virus (SHFV). Included are: host, genome, classification, morphology, physicochemical and physical properties, nucleic acid, proteins, lipids, carbohydrates, geographic range, phylogenetic properties, biological pro...

  12. Zika Virus Infection

    MedlinePLUS

    ... The General Public For Health Authorities Videos on Zika Virus ??? Zika, a new threat. What is it? ... Dengue, chikungunya y zika - Jornada arbovirosis 2015 - Argentina Zika affected areas Zika Resources Missions to support countries ...

  13. Zika Virus Infection

    MedlinePLUS

    ... of Disease Still Unclear PAHO answers questions about mosquito control for Zika Virus Sesame Street Muppets Join PAHO to Educate Families About Preventing Zika Mosquito Bites Misión de la OPS/OMS propone reforzar ...

  14. Respiratory syncytial virus (RSV)

    MedlinePLUS

    ... RSV often spreads quickly in crowded households and day care centers. The virus can live for a half ... The following increase the risk for RSV: Attending day care Being near tobacco smoke Having school-aged brothers ...

  15. Hepatitis B virus (image)

    MedlinePLUS

    Hepatitis B is also known as serum hepatitis and is spread through blood and sexual contact. It is ... population. This photograph is an electronmicroscopic image of hepatitis B virus particles. (Image courtesy of the Centers for ...

  16. Ebola (Ebola Virus Disease)

    MedlinePLUS

    ... Confirmed Patients with Ebola Virus Disease in the United States What's New (Continued) More Information for Specific Groups Travelers U.S. Healthcare Workers and Settings Information for Families and Loved ...

  17. West Nile Virus

    MedlinePLUS

    ... appeared in the United States in 1999. Infected mosquitoes spread the virus that causes it. People who ... barrels Stay indoors between dusk and dawn, when mosquitoes are most active Use screens on windows to ...

  18. 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

  19. 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.

  20. Impression materials and virus.

    PubMed

    Gerhardt, D E; Sydiskis, R J

    1991-05-01

    Results of this study indicate that impression materials vary in their ability to absorb and retain virus. Disinfection procedures specific for each material or groups of materials should be developed. PMID:2045601

  1. 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

  2. Ebola virus disease

    MedlinePLUS

    Ebola hemorrhagic fever; Ebola virus infection; Viral hemorrhagic fever; Ebola ... There is currently no vaccine to protect against Ebola, although a vaccine is being tested. If you plan to travel to one of the countries ...

  3. Herpes Simplex Virus (HSV)

    MedlinePLUS

    ... rash and rashes clinical tools newsletter | contact Share | Herpes Simplex Virus (HSV) A parent's guide to condition ... lips, grouped blisters (vesicles) can occur anywhere in herpes infections. Overview The first eruption of skin or ...

  4. Proteins of Norwalk virus.

    PubMed

    Greenberg, H B; Valdesuso, J R; Kalica, A R; Wyatt, R G; McAuliffe, V J; Kapikian, A Z; Chanock, R M

    1981-03-01

    The proteins of the Norwalk virus were studied by polyacrylamide gel electrophoresis. Highly purified specifically immunoprecipitated virions appeared to contain a single primary structural protein with a molecular weight of 59,000. In addition, a soluble Norwalk viral protein with a molecular weight of 30,000 was identified in fecal specimens containing Norwalk virus. The protein structure of the virion is similar to that of the Calciviridae family. PMID:6785451

  5. Proteins of Norwalk virus.

    PubMed Central

    Greenberg, H B; Valdesuso, J R; Kalica, A R; Wyatt, R G; McAuliffe, V J; Kapikian, A Z; Chanock, R M

    1981-01-01

    The proteins of the Norwalk virus were studied by polyacrylamide gel electrophoresis. Highly purified specifically immunoprecipitated virions appeared to contain a single primary structural protein with a molecular weight of 59,000. In addition, a soluble Norwalk viral protein with a molecular weight of 30,000 was identified in fecal specimens containing Norwalk virus. The protein structure of the virion is similar to that of the Calciviridae family. Images PMID:6785451

  6. Pros and cons of phage therapy

    PubMed Central

    Loc-Carrillo, Catherine

    2011-01-01

    Many publications list advantages and disadvantages associated with phage therapy, which is the use of bacterial viruses to combat populations of nuisance or pathogenic bacteria. The goal of this commentary is to discuss many of those issues in a single location. In terms of Pros, for example, phages can be bactericidal, can increase in number over the course of treatment, tend to only minimally disrupt normal flora, are equally effective against antibiotic-sensitive and antibiotic-resistant bacteria, often are easily discovered, seem to be capable of disrupting bacterial biofilms, and can have low inherent toxicities. In addition to these assets, we consider aspects of phage therapy that can contribute to its safety, economics, or convenience, but in ways that are perhaps less essential to the phage potential to combat bacteria. For example, autonomous phage transfer between animals during veterinary application could provide convenience or economic advantages by decreasing the need for repeated phage application, but is not necessarily crucial to therapeutic success. We also consider possible disadvantages to phage use as antibacterial agents. These Cons, however, tend to be relatively minor. PMID:22334867

  7. Virus templated metallic nanoparticles

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. <=35 nm. CPMV-templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron.Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. <=35 nm. CPMV-templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron. Electronic supplementary information (ESI) available: Additional experimental detail, agarose gel electrophoresis results, energy dispersive X-ray spectra, ζ-potential measurements, dynamic light scattering data, nanoparticle tracking analysis and an atomic force microscopy image of Ni-CPMV. See DOI: 10.1039/c0nr00525h

  8. Hepatitis B virus infection.

    PubMed

    Trpo, 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

  9. West Nile virus.

    PubMed

    Campbell, Grant L; Marfin, Anthony A; Lanciotti, Robert S; Gubler, Duane J

    2002-09-01

    West Nile (WN) virus is a mosquito-borne flavivirus and human, equine, and avian neuropathogen. The virus is indigenous to Africa, Asia, Europe, and Australia, and has recently caused large epidemics in Romania, Russia, and Israel. Birds are the natural reservoir (amplifying) hosts, and WN virus is maintained in nature in a mosquito-bird-mosquito transmission cycle primarily involving Culex sp mosquitoes. WN virus was recently introduced to North America, where it was first detected in 1999 during an epidemic of meningoencephalitis in New York City. During 1999-2002, the virus extended its range throughout much of the eastern parts of the USA, and its range within the western hemisphere is expected to continue to expand. During 1999-2001, 142 cases of neuroinvasive WN viral disease of the central nervous system (including 18 fatalities), and seven cases of uncomplicated WN fever were reported in the USA. Most human WN viral infections are subclinical but clinical infections can range in severity from uncomplicated WN fever to fatal meningoencephalitis; the incidence of severe neuroinvasive disease and death increase with age. Serology remains the mainstay of laboratory diagnosis. No WN virus-specific treatment or vaccine is available. Prevention depends on organised, sustained vector mosquito control, and public education. PMID:12206968

  10. Control of cucurbit viruses.

    PubMed

    Lecoq, Herv; Katis, Nikolaos

    2014-01-01

    More than 70 well-characterized virus species transmitted by a diversity of vectors may infect cucurbit crops worldwide. Twenty of those cause severe epidemics in major production areas, occasionally leading to complete crop failures. Cucurbit viruses' control is based on three major axes: (i) planting healthy seeds or seedlings in a clean environment, (ii) interfering with vectors activity, and (iii) using resistant cultivars. Seed disinfection and seed or seedling quality controls guarantee growers on the sanitary status of their planting material. Removal of virus or vector sources in the crop environment can significantly delay the onset of viral epidemics. Insecticide or oil application may reduce virus spread in some situations. Diverse cultural practices interfere with or prevent vector reaching the crop. Resistance can be obtained by grafting for soil-borne viruses, by cross-protection, or generally by conventional breeding or genetic engineering. The diversity of the actions that may be taken to limit virus spread in cucurbit crops and their limits will be discussed. The ultimate goal is to provide farmers with technical packages that combine these methods within an integrated disease management program and are adapted to different countries and cropping systems. PMID:25410104

  11. Viruses and Multiple Sclerosis

    PubMed Central

    Virtanen, Jussi Oskari; Jacobson, Steve

    2016-01-01

    Multiple sclerosis (MS) is a heterogeneous disease that develops as an interplay between the immune system and environmental stimuli in genetically susceptible individuals. There is increasing evidence that viruses may play a role in MS pathogenesis acting as these environmental triggers. However, it is not known if any single virus is causal, or rather several viruses can act as triggers in disease development. Here, we review the association of different viruses to MS with an emphasis on two herpesviruses, Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6). These two agents have generated the most impact during recent years as possible co-factors in MS disease development. The strongest argument for association of EBV with MS comes from the link between symptomatic infectious mononucleosis and MS and from seroepidemiological studies. In contrast to EBV, HHV-6 has been found significantly more often in MS plaques than in MS normal appearing white matter or non-MS brains and HHV-6 re-activation has been reported during MS clinical relapses. In this review we also suggest new strategies, including the development of new infectious animal models of MS and antiviral MS clinical trials, to elucidate roles of different viruses in the pathogenesis of this disease. Furthermore, we introduce the idea of using unbiased sequence-independent pathogen discovery methodologies, such as next generation sequencing, to study MS brain tissue or body fluids for detection of known viral sequences or potential novel viral agents. PMID:22583435

  12. [West Nile virus infection].

    PubMed

    Prez Ruiz, Mercedes; Gmez, Sara Sanbonmatsu; Clavero, Miguel Angel Jimnez

    2011-12-01

    West Nile virus (WNV) is an arbovirus usually transmitted by mosquitoes. The main reservoirs are birds, although the virus may infect several vertebrate species, such as horses and humans. Up to 80% of human infections are asymptomatic. The most frequent clinical presentation is febrile illness, and neuroinvasive disease can occur in less than 1% of cases. Spain is considered a high-risk area for the emergence of WNV due to its climate and the passage of migratory birds from Africa (where the virus is endemic). These birds nest surrounding wetlands where populations of possible vectors for the virus are abundant. Diagnosis of human neurological infections can be made by detection of IgM in serum and/or cerebrospinal fluid samples, demonstration of a four-fold increase in IgG antibodies between acute-phase and convalescent-phase serum samples, or by detection of viral genome by reverse transcription-polymerase chain reaction (especially useful in transplant recipients). Since WNV is a biosafety level 3 agent, techniques that involve cell culture are restricted to laboratories with this level of biosafety, such as reference laboratories. The National Program for the Surveillance of WNV Encephalitis allows the detection of virus circulation among birds and vectors in areas especially favorable for the virus, such as wetlands, and provides information for evaluation of the risk of disease in horses and humans. PMID:22305666

  13. Viruses and multiple sclerosis.

    PubMed

    Virtanen, Jussi Oskari; Jacobson, Steve

    2012-08-01

    Multiple sclerosis (MS) is a heterogeneous disease that develops as an interplay between the immune system and environmental stimuli in genetically susceptible individuals. There is increasing evidence that viruses may play a role in MS pathogenesis acting as these environmental triggers. However, it is not known if any single virus is causal, or rather several viruses can act as triggers in disease development. Here, we review the association of different viruses to MS with an emphasis on two herpesviruses, Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6). These two agents have generated the most impact during recent years as possible co-factors in MS disease development. The strongest argument for association of EBV with MS comes from the link between symptomatic infectious mononucleosis and MS and from seroepidemiological studies. In contrast to EBV, HHV-6 has been found significantly more often in MS plaques than in MS normal appearing white matter or non-MS brains and HHV-6 re-activation has been reported during MS clinical relapses. In this review we also suggest new strategies, including the development of new infectious animal models of MS and antiviral MS clinical trials, to elucidate roles of different viruses in the pathogenesis of this disease. Furthermore, we introduce the idea of using unbiased sequence-independent pathogen discovery methodologies, such as next generation sequencing, to study MS brain tissue or body fluids for detection of known viral sequences or potential novel viral agents. PMID:22583435

  14. 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

  15. Smaller Fleas: Viruses of Microorganisms

    PubMed Central

    Hyman, Paul; Abedon, Stephen T.

    2012-01-01

    Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world's most abundant somewhat autonomous genetic entities and include the viruses of domain Bacteria (bacteriophages), the viruses of domain Archaea (archaeal viruses), the viruses of protists, the viruses of microscopic fungi such as yeasts (mycoviruses), and even the viruses of other viruses (satellite viruses). In this paper we provide an introduction to the concept of viruses of microorganisms, a.k.a., viruses of microbes. We provide broad discussion particularly of VoM diversity. VoM diversity currently spans, in total, at least three-dozen virus families. This is roughly ten families per category—bacterial, archaeal, fungal, and protist—with some virus families infecting more than one of these microorganism major taxa. Such estimations, however, will vary with further discovery and taxon assignment and also are dependent upon what forms of life one includes among microorganisms. PMID:24278736

  16. Dinoflagellates, diatoms, and their viruses.

    PubMed

    Nagasaki, Keizo

    2008-06-01

    Since the first discovery of the very high virus abundance in marine environments, a number of researchers were fascinated with the world of "marine viruses", which had previously been mostly overlooked in studies on marine ecosystems. In the present paper, the possible role of viruses infecting marine eukaryotic microalgae is enlightened, especially summarizing the most up-to-the-minute information of marine viruses infecting bloom-forming dinoflagellates and diatoms. To author's knowledge, approximately 40 viruses infecting marine eukaryotic algae have been isolated and characterized to different extents. Among them, a double-stranded DNA (dsDNA) virus "HcV" and a single-stranded RNA (ssRNA) virus "HcRNAV" are the only dinoflagellate-infecting (lytic) viruses that were made into culture; their hosts are a bivalve-killing dinoflagellate Heterocapsa circularisquama. In this article, ecological relationship between H. circularisquama and its viruses is focused. On the other hand, several diatom-infecting viruses were recently isolated and partially characterized; among them, one is infectious to a pen-shaped bloom-forming diatom species Rhizosolenia setigera; some viruses are infectious to genus Chaetoceros which is one of the most abundant and diverse diatom group. Although the ecological relationships between diatoms and their viruses have not been sufficiently elucidated, viral infection is considered to be one of the significant factors affecting dynamics of diatoms in nature. Besides, both the dinoflagellate-infecting viruses and diatom-infecting viruses are so unique from the viewpoint of virus taxonomy; they are remarkably different from any other viruses ever reported. Studies on these viruses lead to an idea that ocean may be a treasury of novel viruses equipped with fascinating functions and ecological roles. PMID:18604491

  17. Virus-associated human tumors: cervical carcinomas and papilloma viruses.

    PubMed

    Kisseljov, F L

    2000-01-01

    The latest experimental data on the role of viruses in the origin of human tumors are discussed. This group of viruses consists of T-cell leukemia virus type 1 (HTLV 1), herpes viruses (HHV 8 and Epstein-Barr virus), hepatitis B virus, and human papilloma viruses. The most typical feature of this group of viruses is a very long latent period from the initial infection to the development of the disease that varies between 10 and 40 years. The mechanism of malignant cell conversion is specific for each viral type but is mainly associated with a disruption of functions of cellular genes participating in the control of cell division and proliferation. It can be a direct inactivation of tumor suppressor genes by their interaction with viral gene products (papilloma viruses), or a trans-activation of cellular genes modulating cell proliferation by viral gene products (hepatitis B virus and HTLV 1). Viruses play an initiative role and additional genetic changes in the genome of infected cells are necessary for complete expression of the oncogenic potential of the viral genes. Only these cells will give rise to a monoclonal cell population with uncontrolled proliferation. New approaches for the creation of vaccines against cancers associated with hepatitis B virus and papilloma viruses (hepatocellular carcinomas and cervical tumors, respectively) are in progress. These vaccines have been found to be effective in prevention of the disease in the experimental models and are now beginning to be used for human vaccination. PMID:10702642

  18. Avian Influenza A Virus Infections in Humans

    MedlinePLUS

    ... Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Español Recommend on ... Avian Influenza A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses usually ...

  19. Influenza Type A Viruses and Subtypes

    MedlinePLUS

    ... this? Submit Button Past Newsletters Influenza Type A Viruses Language: English Español Recommend on Facebook Tweet ... influenza type A viruses. Subtypes of Influenza A Viruses Influenza A viruses are divided into subtypes on ...

  20. Ebola Virus Disease in West Africa

    MedlinePLUS

    ... Situation reports Publications Ebola virus disease outbreak Ebola virus disease Ebola virus disease (formerly known as Ebola haemorrhagic fever) is ... contact with sick people and deceased patients. Ebola virus disease outbreak website Cholera Cholera fact sheet Crimean- ...

  1. Swine Influenza/Variant Influenza Viruses

    MedlinePLUS

    ... Past Newsletters Information on Swine Influenza/Variant Influenza Viruses Language: English Español Recommend on Facebook Tweet ... the Spread of Influenza A Viruses Variant Influenza Viruses in Humans Variant (Swine Origin) Influenza Viruses in ...

  2. Structural basis of efficient contagion: measles variations on a theme by parainfluenza viruses.

    PubMed

    Mateo, Mathieu; Navaratnarajah, Chanakha K; Cattaneo, Roberto

    2014-04-01

    A quartet of attachment proteins and a trio of fusion protein subunits play the cell entry concert of parainfluenza viruses. While many of these viruses bind sialic acid to enter cells, wild type measles binds exclusively two tissue-specific proteins, the lymphatic receptor signaling lymphocytic activation molecule (SLAM), and the epithelial receptor nectin-4. SLAM binds near the stalk-head junction of the hemagglutinin. Nectin-4 binds a hydrophobic groove located between blades 4 and 5 of the hemagglutinin β-propeller head. The mutated vaccine strain hemagglutinin binds in addition the ubiquitous protein CD46, which explains attenuation. The measles virus entry concert has four movements. Andante misterioso: the virus takes over the immune system. Allegro con brio: it rapidly spreads in the upper airway's epithelia. 'Targeting' fugue: the versatile orchestra takes off. Presto furioso: the virus exits the host with thunder. Be careful: music is contagious. PMID:24492202

  3. Structural basis of efficient contagion: measles variations on a theme by parainfluenza viruses

    PubMed Central

    Mateo, Mathieu; Navaratnarajah, Chanakha K.; Cattaneo, Roberto

    2014-01-01

    A quartet of attachment proteins and a trio of fusion protein subunits play the cell entry concert of parainfluenza viruses. While many of these viruses bind sialic acid to enter cells, wild type measles binds exclusively two tissue-specific proteins, the lymphatic receptor signaling lymphocytic activation molecule (SLAM), and the epithelial receptor nectin-4. SLAM binds near the stalk-head junction of the hemagglutinin. Nectin-4 binds a hydrophobic groove located between blades 4 and 5 of the hemagglutinin β-propeller head. The mutated vaccine strain hemagglutinin binds in addition the ubiquitous protein CD46, which explains attenuation. The measles virus entry concert has four movements. Andante misterioso: the virus takes over the immune system. Allegro con brio: it rapidly spreads in the upper airway’s epithelia. “Targeting” fugue: the versatile orchestra takes off. Presto furioso: the virus exits the host with thunder. Be careful: music is contagious. PMID:24492202

  4. Recombinant vaccinia virus/Venezuelan equine encephalitis (VEE) virus protects mice from peripheral VEE virus challenge.

    PubMed Central

    Kinney, R M; Esposito, J J; Mathews, J H; Johnson, B J; Roehrig, J T; Barrett, A D; Trent, D W

    1988-01-01

    Mice immunized with recombinant vaccinia virus (VACC) expressing Venezuelan equine encephalitis (VEE) virus capsid protein and glycoproteins E1 and E2 or with attenuated VEE TC-83 virus vaccine developed VEE-specific neutralizing antibody and survived intraperitoneal challenge with virulent VEE virus strains including Trinidad donkey (subtype 1AB), P676 (subtype 1C), 3880 (subtype 1D), and Everglades (subtype 2). However, unlike immunization with TC-83 virus, immunization with the recombinant VACC/VEE virus did not protect mice from intranasal challenge with VEE Trinidad donkey virus. These results suggest that recombinant VACC/VEE virus is a vaccine candidate for equines and humans at risk of mosquito-transmitted VEE disease but not for laboratory workers at risk of accidental exposure to aerosol infection with VEE virus. PMID:3184276

  5. Recombinant Vaccinia Virus: Immunization against Multiple Pathogens

    NASA Astrophysics Data System (ADS)

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

    1985-09-01

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

  6. Attenuation of Vaccinia Virus

    PubMed Central

    Yakubitskiy, S. N.; Kolosova, I. V.; Maksyutov, R. A.; Shchelkunov, S. N.

    2015-01-01

    Since 1980, in the post-smallpox vaccination era the human population has become increasingly susceptible compared to a generation ago to not only the variola (smallpox) virus, but also other zoonotic orthopoxviruses. The need for safer vaccines against orthopoxviruses is even greater now. The Lister vaccine strain (LIVP) of vaccinia virus was used as a parental virus for generating a recombinant 1421ABJCN clone defective in five virulence genes encoding hemagglutinin (A56R), the IFN-?-binding protein (B8R), thymidine kinase (J2R), the complement-binding protein (C3L), and the Bcl-2-like inhibitor of apoptosis (N1L). We found that disruption of these loci does not affect replication in mammalian cell cultures. The isogenic recombinant strain 1421ABJCN exhibits a reduced inflammatory response and attenuated neurovirulence relative to LIVP. Virus titers of 1421ABJCN were 3 lg lower versus the parent VACV LIVP when administered by the intracerebral route in new-born mice. In a subcutaneous mouse model, 1421ABJCN displayed levels of VACV-neutralizing antibodies comparable to those of LIVP and conferred protective immunity against lethal challenge by the ectromelia virus. The VACV mutant holds promise as a safe live vaccine strain for preventing smallpox and other orthopoxvirus infections. PMID:26798498

  7. Attenuation of Vaccinia Virus.

    PubMed

    Yakubitskiy, S N; Kolosova, I V; Maksyutov, R A; Shchelkunov, S N

    2015-01-01

    Since 1980, in the post-smallpox vaccination era the human population has become increasingly susceptible compared to a generation ago to not only the variola (smallpox) virus, but also other zoonotic orthopoxviruses. The need for safer vaccines against orthopoxviruses is even greater now. The Lister vaccine strain (LIVP) of vaccinia virus was used as a parental virus for generating a recombinant 1421ABJCN clone defective in five virulence genes encoding hemagglutinin (A56R), the IFN-γ-binding protein (B8R), thymidine kinase (J2R), the complement-binding protein (C3L), and the Bcl-2-like inhibitor of apoptosis (N1L). We found that disruption of these loci does not affect replication in mammalian cell cultures. The isogenic recombinant strain 1421ABJCN exhibits a reduced inflammatory response and attenuated neurovirulence relative to LIVP. Virus titers of 1421ABJCN were 3 lg lower versus the parent VACV LIVP when administered by the intracerebral route in new-born mice. In a subcutaneous mouse model, 1421ABJCN displayed levels of VACV-neutralizing antibodies comparable to those of LIVP and conferred protective immunity against lethal challenge by the ectromelia virus. The VACV mutant holds promise as a safe live vaccine strain for preventing smallpox and other orthopoxvirus infections. PMID:26798498

  8. Engineered plant virus resistance.

    PubMed

    Galvez, Leny C; Banerjee, Joydeep; Pinar, Hasan; Mitra, Amitava

    2014-11-01

    Virus diseases are among the key limiting factors that cause significant yield loss and continuously threaten crop production. Resistant cultivars coupled with pesticide application are commonly used to circumvent these threats. One of the limitations of the reliance on resistant cultivars is the inevitable breakdown of resistance due to the multitude of variable virus populations. Similarly, chemical applications to control virus transmitting insect vectors are costly to the farmers, cause adverse health and environmental consequences, and often result in the emergence of resistant vector strains. Thus, exploiting strategies that provide durable and broad-spectrum resistance over diverse environments are of paramount importance. The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Genetic engineering offers various options for introducing transgenic virus resistance into crop plants to provide a wide range of resistance to viral pathogens. This review examines the current strategies of developing virus resistant transgenic plants. PMID:25438782

  9. Chlorella viruses isolated in China

    SciTech Connect

    Zhang, Y.; Burbank, D.E.; Van Etten, J.L. )

    1988-09-01

    Plaque-forming viruses of the unicellular, eukaryotic, exsymbiotic, Chlorella-like green algae strain NC64A, which are common in the United States, were also present in fresh water collected in the People's Republic of China. Seven of the Chinese viruses were examined in detail and compared with the Chlorella viruses previously isolated in the United States. Like the American viruses, the Chinese viruses were large polyhedra and sensitive to chloroform. They contained numerous structural proteins and large double-stranded DNA genomes of at least 300 kilobase pairs. Each of the DNAs from the Chinese viruses contained 5-methyldeoxycytosine, which varied from 12.6 to 46.7% of the deoxycytosine, and N{sup 6}-methyldeoxyadenosine, which varied from 2.2 to 28.3% of the deoxyadenosine. Four of the Chinese virus DNAs hybridized extensively with {sup 32}P-labeled DNA from the American virus PBCV-1, and three hybridized poorly.

  10. Herpes Simplex Virus (Cold Sores)

    MedlinePLUS

    ... Español Text Size Email Print Share Herpes Simplex Virus (Cold Sores) Page Content Article Body Herpes simplex ... 2 (HSV-2). However, both strains of the virus can cause sores in any part of the ...

  11. Special Issue: Honey Bee Viruses.

    PubMed

    Gisder, Sebastian; Genersch, Elke

    2015-10-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field. PMID:26702462

  12. Special Issue: Honey Bee Viruses

    PubMed Central

    Gisder, Sebastian; Genersch, Elke

    2015-01-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field. PMID:26702462

  13. Production of virus resistant plants

    DOEpatents

    Dougherty, W.G.; Lindbo, J.A.

    1996-12-10

    A method of suppressing virus gene expression in plants using untranslatable plus sense RNA is disclosed. The method is useful for the production of plants that are resistant to virus infection. 9 figs.

  14. Dengue virus pirates human platelets.

    PubMed

    Rondina, Matthew T; Weyrich, Andrew S

    2015-07-16

    In this issue of Blood, Simon and colleagues provide the first proof that dengue virus (DENV) raids platelets and steals their translational machinery to replicate and produce infectious virus. PMID:26185116

  15. Chlorella viruses isolated in China.

    PubMed Central

    Zhang, Y P; Burbank, D E; Van Etten, J L

    1988-01-01

    Plaque-forming viruses of the unicellular, eucaryotic, exsymbiotic, Chlorella-like green algae strain NC64A, which are common in the United States, were also present in fresh water collected in the People's Republic of China. Seven of the Chinese viruses were examined in detail and compared with the Chlorella viruses previously isolated in the United States. Like the American viruses, the Chinese viruses were large polyhedra and sensitive to chloroform. They contained numerous structural proteins and large double-stranded DNA genomes of at least 300 kilobase pairs. Each of the DNAs from the Chinese viruses contained 5-methyldeoxycytosine, which varied from 12.6 to 46.7% of the deoxycytosine, and N6-methyldeoxyadenosine, which varied from 2.2 to 28.3% of the deoxyadenosine. Four of the Chinese virus DNAs hybridized extensively with DNA from the American virus PBCV-1, and three hybridized poorly. Images PMID:2847652

  16. [Diversification of influenza viruses].

    PubMed

    Marian, Constantin V; Mihăescu, Grigore

    2009-01-01

    The presence of flu in humankind history was cited by numerous sources (the oldest known source was written by Hyppocrates, in 412 BC), but the epidemic impact could be measured only starting with the XVIII-th century, after the pandemics from 1729 - 1733 (with estimates of about two million deaths). Nowadays, health scientists dispenses vaccines, containing the antigenes of the viruses responsible with the flu in the last winter mixed with other two major flu-types. The effect of the current flu vaccines extends over about six months from the moment of innoculation. The reason of that short effectiveness of the vaccines is given by ability of viruses to change themselves very quickly. There are two ways through which the virus can astonish the victim antibodies (humans or animals): the mutation (named antigenic drift) and the genetic recombination of the genomic segments from different strains (named antigenic shift). PMID:20422926

  17. Deformed wing virus.

    PubMed

    de Miranda, Joachim R; Genersch, Elke

    2010-01-01

    Deformed wing virus (DWV; Iflaviridae) is one of many viruses infecting honeybees and one of the most heavily investigated due to its close association with honeybee colony collapse induced by Varroadestructor. In the absence of V.destructor DWV infection does not result in visible symptoms or any apparent negative impact on host fitness. However, for reasons that are still not fully understood, the transmission of DWV by V.destructor to the developing pupae causes clinical symptoms, including pupal death and adult bees emerging with deformed wings, a bloated, shortened abdomen and discolouration. These bees are not viable and die soon after emergence. In this review we will summarize the historical and recent data on DWV and its relatives, covering the genetics, pathobiology, and transmission of this important viral honeybee pathogen, and discuss these within the wider theoretical concepts relating to the genetic variability and population structure of RNA viruses, the evolution of virulence and the development of disease symptoms. PMID:19909976

  18. Simian Varicella Virus Pathogenesis

    PubMed Central

    Mahalingam, Ravi; Messaoudi, Ilhem; Gilden, Don

    2010-01-01

    Because varicella zoster virus (VZV) is an exclusively human pathogen, the development of an animal model is necessary to study pathogenesis, latency, and reactivation. The pathological, virological, and immunological features of simian varicella virus (SVV) infection in nonhuman primates are similar to those of VZV infection in humans. Both natural infection of cynomolgus and African green monkeys as well as intrabronchial inoculation of rhesus macaques with SVV provide the most useful models to study viral and immunological aspects of latency and the host immune response. Experimental immunosuppression of monkeys latently infected with SVV results in zoster, thus providing a new model system to study how the loss of adaptive immunity modulates virus reactivation. PMID:20186611

  19. Oncolytic viruses: finally delivering.

    PubMed

    Seymour, Leonard W; Fisher, Kerry D

    2016-02-16

    Oncolytic viruses can be found at the confluence of virology, genetic engineering and pharmacology where versatile platforms for molecularly targeted anticancer agents can be designed and optimised. Oncolytic viruses offer several important advantages over traditional approaches, including the following. (1) Amplification of the active agent (infectious virus particles) within the tumour. This avoids unnecessary exposure to normal tissues experienced during delivery of traditional stoichiometric chemotherapy and maximises the therapeutic index. (2) The active cell-killing mechanisms, often independent of programmed death mechanisms, should decrease the emergence of acquired drug resistance. (3) Lytic death of cancer cells provides a pro-inflammatory microenvironment and the potential for induction of an anticancer vaccine response. (4) Tumour-selective expression and secretion of encoded anticancer biologics, providing a new realm of potent and cost-effective-targeted therapeutics. PMID:26766734

  20. Protecting Your Computer from Viruses

    ERIC Educational Resources Information Center

    Descy, Don E.

    2006-01-01

    A computer virus is defined as a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer. The existence of computer viruses--or the necessity of avoiding viruses--is part of using a computer. With the advent of the Internet, the door was opened wide for these

  1. Protecting Your Computer from Viruses

    ERIC Educational Resources Information Center

    Descy, Don E.

    2006-01-01

    A computer virus is defined as a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer. The existence of computer viruses--or the necessity of avoiding viruses--is part of using a computer. With the advent of the Internet, the door was opened wide for these…

  2. Raspberry latent virus in Rubus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raspberry latent virus (RpLV) is a recently characterized virus reported from the Pacific Northwest, including Oregon and Washington in the United States and British Columbia in Canada. The virus appears to spread rapidly in the Fraser River Valley (northwest Washington and southwest British Columb...

  3. The biology of influenza viruses.

    PubMed

    Bouvier, Nicole M; Palese, Peter

    2008-09-12

    The influenza viruses are characterized by segmented, negative-strand RNA genomes requiring an RNA-dependent RNA polymerase of viral origin for replication. The particular structure ofthe influenza virus genome and function of its viral proteins enable antigenic drift and antigenic shift. These processes result in viruses able to evade the long-term adaptive immune responses in many hosts. PMID:19230160

  4. Virus infection improves drought tolerance.

    PubMed

    Xu, Ping; Chen, Fang; Mannas, Jonathan P; Feldman, Tracy; Sumner, Lloyd W; Roossinck, Marilyn J

    2008-01-01

    Viruses are obligate intracellular symbionts. Plant viruses are often discovered and studied as pathogenic parasites that cause diseases in agricultural plants. However, here it is shown that viruses can extend survival of their hosts under conditions of abiotic stress that could benefit hosts if they subsequently recover and reproduce. Various plant species were inoculated with four different RNA viruses, Brome mosaic virus (BMV), Cucumber mosaic virus (CMV), Tobacco mosaic virus and Tobacco rattle virus. The inoculated plants were stressed by withholding water. The onset of drought symptoms in virus-infected plants was compared with that in the plants that were inoculated with buffer (mock-inoculated plants). Metabolite profiling analysis was conducted and compared between mock-inoculated and virus-infected plants before and after being subjected to drought stress. In all cases, virus infection delayed the appearance of drought symptoms. Beet plants infected with CMV also exhibited significantly improved tolerance to freezing. Metabolite profiling analysis showed an increase in several osmoprotectants and antioxidants in BMV-infected rice and CMV-infected beet plants before and after drought stress. These results indicate that virus infection improves plant tolerance to abiotic stress, which correlates with increased osmoprotectant and antioxidant levels in infected plants. PMID:18823313

  5. Avian influenza virus RNA extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from expe...

  6. 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.

  7. Computer Bytes, Viruses and Vaccines.

    ERIC Educational Resources Information Center

    Palmore, Teddy B.

    1989-01-01

    Presents a history of computer viruses, explains various types of viruses and how they affect software or computer operating systems, and describes examples of specific viruses. Available vaccines are explained, and precautions for protecting programs and disks are given. (nine references) (LRW)

  8. Pathobiology of avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus causes serious disease in a wide variety of birds and mammals. Its natural hosts are wild aquatic birds, in which most infections are unapparent. Avian Influenza (AI) viruses are classified into 16 hemagglutinin (H1-16) and nine neuraminidase (N1-9) subtypes. Each virus has on...

  9. Ipomoviruses: Squash vein yellowing virus, Cucumber vein yellowing virus, Cassava brown streak virus, and Ugandan cassava brown streak virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ipomoviruses including Squash vein yellowing virus, Cucumber vein yellowing virus and Cassava brown streak virus are currently causing significant economic impact on crop production in several regions of the world. Only recently have results of detailed characterization of their whitefly transmissi...

  10. Epstein-Barr virus test

    MedlinePLUS

    Epstein-Barr virus test is a blood test to detect antibodies to the Epstein-Barr virus ( EBV ) antigens. See also: Monospot test ... specialist looks for antibodies to the Epstein-Barr virus. In the first stages of an illness, little ...

  11. Ecology of prokaryotic viruses.

    PubMed

    Weinbauer, Markus G

    2004-05-01

    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 point of view'. The abundance of viruses varies strongly in different environments and is related to bacterial abundance or activity suggesting that the majority of the viruses found in the environment are typically phages. Data on phage diversity are sparse but indicate that phages are extremely diverse in natural systems. Lytic phages are predators of prokaryotes, whereas lysogenic and chronic infections represent a parasitic interaction. Some forms of lysogeny might be described best as mutualism. The little existing ecological data on phage populations indicate a large variety of environmental niches and survival strategies. The host cell is the main resource for phages and the resource quality, i.e., the metabolic state of the host cell, is a critical factor in all steps of the phage life cycle. Virus-induced mortality of prokaryotes varies strongly on a temporal and spatial scale and shows that phages can be important predators of bacterioplankton. This mortality and the release of cell lysis products into the environment can strongly influence microbial food web processes and biogeochemical cycles. Phages can also affect host diversity, e.g., by 'killing the winner' and keeping in check competitively dominant species or populations. Moreover, they mediate gene transfer between prokaryotes, but this remains largely unknown in the environment. Genomics or proteomics are providing us now with powerful tools in phage ecology, but final testing will have to be performed in the environment. PMID:15109783

  12. 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.

  13. Human Immunodeficiency Virus Prevention.

    PubMed

    Davis, Teaniese Latham; DiClemente, Ralph

    2016-04-01

    Human immunodeficiency virus (HIV) is the virus that causes AIDS. Surveillance data from 2012 indicate an estimated 1.2 million people aged 13 years and older were living with HIV infection in the United States, and 12.8% do not know their status. There are approximately 50,000 new HIV infections annually. With no available cure for HIV, primary prevention to reduce incident cases of HIV is essential. Strategies to prevent HIV transmission include reducing sexual risk behavior and needle sharing. The Centers for Disease Control and Prevention has multiple resources available for primary and secondary prevention to reduce disease transmission and severity. PMID:26980130

  14. Zika virus outside Africa.

    PubMed

    Hayes, Edward B

    2009-09-01

    Zika virus (ZIKV) is a flavivirus related to yellow fever, dengue, West Nile, and Japanese encephalitis viruses. In 2007 ZIKV caused an outbreak of relatively mild disease characterized by rash, arthralgia, and conjunctivitis on Yap Island in the southwestern Pacific Ocean. This was the first time that ZIKV was detected outside of Africa and Asia. The history, transmission dynamics, virology, and clinical manifestations of ZIKV disease are discussed, along with the possibility for diagnostic confusion between ZIKV illness and dengue.The emergence of ZIKV outside of its previously known geographic range should prompt awareness of the potential for ZIKV to spread to other Pacific islands and the Americas. PMID:19788800

  15. Zika Virus and Microcephaly.

    PubMed

    Rubin, Eric J; Greene, Michael F; Baden, Lindsey R

    2016-03-10

    Zika virus has been sweeping through South and Central America, with more than a million suspected cases during the past few months, along with a substantial increase in reporting of infants born with microcephaly.(1),(2) Thus far, the two outbreaks have largely been epidemiologically associated in time and geography. However, Mlakar and colleagues(3) now report in the Journal molecular genetic and electron-microscopic data from a case that helps to strengthen the biologic association. This group cared for a pregnant European woman in whom a syndrome compatible with Zika virus infection developed at 13 weeks of gestation while she was working ... PMID:26862812

  16. Barley yellow dwarf viruses.

    PubMed

    Miller, W A; Rasochová, L

    1997-01-01

    Barley yellow dwarf viruses represent one of the most economically important and ubiquitous groups of plant viruses. This review focuses primarily on four research areas in which progress has been most rapid. These include (a) evidence supporting reclassification of BYDVs into two genera; (b) elucidation of gene function and novel mechanisms controlling gene expression; (c) initial forays into understanding the complex interactions between BYDV virions and their aphid vectors; and (d) replication of a BYDV satellite RNA. Economic losses, symptomatology, and means of control of BYD are also discussed. PMID:15012520

  17. 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

  18. Zika Virus Outside Africa

    PubMed Central

    2009-01-01

    Zika virus (ZIKV) is a flavivirus related to yellow fever, dengue, West Nile, and Japanese encephalitis viruses. In 2007 ZIKV caused an outbreak of relatively mild disease characterized by rash, arthralgia, and conjunctivitis on Yap Island in the southwestern Pacific Ocean. This was the first time that ZIKV was detected outside of Africa and Asia. The history, transmission dynamics, virology, and clinical manifestations of ZIKV disease are discussed, along with the possibility for diagnostic confusion between ZIKV illness and dengue.The emergence of ZIKV outside of its previously known geographic range should prompt awareness of the potential for ZIKV to spread to other Pacific islands and the Americas. PMID:19788800

  19. Virus species and virus identification: past and current controversies.

    PubMed

    Van Regenmortel, M H V

    2007-01-01

    The basic concepts used in virus classification are analyzed. A clear distinction is drawn between viruses that are real, concrete objects studied by virologists and virus species that are man-made taxonomic constructions that exist only in the mind. Classical views regarding the nature of biological species are reviewed and the concept of species used in virology is explained. The use of pair-wise sequence comparisons between the members of a virus family for delineating species and genera is reviewed. The difference between the process of virus identification using one or a few diagnostic properties and the process of creating virus taxa using a combination of many properties is emphasized. The names of virus species in current use are discussed as well as a binomial system that may be introduced in the future. PMID:16713373

  20. Newcastle disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Newcastle disease virus (NDV), a member of the Avulavirus genus in the Paramyxoviridae family, has a ribonucleic acid (RNA) genome that is negative sense, non-segmented, and single-stranded. The genome codes for six structural proteins: nucleocapsid, phosphoprotein, matrix, fusion, hemagglutinin-neu...

  1. Tomato ringspot virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato ringspot virus (ToRSV) causes a nematode-vectored disease of highbush blueberry in New York, Oregon, Pennsylvania and Washington in the United States but has not been reported elsewhere in the world on this crop or on other Vaccinium spp. The occurrence and intensity of symptoms vary among b...

  2. From Shakespeare to Viruses

    SciTech Connect

    Kim, Sung-Hou

    2009-01-01

    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.

  3. Cold Facts about Viruses.

    ERIC Educational Resources Information Center

    Pea, Celeste; Sterling, Donna R.

    2002-01-01

    Provides ways for students to demonstrate their understanding of scientific concepts and skills. Describes a mini-unit around the cold in which students can relate humans to viruses. Includes activities and a modified simulation that provides questions to guide students. Discusses ways that allows students to apply prior knowledge, take ownership

  4. Using viruses as nanomedicines

    PubMed Central

    van Kan-Davelaar, H E; van Hest, J C M; Cornelissen, J J L M; Koay, M S T

    2014-01-01

    The field of nanomedicine involves the design and fabrication of novel nanocarriers for the intracellular delivery of therapeutic cargo or for use in molecular diagnostics. Although traditionally recognized for their ability to invade and infect host cells, viruses and bacteriophages have been engineered over the past decade as highly promising molecular platforms for the targeted delivery and treatment of many human diseases. Inherently biodegradable, the outer capsids of viruses are composed entirely of protein building blocks, which can be genetically or chemically engineered with molecular imaging reagents, targeting ligands and therapeutic molecules. While there are several examples of viruses as in vitro molecular cargo carriers, their potential for applications in nanomedicine has only recently emerged. Here we highlight recent developments towards the design and engineering of viruses for the treatment of cancer, bacterial infections and immune system-related diseases. Linked Articles This article is part of a themed section on Nanomedicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-17 PMID:24571489

  5. Varicella zoster virus latency

    PubMed Central

    Eshleman, Emily; Shahzad, Aamir; Cohrs, Randall J

    2011-01-01

    Primary infection by varicella zoster virus (VZV) typically results in childhood chickenpox, at which time latency is established in the neurons of the cranial nerve, dorsal root and autonomic ganglia along the entire neuraxis. During latency, the histone-associated virus genome assumes a circular episomal configuration from which transcription is epigenetically regulated. The lack of an animal model in which VZV latency and reactivation can be studied, along with the difficulty in obtaining high-titer cell-free virus, has limited much of our understanding of VZV latency to descriptive studies of ganglia removed at autopsy and analogy to HSV-1, the prototype alphaherpesvirus. However, the lack of miRNA, detectable latency-associated transcript and T-cell surveillance during VZV latency highlight basic differences between the two neurotropic herpesviruses. This article focuses on VZV latency: establishment, maintenance and reactivation. Comparisons are made with HSV-1, with specific attention to differences that make these viruses unique human pathogens. PMID:21695042

  6. 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...

  7. Human Viruses and Cancer

    PubMed Central

    Morales-Snchez, Abigail; Fuentes-Panan, 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 Burkitts 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

  8. Wineberry latent virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wineberry latent virus (WLV) was discovered in a single symptomless plant of wineberry, Rubus phoenicolasius, which was growing in an experimental planting in Scotland. The plant originated in the United States, where wineberry is established in the wild in the Northeast. Experimentally, WLV can be ...

  9. Raspberry leaf curl virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raspberry leaf curl virus (RLCV) is limited to hosts in the genus Rubus and is transmitted persistently by the small raspberry aphid, Aphis rubicola Oestlund. It is found only in North America, principally in the northeastern United States and southeastern Canada and in the Rocky Mountain regions of...

  10. 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

  11. Turnip Yellow Mosaic Virus

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The bumpy exterior of the turnip yellow mosaic virus (TYMV) protein coat, or capsid, was defined in detail by Dr. Alexander McPherson of the University of California, Irvin using proteins crystallized in space for analysis on Earth. TYMV is an icosahedral virus constructed from 180 copies of the same protein arranged into 12 clusters of five proteins (pentamers), and 20 clusters of six proteins (hexamers). The final TYMV structure led to the unexpected hypothesis that the virus releases its RNA by essentially chemical-mechanical means. Most viruses have fairly flat coats, but in TYNV, the fold in each protein, called the jellyroll, is clustered at the points where the protein pentamers and hexamers join. The jellyrolls are almost standing on end, producing a bumpy surface with knobs at all of the pentamers and hexamers. At the inside surface of the pentamers is a void that is not present at the hexamers. The coating had been seen in early stuties of TYMV, but McPherson's atomic structure shows much more detail. The inside surface is strikingly, and unexpectedly, different than the outside. While the pentamers contain a central void on the inside, the hexameric units contain peptides linked to each other, forming a ring or, more accurately, rings to fill the void. Credit: Dr. Alexander McPherson, University of California, Irvine

  12. Viruses of Haloarchaea

    PubMed Central

    Luk, Alison W. S.; Williams, Timothy J.; Erdmann, Susanne; Papke, R. Thane; Cavicchioli, Ricardo

    2014-01-01

    In hypersaline environments, haloarchaea (halophilic members of the Archaea) are the dominant organisms, and the viruses that infect them, haloarchaeoviruses are at least ten times more abundant. Since their discovery in 1974, described haloarchaeoviruses include head-tailed, pleomorphic, spherical and spindle-shaped morphologies, representing Myoviridae, Siphoviridae, Podoviridae, Pleolipoviridae, Sphaerolipoviridae and Fuselloviridae families. This review overviews current knowledge of haloarchaeoviruses, providing information about classification, morphotypes, macromolecules, life cycles, genetic manipulation and gene regulation, and host-virus responses. In so doing, the review incorporates knowledge from laboratory studies of isolated viruses, field-based studies of environmental samples, and both genomic and metagenomic analyses of haloarchaeoviruses. What emerges is that some haloarchaeoviruses possess unique morphological and life cycle properties, while others share features with other viruses (e.g., bacteriophages). Their interactions with hosts influence community structure and evolution of populations that exist in hypersaline environments as diverse as seawater evaporation ponds, to hot desert or Antarctic lakes. The discoveries of their wide-ranging and important roles in the ecology and evolution of hypersaline communities serves as a strong motivator for future investigations of both laboratory-model and environmental systems. PMID:25402735

  13. Apple mosaic virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apple mosaic virus (ApMV), a member of the ilarvirus group, naturally infects Betula, Aesculus, Humulus, and several crop genera in the family Rosaceae (Malus, Prunus, Rosa and Rubus). ApMV was first reported in Rubus in several blackberry and raspberry cultivars in the United States and subsequentl...

  14. Blueberry shock virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry shock disease first observed in Washington state in 1987 and initially confused with blueberry scorch caused by Blueberry scorch virus (BlScV). However, shock affected plants produced a second flush of leaves after flowering and the plants appeared normal by late summer except for the lac...

  15. 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

  16. Honey Bee Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viruses are significant threats to the health and well-being of the honey bee, Apis mellifera. To alleviate the threats posed by these invasive organisms, a better understanding of bee viral infections will be of crucial importance in developing effective and environmentally-benign disease control ...

  17. GENOME OF HORSEPOX VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we present the genomic sequence of horsepox virus (HSPV) isolate MNR-76, an orthopoxvirus (OPV) isolated in 1976 from diseased Mongolian horses. The 212 kbp genome contained 7.5 kbp inverted terminal repeats (ITR) and lacked extensive terminal tandem repetition. HSPV contained 236 ORFs with sim...

  18. [Virus in sheep's skin].

    PubMed

    Ackermann, M

    2005-04-01

    In a double sense, the ovine gamma herpesvirus type 2 (OvHV-2) is a virus in sheep's skin. Not only is it present world wide in all sheep breeds but also it causes malignant catarrhal fever (MCF) in cattle pigs, elk, and bison. OvHV-2 cannot be propagated in cell culture. Therefore, new results from OvHV-2 research are based on molecular techniques and may be summarized as follows. OvHV-2 is transmitted by respiratory routes as well as by sexual intercourse. Lambs are infected within the first few months of life. Leucocytes, primarily latently infected lymphocytes, are responsible for disseminating the virus over the entire organism. On rare occasions, virus particles could be visualized by electron microscopy in explanted lymphocyte cultures. Structural antigens were detected by immunohistology in M-cells of diseased rabbits. Immunologically and cell biologically active genes have been detected on the viral genome.The products arising from those are thought to fine balance, the number of latently infected cells in sheep and to keep them alive without causing harm. Thus, it seems that this balance has been found through co-evolution, favoring both virus and natural host. In contrast, other host species that were exclude from the process of co-evolution, are bound to fall from MCF. PMID:15861922

  19. Viruses--a conundrum.

    PubMed

    Pandit, H M

    1996-01-01

    To understand the pathophysiology of a disease, it is important to know the origin, causes and effects. This also helps to control and to treat the disease. In virus infections, it is difficult and confusing when the origin is sought. In this article it is hypothesized that the viruses, which are nucleoproteins, arise as fragments or broken segments of DNA or RNA. Various factors, such as radiation, toxic chemicals, pollution, are listed as possible causes of such fragmentations. It is logical that these DNA or RNA fragments must come from the genomes or the genes essential for the proliferation or cell division. The symbiotic and parasitic interrelationships of bacteria, plants and animals make the problem more complex and confusing, because all of them thrive and grow in each other cells, thus producing more nucleoproteins of each. Virions contain a small quantum of energy as the initial source of bioenergy to ignite and initiate the complex chemical reactions needed to use the potential energy reservoirs from the host. In this respect viruses can be considered as borderline between the living and the non-living. If one has to develop an effective drug or method for treating virus infections or cancers, the drug must have an antimitotic activity without affecting other normal functions. Such seems to be the case of globin derivatives of sickle cell and thalassemia red blood cells. PMID:8875804

  20. Cell injury with viruses.

    PubMed Central

    Tamm, I.

    1975-01-01

    The inhibitions of cellular protein and RNA synthesis in picornavirus-infected cells are early events which require only limited synthesis of virus-specific proteins. The inhibition of cellular protein synthesis appears to be due to blocking of the association of ribosomes with host messenger RNA. Inhibition of cellular RNA synthesis involves inactivation of the template-enzyme complex and affects ribosomal RNA synthesis before messenger RNA synthesis. Inhibition of cellular DNA synthesis also occurs early and may be secondary to inhibition of cellular protein synthesis. Early chromatid breaks may be related to inhibitions of cellular protein and nucleic acid synthesis. Stimulation of phospholipid synthesis in picornavirus-infected cells also requires only limited synthesis of virus-specific proteins. In contrast, release of lysosomal enzymes, proliferation of smooth cytoplasmic membranes, cellular vacuolization, retraction, and rounding, and diffuse chromosomal changes related to karyorrhexis and pyknosis are all dependent on considerable synthesis of virus-specific proteins during the middle part of the picornavirus growth cycle. The early virus-induced alterations in cellular biosynthetic processes are not the direct or sole cause of the subsequent marked pathologic changes in the membranes and chromosomes of the cell. Images Figure 1 PMID:1180330

  1. From Shakespeare to Viruses

    SciTech Connect

    Sung-Hou Kim

    2009-02-09

    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

  2. Plant virus replication and movement.

    PubMed

    Heinlein, Manfred

    2015-05-01

    Replication and intercellular spread of viruses depend on host mechanisms supporting the formation, transport and turnover of functional complexes between viral genomes, virus-encoded products and cellular factors. To enhance these processes, viruses assemble and replicate in membrane-associated complexes that may develop into "virus factories" or "viroplasms" in which viral components and host factors required for replication are concentrated. Many plant viruses replicate in association with the cortical ER-actin network that is continuous between cells through plasmodesmata. The replication complexes can be highly organized and supported by network interactions between the viral genome and the virus-encoded proteins. Intracellular PD targeting of replication complexes links the process of movement to replication and provides specificity for transport of the viral genome by the virus-encoded movement proteins. The formation and trafficking of replication complexes and also the development and anchorage of replication factories involves important roles of the cortical cytoskeleton and associated motor proteins. PMID:25746797

  3. 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.

  4. Bat Flight and Zoonotic Viruses

    PubMed Central

    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. PMID:24750692

  5. Genome of deerpox virus.

    PubMed

    Afonso, C L; Delhon, G; Tulman, E R; Lu, Z; Zsak, A; Becerra, V M; Zsak, L; Kutish, G F; Rock, D L

    2005-01-01

    Deerpox virus (DPV), an uncharacterized and unclassified member of the Poxviridae, has been isolated from North American free-ranging mule deer (Odocoileus hemionus) exhibiting mucocutaneous disease. Here we report the genomic sequence and comparative analysis of two pathogenic DPV isolates, W-848-83 (W83) and W-1170-84 (W84). The W83 and W84 genomes are 166 and 170 kbp, containing 169 and 170 putative genes, respectively. Nucleotide identity between DPVs is 95% over the central 157 kbp. W83 and W84 share similar gene orders and code for similar replicative, structural, virulence, and host range functions. DPV open reading frames (ORFs) with putative virulence and host range functions include those similar to cytokine receptors (R), including gamma interferon receptor (IFN-gammaR), interleukin 1 receptor (IL-1R), and type 8 CC-chemokine receptors; cytokine binding proteins (BP), including IL-18BP, IFN-alpha/betaBP, and tumor necrosis factor binding protein (TNFBP); serpins; and homologues of vaccinia virus (VACV) E3L, K3L, and A52R proteins. DPVs also encode distinct forms of major histocompatibility complex class I, C-type lectin-like protein, and transforming growth factor beta1 (TGF-beta1), a protein not previously described in a mammalian chordopoxvirus. Notably, DPV encodes homologues of cellular endothelin 2 and IL-1R antagonist, novel poxviral genes also likely involved in the manipulation of host responses. W83 and W84 differ from each other by the presence or absence of five ORFs. Specifically, homologues of a CD30 TNFR family protein, swinepox virus SPV019, and VACV E11L core protein are absent in W83, and homologues of TGF-beta1 and lumpy skin disease virus LSDV023 are absent in W84. Phylogenetic analysis indicates that DPVs are genetically distinct from viruses of other characterized poxviral genera and that they likely comprise a new genus within the subfamily Chordopoxvirinae. PMID:15613325

  6. Viruses and neurodegeneration

    PubMed Central

    2013-01-01

    Neurodegenerative diseases (NDs) are chronic degenerative diseases of the central nervous system (CNS), which affect 37 million people worldwide. As the lifespan increases, the NDs are the fourth leading cause of death in the developed countries and becoming increasingly prevalent in developing countries. Despite considerable research, the underlying mechanisms remain poorly understood. Although the large majority of studies do not show support for the involvement of pathogenic aetiology in classical NDs, a number of emerging studies show support for possible association of viruses with classical neurodegenerative diseases in humans. Space does not permit for extensive details to be discussed here on non-viral-induced neurodegenerative diseases in humans, as they are well described in literature. Viruses induce alterations and degenerations of neurons both directly and indirectly. Their ability to attack the host immune system, regions of nervous tissue implies that they can interfere with the same pathways involved in classical NDs in humans. Supporting this, many similarities between classical NDs and virus-mediated neurodegeneration (non-classical) have been shown at the anatomic, sub-cellular, genomic and proteomic levels suggesting that viruses can explain neurodegenerative disorders mechanistically. The main objective of this review is to provide readers a detailed snapshot of similarities viral and non-viral neurodegenerative diseases share, so that mechanistic pathways of neurodegeneration in human NDs can be clearly understood. Viruses can guide us to unveil these pathways in human NDs. This will further stimulate the birth of new concepts in the biological research, which is needed for gaining deeper insights into the treatment of human NDs and delineate mechanisms underlying neurodegeneration. PMID:23724961

  7. Viruses and bacteriophages.

    PubMed

    Kott, Y

    1981-04-01

    Many of the enteric viruses which are transmitted from person to person by the fecal-oral route are found in raw and treated wastewater, and because of their persistence under adverse conditions may also be found in slightly polluted waters. There is no routine examination procedure of water and wastewater for enteroviruses, mainly because of the cumbersome isolation techniques, high cost and the need for highly skilled laboratory personnel. Phages are specific to single species of bacteria, are known for many enteric bacteria, and are very often used for final identification of enteric pathogenic bacteria. Coliphages are prevalent in raw and treated sewage as well as in polluted water, where enteric viruses may also be found. Coliphages were often mentioned as possible viral indicators in polluted water. To be a perfect indicator, they should comply with minimum criteria as follows: (a) they should be present wherever human enteric viruses are present; (b) the coliphage numbers recovered should be equal to or larger than those of enteric viruses recovered; (c) the coliphages should be at least as resistant as enteric viruses to adverse environmental conditions; (d) isolation and quantification of the coliphage should be faster and less expensive than isolation of the enteroviruses. Comparative studies show that the coliphage to enterovirus ratio in wastewater is about 10(3):1. Levels of poliovirus 1 (attenuated) to coliphage f2 remained stable for a few months in oxidation pond effluents. f2 coliphage exhibited higher resistance to chlorination than poliovirus 1 (attenuated). When the two strains were kept in water of different quality, f2 survived longer. In addition, all coliphage counts were completed within 24 h. while those of enteroviruses required about a week. Results indicate very strongly that coliphages can be used as viral indicators and this is already the practice in a few European and other countries. PMID:6262909

  8. Suppression of lymphocyte proliferation by parainfluenza virus type 3-infected bovine alveolar macrophages.

    PubMed Central

    Basaraba, R J; Brown, P R; Laegreid, W W; Silflow, R M; Evermann, J F; Leid, R W

    1993-01-01

    Lymphocytes stimulated with concanavalin A (Con A) or antigen in the presence of bovine parainfluenza virus type 3 (PIV-3) infected bovine alveolar macrophages (BAM) or monocytes, had depressed [3H]thymidine incorporation. This failure of lymphocytes to incorporate radiolabel required live virus, was time dependent and was most pronounced when BAM were infected for 48 hr prior to the addition of lymphocytes. The rate of infection of alveolar macrophages and the release of infectious virus into culture supernatants paralleled suppression of lymphocyte mitogenesis by PIV-3. However, the peak titre of exogenous, live or inactivated virus was not suppressive when added to lymphocyte macrophage cultures just prior to Con A stimulation. Neither the loss of viable alveolar macrophages nor a shift in antigen or mitogen dose response in virally infected cultures could account for the deficit in [3H]thymidine incorporation by lymphocytes. Despite the presence of lymphocyte-associated virus antigen detected by direct immunofluorescence, no increase in PIV-3 titre above baseline was seen from infected lymphocytes, irrespective of mitogen stimulation. Likewise, lymphocytes did not contribute to the extracellular virus pool in lymphocyte-macrophage cultures as the increases in viral titre above basal levels in supernatants were equal to levels released by macrophages alone. The expression of viral antigen on lymphocytes stimulated in the presence of PIV-3-infected BAM suggests a non-productive or abortive infection of lymphocytes mediated through contact with infected macrophages. Images Figure 6 Figure 7 Figure 8 PMID:8393834

  9. Virus movement within grafted watermelon plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon production in Florida is impacted by several viruses including whitefly-transmitted Squash vein yellowing virus (SqVYV), Cucurbit yellow stunting disorder virus and Cucurbit leaf crumple virus, and aphid-transmitted Papaya ringspot virus type W (PRSV-W). While germplasm resistant to some...

  10. SEN virus infection--a new hepatitis virus: a review.

    PubMed

    Sehgal, R

    2003-04-01

    Approximately 10% of transfusion associated hepatitis and 20% of community acquired hepatitis cases do not have a defined etiology, suggesting the existence of an additional causative agent. The recent agents which have been detected in blood were Hepatitis G virus (HGV) and TT virus (TTV), members of the family Circoviridae. These viruses were initially thought to be associated with post-transfusion hepatitis but later studies negated this causal effect. Recently, a novel DNA virus at the moment designated as SEN virus (SEN-V) was discovered and is thought to be associated with post-transfusion hepatitis. This virus is related to the above two agents and belongs to the same family. Whether, like HGV and TTV causal relationship with hepatitis is finally confirmed only time will tell, but, at the moment the association appears to present. The present review summarizes the present available data on this new agent of hepatitis. PMID:15022932

  11. Virus entry mediated by hepatitis B virus envelope proteins

    PubMed Central

    Taylor, John M

    2013-01-01

    Hepatitis B virus (HBV), a major cause of human liver disease worldwide, encodes three envelope proteins needed for the attachment and entry of the virus into susceptible host cells. A second virus, hepatitis delta virus, which is known to enhance liver disease in HBV infected patients, diverts the same HBV envelope proteins to achieve its own assembly and infection. In the lab, lentiviral vectors based on human immunodeficiency virus type 1 can be assembled using the HBV envelope proteins, and will similarly infect susceptible cells. This article provides a partial review and some personal reflections of how these three viruses infect and of how recipient cells become susceptible, along with some consideration of questions that remain to be answered. PMID:24187448

  12. 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 ...

  13. Viruses of Entamoeba histolytica. VII. Novel beaded virus.

    PubMed Central

    Mattern, C F; Keister, D B; Daniel, W A; Diamond, L S; Kontonis, A D

    1977-01-01

    A third amoebal virus type was isolated from four different strains of Entamoeba histolytica. The virus was most frequently seen as a linear structure about 235 nm long and consisting of 14 beadlike structures about 19 nm in diameter. A "dimer" of twice the length and consisting of 28 beads was occationally encountered. The virus replicated in the nucleus, forming ordered arrays. Acridine orange staining of viral aggregates in infected nuclei suggested the presence of double-stranded nucleic acid. Images PMID:197265

  14. Engineered Viruses as Genome Editing Devices

    PubMed Central

    Chen, Xiaoyu; Gonçalves, Manuel A F V

    2016-01-01

    Genome editing based on sequence-specific designer nucleases, also known as programmable nucleases, seeks to modify in a targeted and precise manner the genetic information content of living cells. Delivering into cells designer nucleases alone or together with donor DNA templates, which serve as surrogate homologous recombination (HR) substrates, can result in gene knockouts or gene knock-ins, respectively. As engineered replication-defective viruses, viral vectors are having an increasingly important role as delivery vehicles for donor DNA templates and designer nucleases, namely, zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered, regularly interspaced, short palindromic repeats (CRISPR)-associated Cas9 (CRISPR−Cas9) nucleases, also known as RNA-guided nucleases (RGNs). We review this dual role played by engineered viral particles on genome editing while focusing on their main scaffolds, consisting of lentiviruses, adeno-associated viruses, and adenoviruses. In addition, the coverage of the growing body of research on the repurposing of viral vectors as delivery systems for genome editing tools is complemented with information regarding their main characteristics, pros, and cons. Finally, this information is framed by a concise description of the chief principles, tools, and applications of the genome editing field as a whole. PMID:26336974

  15. Engineered Viruses as Genome Editing Devices.

    PubMed

    Chen, Xiaoyu; Gonçalves, Manuel A F V

    2016-03-01

    Genome editing based on sequence-specific designer nucleases, also known as programmable nucleases, seeks to modify in a targeted and precise manner the genetic information content of living cells. Delivering into cells designer nucleases alone or together with donor DNA templates, which serve as surrogate homologous recombination (HR) substrates, can result in gene knockouts or gene knock-ins, respectively. As engineered replication-defective viruses, viral vectors are having an increasingly important role as delivery vehicles for donor DNA templates and designer nucleases, namely, zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered, regularly interspaced, short palindromic repeats (CRISPR)-associated Cas9 (CRISPR-Cas9) nucleases, also known as RNA-guided nucleases (RGNs). We review this dual role played by engineered viral particles on genome editing while focusing on their main scaffolds, consisting of lentiviruses, adeno-associated viruses, and adenoviruses. In addition, the coverage of the growing body of research on the repurposing of viral vectors as delivery systems for genome editing tools is complemented with information regarding their main characteristics, pros, and cons. Finally, this information is framed by a concise description of the chief principles, tools, and applications of the genome editing field as a whole. PMID:26336974

  16. Discrete virus infection model of hepatitis B virus.

    PubMed

    Zhang, Pengfei; Min, Lequan; Pian, Jianwei

    2015-01-01

    In 1996 Nowak and his colleagues proposed a differential equation virus infection model, which has been widely applied in the study for the dynamics of hepatitis B virus (HBV) infection. Biological dynamics may be described more practically by discrete events rather than continuous ones. Using discrete systems to describe biological dynamics should be reasonable. Based on one revised Nowak et al's virus infection model, this study introduces a discrete virus infection model (DVIM). Two equilibriums of this model, E1 and E2, represents infection free and infection persistent, respectively. Similar to the case of the basic virus infection model, this study deduces a basic virus reproductive number R0 independing on the number of total cells of an infected target organ. A proposed theorem proves that if the basic virus reproductive number R0<1 then the virus free equilibrium E1 is locally stable. The DVIM is more reasonable than an abstract discrete susceptible-infected-recovered model (SIRS) whose basic virus reproductive number R0 is relevant to the number of total cells of the infected target organ. As an application, this study models the clinic HBV DNA data of a patient who was accepted via anti-HBV infection therapy with drug lamivudine. The results show that the numerical simulation is good in agreement with the clinic data. PMID:26405998

  17. Resveratrol, sirtuins, and viruses.

    PubMed

    Yang, Tao; Li, Shugang; Zhang, Xuming; Pang, Xiaowu; Lin, Qinlu; Cao, Jianzhong

    2015-11-01

    Resveratrol is a natural phenolic product found in some plants in response to stress and has been linked to the many health benefits of red wine. Over the past several decades, a great deal of research has identified diverse biological roles associated with resveratrol, including anti-oxidant, anti-proliferation, anti-inflammation, anti-cancer, anti-fungal, and antiviral activities. Such biological activities of resveratrol are likely mediated through multiple cellular targets or pathways, such as sirtuins, a family of NAD(+) -dependent deacetylases. In this treatise, the literatures focusing on the roles of resveratrol and sirtuins in modulating infections by a broad-spectrum of viruses are reviewed, with an emphasis on its potential antiviral mechanisms. A working model about the effects of resveratrol on virus infection is proposed to stimulate further researches on this exciting topic. Copyright 2015 John Wiley & Sons, Ltd. PMID:26479742

  18. 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

  19. Origin of hepatitis ? virus

    PubMed Central

    Taylor, John; Pelchat, Martin

    2010-01-01

    This article addresses some of the questions relating to how hepatitis ? virus (HDV), an agent so far unique in the animal world, might have arisen. HDV was discovered in patients infected with hepatitis B virus (HBV). It generally makes HBV infections more damaging to the liver. It is a subviral satellite agent that depends upon HBV envelope proteins for its assembly and ability to infect new cells. In other aspects of replication, HDV is both independent of and very different from HBV. In addition, the small single-stranded circular RNA genome of HDV, and its mechanism of replication, demonstrate an increasing number of similarities to the viroids a large family of helper-independent subviral agents that cause pathogenesis in plants. PMID:20210550

  20. 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.

  1. Mechanisms of Virus Assembly

    PubMed Central

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-01-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid, and in some cases surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assembles within their host cells and in vitro. We describe the thermodynamics and kinetics for assembly of protein subunits into icosahedral capsid shells, and how these are modified in cases where the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques that have been used to characterize capsid assembly, and we highlight aspects of virus assembly which are likely to receive significant attention in the near future. PMID:25532951

  2. [Innate immunity against viruses].

    PubMed

    Drutskaia, M S; Belousov, P V; Nedospasov, S A

    2011-01-01

    Viruses are obligate parasites which are able to infect cells of all living organisms. Multiple antiviral defense mechanisms have appeared early in evolution of the immune system. Higher vertebrates have the most complex antiviral immunity which is based on both innate and adoptive immune responses. However, majority of living organisms, including plants and invertebrates, rely exclusively on innate immune mechanisms for protection against viral infections. There are some striking similarities in several components of the innate immune recognition between mammals, plants and insects, rendering these signaling cascades as highly conserved in the evolution of the immune system. This review summarizes recent advances in the field of innate immune recognition of viruses, with particular interest on pattern-recognition receptors. PMID:21485493

  3. 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

  4. 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

  5. The phylogeography of human viruses.

    PubMed

    Holmes, Edward C

    2004-04-01

    Viruses, especially those with RNA genomes, represent ideal organisms to study the dynamics of microevolutionary change. In particular, their rapid rate of nucleotide substitution means that the epidemiological processes that shape their diversity act on the same time-scale as mutations are fixed in viral populations. Consequently, the branching structure of virus phylogenies provides a unique insight into spatial and temporal dynamics. Herein, I describe the key processes in virus phylogeography. These are generally associated with the relative rates of dispersal among populations and virus-host codivergence (vicariance), and the division between acute (short-term) and persistent (long-term) infections. These processes will be illustrated by important human viruses - HIV, dengue, rabies, polyomavirus JC and human papillomavirus - which display varying spatial and temporal structures and virus-host relationships. Key research questions for the future will also be established. PMID:15012753

  6. VIRUS instrument collimator assembly

    NASA Astrophysics Data System (ADS)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  7. Reemergence of Chikungunya Virus

    PubMed Central

    2014-01-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes acute fever and acute and chronic musculoskeletal pain in humans. Since 2004, CHIKV has caused millions of cases of disease in the Indian Ocean region and has emerged in new areas, including Europe, the Middle East, and the Pacific region. The mosquito vectors for this virus are globally distributed in tropical and temperate zones, providing the opportunity for CHIKV to continue to expand into new geographic regions. In October 2013, locally acquired cases of CHIKV infection were identified on the Caribbean island of Saint Martin, signaling the arrival of the virus in the Western Hemisphere. In just 9 months, CHIKV has spread to 22 countries in the Caribbean and Central and South America, resulting in hundreds of thousands of cases. CHIKV disease can be highly debilitating, and large epidemics have severe economic consequences. Thus, there is an urgent need for continued research into the epidemiology, pathogenesis, prevention, and treatment of these infections. PMID:25078691

  8. Reemergence of chikungunya virus.

    PubMed

    Morrison, Thomas E

    2014-10-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes acute fever and acute and chronic musculoskeletal pain in humans. Since 2004, CHIKV has caused millions of cases of disease in the Indian Ocean region and has emerged in new areas, including Europe, the Middle East, and the Pacific region. The mosquito vectors for this virus are globally distributed in tropical and temperate zones, providing the opportunity for CHIKV to continue to expand into new geographic regions. In October 2013, locally acquired cases of CHIKV infection were identified on the Caribbean island of Saint Martin, signaling the arrival of the virus in the Western Hemisphere. In just 9 months, CHIKV has spread to 22 countries in the Caribbean and Central and South America, resulting in hundreds of thousands of cases. CHIKV disease can be highly debilitating, and large epidemics have severe economic consequences. Thus, there is an urgent need for continued research into the epidemiology, pathogenesis, prevention, and treatment of these infections. PMID:25078691

  9. Marek's disease virus morphogenesis.

    PubMed

    Denesvre, Caroline

    2013-06-01

    Marek's disease virus (MDV) is a highly contagious virus that induces T-lymphoma in chicken. This viral infection still circulates in poultry flocks despite the use of vaccines. With the emergence of new virulent strains in the field over time, MDV remains a serious threat to the poultry industry. More than 40 yr after MDV identification as a herpesvirus, the visualization and purification of fully enveloped infectious particles remain a challenge for biologists. The various strategies used to detect such hidden particles by electron microscopy are reviewed herein. It is now generally accepted that the production of cell-free virions only occurs in the feather follicle epithelium and is associated with viral, cellular, or both molecular determinants expressed in this tissue. This tissue is considered the only source of efficient virus shedding into the environment and therefore the origin of successful transmission in birds. In other avian tissues or permissive cell cultures, MDV replication only leads to a very low number of intracellular enveloped virions. In the absence of detectable extracellular enveloped virions in cell culture, the nature of the transmitted infectious material and its mechanisms of spread from cell to cell remain to be deciphered. An attempt is made to bring together the current knowledge on MDV morphogenesis and spread, and new approaches that could help understand MDV morphogenesis are discussed. PMID:23901745

  10. Viruses manipulate the marine environment.

    PubMed

    Rohwer, Forest; Thurber, Rebecca Vega

    2009-05-14

    Marine viruses affect Bacteria, Archaea and eukaryotic organisms and are major components of the marine food web. Most studies have focused on their role as predators and parasites, but many of the interactions between marine viruses and their hosts are much more complicated. A series of recent studies has shown that viruses have the ability to manipulate the life histories and evolution of their hosts in remarkable ways, challenging our understanding of this almost invisible world. PMID:19444207

  11. NIAID's Role in Addressing West Nile Virus

    MedlinePLUS

    ... about to begin feeding on a human host. Credit: CDC West Nile Virus West Nile virus (WNV) ... encephalitis.​ Transmission electron micrograph of West Nile virus. Credit: CDC WNV was first isolated in Uganda in ...

  12. Human Immunodeficiency Virus (HIV) Primary Infection

    MedlinePLUS

    ... rashes clinical tools newsletter | contact Share | Human Immunodeficiency Virus (HIV) Primary Infection Information for adults A A ... weeks following exposure to HIV (the human immunodeficiency virus). Chronic infection with this virus can cause AIDS ( ...

  13. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePLUS

    ... Submit Button Past Newsletters Variant (Swine Origin) Influenza Viruses in Humans Language: English Español Recommend on ... United States since 2005 Background On Variant Influenza Viruses Swine flu viruses do not normally infect humans. ...

  14. NATIONAL RESPIRATORY AND ENTERIC VIRUS SURVEILLANCE SYSTEM

    EPA Science Inventory

    The National Respiratory and Enteric Virus Surveillance System is a lab based system which monitors temporal and geographic patterns associated with the detection of respiratory syncytial virus (RSV), human parainfluenza viruses (HPIV), respiratory and enteric adenoviruses, and r...

  15. WHO: Zika Virus an International Health Threat

    MedlinePLUS

    ... nih.gov/medlineplus/news/fullstory_157003.html WHO: Zika Virus an International Health Threat Virus suspected of causing ... Health Organization on Monday declared the mosquito-borne Zika virus a global health threat, based on the suspicion ...

  16. New Dengue Virus Vaccine Shows Promise

    MedlinePLUS

    ... Promise Research may also aid in development of Zika virus vaccine, expert suggests To use the sharing features ... of other major health concerns such as the Zika virus. "The dengue virus is closely related to Zika ...

  17. Introducing Virological Concepts Using an Insect Virus.

    ERIC Educational Resources Information Center

    Sheppard, Roger F.

    1980-01-01

    A technique is presented which utilizes wax moth larvae in a laboratory investigation of an insect virus. Describes how an insect virus can be used to introduce undergraduate biology students to laboratory work on viruses and several virological concepts. (SA)

  18. Advances in virus research. Volume 29

    SciTech Connect

    Lauffer, M.A.; Maramorosch, K.

    1984-01-01

    This book contains nine chapters. Some of the titles are: Molecular Biology of Wound Tumor Virus; The Application of Monoclonal Antibodies in the Study of Viruses; Prions: Novel Infectious Pathogens; and Monoclonal Antibodies Against Plant Viruses.

  19. RECOVIR Software for Identifying Viruses

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  20. Are Viruses Important in Carcinogenesis?

    PubMed Central

    Rapp, Fred; Buss, Ellen R.

    1974-01-01

    The role of viruses in the etiology of animal cancers is fairly certain. Information derived under both natural and experimental conditions supports the concept that either DNA- or RNA-containing viruses can fulfill this function. The DNA-containing herpesviruses, especially the Epstein-Barr virus, are currently the primary objects of intense investigation concerning their role in human cancer. This article will focus on the properties of counterpart herpesviruses in lower animals as well as the human virus candidates with an assessment of the observations concerning their oncogenic potential. ImagesFig 1 PMID:4374889

  1. Review: influenza virus in pigs.

    PubMed

    Crisci, Elisa; Mussá, Tufária; Fraile, Lorenzo; Montoya, Maria

    2013-10-01

    Influenza virus disease still remains one of the major threats to human health, involving a wide range of animal species and pigs play an important role in influenza ecology. Pigs were labeled as "mixing vessels" since they are susceptible to infection with avian, human and swine influenza viruses and genetic reassortment between these viruses can occur. After the H1N1 influenza pandemic of 2009 with a swine origin virus, the most recent research in "influenzology" is directed at improving knowledge of porcine influenza virus infection. This tendency is probably due to the fact that domestic pigs are closely related to humans and represent an excellent animal model to study various microbial infectious diseases. In spite of the role of the pig in influenza virus ecology, swine immune responses against influenza viruses are not fully understood. Considering these premises, the aim of this review is to focus on the in vitro studies performed with porcine cells and influenza virus and on the immune responses of pigs against human, avian and swine influenza viruses in vivo. The increased acceptance of pigs as suitable and valuable models in the scientific community may stimulate the development of new tools to assess porcine immune responses, paving the way for their consideration as the future "gold standard" large-animal model in immunology. PMID:23523121

  2. 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. PMID:26029198

  3. 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

  4. Interferon production and virus replication in lymphoblastoid cells infected with different viruses.

    PubMed

    Heremans, H; de Ley, M; Volckaert-Vervliet, G; Billiau, A

    1980-01-01

    A semicontinuous infection system was used to test viral replication and interferon induction in lymphoblastoid cells: measles virus, Newcastle disease virus (NDV), Sendai virus, human parainfluenza virus (type II and III), Semliki forest virus (SFV) and Vesicular stomatitis virus (VSV). With the exception of Sendai virus, all viruses replicated in the Namalva cell line. Only measles virus was able to induce high levels of interferon. Three other cell lines, NC37, Raji (TK+-variant) and Raji (TK--variant) were tested using measles virus as inducer. The interferon yields from these cells were inferior to those obtained from Namalva cells. PMID:6243928

  5. Avian infectious bronchitis virus.

    PubMed

    Ignjatovi?, J; Sapats, S

    2000-08-01

    Infectious bronchitis virus (IBV) is prevalent in all countries with an intensive poultry industry, with the incidence of infection approaching 100% in most locations. Vaccination is only partially successful due to the continual emergence of antigenic variants. At many sites, multiple antigenic types are simultaneously present, requiring the application of multiple vaccines. Although many countries share some common antigenic types, IBV strains within a geographic region are unique and distinct, examples are Europe, the United States of America and Australia. Measures to restrict the introduction of exotic IBV strains should therefore be considered. Infectious bronchitis has a significant economic impact; in broilers, production losses are due to poor weight gains, condemnation at processing and mortality, whilst in laying birds, losses are due to suboptimal egg production and downgrading of eggs. Chickens and commercially reared pheasants are the only natural hosts for IBV. Other species are not considered as reservoirs of IBV. The majority of IBV strains cause tracheal lesions and respiratory disease with low mortality due to secondary bacterial infections, primarily in broilers. Nephropathogenic strains, in addition to tracheal lesions, also induce prominent kidney lesions with mortality of up to 25% in broilers. Strains of both pathotypes infect adult birds and affect egg production and egg quality to a variable degree. Infected chicks are the major source of virus in the environment. Contaminated equipment and material are a potential source for indirect transmission over large distances. Virus is present in considerable titres in tracheal mucus and in faeces in the acute and recovery phases of disease, respectively. Virus spreads horizontally by aerosol (inhalation) or ingestion of faeces or contaminated feed or water. The virus is highly infectious. Clinical signs will develop in contact chicks within 36 h and in nearby sheds within one to two days. Infection is resolved within fourteen days with a rise in antibody titres. In a small number of chicks, latent infection is established with subsequent erratic shedding of virus for a prolonged period of time via both faeces and aerosol. Movement of live birds should be considered as a potential source for the introduction of IBV. Isolation and identification of IBV is needed for positive diagnosis. The preferred method of isolation is to passage a sample in embryonating specified-pathogen-free chicken eggs. Identification is either by monoclonal antibody based enzyme-linked immunosorbent assay (ELISA) or polymerase chain reaction. Virus neutralisation test in tracheal organ culture is the best method for antigenic typing. Continual use of live vaccines complicates diagnosis since no simple diagnostic tool can differentiate a field from a vaccine strain. Nucleotide sequencing of the S1 glycoprotein is the only method to discriminate between all IBV strains. Serology is also complicated by continual use of live vaccines. For surveillance purposes, ELISA is the method of choice, regardless of the antigenic type of IBV involved. The assay is used to monitor the response to vaccination, but field challenge can only be detected if flock antibody status is monitored continually. The antigenic type of a challenge strain involved cannot be ascertained by ELISA. PMID:10935276

  6. Structure of Flexible Filamentous Plant Viruses

    SciTech Connect

    Kendall, Amy; McDonald, Michele; Bian, Wen; Bowles, Timothy; Baumgarten, Sarah C.; Shi, Jian; Stewart, Phoebe L.; Bullitt, Esther; Gore, David; Irving, Thomas C.; Havens, Wendy M.; Ghabrial, Said A.; Wall, Joseph S.; Stubbs, Gerald

    2008-10-23

    Flexible filamentous viruses make up a large fraction of the known plant viruses, but in comparison with those of other viruses, very little is known about their structures. We have used fiber diffraction, cryo-electron microscopy, and scanning transmission electron microscopy to determine the symmetry of a potyvirus, soybean mosaic virus; to confirm the symmetry of a potexvirus, potato virus X; and to determine the low-resolution structures of both viruses. We conclude that these viruses and, by implication, most or all flexible filamentous plant viruses share a common coat protein fold and helical symmetry, with slightly less than 9 subunits per helical turn.

  7. 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.

  8. 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...

  9. Parainfluenza Virus 5 Expressing the G Protein of Rabies Virus Protects Mice after Rabies Virus Infection

    PubMed Central

    Huang, Ying; Chen, Zhenhai; Huang, Junhua

    2014-01-01

    Rabies remains a major public health threat around the world. Once symptoms appear, there is no effective treatment to prevent death. In this work, we tested a recombinant parainfluenza virus 5 (PIV5) strain expressing the glycoprotein (G) of rabies (PIV5-G) as a therapy for rabies virus infection: we have found that PIV5-G protected mice as late as 6 days after rabies virus infection. PIV5-G is a promising vaccine for prevention and treatment of rabies virus infection. PMID:25552723

  10. Parainfluenza virus 5 expressing the G protein of rabies virus protects mice after rabies virus infection.

    PubMed

    Huang, Ying; Chen, Zhenhai; Huang, Junhua; Fu, ZhenFang; He, Biao

    2015-03-01

    Rabies remains a major public health threat around the world. Once symptoms appear, there is no effective treatment to prevent death. In this work, we tested a recombinant parainfluenza virus 5 (PIV5) strain expressing the glycoprotein (G) of rabies (PIV5-G) as a therapy for rabies virus infection: we have found that PIV5-G protected mice as late as 6 days after rabies virus infection. PIV5-G is a promising vaccine for prevention and treatment of rabies virus infection. PMID:25552723

  11. Paper Models Illustrating Virus Symmetry.

    ERIC Educational Resources Information Center

    McCarthy, D. A.

    1990-01-01

    Instructions are given for constructing two models, one to illustrate the general principles of symmetry in T=1, T=3, and T=4 viruses, and the other to illustrate the disposition of protein subunits in the T=3 plant viruses and the picornaviruses. (Author/CW)

  12. Antiviral immunity and virus vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As obligate intracellular organisms, viruses have co-evolved with their respective host species, which in turn have evolved diverse and sophisticated capabilities to protect themselves against viral infections and their associated diseases. Viruses have also evolved a remarkable variety of strategie...

  13. 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 organismthe virusproducing 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.

  14. Virioplankton: Viruses in Aquatic Ecosystems†

    PubMed Central

    Wommack, K. Eric; Colwell, Rita R.

    2000-01-01

    The discovery that viruses may be the most abundant organisms in natural waters, surpassing the number of bacteria by an order of magnitude, has inspired a resurgence of interest in viruses in the aquatic environment. Surprisingly little was known of the interaction of viruses and their hosts in nature. In the decade since the reports of extraordinarily large virus populations were published, enumeration of viruses in aquatic environments has demonstrated that the virioplankton are dynamic components of the plankton, changing dramatically in number with geographical location and season. The evidence to date suggests that virioplankton communities are composed principally of bacteriophages and, to a lesser extent, eukaryotic algal viruses. The influence of viral infection and lysis on bacterial and phytoplankton host communities was measurable after new methods were developed and prior knowledge of bacteriophage biology was incorporated into concepts of parasite and host community interactions. The new methods have yielded data showing that viral infection can have a significant impact on bacteria and unicellular algae populations and supporting the hypothesis that viruses play a significant role in microbial food webs. Besides predation limiting bacteria and phytoplankton populations, the specific nature of virus-host interaction raises the intriguing possibility that viral infection influences the structure and diversity of aquatic microbial communities. Novel applications of molecular genetic techniques have provided good evidence that viral infection can significantly influence the composition and diversity of aquatic microbial communities. PMID:10704475

  15. INFECTIOUS DOSE OF NORWALK VIRUS

    EPA Science Inventory

    The Norwalk virus and related viruses (caliciviruses) have been identified as a common cause of waterborne disease. Moreover, there are many outbreaks of waterborne disease every year where the causative agent was never identified, and it is thought that many of these are due to ...

  16. 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 ...

  17. Influenza Virus Assembly and Budding

    PubMed Central

    Rossman, Jeremy S.; Lamb, Robert A.

    2011-01-01

    Influenza A virus causes seasonal epidemics, sporadic pandemics and is a significant global heath burden. Influenza virus is an enveloped virus that contains a segmented negative strand RNA genome. Assembly and budding of progeny influenza virions is a complex, multistep process that occurs in lipid raft domains on the apical membrane of infected cells. The viral proteins hemagglutinin (HA) and neuraminidase (NA) are targeted to lipid rafts, causing the coalescence and enlargement of the raft domains. This clustering of HA and NA may cause a deformation of the membrane and the initiation of the virus budding event. M1 is then thought to bind to the cytoplasmic tails of HA and NA where it can then polymerize and form the interior structure of the emerging virion. M1, bound to the cytoplasmic tails of HA and NA, additionally serves as a docking site for the recruitment of the viral RNPs and may mediate the recruitment of M2 to the site of virus budding. M2 initially stabilizes the site of budding, possibly enabling the polymerization of the matrix protein and the formation of filamentous virions. Subsequently, M2 is able to alter membrane curvature at the neck of the budding virus, causing membrane scission and the release of the progeny virion. This review investigates the latest research on influenza virus budding in an attempt to provide a step-by-step analysis of the assembly and budding processes for influenza viruses. PMID:21237476

  18. Virus Detection and Field Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are two primary pathogens of Oat Crown Rust and the Luteoviruses Barley and Cereal Yellow Dwarf Virus (BYDV and CYDV). These viruses can only be transmitted by aphids, are limited to the vascular system in infected plants and can lead to severe stunting and a concomitant yield loss. In 200...

  19. 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...

  20. Zika Virus Infection and Microcephaly.

    PubMed

    Millichap, J Gordon

    2016-01-01

    A Task Force established by the Brazil Ministry of Health investigated the possible association of microcephaly with Zika virus infection during pregnancy and a registry for microcephaly cases among women suspected to have had Zika virus infection during pregnancy. PMID:27004142

  1. Genetic Diversity of Toscana Virus

    PubMed Central

    Collao, Ximena; Palacios, Gustavo; Sanbonmatsu-Gmez, Sara; Prez-Ruiz, Mercedes; Negredo, Ana I.; Navarro-Mar, Jos-Mara; Grandadam, Marc; Aransay, Ana Maria; Lipkin, W. Ian; Tenorio, Antonio

    2009-01-01

    Distribution of Toscana virus (TOSV) is evolving with climate change, and pathogenicity may be higher in nonexposed populations outside areas of current prevalence (Mediterranean Basin). To characterize genetic diversity of TOSV, we determined the coding sequences of isolates from Spain and France. TOSV is more diverse than other well-studied phleboviruses (e.g.,Rift Valley fever virus). PMID:19331735

  2. Tobacco ringspot virus in Rubus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tobacco ringspot virus (TRSV) has a broad host range among woody and perennial plants and has been reported from blackberry but not from red or black raspberry. The virus has been detected in blackberry in the southeastern United States with a single report from blackberry in British Columbia, Cana...

  3. Tomato ringspot virus in Rubus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato ringspot virus (ToRSV) is the most widespread and important of the nematode-transmitted viruses affecting cultivated Rubus in North and South America but is not known to occur outside of the Western Hemisphere. A recent report from Turkey on ToRSV in blackberry in borders of stone fruit orcha...

  4. Groundnut Ringspot Virus in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tospoviruses in vegetable crops are difficult to manage due to a shortage of basic information about the viruses and their vectors. This is especially true for the recently detected Groundnut ringspot virus (GRSV). This publication presents all current knowledge of GRSV in Florida....

  5. New aspects of influenza viruses.

    PubMed Central

    Shaw, M W; Arden, N H; Maassab, H F

    1992-01-01

    Influenza virus infections continue to cause substantial morbidity and mortality with a worldwide social and economic impact. The past five years have seen dramatic advances in our understanding of viral replication, evolution, and antigenic variation. Genetic analyses have clarified relationships between human and animal influenza virus strains, demonstrating the potential for the appearance of new pandemic reassortants as hemagglutinin and neuraminidase genes are exchanged in an intermediate host. Clinical trials of candidate live attenuated influenza virus vaccines have shown the cold-adapted reassortants to be a promising alternative to the currently available inactivated virus preparations. Modern molecular techniques have allowed serious consideration of new approaches to the development of antiviral agents and vaccines as the functions of the viral genes and proteins are further elucidated. The development of techniques whereby the genes of influenza viruses can be specifically altered to investigate those functions will undoubtedly accelerate the pace at which our knowledge expands. PMID:1310439

  6. Epidemic of cell phone virus

    NASA Astrophysics Data System (ADS)

    Wang, Pu; Gonzlez, Marta; Barabsi, Albert-Lszl.

    2008-03-01

    Standard operating systems and Bluetooth technology will be a trend for future cell phone features. These will enable cell phone viruses to spread either through SMS or by sending Bluetooth requests when cell phones are physically close enough. The difference in spreading methods gives these two types of viruses' different epidemiological characteristics. SMS viruses' spread is mainly based on people's social connections, whereas the spreading of Bluetooth viruses is affected by people's mobility patterns and population distribution. Using cell phone data recording calls, SMS and locations of more than 6 million users, we study the spread of SMS and Bluetooth viruses and characterize how the social network and the mobility of mobile phone users affect such spreading processes.

  7. 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.

  8. Virus manipulation of cell cycle.

    PubMed

    Nascimento, R; Costa, H; Parkhouse, R M E

    2012-07-01

    Viruses depend on host cell resources for replication and access to those resources may be limited to a particular phase of the cell cycle. Thus manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment. For example, viruses capable of infecting nondividing cells induce S phase in order to activate the host DNA replication machinery and provide the nucleotide triphosphates necessary for viral DNA replication (Flemington in J Virol 75:4475-4481, 2001; Sullivan and Pipas in Microbiol Mol Biol Rev 66:179-202, 2002). Viruses have developed several strategies to subvert the cell cycle by association with cyclin and cyclin-dependent kinase complexes and molecules that regulate their activity. Viruses tend to act on cellular proteins involved in a network of interactions in a way that minimal protein-protein interactions lead to a major effect. The complex and interactive nature of intracellular signaling pathways controlling cell division affords many opportunities for virus manipulation strategies. Taking the maxim "Set a thief to catch a thief" as a counter strategy, however, provides us with the very same virus evasion strategies as "ready-made tools" for the development of novel antivirus therapeutics. The most obvious are attenuated virus vaccines with critical evasion genes deleted. Similarly, vaccines against viruses causing cancer are now being successfully developed. Finally, as viruses have been playing chess with our cell biology and immune responses for millions of years, the study of their evasion strategies will also undoubtedly reveal new control mechanisms and their corresponding cellular intracellular signaling pathways. PMID:21986922

  9. The Acute bee paralysis virus-Kashmir bee virus-Israeli acute paralysis virus complex.

    PubMed

    de Miranda, Joachim R; Cordoni, Guido; Budge, Giles

    2010-01-01

    Acute bee paralysis virus (ABPV), Kashmir bee virus (KBV) and Israeli acute paralysis virus (IAPV) are part of a complex of closely related viruses from the Family Dicistroviridae. These viruses have a widespread prevalence in honey bee (Apis mellifera) colonies and a predominantly sub-clinical etiology that contrasts sharply with the extremely virulent pathology encountered at elevated titres, either artificially induced or encountered naturally. These viruses are frequently implicated in honey bee colony losses, especially when the colonies are infested with the parasitic mite Varroa destructor. Here we review the historical and recent literature of this virus complex, covering history and origins; the geographic, host and tissue distribution; pathology and transmission; genetics and variation; diagnostics, and discuss these within the context of the molecular and biological similarities and differences between the viruses. We also briefly discuss three recent developments relating specifically to IAPV, concerning its association with Colony Collapse Disorder, treatment of IAPV infection with siRNA and possible honey bee resistance to IAPV. PMID:19909972

  10. 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

  11. Dengue virus vaccine development.

    PubMed

    Yauch, Lauren E; Shresta, Sujan

    2014-01-01

    Dengue virus (DENV) is a significant cause of morbidity and mortality in tropical and subtropical regions, causing hundreds of millions of infections each year. Infections range from asymptomatic to a self-limited febrile illness, dengue fever (DF), to the life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The expanding of the habitat of DENV-transmitting mosquitoes has resulted in dramatic increases in the number of cases over the past 50 years, and recent outbreaks have occurred in the United States. Developing a dengue vaccine is a global health priority. DENV vaccine development is challenging due to the existence of four serotypes of the virus (DENV1-4), which a vaccine must protect against. Additionally, the adaptive immune response to DENV may be both protective and pathogenic upon subsequent infection, and the precise features of protective versus pathogenic immune responses to DENV are unknown, complicating vaccine development. Numerous vaccine candidates, including live attenuated, inactivated, recombinant subunit, DNA, and viral vectored vaccines, are in various stages of clinical development, from preclinical to phase 3. This review will discuss the adaptive immune response to DENV, dengue vaccine challenges, animal models used to test dengue vaccine candidates, and historical and current dengue vaccine approaches. PMID:24373316

  12. 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...

  13. 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.

  14. Comparison of Immunohistochemistry and Virus Isolation for Diagnosis of West Nile Virus

    PubMed Central

    Ellis, Angela E.; Mead, Daniel G.; Allison, Andrew B.; Gibbs, Samantha E. J.; Gottdenker, Nicole L.; Stallknecht, David E.; Howerth, Elizabeth W.

    2005-01-01

    Immunohistochemistry and virus isolation were performed on 1,057 birds. Immunohistochemistry, virus isolation, or both found 325 birds to be West Nile virus positive. Of these, 271 were positive by both methods. These results indicate that virus isolation and immunohistochemistry are approximately equal in their ability to detect West Nile virus. PMID:15956415

  15. Live-attenuated influenza A virus vaccines using a B virus backbone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The currently FDA-licensed live attenuated influenza virus vaccine contains a trivalent mixture of types A (H1N1 and H3N2) and B vaccine viruses. The two A virus vaccines have the backbone of a cold-adapted influenza A virus and the B virus vaccine has the six backbone segments derived from a cold-...

  16. 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 transcriptionPCR; 6 samples were positive for both viruses. PMID:19624923

  17. Safe Computing: An Overview of Viruses.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    2001-01-01

    A computer virus is a program that replicates itself, in conjunction with an additional program that can harm a computer system. Common viruses include boot-sector, macro, companion, overwriting, and multipartite. Viruses can be fast, slow, stealthy, and polymorphic. Anti-virus products are described. (MLH)

  18. Getah Virus Infection among Racehorses, Japan, 2014.

    PubMed

    Nemoto, Manabu; Bannai, Hiroshi; Tsujimura, Koji; Kobayashi, Minoru; Kikuchi, Takuya; Yamanaka, Takashi; Kondo, Takashi

    2015-05-01

    An outbreak of Getah virus infection occurred among racehorses in Japan during September and October 2014. Of 49 febrile horses tested by reverse transcription PCR, 25 were positive for Getah virus. Viruses detected in 2014 were phylogenetically different from the virus isolated in Japan in 1978. PMID:25898181

  19. Transmitting plant viruses using whiteflies.

    PubMed

    Polston, Jane E; Capobianco, H

    2013-01-01

    Whiteflies, Hemiptera: Aleyrodidae, Bemisia tabaci, a complex of morphologically indistinquishable species(5), are vectors of many plant viruses. Several genera of these whitefly-transmitted plant viruses (Begomovirus, Carlavirus, Crinivirus, Ipomovirus, Torradovirus) include several hundred species of emerging and economically significant pathogens of important food and fiber crops (reviewed by(9,10,16)). These viruses do not replicate in their vector but nevertheless are moved readily from plant to plant by the adult whitefly by various means (reviewed by(2,6,7,9,10,11,17)). For most of these viruses whitefly feeding is required for acquisition and inoculation, while for others only probing is required. Many of these viruses are unable or cannot be easily transmitted by other means. Therefore maintenance of virus cultures, biological and molecular characterization (identification of host range and symptoms)(3,13), ecology(2,12), require that the viruses be transmitted to experimental hosts using the whitefly vector. In addition the development of new approaches to management, such as evaluation of new chemicals(14) or compounds(15), new cultural approaches(1,4,19), or the selection and development of resistant cultivars(7,8,18), requires the use of whiteflies for virus transmission. The use of whitefly transmission of plant viruses for the selection and development of resistant cultivars in breeding programs is particularly challenging(7). Effective selection and screening for resistance employs large numbers of plants and there is a need for 100% of the plants to be inoculated in order to find the few genotypes which possess resistance genes. These studies use very large numbers of viruliferous whiteflies, often several times per year. Whitefly maintenance described here can generate hundreds or thousands of adult whiteflies on plants each week, year round, without the contamination of other plant viruses. Plants free of both whiteflies and virus must be produced to introduce into the whitefly colony each week. Whitefly cultures must be kept free of whitefly pathogens, parasites, and parasitoids that can reduce whitefly populations and/or reduce the transmission efficiency of the virus. Colonies produced in the manner described can be quickly scaled to increase or decrease population numbers as needed, and can be adjusted to accommodate the feeding preferences of the whitefly based on the plant host of the virus. There are two basic types of whitefly colonies that can be maintained: a nonviruliferous and a viruliferous whitefly colony. The nonviruliferous colony is composed of whiteflies reared on virus-free plants and allows the weekly availability of whiteflies which can be used to transmit viruses from different cultures. The viruliferous whitefly colony, composed of whiteflies reared on virus-infected plants, allows weekly availability of whiteflies which have acquired the virus thus omitting one step in the virus transmission process. PMID:24300175

  20. Transmitting Plant Viruses Using Whiteflies

    PubMed Central

    Polston, Jane E.; Capobianco, H.

    2013-01-01

    Whiteflies, Hemiptera: Aleyrodidae, Bemisia tabaci, a complex of morphologically indistinquishable species5, are vectors of many plant viruses. Several genera of these whitefly-transmitted plant viruses (Begomovirus, Carlavirus, Crinivirus, Ipomovirus, Torradovirus) include several hundred species of emerging and economically significant pathogens of important food and fiber crops (reviewed by9,10,16). These viruses do not replicate in their vector but nevertheless are moved readily from plant to plant by the adult whitefly by various means (reviewed by2,6,7,9,10,11,17). For most of these viruses whitefly feeding is required for acquisition and inoculation, while for others only probing is required. Many of these viruses are unable or cannot be easily transmitted by other means. Therefore maintenance of virus cultures, biological and molecular characterization (identification of host range and symptoms)3,13, ecology2,12, require that the viruses be transmitted to experimental hosts using the whitefly vector. In addition the development of new approaches to management, such as evaluation of new chemicals14 or compounds15, new cultural approaches1,4,19, or the selection and development of resistant cultivars7,8,18, requires the use of whiteflies for virus transmission. The use of whitefly transmission of plant viruses for the selection and development of resistant cultivars in breeding programs is particularly challenging7. Effective selection and screening for resistance employs large numbers of plants and there is a need for 100% of the plants to be inoculated in order to find the few genotypes which possess resistance genes. These studies use very large numbers of viruliferous whiteflies, often several times per year. Whitefly maintenance described here can generate hundreds or thousands of adult whiteflies on plants each week, year round, without the contamination of other plant viruses. Plants free of both whiteflies and virus must be produced to introduce into the whitefly colony each week. Whitefly cultures must be kept free of whitefly pathogens, parasites, and parasitoids that can reduce whitefly populations and/or reduce the transmission efficiency of the virus. Colonies produced in the manner described can be quickly scaled to increase or decrease population numbers as needed, and can be adjusted to accommodate the feeding preferences of the whitefly based on the plant host of the virus. There are two basic types of whitefly colonies that can be maintained: a nonviruliferous and a viruliferous whitefly colony. The nonviruliferous colony is composed of whiteflies reared on virus-free plants and allows the weekly availability of whiteflies which can be used to transmit viruses from different cultures. The viruliferous whitefly colony, composed of whiteflies reared on virus-infected plants, allows weekly availability of whiteflies which have acquired the virus thus omitting one step in the virus transmission process. PMID:24300175

  1. Viruses and interactomes in translation.

    PubMed

    Meyniel-Schicklin, Laurne; de Chassey, Benot; Andr, Patrice; Lotteau, Vincent

    2012-07-01

    A decade of high-throughput screenings for intraviral and virus-host protein-protein interactions led to the accumulation of data and to the development of theories on laws governing interactome organization for many viruses. We present here a computational analysis of intraviral protein networks (EBV, FLUAV, HCV, HSV-1, KSHV, SARS-CoV, VACV, and VZV) and virus-host protein networks (DENV, EBV, FLUAV, HCV, and VACV) from up-to-date interaction data, using various mathematical approaches. If intraviral networks seem to behave similarly, they are clearly different from the human interactome. Viral proteins target highly central human proteins, which are precisely the Achilles' heel of the human interactome. The intrinsic structural disorder is a distinctive feature of viral hubs in virus-host interactomes. Overlaps between virus-host data sets identify a core of human proteins involved in the cellular response to viral infection and in the viral capacity to hijack the cell machinery for viral replication. Host proteins that are strongly targeted by a virus seem to be particularly attractive for other viruses. Such protein-protein interaction networks and their analysis represent a powerful resource from a therapeutic perspective. PMID:22371486

  2. Hepatitis viruses: changing patterns of human disease.

    PubMed Central

    Purcell, R H

    1994-01-01

    Viral hepatitis is a disease of antiquity, but evidence for more than one etiologic agent has been recognized only since the 1940s, when two viruses (hepatitis A virus and hepatitis B virus) were thought to account for all disease. In the past 20 years, three additional hepatitis agents (hepatitis C virus, hepatitis D virus, and hepatitis E virus) have been discovered, and there is evidence for at least one additional virus. Each of the five recognized hepatitis viruses belongs to a different virus family, and each has a unique epidemiology. The medical impact of these viruses on society has been strongly influenced by changes in human ecology. This has resulted in some cases in diminished disease and in others in increases in the incidence of disease. PMID:8146130

  3. Improving the performance of the Granulosis virus of Codling moth (Lepidoptera: Tortricideae) by adding the yeast Saccharomyces cerevisiae with sugar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies evaluated the effectiveness of adding Saccharomyces cerevisiae with brown cane sugar (sugar) to the codling moth granulosis virus, CpGV, to improve larval control of Cydia pomonella (L.), on apple. Neither the use of the yeast or sugar alone caused larval mortality greater than the water con...

  4. Xenotropic Murine Leukemia Virus-related Virus (XMRV) Backgrounder

    Cancer.gov

    Researchers have not found evidence that XMRV causes any diseases in humans or in animals. The presence of an infectious agent, such as a virus, in diseased tissue does not mean that the agent causes the disease.

  5. Antiviral Drugs for Viruses Other Than Human Immunodeficiency Virus

    PubMed Central

    Razonable, Raymund R.

    2011-01-01

    Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M2 protein or the enzyme neuraminidase. Combination therapy with Interferon-? and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess antihuman immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M2 inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects. PMID:21964179

  6. 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

  7. Feline immunodeficiency virus latency

    PubMed Central

    2013-01-01

    Despite highly effective anti-retroviral therapy, HIV is thought to persist in patients within long-lived cellular reservoirs in the form of a transcriptionally inactive (latent) integrated provirus. Lentiviral latency has therefore come to the forefront of the discussion on the possibility of a cure for HIV infection in humans. Animal models of lentiviral latency provide an essential tool to study mechanisms of latency and therapeutic manipulation. Of the three animal models that have been described, the feline immunodeficiency virus (FIV)-infected cat is the most recent and least characterized. However, several aspects of this model make it attractive for latency research, and it may be complementary to other model systems. This article reviews what is known about FIV latency and chronic FIV infection and how it compares with that of other lentiviruses. It thereby offers a framework for the usefulness of this model in future research aimed at lentiviral eradication. PMID:23829177

  8. 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

  9. Biosynthesis of Sindbis virus and vesicular stomatitis virus membrane glycoproteins

    SciTech Connect

    Davidson, S.K.F.

    1984-01-01

    Vesicular stomatitis virus and Sindbis virus are RNA-containing viruses which contain one and two major glycoprotein species, respectively, in their lipid-envelopes. These viruses are excellent models for the study of the biosynthesis of integral membrane glycoproteins, both viral and cellular. Both viruses have an extremely wide host cell range in tissue culture, and rapidly inhibit host cell protein synthesis, so that radiolabeled viral glycoproteins synthesized during replication of the viruses are both easily identifiable and abundantly available for analysis. Whereas the viral genomes encode the polypeptide backbones of the glycoproteins, the proteins are glycosylated and transported to the plasma membrane entirely by host cell machinery. The studies presented here have utilized metabolic labelling of the oligosaccharide moieties of the Sindbis and vesicular stomatitis viral glycoproteins with (/sup 3/H) mannose and labeling of the viral polypeptides with (/sup 3/H) leucine, to examine factors which influence the biosynthesis of precursor oligosaccharides and their maturation to different types of mature oligosaccharides. The possible mechanisms and biological significance of both the precursor and mature oligosaccharides of the viral glycoproteins are discussed.

  10. Hepatitis G virus: is it a hepatitis virus?

    PubMed Central

    Cheung, R C; Keeffe, E B; Greenberg, H B

    1997-01-01

    Hepatitis G virus (HGV) and GB virus C (GBV-C) are two newly discovered viral agents, different isolates of a positive-sense RNA virus that represents a new genus of Flaviviridae. The purpose of this review is to analyze new data that have recently been published on the epidemiology and associations between HGV and liver diseases such as posttransfusion hepatitis, acute and chronic non-A-E hepatitis, fulminant hepatitis, cryptogenic cirrhosis, and hepatocellular carcinoma. The role of HGV in coinfection with other hepatitis viruses, the response to antiviral therapy, and the impact of HGV on liver transplantation are also discussed. HGV is a transmissible blood-borne viral agent that frequently occurs as a coinfection with other hepatitis viruses due to common modes of transmission. The prevalence of HGV ranges from 0.9 to 10% among blood donors throughout the world and is found in 1.7% of volunteer blood donors in the United States. The majority of patients infected with HGV by blood transfusion do not develop chronic hepatitis, but hepatitis G viremia frequently persists without biochemical evidence of hepatitis. Serum HGV RNA has been found in 0 to 50% of patients with fulminant hepatitis of unknown etiology and 14 to 36% of patients with cryptogenic cirrhosis. The association between HGV and chronic non-A-E hepatitis remains unclear. Although HGV appears to be a hepatotrophic virus, its role in independently causing acute and chronic liver diseases remains uncertain. PMID:9265860

  11. Concomitant administration of GonaCon and rabies vaccine in female dogs (Canis familiaris) in Mexico.

    PubMed

    Vargas-Pino, Fernando; Gutirrez-Cedillo, Vernica; Canales-Vargas, Erick J; Gress-Ortega, Luis R; Miller, Lowell A; Rupprecht, Charles E; Bender, Scott C; Garca-Reyna, Patricia; Ocampo-Lpez, Juan; Slate, Dennis

    2013-09-13

    Mexico serves as a global model for advances in rabies prevention and control in dogs. The Mexican Ministry of Health (MMH) annual application of approximately 16 million doses of parenteral rabies vaccine has resulted in significant reductions in canine rabies during the past 20 years. One collateral parameter of rabies programs is dog population management. Enhanced public awareness is critical to reinforce responsible pet ownership. Surgical spaying and neutering remain important to prevent reproduction, but are impractical for achieving dog population management goals. GonaCon, an anti-gonadotropin releasing hormone (GnRH) vaccine, was initially tested in captive female dogs on the Navajo Nation, 2008. The MMH led this international collaborative study on an improved formulation of GonaCon in captive dogs with local representatives in Hidalgo, Mexico in 2011. This study contained 20 bitches assigned to Group A (6 control), Group B (7 GonaCon), and Group C (7 GonaCon and rabies vaccine). Vaccines were delivered IM. Animals were placed under observation and evaluated during the 61-day trial. Clinically, all dogs behaved normally. No limping or prostration was observed, in spite of minor muscle atrophy post-mortem in the left hind leg of dogs that received GonaCon. Two dogs that began the study pregnant give birth to healthy pups. Dogs that received a GonaCon injection had macro and microscopic lesions consistent with prior findings, but the adverse injection effects were less frequent and lower in intensity. Both vaccines were immunogenic based on significant increases in rabies virus neutralizing antibodies and anti-GnRH antibodies in treatment Groups B and C. Simultaneous administration of GonaCon and rabies vaccine in Group C did not affect immunogenicity. Progesterone was suppressed significantly in comparison to controls. Future studies that monitor fertility through multiple breeding cycles represent a research need to determine the value of integrating this vaccine into dog rabies management. PMID:23871822

  12. Viruses of eukaryotice green algae

    SciTech Connect

    Van Etten, J.L.

    1989-01-01

    The primary objective of our research was to develop the Chlorella-PBCV-1 virus system so that it can be used as a model system for studying gene expression in a photosynthetic eukaryote. We have made considerable progress and have learned much about PBCV-1 and its replication cycle. In addition, several significant discoveries were made in the last 3 to 4 years. These discoveries include: (i) the finding that morphologically similar, plaque forming, dsDNA containing viruses are common in nature and can be isolated readily from fresh water, (ii) the finding that all of these Chlorella viruses contain methylated bases which range in concentration from 0.1% to 47.5% m{sup 5}dC and 0 to 37% m{sup 6}dA and (iii) the discovery that infection with at least some of these viruses induces the appearance of DNA modification/restriction systems. 26 refs.

  13. About Human Parainfluenza Viruses (HPIVs)

    MedlinePLUS

    ... Overview Laboratory Diagnosis HPIV Seasons Resources & References About Human Parainfluenza Viruses (HPIVs) Recommend on Facebook Tweet Share ... 6348 Email CDC-INFO U.S. Department of Health & Human Services HHS/Open USA.gov Top

  14. 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...

  15. Rabies virus assembly and budding.

    PubMed

    Okumura, Atsushi; Harty, Ronald N

    2011-01-01

    Rabies virus (RABV) and other negative-strand RNA viruses are the causes of serious diseases in humans and animals worldwide. Assembly and budding are important late events in the replication cycles of these negative-strand RNA viruses that have received much attention in the past decade. Indeed, important insights into the molecular mechanisms by which rhabdoviral proteins usurp and/or interact with host proteins to promote efficient virion assembly and egress has greatly enhanced our understanding of the budding process. Assembly/budding of rhabdoviruses is driven largely by the matrix (M) protein. RABV M protein contains a late budding domain that mediates the recruitment of host proteins linked to the vacuolar protein sorting pathway of the cell to facilitate virus-cell separation. This chapter summarizes our current knowledge of the roles that both RABV M protein and interacting host proteins play during the budding process. PMID:21601040

  16. Imaging luciferase-expressing viruses.

    PubMed

    Barry, Michael A; May, Shannon; Weaver, Eric A

    2012-01-01

    Optical imaging of luciferage gene expression has become a powerful tool to track cells and viruses in vivo in small animal models. Luciferase imaging has been used to study the location of infection by replication-defective and replication-competent viruses and to track changes in the distribution of viruses in mouse models. This approach has also been used in oncolytic studies as a noninvasive means to monitor the growth and killing of tumor cells modified with luciferase genes. In this chapter, we describe the techniques used for luciferase imaging as have been applied to track replication-defective and replication-competent adenoviruses in mouse and hamster models of oncolysis and virus pharmacology. Although these methods are simple, the process of obtaining accurate luciferase imaging data has many caveats that are discussed. PMID:21948470

  17. The genome of swinepox virus.

    PubMed

    Afonso, C L; Tulman, E R; Lu, Z; Zsak, L; Osorio, F A; Balinsky, C; Kutish, G F; Rock, D L

    2002-01-01

    Swinepox virus (SWPV), the sole member of the Suipoxvirus genus of the Poxviridae, is the etiologic agent of a worldwide disease specific for swine. Here we report the genomic sequence of SWPV. The 146-kbp SWPV genome consists of a central coding region bounded by identical 3.7-kbp inverted terminal repeats and contains 150 putative genes. Comparison of SWPV with chordopoxviruses reveals 146 conserved genes encoding proteins involved in basic replicative functions, viral virulence, host range, and immune evasion. Notably, these include genes with similarity to genes for gamma interferon (IFN-gamma) receptor, IFN resistance protein, interleukin-18 binding protein, IFN-alpha/beta binding protein, extracellular enveloped virus host range protein, dUTPase, hydroxysteroid dehydrogenase, superoxide dismutase, serpin, herpesvirus major histocompatibility complex inhibitor, ectromelia virus macrophage host range protein, myxoma virus M011L, variola virus B22R, four ankyrin repeat proteins, three kelch-like proteins, five vaccinia virus (VV) A52R-like family proteins, and two G protein-coupled receptors. The most conserved genomic region is centrally located and corresponds to the VV region located between genes F9L and A38L. Within the terminal 13 kbp, colinearity is disrupted and multiple poxvirus gene homologues are absent or share a lower percentage of amino acid identity. Most of these differences involve genes and gene families with likely functions involving viral virulence and host range. Three open reading frames (SPV018, SPV019. and SPV020) are unique for SWPV. Phylogenetic analysis, genome organization, and amino acid identity indicate that SWPV is most closely related to the capripoxvirus lumpy skin disease virus, followed by the yatapoxvirus yaba-like disease virus and the leporipoxviruses. The gene complement of SWPV better defines Suipoxvirus within the Chordopoxvirinae subfamily and provides a basis for future genetic comparisons. PMID:11752168

  18. Virus detection using nanoelectromechanical devices

    NASA Astrophysics Data System (ADS)

    Ilic, B.; Yang, Y.; Craighead, H. G.

    2004-09-01

    We have used a resonating mechanical cantilever to detect immunospecific binding of viruses, captured from liquid. As a model virus, we used a nonpathogenic insect baculovirus to test the ability to specifically bind and detect small numbers of virus particles. Arrays of surface micromachined, antibody-coated polycrystalline silicon nanomechanical cantilever beams were used to detect binding from various concentrations of baculoviruses in a buffer solution. Because of their small mass, the 0.5μm×6μm cantilevers have mass sensitivities on the order of 10-19g/Hz, enabling the detection of an immobilized AcV1 antibody monolayer corresponding to a mass of about 3×10-15g. With these devices, we can detect the mass of single-virus particles bound to the cantilever. Resonant frequency shift resulting from the adsorbed mass of the virus particles distinguished solutions of virus concentrations varying between 105 and 107pfu/ml. Control experiments using buffer solutions without baculovirus showed small amounts (<50attograms) of nonspecific adsorption to the antibody layer.

  19. 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

  20. Antigenic and Morphological Similarities of Progressive Pneumonia Virus, a Recently Isolated Slow Virus of Sheep, to Visna and Maedi Viruses

    PubMed Central

    Takemoto, K. K.; Mattern, C. F. T.; Stone, L. B.; Coe, J. E.; Lavelle, G.

    1971-01-01

    Progressive pneumonia virus, the causative agent of a slow, pulmonary disease of Montana sheep, was shown to be antigenically related to two other slow viruses of sheep, visna and maedi. Electron microscopic examination of infected cells revealed that the virus matures by a budding process and that the budding particles as well as the mature, extracellular virions bear striking resemblances to the oncogenic ribonucleic acid (RNA) viruses. Recent findings of an RNA-dependent deoxyribonucleic acid polymerase associated with the virions of this group of slow viruses lend further support to the notion that they may tentatively be classified with the oncogenic RNA tumor viruses. Images PMID:4101223

  1. Trazando la materia oscura con cmulos globulares

    NASA Astrophysics Data System (ADS)

    Forte, J. C.

    Se describe la estrategia adoptada para mapear la distribucin de materia oscura y barinica en galaxias elpticas cuyos cmulos globulares estn siendo observados con los telescopios VLT y Gemini. Se ejemplifican los resultados con los datos obtenidos en el cmulo de Fornax.

  2. Major tomato viruses in the Mediterranean basin.

    PubMed

    Hanssen, Inge M; Lapidot, Moshe

    2012-01-01

    Tomato (Solanum lycopersicum L.) originated in South America and was brought to Europe by the Spaniards in the sixteenth century following their colonization of Mexico. From Europe, tomato was introduced to North America in the eighteenth century. Tomato plants show a wide climatic tolerance and are grown in both tropical and temperate regions around the world. The climatic conditions in the Mediterranean basin favor tomato cultivation, where it is traditionally produced as an open-field plant. However, viral diseases are responsible for heavy yield losses and are one of the reasons that tomato production has shifted to greenhouses. The major tomato viruses endemic to the Mediterranean basin are described in this chapter. These viruses include Tomato yellow leaf curl virus, Tomato torrado virus, Tomato spotted wilt virus, Tomato infectious chlorosis virus, Tomato chlorosis virus, Pepino mosaic virus, and a few minor viruses as well. PMID:22682165

  3. 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.

  4. 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.

  5. Emerging influenza viruses and the prospect of a universal influenza virus vaccine.

    PubMed

    Krammer, Florian

    2015-05-01

    Influenza viruses cause annual seasonal epidemics and pandemics at irregular intervals. Several cases of human infections with avian and swine influenza viruses have been detected recently, warranting enhanced surveillance and the development of more effective countermeasures to address the pandemic potential of these viruses. The most effective countermeasure against influenza virus infection is the use of prophylactic vaccines. However, vaccines that are currently in use for seasonal influenza viruses have to be re-formulated and re-administered in a cumbersome process every year due to the antigenic drift of the virus. Furthermore, current seasonal vaccines are ineffective against novel pandemic strains. This paper reviews zoonotic influenza viruses with pandemic potential and technological advances towards better vaccines that induce broad and long lasting protection from influenza virus infection. Recent efforts have focused on the development of broadly protective/universal influenza virus vaccines that can provide immunity against drifted seasonal influenza virus strains but also against potential pandemic viruses. PMID:25728134

  6. Quantitative nanoscale electrostatics of viruses

    NASA Astrophysics Data System (ADS)

    Hernando-Pérez, M.; Cartagena-Rivera, A. X.; Lošdorfer Božič, A.; Carrillo, P. J. P.; San Martín, C.; Mateu, M. G.; Raman, A.; Podgornik, R.; de Pablo, P. J.

    2015-10-01

    Electrostatics is one of the fundamental driving forces of the interaction between biomolecules in solution. In particular, the recognition events between viruses and host cells are dominated by both specific and non-specific interactions and the electric charge of viral particles determines the electrostatic force component of the latter. Here we probe the charge of individual viruses in liquid milieu by measuring the electrostatic force between a viral particle and the Atomic Force Microscope tip. The force spectroscopy data of co-adsorbed φ29 bacteriophage proheads and mature virions, adenovirus and minute virus of mice capsids is utilized for obtaining the corresponding density of charge for each virus. The systematic differences of the density of charge between the viral particles are consistent with the theoretical predictions obtained from X-ray structural data. Our results show that the density of charge is a distinguishing characteristic of each virus, depending crucially on the nature of the viral capsid and the presence/absence of the genetic material.Electrostatics is one of the fundamental driving forces of the interaction between biomolecules in solution. In particular, the recognition events between viruses and host cells are dominated by both specific and non-specific interactions and the electric charge of viral particles determines the electrostatic force component of the latter. Here we probe the charge of individual viruses in liquid milieu by measuring the electrostatic force between a viral particle and the Atomic Force Microscope tip. The force spectroscopy data of co-adsorbed φ29 bacteriophage proheads and mature virions, adenovirus and minute virus of mice capsids is utilized for obtaining the corresponding density of charge for each virus. The systematic differences of the density of charge between the viral particles are consistent with the theoretical predictions obtained from X-ray structural data. Our results show that the density of charge is a distinguishing characteristic of each virus, depending crucially on the nature of the viral capsid and the presence/absence of the genetic material. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04274g

  7. Unusual Influenza A Viruses in Bats

    PubMed Central

    Mehle, Andrew

    2014-01-01

    Influenza A viruses infect a remarkably diverse number of hosts. Two completely new influenza A virus subtypes were recently discovered in bats, dramatically expanding the host range of the virus. These bat viruses are extremely divergent from all other known strains and likely have unique replication cycles. Phylogenetic analysis indicates long-term, isolated evolution in bats. This is supported by a high seroprevalence in sampled bat populations. As bats represent ~20% of all classified mammals, these findings suggests the presence of a massive cryptic reservoir of poorly characterized influenza A viruses. Here, we review the exciting progress made on understanding these newly discovered viruses, and discuss their zoonotic potential. PMID:25256392

  8. The control of bovine virus diarrhoea virus in Shetland.

    PubMed

    Synge, B A; Clark, A M; Moar, J A; Nicolson, J T; Nettleton, P F; Herring, J A

    1999-01-01

    A scheme to control and eradicate bovine virus diarrhoea (BVD) was initiated in 1994 in the Shetland Islands by local veterinary surgeons and funded by the Shetland Islands Council and Shetland Enterprise Company. Over a 3-year period every bovine animal on the islands was blood-sampled (heparinised) and laboratory tested using MAb-based ELISAs for BVD virus antibody and antigen detection for evidence of disease. A number of BVD virus positive animals (40) were found and culled. A total of 6150 animals were tested from 213 herds and 43% herds were found to be BVD naive. The remaining herds had experienced infection and contained many BVD antibody positive animals. Some repeat sampling of stock in infected herds determined further virus positive animals which were slaughtered and in 1997 the scheme ceased since it appeared that there were no persistent excretors present. The major risk to the Shetland Islands is from bought-in stock, especially animals which are imported in calf. It is vital that all bought-in animals are tested and proven to be free of BVD virus if these animals are in calf, the calves must be tested a birth to determine status. It is strongly advised that only bulls and bulling heifers or cows are bought into Shetland in future, thus, protecting the present stock. Continued surveillance will be required to claim eradication of BVD from Shetland. PMID:10028174

  9. Replication strategies of rabies virus.

    PubMed

    Finke, Stefan; Conzelmann, Karl-Klaus

    2005-08-01

    Rabies virus (RV) is a prototype neurotropic virus that causes fatal disease in human and animals. RV infects hosts at the periphery, enters motoneurons or sensory nerves and moves to the central nervous system (CNS) via retrograde axonal transport. At later stages, there is also centrifugal spread to major exit portals, such as the salivary glands. Transmission to other hosts is facilitated by behavioral changes related to the CNS infection. Successful accomplishment of the RV infectious cycle depends on multiple functions of the virus, and of individual virus proteins, all together defining the typical pathogenicity and virulence, i.e. the biological fitness of this virus. In particular, it appears important for RV to sneak into the host without causing pronounced host responses and to preserve, at least for some time, the integrity of infected cells and of the neuronal network. The availability of reverse genetics systems that allow generation of engineered recombinant RV has provided tools for a more detailed analysis of viral functions relevant to the typical RV pathogenesis. Novel developments such as tracking of live fluorescent RV are further increasing the opportunities to decipher RV pathogenicity factors. In this review, we describe different aspects of the molecular biology of RV that are relevant to pathogenesis, with a particular emphasis on the accurate control of RV transcription, gene expression, and replication. In addition, the role of individual virus proteins in maintaining host cell integrity and supporting retrograde transport is discussed. The potential of recombinant RVs with single or multiple pathogenicity factors eliminated is being discussed in terms of vaccine and virus vector development. PMID:15885837

  10. Chikungunya virus infection.

    PubMed

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

    2011-06-01

    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 in the past decade with large outbreaks in Africa and around the Indian Ocean and rare autochthonous transmission in temperate areas. This emergence brought new insights on its pathogenesis, notably the role of the A226V mutation that improved CHIKV fitness in Ae. albopictus and the possible CHIKV persistence in deep tissue sanctuaries for months after infection. Massive outbreaks also revealed new aspects of the acute stage: the high number of symptomatic cases, unexpected complications, mother-to-child transmission, and low lethality in debilitated patients. The follow-up of patients in epidemic areas has identified frequent, long-lasting, rheumatic disorders, including rare inflammatory joint destruction, and common chronic mood changes associated with quality-of-life impairment. Thus, the globalization of CHIKV exposes countries with Aedes mosquitoes both to brutal outbreaks of acute incapacitating episodes and endemic long-lasting disorders. PMID:21465340

  11. Ebola, the killer virus.

    PubMed

    Ghazanfar, Haider; Orooj, Fizza; Abdullah, Muhammad Ahmed; Ghazanfar, Ali

    2015-01-01

    Ebola virus disease (EVD) has mostly affected economically deprived countries as limited resources adversely affect a country's infrastructure and administration. Probing into the factors that led to the widespread outbreak, setting forth plans to counter EVD cases in developing countries, and devising definitive measures to limit the spread of the disease are essential steps that must be immediately taken. In this review we summarize the pathogenesis of EVD and the factors that led to its spread. We also highlight interventions employed by certain countries that have successfully limited the epidemic, and add a few preventive measures after studying the current data. According to the available data, barriers to prevent and control the disease in affected countries include irresolute and disorganized health systems, substandard sanitary conditions, poor personal hygiene practices, and false beliefs and stigma related to EVD. The public health sector along with the respective chief authorities in developing countries must devise strategies, keeping the available resources in mind, to deal with the outbreak before it occurs. As a first step, communities should be educated on EVD's symptoms, history, mode of transmission, and methods of protection, including the importance of personal hygiene practices, via seminars, newspapers, and other social media. A popular opinion leader (POL) giving this information would further help to remove the misconception about the nature of the disease and indirectly improve the quality of life of affected patients and their families. PMID:25866626

  12. Dengue viruses - an overview.

    PubMed

    Bäck, Anne Tuiskunen; Lundkvist, Ake

    2013-01-01

    Dengue viruses (DENVs) cause the most common arthropod-borne viral disease in man with 50-100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF) is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS) are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence. PMID:24003364

  13. Viruses and viruslike particles of eukaryotic algae.

    PubMed Central

    Van Etten, J L; Lane, L C; Meints, R H

    1991-01-01

    Until recently there was little interest or information on viruses and viruslike particles of eukaryotic algae. However, this situation is changing. In the past decade many large double-stranded DNA-containing viruses that infect two culturable, unicellular, eukaryotic green algae have been discovered. These viruses can be produced in large quantities, assayed by plaque formation, and analyzed by standard bacteriophage techniques. The viruses are structurally similar to animal iridoviruses, their genomes are similar to but larger (greater than 300 kbp) than that of poxviruses, and their infection process resembles that of bacteriophages. Some of the viruses have DNAs with low levels of methylated bases, whereas others have DNAs with high concentrations of 5-methylcytosine and N6-methyladenine. Virus-encoded DNA methyltransferases are associated with the methylation and are accompanied by virus-encoded DNA site-specific (restriction) endonucleases. Some of these enzymes have sequence specificities identical to those of known bacterial enzymes, and others have previously unrecognized specificities. A separate rod-shaped RNA-containing algal virus has structural and nucleotide sequence affinities to higher plant viruses. Quite recently, viruses have been associated with rapid changes in marine algal populations. In the next decade we envision the discovery of new algal viruses, clarification of their role in various ecosystems, discovery of commercially useful genes in these viruses, and exploitation of algal virus genetic elements in plant and algal biotechnology. Images PMID:1779928

  14. 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

  15. Autophagic machinery activated by dengue virus enhances virus replication

    SciTech Connect

    Lee, Y.-R.; Lei, H.-Y.; Liu, M.-T.; Wang, J.-R.; Chen, S.-H.; Jiang-Shieh, Y.-F.; Lin, Y.-S.; Yeh, T.-M.; Liu, C.-C.; Liu, H.-S.

    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.

  16. 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

  17. [Bats and Viruses: complex relationships].

    PubMed

    Rodhain, E

    2015-10-01

    With more than 1 200 species, bats and flying foxes (Order Chiroptera) constitute the most important and diverse order of Mammals after Rodents. Many species of bats are insectivorous while others are frugivorous and few of them are hematophagous. Some of these animals fly during the night, others are crepuscular or diurnal. Some fly long distances during seasonal migrations. Many species are colonial cave-dwelling, living in a rather small home range while others are relatively solitary. However, in spite of the importance of bats for terrestrial biotic communities and ecosystem ecology, the diversity in their biology and lifestyles remain poorly known and underappreciated. More than sixty viruses have been detected or isolated in bats; these animals are therefore involved in the natural cycles of many of them. This is the case, for instance, of rabies virus and other Lyssavirus (Family Rhabdoviridae), Nipah and Hendra viruses (Paramyxoviridae), Ebola and Marburg viruses (Filoviridae), SARS-CoV and MERS-CoV (Coronaviridae). For these zoonotic viruses, a number of bat species are considered as important reservoir hosts, efficient disseminators or even directly responsible of the transmission. Some of these bat-borne viruses cause highly pathogenic diseases while others are of potential significance for humans and domestic or wild animals; so, bats are an important risk in human and animal public health. Moreover, some groups of viruses developed through different phylogenetic mechanisms of coevolution between viruses and bats. The fact that most of these viral infections are asymptomatic in bats has been observed since a long time but the mechanisms of the viral persistence are not clearly understood. The various bioecology of the different bat populations allows exchange of virus between migrating and non-migrating conspecific species. For a better understanding of the role of bats in the circulation of these viral zoonoses, epidemiologists must pay attention to some of their biologic properties which are not fully documented, like their extreme longevity, their diet, the population size and the particular densities observed in species with crowded roosting behavior, the population structure and migrations, the hibernation permitting overwintering of viruses, their particular innate and acquired immune response, probably related at least partially to their ability to fly, allowing persistent virus infections and preventing immunopathological consequences, etc. It is also necessary to get a better knowledge of the interactions between bats and ecologic changes induced by man and to attentively follow bat populations and their viruses through surveillance networks involving human and veterinary physicians, specialists of wild fauna, ecologists, etc. in order to understand the mechanisms of disease emergence, to try to foresee and, perhaps, to prevent viral emergences beforehand. Finally, a more fundamental research about immune mechanisms developed in viral infections is essential to reveal the reasons why Chiroptera are so efficient reservoir hosts. Clearly, a great deal of additional work is needed to document the roles of bats in the natural history of viruses. PMID:26330152

  18. Coping with Computer Viruses: General Discussion and Review of Symantec Anti-Virus for the Macintosh.

    ERIC Educational Resources Information Center

    Primich, Tracy

    1992-01-01

    Discusses computer viruses that attack the Macintosh and describes Symantec AntiVirus for Macintosh (SAM), a commercial program designed to detect and eliminate viruses; sample screen displays are included. SAM is recommended for use in library settings as well as two public domain virus protection programs. (four references) (MES)

  19. Circulative, “Nonpropagative” Virus Transmission: An orchestra of virus, insect and plant derived instruments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The many species of plant viruses within the Luteoviridae, Geminiviridae and Nanoviridae are all transmitted by phloem feeding insects in a circulative, nonpropagative manner. The precise route of virus movement through the vector can differ across and within virus families, but these viruses all sh...

  20. Strains of Citrus tristeza virus do not exclude superinfection by other strains of the virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Superinfection exclusion or homologous interference, a phenomenon in which a primary viral infection prevents a secondary infection with the same or closely-related virus, has been observed commonly for viruses in various systems, including viruses of bacteria, plants, and animals. With plant viruse...

  1. Infectious particles derived from Semliki Forest virus vectors encoding murine leukemia virus envelopes.

    PubMed Central

    Lebedeva, I; Fujita, K; Nihrane, A; Silver, J

    1997-01-01

    Semliki Forest virus vectors encoding murine leukemia virus (MLV) envelope protein with a truncated cytoplasmic tail generate submicrometer, cell-associated, membranous particles that transmit replication-competent vector RNA specifically to cells bearing the MLV receptor. Such "minimal" viruses could have applications as retroviral vaccines or in the study of virus evolution. PMID:9261436

  2. Dot immunobinding assay for simultaneous detection of specific immunoglobulin G antibodies to measles virus, mumps virus, and rubella virus.

    PubMed Central

    Condorelli, F; Ziegler, T

    1993-01-01

    A dot immunobinding assay was used to detect antibodies to measles virus, mumps virus, and rubella virus antigens. Filter paper soaked with serum or whole blood was directly applied to the antigen-coated nitrocellulose sheets. The test was easy to perform, and its results agreed very well with those obtained by standard enzyme immunoassay. PMID:8458970

  3. Spiroplasmal viruses: group 1 characteristics.

    PubMed

    Liss, A; Cole, R M

    1982-01-01

    Virus-like particles of three morphologic groups have been detected by electron microscopy in 90% of spiroplasma strains. In this study, virus-like particles of group 1 (SpV1)--unenveloped rods 230-280 nm by 10-15 nm--were found in 575 of spiroplasmas. SpV1 occurred spontaneously in large numbers in cultures of strains B (corn stunt), G1 (tulip tree flower), BC3 (honeybee), and KC3 (honeybee), respectively; the viruses were isolated and assayed as plaque-forming units, with several of the same strains used as indicators. No virus plaqued on its strain of origin, and all except one (SpV1/BC3) plaqued best on strain BC3. Host range and yields of progeny virus differed. All isolates were identical in morphology, size, and buoyant densities; contained DNA; formed turbid 1.5 to 5.0-mm plaques; produced nonlytic infections and similar one-step growth curves; were inactivated by a single antiserum; had similar kinetics of adsorption and heat inactivation; and demonstrated similar patterns of resistance and sensitivity to a variety of physical and chemical agents, as well as an inability to infect resistant host mutants. SPV1 isolates from diverse host strains apparently share many physicochemical and biological properties, but are not identical in all biological respects. PMID:7123048

  4. Electrical detection of single viruses

    NASA Astrophysics Data System (ADS)

    Patolsky, Fernando; Zheng, Gengfeng; Hayden, Oliver; Lakadamyali, Melike; Zhuang, Xiaowei; Lieber, Charles M.

    2004-09-01

    We report direct, real-time electrical detection of single virus particles with high selectivity by using nanowire field effect transistors. Measurements made with nanowire arrays modified with antibodies for influenza A showed discrete conductance changes characteristic of binding and unbinding in the presence of influenza A but not paramyxovirus or adenovirus. Simultaneous electrical and optical measurements using fluorescently labeled influenza A were used to demonstrate conclusively that the conductance changes correspond to binding/unbinding of single viruses at the surface of nanowire devices. pH-dependent studies further show that the detection mechanism is caused by a field effect, and that the nanowire devices can be used to determine rapidly isoelectric points and variations in receptor-virus binding kinetics for different conditions. Lastly, studies of nanowire devices modified with antibodies specific for either influenza or adenovirus show that multiple viruses can be selectively detected in parallel. The possibility of large-scale integration of these nanowire devices suggests potential for simultaneous detection of a large number of distinct viral threats at the single virus level.

  5. Control of viruses infecting grapevine.

    PubMed

    Maliogka, Varvara I; Martelli, Giovanni P; Fuchs, Marc; Katis, Nikolaos I

    2015-01-01

    Grapevine is a high value vegetatively propagated fruit crop that suffers from numerous viruses, including some that seriously affect the profitability of vineyards. Nowadays, 64 viruses belonging to different genera and families have been reported in grapevines and new virus species will likely be described in the future. Three viral diseases namely leafroll, rugose wood, and infectious degeneration are of major economic importance worldwide. The viruses associated with these diseases are transmitted by mealybugs, scale and soft scale insects, or dagger nematodes. Here, we review control measures of the major grapevine viral diseases. More specifically, emphasis is laid on (i) approaches for the production of clean stocks and propagative material through effective sanitation, robust diagnosis, as well as local and regional certification efforts, (ii) the management of vectors of viruses using cultural, biological, and chemical methods, and (iii) the production of resistant grapevines mainly through the application of genetic engineering. The benefits and limitations of the different control measures are discussed with regard to accomplishments and future research directions. PMID:25591880

  6. Droplet Microfluidics for Virus Discovery

    NASA Astrophysics Data System (ADS)

    Rotem, Assaf; Cockrell, Shelley; Guo, Mira; Pipas, James; Weitz, David

    2012-02-01

    The ability to detect, isolate, and characterize an infectious agent is important for diagnosing and curing infectious diseases. Detecting new viral diseases is a challenge because the number of virus particles is often low and/or localized to a small subset of cells. Even if a new virus is detected, it is difficult to isolate it from clinical or environmental samples where multiple viruses are present each with very different properties. Isolation is crucial for whole genome sequencing because reconstructing a genome from fragments of many different genomes is practically impossible. We present a Droplet Microfluidics platform that can detect, isolate and sequence single viral genomes from complex samples containing mixtures of many viruses. We use metagenomic information about the sample of mixed viruses to select a short genomic sequence whose genome we are interested in characterizing. We then encapsulate single virions from the same sample in picoliter volume droplets and screen for successful PCR amplification of the sequence of interest. The selected drops are pooled and their contents sequenced to reconstruct the genome of interest. This method provides a general tool for detecting, isolating and sequencing genetic elements in clinical and environmental samples.

  7. Optical tweezers to study viruses.

    PubMed

    Arias-Gonzalez, J Ricardo

    2013-01-01

    A virus is a complex molecular machine that propagates by channeling its genetic information from cell to cell. Unlike macroscopic engines, it operates in a nanoscopic world under continuous thermal agitation. Viruses have developed efficient passive and active strategies to pack and release nucleic acids. Some aspects of the dynamic behavior of viruses and their substrates can be studied using structural and biochemical techniques. Recently, physical techniques have been applied to dynamic studies of viruses in which their intrinsic mechanical activity can be measured directly. Optical tweezers are a technology that can be used to measure the force, torque and strain produced by molecular motors, as a function of time and at the single-molecule level. Thanks to this technique, some bacteriophages are now known to be powerful nanomachines; they exert force in the piconewton range and their motors work in a highly coordinated fashion for packaging the viral nucleic acid genome. Nucleic acids, whose elasticity and condensation behavior are inherently coupled to the viral packaging mechanisms, are also amenable to examination with optical tweezers. In this chapter, we provide a comprehensive analysis of this laser-based tool, its combination with imaging methods and its application to the study of viruses and viral molecules. PMID:23737055

  8. Quantitative nanoscale electrostatics of viruses.

    PubMed

    Hernando-Prez, M; Cartagena-Rivera, A X; Lodorfer Boi?, A; Carrillo, P J P; San Martn, C; Mateu, M G; Raman, A; Podgornik, R; de Pablo, P J

    2015-11-01

    Electrostatics is one of the fundamental driving forces of the interaction between biomolecules in solution. In particular, the recognition events between viruses and host cells are dominated by both specific and non-specific interactions and the electric charge of viral particles determines the electrostatic force component of the latter. Here we probe the charge of individual viruses in liquid milieu by measuring the electrostatic force between a viral particle and the Atomic Force Microscope tip. The force spectroscopy data of co-adsorbed ?29 bacteriophage proheads and mature virions, adenovirus and minute virus of mice capsids is utilized for obtaining the corresponding density of charge for each virus. The systematic differences of the density of charge between the viral particles are consistent with the theoretical predictions obtained from X-ray structural data. Our results show that the density of charge is a distinguishing characteristic of each virus, depending crucially on the nature of the viral capsid and the presence/absence of the genetic material. PMID:26228582

  9. Physicochemical Properties of Tipula Iridescent Virus 1

    PubMed Central

    Kalmakoff, J.; Tremaine, J. H.

    1968-01-01

    The molecular weight of Tipula iridescent virus, based on sedimentation and diffusion coefficients, was 5.51 × 108, with hydration of 0.57 g of water per g of virus. Deoxyribonucleic acid content, based on total inorganic phosphorus liberated, was 19 ± 0.2%. At 260 mμ, the virus gave an uncorrected absorbance of 18.2 cm2/mg of virus and a light-scattering corrected absorbance of 9.8 cm2/mg of virus. Amino acid analyses of the virus protein revealed a remarkable similarity to Sericesthis iridescent virus. The possibility is discussed that the four iridescent insect viruses reported to date bear a strain relationship. Images PMID:16789085

  10. Researchers Uncover Different Variations of MERS Virus

    MedlinePLUS

    ... 156284.html Researchers Uncover Different Variations of MERS Virus And, a second team reports progress on a ... About 35 percent of people who contracted the virus died, the researchers said. Arabian camels are the ...

  11. Swine influenza virus infections in humans.

    PubMed

    Dowdle, W R; Hattwick, M A

    1977-12-01

    Influenza in swine was first recognized as an epizootic disease in 1918. During that same year influenza virus in humans caused the worst pandemic on record. The virus of swine influenza was isolated in 1930. Swine influenza virus was first isolated from humans in 1974. Since then, including the cases at Fort Dix, there have been a total of nine viral isolations from humans in the United States. Serologic evidence of infections with swine influenza virus in humans has also been obtained. Evidence for transmission of swine influenza virus to humans before 1974 is minimal and circumstantial. Recent recognition of infections with swine influenza virus may be the result of better surveillance, increased numbers of susceptible humans, or increased viral infectivity for humans. Nevertheless, the apparent frequency of human infections and the declining levels of antibodies to swine influenza virus in the human population suggest that influenza viruses of swine may be a potential sources of epidemic disease for humans. PMID:342616

  12. Child Paralysis Cases Spiked During Virus Outbreak

    MedlinePLUS

    ... fullstory_156356.html Child Paralysis Cases Spiked During Virus Outbreak: Study But definitive cause of polio-like ... during a national outbreak of enterovirus D68, a virus in the same family as polio, researchers report ...

  13. About Epstein-Barr Virus (EBV)

    MedlinePLUS

    ... Providers Laboratory Testing References & Resources About Epstein-Barr Virus (EBV) Recommend on Facebook Tweet Share Compartir On ... Page Symptoms Transmission Diagnosis Prevention & Treatment Epstein-Barr virus (EBV), also known as human herpesvirus 4, is ...

  14. West Nile Virus: Prevention and Control

    MedlinePLUS

    ... a regular basis. Help Your Community West Nile Virus Surveillance and Control Programs Support your local community ... birds may be a sign that West Nile virus is circulating between birds and the mosquitoes in ...

  15. A "virus" disease of chinook salmon

    USGS Publications Warehouse

    Ross, A.J.; Rucker, R.R.

    1960-01-01

    Epizootics among chinook salmon fingerlings at the Coleman National Fish Hatchery have occurred periodically since 1941. A virus or virus-like filterable agent has been demonstrated to be the causative agent of this disease.

  16. Screening for Human Immunodeficiency Virus (HIV)

    MedlinePLUS

    Understanding Task Force Recommendations Screening for Human Immunodeficiency Virus (HIV) The U.S. Preventive Services Task Force (Task ... final recommendation statement on Screening for Human Immunodeficiency Virus (HIV) . This final recommendation statement applies to all ...

  17. Many Americans Misinformed about Zika Virus

    MedlinePLUS

    ... news/fullstory_158016.html Many Americans Misinformed About Zika Virus Harvard poll shows they don't know how ... when it comes to understanding the risks of Zika virus, a new Harvard poll has found. The mosquito- ...

  18. Concurrent infection with influenza virus and mumps virus or pneumonia virus of mice as bearing on the inhibition of virus multiplication by bacterial polysaccharides.

    PubMed

    GINSBERG, H S; HORSFALL, F L

    1949-01-01

    Preexisting infection with PVM or mumps virus does not prevent multiplication of the virus of influenza A or B in the same tissue. Similarly, pre-existing infection with one or another of the influenza viruses does not prevent multiplication of either PVM or mumps virus in the same tissue. The failure of these two groups of viruses to interfere with the multiplication of each other is discussed in relation to the mechanism of inhibition of multiplication of mumps virus and PVM by the capsular polysaccharides of Friedlnder bacilli, and the ability of influenza A and influenza B viruses to multiply in the presence of large quantities of these carbohydrates. It is suggested that differences in the requirements of the two groups of viruses for host cell metabolic systems may serve to explain both the lack of interference between them and the differing effect of polysaccharides upon their multiplication. PMID:18099164

  19. West Nile Virus: Symptoms and Treatment

    MedlinePLUS

    ... CDC Cancel Submit Search The CDC West Nile virus Note: Javascript is disabled or is not supported ... visit this page: About CDC.gov . West Nile Virus Home Frequently Asked Questions General Questions Preguntas frecuentes ...

  20. 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.

  1. Historical review: viruses, crystals and geodesic domes.

    PubMed

    Morgan, Gregory J

    2003-02-01

    In the mid 1950s, Francis Crick and James Watson attempted to explain the structure of spherical viruses. They hypothesized that spherical viruses consist of 60 identical equivalently situated subunits. Such an arrangement has icosahedral symmetry. Subsequent biophysical and electron micrographic data suggested that many viruses had >60 subunits. Drawing inspiration from architecture, Donald Caspar and Aaron Klug discovered a solution to the problem - they proposed that spherical viruses were structured like miniature geodesic domes. PMID:12575996

  2. Structural Proteins of Pichinde Virus

    PubMed Central

    Ramos, Blanca A.; Courtney, Richard J.; Rawls, William E.

    1972-01-01

    Pichinde virus, a member of the arenovirus group, was found to have four polypeptides by polyacrylamide gel electrophoresis. Two components, VI and VII, had molecular weights of about 72,000, whereas VIII had a molecular weight of 34,000. A minor component, VIV, had a molecular weight of about 12,000. Glucosamine was incorporated into VII and VIII, suggesting that these components were glycopeptides whereas VI and VIV were polypeptides. Treatment of the virus with Nonidet P-40 removed VIII, but VI and VII remained associated with the virus nucleic acid. This suggests a functional role of a ribonucleoprotein for VI and an envelope glycoprotein for VIII. VII, the major glycopeptide, could function both as a membrane component and as a nucleoprotein. PMID:4673488

  3. The Hepatitis B Virus Receptor.

    PubMed

    Li, Wenhui

    2015-11-13

    Hepatitis B virus (HBV) infection affects 240 million people worldwide. A liver-specific bile acid transporter named the sodium taurocholate cotransporting polypeptide (NTCP) has been identified as the cellular receptor for HBV and its satellite, the hepatitis D virus (HDV). NTCP likely acts as a major determinant for the liver tropism and species specificity of HBV and HDV at the entry level. NTCP-mediated HBV entry interferes with bile acid transport in cell cultures and has been linked with alterations in bile acid and cholesterol metabolism in vivo. The human liver carcinoma cell line HepG2, complemented with NTCP, now provides a valuable platform for studying the basic biology of the viruses and developing treatments for HBV infection. This review summarizes critical findings regarding NTCP's role as a viral receptor for HBV and HDV and discusses important questions that remain unanswered. PMID:26436705

  4. Redefining viruses: lessons from Mimivirus.

    PubMed

    Raoult, Didier; Forterre, Patrick

    2008-04-01

    Viruses are the most abundant living entities and probably had a major role in the evolution of life, but are still defined using negative criteria. Here, we propose to divide biological entities into two groups of organisms: ribosome-encoding organisms, which include eukaryotic, archaeal and bacterial organisms, and capsid-encoding organisms, which include viruses. Other replicons (for example, plasmids and viroids) can be termed 'orphan replicons'. Based on this suggested classification system, we propose a new definition for a virus--a capsid-encoding organism that is composed of proteins and nucleic acids, self-assembles in a nucleocapsid and uses a ribosome-encoding organism for the completion of its life cycle. PMID:18311164

  5. Herpes simplex virus and varicella zoster virus, the house guests who never leave

    PubMed Central

    2012-01-01

    Human alphaherpesviruses including herpes simplex viruses (HSV-1, HSV-2) and varicella zoster virus (VZV) establish persistent latent infection in sensory neurons for the life of the host. All three viruses have the potential to reactivate causing recurrent disease. Regardless of the homology between the different virus strains, the three viruses are characterized by varying pathologies. This review will highlight the differences in infection pattern, immune response, and pathogenesis associated with HSV-1 and VZV. PMID:22691604

  6. CLASSIFICATION AND NOMENCLATURE OF VIRUSES OF CYANOBACTERIA

    EPA Science Inventory

    The Study Group finds it appropriate that viruses which have as their host cyanobacteria (blue-green algae) should be grouped within the well-categorized families of the bacterial viruses. Thus, the term cyanophage is adopted as a synonym for the vernacular name BGA virus (BGAV) ...

  7. Computer Viruses and Safe Educational Practices.

    ERIC Educational Resources Information Center

    Azarmsa, Reza

    1991-01-01

    This discussion of computer viruses explains how these viruses may be transmitted, describes their effects on data and/or computer application programs, and identifies three groups that propagate them. Ten major viruses are listed and described, and measures to deal with them are discussed. Nineteen antiviral programs are also listed and

  8. Ecological dynamics of emerging bat virus spillover.

    PubMed

    Plowright, Raina K; Eby, Peggy; Hudson, Peter J; Smith, Ina L; Westcott, David; Bryden, Wayne L; Middleton, Deborah; Reid, Peter A; McFarlane, Rosemary A; Martin, Gerardo; Tabor, Gary M; Skerratt, Lee F; Anderson, Dale L; Crameri, Gary; Quammen, David; Jordan, David; Freeman, Paul; Wang, Lin-Fa; Epstein, Jonathan H; Marsh, Glenn A; Kung, Nina Y; McCallum, Hamish

    2015-01-01

    Viruses that originate in bats may be the most notorious emerging zoonoses that spill over from wildlife into domestic animals and humans. Understanding how these infections filter through ecological systems to cause disease in humans is of profound importance to public health. Transmission of viruses from bats to humans requires a hierarchy of enabling conditions that connect the distribution of reservoir hosts, viral infection within these hosts, and exposure and susceptibility of recipient hosts. For many emerging bat viruses, spillover also requires viral shedding from bats, and survival of the virus in the environment. Focusing on Hendra virus, but also addressing Nipah virus, Ebola virus, Marburg virus and coronaviruses, we delineate this cross-species spillover dynamic from the within-host processes that drive virus excretion to land-use changes that increase interaction among species. We describe how land-use changes may affect co-occurrence and contact between bats and recipient hosts. Two hypotheses may explain temporal and spatial pulses of virus shedding in bat populations: episodic shedding from persistently infected bats or transient epidemics that occur as virus is transmitted among bat populations. Management of livestock also may affect the probability of exposure and disease. Interventions to decrease the probability of virus spillover can be implemented at multiple levels from targeting the reservoir host to managing recipient host exposure and susceptibility. PMID:25392474

  9. Ecological dynamics of emerging bat virus spillover

    PubMed Central

    Plowright, Raina K.; Eby, Peggy; Hudson, Peter J.; Smith, Ina L.; Westcott, David; Bryden, Wayne L.; Middleton, Deborah; Reid, Peter A.; McFarlane, Rosemary A.; Martin, Gerardo; Tabor, Gary M.; Skerratt, Lee F.; Anderson, Dale L.; Crameri, Gary; Quammen, David; Jordan, David; Freeman, Paul; Wang, Lin-Fa; Epstein, Jonathan H.; Marsh, Glenn A.; Kung, Nina Y.; McCallum, Hamish

    2015-01-01

    Viruses that originate in bats may be the most notorious emerging zoonoses that spill over from wildlife into domestic animals and humans. Understanding how these infections filter through ecological systems to cause disease in humans is of profound importance to public health. Transmission of viruses from bats to humans requires a hierarchy of enabling conditions that connect the distribution of reservoir hosts, viral infection within these hosts, and exposure and susceptibility of recipient hosts. For many emerging bat viruses, spillover also requires viral shedding from bats, and survival of the virus in the environment. Focusing on Hendra virus, but also addressing Nipah virus, Ebola virus, Marburg virus and coronaviruses, we delineate this cross-species spillover dynamic from the within-host processes that drive virus excretion to land-use changes that increase interaction among species. We describe how land-use changes may affect co-occurrence and contact between bats and recipient hosts. Two hypotheses may explain temporal and spatial pulses of virus shedding in bat populations: episodic shedding from persistently infected bats or transient epidemics that occur as virus is transmitted among bat populations. Management of livestock also may affect the probability of exposure and disease. Interventions to decrease the probability of virus spillover can be implemented at multiple levels from targeting the reservoir host to managing recipient host exposure and susceptibility. PMID:25392474

  10. Viruses take center stage in cellular evolution

    PubMed Central

    Claverie, Jean-Michel

    2006-01-01

    The origins of viruses are shrouded in mystery, but advances in genomics and the discovery of highly complex giant DNA viruses have stimulated new hypotheses that DNA viruses were involved in the emergence of the eukaryotic cell nucleus, and that they are worthy of being considered as living organisms. PMID:16787527

  11. Distribution of viruses in the Chesapeake Bay.

    PubMed Central

    Wommack, K E; Hill, R T; Kessel, M; Russek-Cohen, E; Colwell, R R

    1992-01-01

    High virus counts were found in water samples collected from the Chesapeake Bay. Viruses were enumerated by ultracentrifugation of water samples onto grids which were visualized by transmission electron microscopy. Virus counts in September 1990, April 1991, June 1991, August 1991, and October 1991 ranged between 2.6 x 10(6) and 1.4 x 10(8) viruses ml-1 with a mean of 2.5 x 10(7) viruses ml-1. Virus counts were usually at least three times higher than direct bacterial counts in corresponding samples. Virus counts in August and October were significantly higher than at the other sampling times, whereas bacterial counts were significantly lower at that time, yielding mean virus-to-bacterium ratios of 12.6 and 25.6, respectively. From analysis of morphology of the virus particles, it is concluded that a large proportion of the viruses are bacteriophages. The high virus counts obtained in this study suggest that viruses may be an important factor affecting bacterial populations in the Chesapeake Bay, with implications for gene transfer in natural aquatic bacterial populations and release of genetically engineered microorganisms to estuarine and coastal environments. PMID:1444409

  12. Advances in virus research. Volume 31

    SciTech Connect

    Maramorosch, K.; Murphy, F.A.; Shatkin, A.J.

    1986-01-01

    This book presents topics in virus research and advances made in this field. Topics covered include: ambisense RNA genomes of arenaviruses and phleboviruses; the molecular basis of antigenic variation in influenza virus; epitope mapping of flavivirus glycoproteins; regulation of adenovirus mRNA formation; regulation of protein synthesis in virus infected animal cells; and antibody-dependent enhancement of vira infectivity.

  13. 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...

  14. Detection and Diagnosis of Plant Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases caused by viruses are a constant and major problem for crop production worldwide. Human interest in plant genetic resources and globalization of human activities has inadvertently contributed to the spread of viruses throughout the world, increasing the frequency of plant virus outbreaks. C...

  15. 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...

  16. Virus Diseases of Blackberry and Raspberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two viruses have been associated with Blackberry yellow vein disease (BYVD). One of these viruses, Blackberry yellow vein associated virus (BYVaV) is a member of the genus Crinivirus and has been identified in blackberries exhibiting the BYVD in several states in the southeastern United States. If ...

  17. 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

  18. Advances in virus research. Volume 32

    SciTech Connect

    Maramorosch, K.; Murphy, F.A.; Shatkin, A.J.

    1987-01-01

    This book describes advances in the field of virus research. Topics covered include: Retroid virus genome replication; viral oncogenes, v-yes and kerbB, and their cellular counterparts; hepatitis A; and molecular studies of brome Mosaic virus using infectious transcripts from cloned cDNA.

  19. Ebola Virus Persistence in Semen Ex Vivo.

    PubMed

    Fischer, Robert J; Judson, Seth; Miazgowicz, Kerri; Bushmaker, Trent; Munster, Vincent J

    2016-02-01

    On March 20, 2015, a case of Ebola virus disease was identified in Liberia that most likely was transmitted through sexual contact. We assessed the efficiency of detecting Ebola virus in semen samples by molecular diagnostics and the stability of Ebola virus in ex vivo semen under simulated tropical conditions. PMID:26811984

  20. Virus detection and quantification using electrical parameters

    PubMed Central

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

    2014-01-01

    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. PMID:25355078

  1. 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.

  2. Ebola Virus Persistence in Semen Ex Vivo

    PubMed Central

    Fischer, Robert J.; Judson, Seth; Miazgowicz, Kerri; Bushmaker, Trent

    2016-01-01

    On March 20, 2015, a case of Ebola virus disease was identified in Liberia that most likely was transmitted through sexual contact. We assessed the efficiency of detecting Ebola virus in semen samples by molecular diagnostics and the stability of Ebola virus in ex vivo semen under simulated tropical conditions. PMID:26811984

  3. MODEL OF VIRUS TRANSPORT IN UNSATURATED SOIL

    EPA Science Inventory

    As a result of the recently-proposed mandatory ground-water disinfection requirements to inactivate viruses in potable water supplies, there has been increasing interest in virus fate and transport in the subsurface. everal models have been developed to predict the fate of viruse...

  4. Lagos Bat Virus in Kenya?

    PubMed Central

    Kuzmin, Ivan V.; Niezgoda, Michael; Franka, Richard; Agwanda, Bernard; Markotter, Wanda; Beagley, Janet C.; Urazova, Olga Y.; Breiman, Robert F.; Rupprecht, Charles E.

    2008-01-01

    During lyssavirus surveillance, 1,221 bats of at least 30 species were collected from 25 locations in Kenya. One isolate of Lagos bat virus (LBV) was obtained from a dead Eidolon helvum fruit bat. The virus was most similar phylogenetically to LBV isolates from Senegal (1985) and from France (imported from Togo or Egypt; 1999), sharing with these viruses 100% nucleoprotein identity and 99.8 to 100% glycoprotein identity. This genome conservancy across space and time suggests that LBV is well adapted to its natural host species and that populations of reservoir hosts in eastern and western Africa have sufficient interactions to share pathogens. High virus concentrations, in addition to being detected in the brain, were detected in the salivary glands and tongue and in an oral swab, suggesting that LBV is transmitted in the saliva. In other extraneural organs, the virus was generally associated with innervations and ganglia. The presence of infectious virus in the reproductive tract and in a vaginal swab implies an alternative opportunity for transmission. The isolate was pathogenic for laboratory mice by the intracerebral and intramuscular routes. Serologic screening demonstrated the presence of LBV-neutralizing antibodies in E. helvum and Rousettus aegyptiacus fruit bats. In different colonies the seroprevalence ranged from 40 to 67% and 29 to 46% for E. helvum and R. aegyptiacus, respectively. Nested reverse transcription-PCR did not reveal the presence of viral RNA in oral swabs of bats in the absence of brain infection. Several large bat roosts were identified in areas of dense human populations, raising public health concerns for the potential of lyssavirus infection. PMID:18305130

  5. 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

  6. Household Transmission of Influenza Virus.

    PubMed

    Tsang, Tim K; Lau, Lincoln L H; Cauchemez, Simon; Cowling, Benjamin J

    2016-02-01

    Human influenza viruses cause regular epidemics and occasional pandemics with a substantial public health burden. Household transmission studies have provided valuable information on the dynamics of influenza transmission. We reviewed published studies and found that once one household member is infected with influenza, the risk of infection in a household contact can be up to 38%, and the delay between onset in index and secondary cases is around 3 days. Younger age was associated with higher susceptibility. In the future, household transmission studies will provide information on transmission dynamics, including the correlation of virus shedding and symptoms with transmission, and the correlation of new measures of immunity with protection against infection. PMID:26612500

  7. Resistant pathogens, fungi, and viruses.

    PubMed

    Guidry, Christopher A; Mansfield, Sara A; Sawyer, Robert G; Cook, Charles H

    2014-12-01

    Although originally described in Staphylococcus aureus, resistance among bacteria has now become a race to determine which classes of bacteria will become more resistant. Availability of antibacterial agents has allowed the development of entirely new diseases caused by nonbacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. This article presents the growing body of knowledge of the herpes family of viruses, and their occurrence and consequences in patients with concomitant surgical disease or critical illness. The focus is on previously immunocompetent patients, as the impact of herpes viruses in immunosuppressed patients has received thorough coverage elsewhere. PMID:25440119

  8. Development of high-yield influenza A virus vaccine viruses

    PubMed Central

    Ping, Jihui; Lopes, Tiago J.S.; Nidom, Chairul A.; Ghedin, Elodie; Macken, Catherine A.; Fitch, Adam; Imai, Masaki; Maher, Eileen A.; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for use in humans, but their yields are often suboptimal. Here, we screened A/Puerto Rico/8/34 (PR8) virus mutant libraries to develop vaccine backbones (defined here as the six viral RNA segments not encoding haemagglutinin and neuraminidase) that support high yield in cell culture. We also tested mutations in the coding and regulatory regions of the virus, and chimeric haemagglutinin and neuraminidase genes. A combination of high-yield mutations from these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin–Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in seasonal and pandemic influenza vaccine development. PMID:26334134

  9. Virus and Virus-Like Diseases of Importance in Blueberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past 15 years, blueberry production has increased dramatically in acres grown and in the number of countries producing blueberries. It should be expected that as blueberry cultivation continues to expand into new areas, the plants will become exposed to viruses that have not been observed i...

  10. Development of high-yield influenza A virus vaccine viruses.

    PubMed

    Ping, Jihui; Lopes, Tiago J S; Nidom, Chairul A; Ghedin, Elodie; Macken, Catherine A; Fitch, Adam; Imai, Masaki; Maher, Eileen A; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for use in humans, but their yields are often suboptimal. Here, we screened A/Puerto Rico/8/34 (PR8) virus mutant libraries to develop vaccine backbones (defined here as the six viral RNA segments not encoding haemagglutinin and neuraminidase) that support high yield in cell culture. We also tested mutations in the coding and regulatory regions of the virus, and chimeric haemagglutinin and neuraminidase genes. A combination of high-yield mutations from these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin-Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in seasonal and pandemic influenza vaccine development. PMID:26334134

  11. Virus and Virus-Like Diseases in Blueberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past 15 years, blueberry production has increased dramatically in hectares grown and in the number of countries producing blueberries. It should be expected that as blueberry cultivation continues to expand into new areas, the plants will become exposed to viruses that have not been observe...

  12. Virus and Virus-Like Diseases of Blueberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past 15 years, blueberry production has increased dramatically in hectares grown and in the number of countries producing blueberries. It should be expected that as blueberry cultivation continues to expand into new areas, the plants will become exposed to viruses that have not been observe...

  13. 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...

  14. Suramin inhibits in vitro infection by duck hepatitis B virus, Rous sarcoma virus, and hepatitis delta virus.

    PubMed

    Petcu, D J; Aldrich, C E; Coates, L; Taylor, J M; Mason, W S

    1988-12-01

    Suramin blocked in vitro infection by duck hepatitis B virus, a hepadnavirus, and Rous sarcoma virus, a retrovirus. Although suramin was able to inhibit the virus-encoded reverse transcriptase activities of these two viruses, this inhibition did not appear to account for the anti-viral effect of the drug. In particular, suramin was unable to block synthesis within cells of full-length viral DNAs when added subsequent to infection. The results are consistent with the hypothesis that suramin acted by blocking virus uptake or uncoating. As further support of this hypothesis, we found that suramin also blocked infection by hepatitis delta virus, an RNA virus that is not known to employ reverse transcriptase during the initiation of infection. PMID:2462306

  15. Viruses and host evolution: virus-mediated self identity.

    PubMed

    Villarreal, Luis

    2012-01-01

    Virus evolution has become a topic that involves population based selection. Both quasispecies based populations and reticulated mosaic exchange of populations of genetic elements are now well established. This has led us to the understanding that a cooperative consortia can be a crucial aspect of virus driven evolution. Thus viruses exist in groups that can cooperate. However, consortial based evolution (group selection) has long been dismissed by evolutionary biologist. Recently, biocommunication theory has concluded that the evolution and editing of any code or language requires a consortial based process in order to adhere to pragmatic (context) requirements for meaning (in conflict with survival of the fittest concepts). This has led to the idea that viruses are the natural editors of biological codes or language. In this chapter, I present the view that the persistence of virus information in their host provides a natural process of host code editing that is inherently consortial. Since persistence requires mechanisms to attain stability and preclude competition, it also provided mechanisms that promote group identity. Accordingly, I review the viral origins of addiction modules and how these affect both persistence and group identity. The concepts emerging from addiction module based group identity are then generalized and applied to social identity systems as well. I then examine the prokaryotes and the involvement of viral elements in the emergence of their group identity systems (biofilms). Here, integrating dsDNA agents prevailed. In the eukaryotes, however, a large shift in virus-host evolution occurred in which the role of dsDNA agents was diminished but the role of retroviruses and retroposons was greatly enhanced. These agents provided greatly expanded and network based regulatory complexity that was controlled by sensory inputs. From this perspective, the role of virus in the origin of the adaptive immune system is then outlined. I then consider human evolution from the perspective of the great HERV colonization. The origin of a large social brain able to support the learning of language is presented from this viral perspective. The role of addiction modules in the origin of extended social bonding of humans is outlined and applied to the emergence of language as a system of group identity. PMID:22399381

  16. [Double meningoencephalitis with herpes simplex virus and rubella virus].

    PubMed

    Hattori, S; Isogai, Y; Morimoto, Y

    1993-06-01

    A 47-year-old man suffered from a headache, fever and memory disturbance. He was admitted to Morimoto Hospital. Neurological examination revealed disturbance of memory of recent events. Cranial nerves were normal. Muscle strength of the extremities was normal, except for Barr's sign of the right upper extremity. Deep tendon reflexes were exaggerated bilaterally, and extensor plantar response of the left side was elicited. Sensory examination showed no abnormality. Cerebellar sign was not recognized. Meningeal sign was slightly but clearly showed. CT scan demonstrated brain swelling at the right insular cortex region followed by severe hydrocephalus with dilatation of the lateral and the third ventricles. Cerebrospinal fluid showed high CSF pressure (250 mmH2O), pleocytosis (C.C. 359/mm3) and elevated protein level (213 mg/dl). Virological examination revealed herpes simplex virus (HSV) (CF) 32x, HSV-1 IgG (EIA) 4,050X, rubella virus IgE (EIA) 6,060X, cytomegalovirus (CMV) IgG (EIA) 1,130X in serum and HSV (CF) 1X, HSV-1 IGg (EIA) 1,430X, rubella virus IgG (EIA) 1,480X, CMV IgG (EIA) 587X in CSF. The ratio of serum/CSF of HSV and rubella virus titers by EIA methods were 2.83 and 4.10, respectively. He was treated by acyclovir 1,000 mg/day and gamma globulin, but his condition get worse acutely and died at 15th hospital days. This case was considered as a meningoencephalitis caused by simultaneous HSV and rubella virus infection. PMID:8403685

  17. [Skin manifestations related to hepatitis C viruses].

    PubMed

    Doutre, M S; Beylot, C; Beylot-Barry, M; Couzigou, P; Beylot, J

    1995-01-01

    The hepatitis C virus causes both hepatic and extrahepatic disorders, particularly as regards dermatology. The link between essential mixed cryoglobulinemias and the C virus infection has been clearly evidenced., whereas its frequency seems low in other systemic vasculitis such as polyarteritis nodosa. Similarly, the link between C virus hepatopathy and porphyria cutanea tarda is now proven. Lichen planus is also described as being associated with this virus, but further epidemiological studies are required to determine the exact prevalence of lichen in C virus hepatopathy cases. Finally, various cutaneous disorders, such as urticaria, erythema multiforme, dermo-hypodermitis, etc, occasionally arise during acute or chronic hepatitis C. PMID:7481154

  18. Disinfection of human enteric viruses on fomites.

    PubMed

    Abad, F X; Pint, R M; Bosch, A

    1997-11-01

    The virucidal action of several commercially available disinfectant preparations was assayed against hepatitis A virus and human rotavirus dried on polystyrene. Overall, the level of virus disinfection achieved was very poor, usually inducing less than 3 log titre reduction. Suspension tests performed with the same disinfectants showed different virus inactivation rates, thus failing to provide a reliable indication of the actual virus disinfection on fomites. In our studies, bacteriophages of Bacteroides fragilis proved to be a simple, cheap and reliable screening tool for the evaluation of virus disinfection on non-porous surfaces. The same conclusion cannot be drawn for poliovirus. PMID:9368367

  19. Influenza virus activation of the interferon system

    PubMed Central

    Killip, Marian J.; Fodor, Ervin; Randall, Richard E.

    2015-01-01

    The host interferon (IFN) response represents one of the first barriers that influenza viruses must surmount in order to establish an infection. Many advances have been made in recent years in understanding the interactions between influenza viruses and the interferon system. In this review, we summarise recent work regarding activation of the type I IFN response by influenza viruses, including attempts to identify the viral RNA responsible for IFN induction, the stage of the virus life cycle at which it is generated and the role of defective viruses in this process. PMID:25678267

  20. Nanoparticulas basadas en complejos de Fe(II) con transicion de espin: sintesis, caracterizacion y aplicaciones en electronica molecular

    NASA Astrophysics Data System (ADS)

    Monrabal Capilla, Maria

    Esta tesis doctoral esta organizada en 5 capitulos y esta destinada al estudio de sistemas de Fe (II) que presentan el fenomeno de la transicion de espin a escala nanometrica. El capitulo 1 contiene una introduccion general sobre materiales moleculares multifuncionales, destacando aquellos ejemplos mas importantes. Por otro lado, se explicara el fenomeno de la transicion de espin, tratando aspectos conceptuales, los antecedentes mas importantes y la situacion actual. En el capitulo 2 se describen los diferentes procesos existentes para la obtencion de diferentes tipos de nanoparticulas. Ademas, se presenta la sintesis y caracterizacion de nanoparticulas del polimero de coordinacion unidimensional [Fe(Htrz)2(trz)]BF4, obtenidas mediante el metodo de micelas inversas. Estas nanoparticulas, con una estrecha distribucion de tamanos centrada alrededor de los 11 nm, presentan una transicion de espin muy abrupta, con un ancho ciclo de histeresis termica de unos 40K. En el capitulo 3 se describe el proceso de modificacion del tamano de las nanoparticulas descritas en el capitulo anterior, llevado a cabo variando la proporcion de surfactante/H2O en el medio. Ademas, con el objetivo de modificar las propiedades magneticas de las nanoparticulas obtenidas en el capitulo 2, se lleva a cabo la sintesis de nanoparticulas de polimeros de la misma familia del [Fe(Htrz)2(trz)]BF4. En concreto se sintetizaron 3 nuevos tipos de nanoparticulas basadas en el polimero [Fe(Htrz)1-x(NH2trz)x](ClO4)2, siendo x = 0.05, 0.15 y 0.3, en cada caso. Estas nanoparticulas siguen presentando una estrecha distribucion de tamanos y una transicion de espin muy abrupta y con un ancho ciclo de histeresis. Ademas, se observa que este ciclo se desplaza a temperaturas mas proximas a la temperatura ambiente a medida que se aumenta el porcentaje de 4-amino-1, 2, 4- triazol en la muestra. Pero al mismo tiempo se produce una disminucion de la anchura de este ciclo. Por ultimo, en este capitulo se presenta la sintesis de otro nuevo tipo de nanoparticulas, obtenidas a partir de otro polimero de la misma familia, el [FeO8ZnO2(Htrz)3](BF4). Estas nanoparticulas se sintetizaron con el objetivo de estudiar el efecto de la dilucion del metal en la muestra. Como resultado se obtuvieron nanoparticulas que tambien presentan una estrecha distribucion de tamanos pero en este caso la transicion de espin no es tan abrupta como en los casos anteriores. Aunque sigue presentando un ciclo de histeresis termica bastante ancho y a temperaturas proximas a la temperatura ambiente. En el capitulo 4 se describiran las estrategias que se han seguido para mejorar la estabilidad y afinidad sobre diferentes sustratos de las nanoparticulas sintetizadas en el capitulo 2. Tambien se hablara de los intentos realizados parar depositarlas en superficies y embeberlas en diferentes matrices organicas e inorganicas. En el capitulo 5 presentaremos la obtencion de un interruptor molecular realizado poniendo en contacto nanoparticulas individuales sintetizadas en el capitulo 2, con unos electrodos separados varios nanometros. Este dispositivo exhibe "switching" y efecto memoria a temperaturas proximas a la temperatura ambiente como consecuencia de la biestabilidad intrinseca de las nanoparticulas. Ademas demostraremos que el estado magnetico de estas nanoparticulas puede ser controlado electricamente, ya que la transicion de espin en este nanodispositivo molecular puede ser inducida simplemente aplicando un voltaje, lo que puede ser de gran interes para la electronica molecular.

  1. Human viruses in sediments, sludges, and soils*

    PubMed Central

    Rao, V. Chalapati; Metcalf, Theodore G.; Melnick, Joseph L.

    1986-01-01

    Recent studies have provided a greater understanding of the movement of viruses in the environment by their attachment to solids. These studies have focused on solids-associated viruses present in wastewater discharged into the ocean and on viruses in sludge and wastewater that may be retained in soil following their land disposal. Such ocean or land disposal of wastewater and sludge may result in a discharge of one or more of 120 human enteric virus pathogens including those causing poliomyelitis, viral hepatitis A and acute gastroenteritis. Solids-associated viruses in effluents discharged into coastal waters accumulate in bottom sediments, which may contain 10 to 10 000 more virus per unit volume than the overlying seawater. Solids-associated viruses resuspended by water turbulence may be transported from polluted to distant non-polluted recreational or shellfish-growing water. Transmission of viruses causing hepatitis or gastroenteritis may result from contact by bathers or swimmers with these viruses in recreational waters, or from ingestion of raw or improperly cooked shellfish in which the solids-associated virus had been bioaccumulated. The land disposal of sludge and wastewater has a potential of causing infections in farm workers, contamination of crops, pollution of raw potable water sources or infiltration of ground water. Viruses retained on soils can be released by rain water and may contaminate ground water through lateral and vertical movements. PMID:3015442

  2. Method for detecting viruses in aerosols.

    PubMed Central

    Wallis, C; Melnick, J L; Rao, V C; Sox, T E

    1985-01-01

    A simple method with poliovirus as the model was developed for recovering human enteric viruses from aerosols. Filterite filters (pore size, 0.45 micron; Filterite Corp., Timonium, Md.) moistened with glycine buffer (pH 3.5) were used for adsorbing the aerosolized virus. No virus passed the filter, even with air flow rates of 100 liters/min. Virus recovery from the filter was achieved by rapid elution with 800 ml of glycine buffer, pH 10. The virus in the primary eluate was reconcentrated by adjusting the pH to 3.5, adding AlCl3 to 0.0005 M, collecting the virus on a 0.25-micron-pore Filerite disk (diameter, 25 mm) and and eluting with 6 ml of buffer, pH 10. With this method, virus could be detected regularly in aerosols produced by flushing when 3 X 10(8) PFU of poliovirus were present in the toilet bowl. Poliovirus-containing fecal material from two of four infants who had recently received oral polio vaccine also yielded virus in the aerosols when feces containing 2.4 X 10(7) to 4.5 X 10(7) PFU of virus had been added to the toilet bowl. Persons infected with a variety of natural enteric viruses are known to excrete this amount of virus in their daily stools. Images PMID:3004329

  3. Evolution of Avian Tumor Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-induced neoplastic diseases of poultry, namely Marek’s disease (MD), induced by a herpesvirus, and the avian leukosis and reticuloendotheliosis induced by retroviruses, can cause significant economic losses from tumor mortality as well as poor performance. Successful control of MD is and has ...

  4. 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.

  5. Viruses Associated with Human Cancer

    PubMed Central

    McLaughlin-Drubin, Margaret E.; Munger, Karl

    2008-01-01

    It is estimated that viral infections contribute to 1520% of all human cancers. As obligatory intracellular parasites, viruses encode proteins that reprogram host cellular signaling pathways that control proliferation, differentiation, cell death, genomic integrity, and recognition by the immune system. These cellular processes are governed by complex and redundant regulatory networks and are surveyed by sentinel mechanisms that ensure that aberrant cells are removed from the proliferative pool. Given that the genome size of a virus is highly restricted to ensure packaging within an infectious structure, viruses must target cellular regulatory nodes with limited redundancy and need to inactivate surveillance mechanisms that would normally recognize and extinguish such abnormal cells. In many cases, key proteins in these same regulatory networks are subject to mutation in non-virally associated diseases and cancers. Oncogenic viruses have thus served as important experimental models to identify and molecularly investigate such cellular networks. These include the discovery of oncogenes and tumor suppressors, identification of regulatory networks that are critical for maintenance of genomic integrity, and processes that govern immune surveillance. PMID:18201576

  6. 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

  7. Turnip Yellow Mosaic Virus Structure

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The bumpy exterior of the turnip yellow mosaic virus (TYMV) protein coat, or capsid, was defined in detail by Dr. Alexander McPherson of the University of California, Irvin using protein crystallized in space for analysis on Earth. TYMV is an icosahedral virus constructed from 180 copies of the same protein arranged into 12 clusters of five proteins (pentamers), and 20 clusters of six proteins (hexamers). The final TYMV structure led to the enexpected hypothesis that the virus release its RNA by essentially chemical-mechanical means. Most viruses have farly flat coats, but in TYMV, the fold in each protein, called the jellyroll, is clustered at the points where the protein pentamers and hexamers join. The jellyrolls are almost standing on end, producing a bumpy surface with knobs at all of the pentamers and hexamers. At the inside surface of the pentamers is a void that is not present at the hexamers. The coating had been seen in early studies of TYMV, but McPhereson's atomic structure shows much more detail. The inside surface is strikingly, and unexpectedly, different than the outside. While the pentamers contain a central viod on the inside, the hexameric units contain peptides liked to each other, forming a ring or, more accurately, rings to fill the voild. Credit: Dr. Alexander McPherson, University of California, Irvine.

  8. Satellite Tobacco Mosaic Virus (STMV)

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The structure of the Satellite Tobacco Mosaic Virus (STMV)--one of the smallest viruses known--has been successfully deduced using STMV crystals grown aboard the Space Shuttle in 1992 and 1994. The STMV crystals were up to 30 times the volume of any seen in the laboratory. At the same time they gave the best resolution data ever obtained on any virus crystal. STMV is a small icosahedral plant virus, consisting of a protein shell made up of 60 identical protein subunits of molecular weight 17,500. Particularly noteworthy is the fact that, in contrast to the crystal grown on Earth, the crystals grown under microgravity conditions were viusally perfect, with no striations or clumping of crystals. Furthermore, the X-ray diffraction data obtained from the space-grown crystals was of a much higher quality than the best data available at that time from ground-based crystals. This computer model shows the external coating or capsid. STMV is used because it is a simple protein to work with; studies are unrelated to tobacco. Credit: Dr. Alex McPherson, Univeristy of California at Irvin.

  9. Mayaro fever virus, Brazilian Amazon.

    PubMed

    Azevedo, Raimunda S S; Silva, Eliana V P; Carvalho, Valria L; Rodrigues, Sueli G; Nunes-Neto, Joaquim P; Monteiro, Hamilton; Peixoto, Victor S; Chiang, Jannifer O; Nunes, Mrcio R T; Vasconcelos, Pedro F C

    2009-11-01

    In February 2008, a Mayaro fever virus (MAYV) outbreak occurred in a settlement in Santa Barbara municipality, northern Brazil. Patients had rash, fever, and severe arthralgia lasting up to 7 days. Immunoglobulin M against MAYV was detected by ELISA in 36 persons; 3 MAYV isolates sequenced were characterized as genotype D. PMID:19891877

  10. 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

  11. Enumerating Viruses in Coral Mucus

    PubMed Central

    Leruste, Amandine; Bouvier, Thierry

    2012-01-01

    The distribution of viruses inhabiting the coral mucus remains undetermined, as there is no suitable standardized procedure for their separation from this organic matrix, principally owing to its viscosity and autofluorescence. Seven protocols were tested, and the most efficient separations were obtained from a chemical treatment requiring potassium citrate. PMID:22729548

  12. Mayaro Fever Virus, Brazilian Amazon

    PubMed Central

    Azevedo, Raimunda S.S.; Silva, Eliana V.P.; Carvalho, Valria L.; Rodrigues, Sueli G.; Neto, Joaquim P. Nunes; Monteiro, Hamilton A.O.; Peixoto, Victor S.; Chiang, Jannifer O.; Nunes, Mrcio R.T.

    2009-01-01

    In February 2008, a Mayaro fever virus (MAYV) outbreak occurred in a settlement in Santa Barbara municipality, northern Brazil. Patients had rash, fever, and severe arthralgia lasting up to 7 days. Immunoglobulin M against MAYV was detected by ELISA in 36 persons; 3 MAYV isolates sequenced were characterized as genotype D. PMID:19891877

  13. 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

  14. Cucumber mosaic virus in Rubus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucumber mosaic virus (CMV) has been reported on red raspberry in Chile, Scotland and the Soviet Union and in Chile on blackberry. Its occurrence in Rubus is rare and seems to cause little damage. Except for one early, unconfirmed report, CMV has not been reported on Rubus in North America. This vir...

  15. Emerging infectious diseases associated with bat viruses.

    PubMed

    Shi, ZhengLi

    2013-08-01

    Bats play important roles as pollen disseminators and pest predators. However, recent interest has focused on their role as natural reservoirs of pathogens associated with emerging infectious diseases. Prior to the outbreak of severe acute respiratory syndrome (SARS), about 60 bat virus species had been reported. The number of identified bat viruses has dramatically increased since the initial SARS outbreak, and most are putative novel virus species or genotypes. Serious infectious diseases caused by previously identified bat viruses continue to emerge throughout in Asia, Australia, Africa and America. Intriguingly, bats infected by these different viruses seldom display clinical symptoms of illness. The pathogenesis and potential threat of bat-borne viruses to public health remains largely unknown. This review provides a brief overview of bat viruses associated with emerging human infectious diseases. PMID:23917838

  16. 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

  17. 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

  18. Neutrophil uptake of vaccinia virus in vitro

    SciTech Connect

    West, B.C.; Eschete, M.L.; Cox, M.E.; King, J.W.

    1987-10-01

    We studied human neutrophils for uptake of vaccinia virus. Uptake was determined radiometrically and by electron microscopy. Vaccinia virus was labeled with /sup 14/C or /sup 3/H, incubated with neutrophils, and quantified in neutrophil pellets in a new radiometric phagocytosis assay. Better results were obtained from assays of (/sup 3/H)thymidine-labeled virus; uptake increased through 1 hr and then plateaued. Phagocytosis of 3H-labeled Staphylococcus aureus was normal. Uptake of virus was serum dependent. Hexose monophosphate shunt activity was measured by two methods. No /sup 14/CO/sub 2/ from (/sup 14/C)1-glucose accompanied uptake of vaccinia virus, in contrast to the respiratory burst accompanying bacterial phagocytosis. Electron microscopy showed intact to slightly digested intraphagolysosomal vaccinia virus. Pock reduction assay showed a decrease in viral content due to neutrophils until 6 hr of incubation, when a modest but significant increase was observed. Thus, neutrophil uptake of vaccinia virus is distinguished from bacterial phagocytosis.

  19. Virus Clearance through Apoptosis-Dependent Phagocytosis of Influenza A Virus-Infected Cells by Macrophages

    PubMed Central

    Fujimoto, Ippei; Pan, Jiehong; Takizawa, Takenori; Nakanishi, Yoshinobu

    2000-01-01

    Some cultured cell lines undergo typical apoptosis upon infection with influenza virus. However, the release of replicated virus into the culture medium does not change when apoptosis is inhibited. Since apoptotic cells are heterophagically eliminated at early stages of the apoptosis pathway, we anticipated that the coexistence of phagocytic cells with virus-infected cells affects the extent of virus growth. When influenza A virus-infected HeLa cells were mixed with activated mouse peritoneal macrophages, efficient phagocytosis, which was abrogated in the presence of a caspase inhibitor, occurred. At the same time, the release of virus into the culture medium was completely inhibited, and this required direct contact between virus-infected cells and macrophages. Furthermore, an immunoelectron microscopic analysis detected influenza virus particles associated with phagosome-like structures within macrophages. These results indicate that apoptosis-dependent phagocytosis of virus-infected cells may lead to direct elimination of the pathogen. PMID:10708457

  20. A recombinant influenza virus vaccine expressing the F protein of respiratory syncytial virus

    PubMed Central

    Fonseca, Wendy; Ozawa, Makoto; Hatta, Masato; Orozco, Esther; Martnez, Mximo B; Kawaoka, Yoshihiro

    2014-01-01

    Infections with influenza and respiratory syncytial virus (RSV) rank high among the most common human respiratory diseases worldwide. Previously, we developed a replication-incompetent influenza virus by replacing the coding sequence of the PB2 gene, which encodes one of the viral RNA polymerase subunits, with that of a reporter gene. Here, we generated a PB2-knockout recombinant influenza virus expressing the F protein of RSV (PB2-RSVF virus) and tested its potential as a bivalent vaccine. In mice intranasally immunized with the PB2-RSVF virus, we detected high levels of antibodies against influenza virus, but not RSV. PB2-RSVF virus-immunized mice were protected from a lethal challenge with influenza virus but experienced severe body weight loss when challenged with RSV, indicating that PB2-RSVF vaccination enhanced RSV-associated disease. These results highlight one of the difficulties of developing an effective bivalent vaccine against influenza virus and RSV infections. PMID:24292020

  1. Tanay virus, a new species of virus isolated from mosquitoes in the Philippines.

    PubMed

    Nabeshima, Takeshi; Inoue, Shingo; Okamoto, Kenta; Posadas-Herrera, Guillermo; Yu, Fuxun; Uchida, Leo; Ichinose, Akitoyo; Sakaguchi, Miako; Sunahara, Toshihiko; Buerano, Corazon C; Tadena, Florencio P; Orbita, Ildefonso B; Natividad, Filipinas F; Morita, Kouichi

    2014-06-01

    In 2005, we isolated a new species of virus from mosquitoes in the Philippines. The virion was elliptical in shape and had a short single projection. The virus was named Tanay virus (TANAV) after the locality in which it was found. TANAV genomic RNA was a 9562 nt+poly-A positive strand, and polycistronic. The longest ORF contained putative RNA-dependent RNA polymerase (RdRP); however, conserved short motifs in the RdRP were permuted. TANAV was phylogenetically close to Negevirus, a recently proposed taxon of viruses isolated from haemophagic insects, and to some plant viruses, such as citrus leprosis virus C, hibiscus green spot virus and blueberry necrotic ring blotch virus. In this paper, we describe TANAV and the permuted structure of its RdRP, and discuss its phylogeny together with those of plant viruses and negevirus. PMID:24646751

  2. Psoralen inactivation of influenza and herpes simplex viruses and of virus-infected cells

    SciTech Connect

    Redfield, D.C.; Richman, D.D.; Oxman, M.N.; Kronenberg, L.H.

    1981-06-01

    Psoralen compounds covalently bind to nucleic acids when irradiated with long-wavelength ultraviolet light. This treatment can destroy the infectivity of deoxyribonucleic acid and ribonucleic acid viruses. Two psoralen compounds, 4'-hydroxymethyltrioxsalen and 4'-aminomethyltrioxsalen, were used with long-wavelength ultraviolet light to inactivate cell-free herpes simplex and influenza viruses and to render virus-infected cells noninfectious. This method of inactivation was compared with germicidal (short-wavelength) ultraviolet light irradiation. The antigenicity of the treated, virus-infected, antigen-bearing cells was examined by immunofluorescence and radioimmunoassay and by measuring the capacity of the herpes simplex virus-infected cells to stimulate virus-specific lymphocyte proliferation. The infectivity of the virus-infected cells could be totally eliminated without altering their viral antigenicity. The use of psoralen plus long-wavelength ultraviolet light is well suited to the preparation of noninfectious virus antigens and virus antigen-bearing cells for immunological assays.

  3. Ependimoma myxopapilar sacro gigante con osteolisis

    PubMed Central

    Ajler, Pablo; Landriel, Federico; Goldschmidt, Ezequiel; Campero, lvaro; Yampolsky, Claudio

    2014-01-01

    Objetivo: la presentacin de un caso de una paciente con un ependimoma sacro con extensa infiltracin y destruccin sea local. Descripcin del caso: una mujer de 53 aos acudi a la consulta por dolor lumbosacro y alteraciones sensitivas perineales y esfinterianas. La imgenes por Resonancia Magntica (IRM) y la Tomografa Axial Computada (TAC) mostraron una lesin expansiva gigante a nivel S2-S4 con extensa ostelisis e invasin de tejidos adyacentes. Se realiz una exresis tumoral completa con mejora del estatus funcional. La anatoma patolgica inform ependimoma mixopapilar. Discusin: la extensin de la reseccin quirrgica es el mejor predictor de buen pronstico. El tratamiento radiante se reserva como opcin adyuvante para las resecciones incompletas y recidiva tumoral. La quimioterapia slo debera utilizarse en casos en que la ciruga y la radioterapia estn contraindicadas. Conclusin: Los ependimomas mixopapilares sacros con destruccin sea y presentacin intra y extradural son muy infrecuentes y deben ser tenidos en cuenta entre los diagnsticos diferenciales preoperatorios. Su reseccin total, siempre que sea posible, es la mejor alternativa teraputica. PMID:25165615

  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. Chikungunya virus infection: an overview.

    PubMed

    Caglioti, Claudia; Lalle, Eleonora; Castilletti, Concetta; Carletti, Fabrizio; Capobianchi, Maria Rosaria; Bordi, Licia

    2013-07-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus belonging to the Togaviridae family, first isolated in Tanzania in 1952. The main vectors are mosquitoes from the Aedes species. Recently, the establishment of an envelope mutation increased infectivity for A. albopictus. CHIKV has recently re-emerged causing millions of infections in countries around the Indian Ocean characterized by climate conditions favourable to high vector density. Importation of human cases to European regions with high density of suitable arthropod vectors (such as A. albopictus) may trigger autochthonous outbreaks. The clinical signs of CHIKV infection include non-specific flu-like symptoms, and a characteristic rash accompanied by joint pain that may last for a long time after the resolution of the infection. The death rate is not particularly high, but excess mortality has been observed in concomitance with large CHIKV outbreaks. Deregulation of innate defense mechanisms, such as cytokine inflammatory response, may participate in the main clinical signs of CHIKV infection, and the establishment of persistent (chronic) disease. There is no specific therapy, and prevention is the main countermeasure. Prevention is based on insect control and in avoiding mosquito bites in endemic countries. Diagnosis is based on the detection of virus by molecular methods or by virus culture on the first days of infection, and by detection of an immune response in later stages. CHIKV infection must be suspected in patients with compatible clinical symptoms returning from epidemic/endemic areas. Differential diagnosis should take into account the cross-reactivity with other viruses from the same antigenic complex (i.e. O'nyong-nyong virus). PMID:23912863

  6. Full Genome Characterization of the Culicoides-Borne Marsupial Orbiviruses: Wallal Virus, Mudjinbarry Virus and Warrego Viruses

    PubMed Central

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

    2014-01-01

    Viruses belonging to the species Wallal virus and Warrego virus of the genus Orbivirus were identified as causative agents of blindness in marsupials in Australia during 1994/5. Recent comparisons of nucleotide (nt) and amino acid (aa) sequences have provided a basis for the grouping and classification of orbivirus isolates. However, full-genome sequence data are not available for representatives of all Orbivirus species. We report full-genome sequence data for three additional orbiviruses: Wallal virus (WALV); Mudjinabarry virus (MUDV) and Warrego virus (WARV). Comparisons of conserved polymerase (Pol), sub-core-shell ‘T2’ and core-surface ‘T13’ proteins show that these viruses group with other Culicoides borne orbiviruses, clustering with Eubenangee virus (EUBV), another orbivirus infecting marsupials. WARV shares <70% aa identity in all three conserved proteins (Pol, T2 and T13) with other orbiviruses, consistent with its classification within a distinct Orbivirus species. Although WALV and MUDV share <72.86%/67.93% aa/nt identity with other orbiviruses in Pol, T2 and T13, they share >99%/90% aa/nt identities with each other (consistent with membership of the same virus species - Wallal virus). However, WALV and MUDV share <68% aa identity in their larger outer capsid protein VP2(OC1), consistent with membership of different serotypes within the species - WALV-1 and WALV-2 respectively. PMID:25299687

  7. Clinical and biological differences between recurrent herpes simplex virus and varicella-zoster virus infections

    SciTech Connect

    Straus, S.E. )

    1989-12-01

    The major features that distinguish recurrent herpes simplex virus infections from zoster are illustrated in this article by two case histories. The clinical and epidemiologic features that characterize recurrent herpes simplex virus and varicella-zoster virus infections are reviewed. It is noted that herpesvirus infections are more common and severe in patients with cellular immune deficiency. Each virus evokes both humoral and cellular immune response in the course of primary infection. DNA hybridization studies with RNA probes labelled with sulfur-35 indicate that herpes simplex viruses persist within neurons, and that varicella-zoster virus is found in the satellite cells that encircle the neurons.

  8. Virus-Specific Cellular Response in Hepatitis C Virus Infection.

    PubMed

    Kaźmierczak, Justyna; Caraballo Cortes, Kamila; Bukowska-Ośko, Iwona; Radkowski, Marek

    2016-04-01

    Studies performed on chimpanzees and humans have revealed that strong, multispecific and sustained CD4(+) and CD8(+) T cell immune responses is a major determinant of hepatitis C virus (HCV) clearance. However, spontaneous elimination of the virus occurs in minority of infected individuals and cellular response directed against HCV antigens is not persistent in individuals with chronic infection. This review presents characteristics of the HCV-specific T cell response in patients with different clinical course of infection, including acute and chronic infection, persons who spontaneously eliminated HCV and non-infected subjects exposed to HCV. Detection of HCV-specific response, especially in non-infected subjects exposed to HCV, may be indicative of HCV prevalence in population and rate of spontaneous viral clearance. Understanding the mechanisms and role of HCV-specific cellular immune response would contribute to better understanding of HCV epidemiology, immunopathogenesis and may help to design an effective vaccine. PMID:26429740

  9. Host-virus interactions in hepatitis B virus infection.

    PubMed

    Guidotti, Luca G; Isogawa, Masanori; Chisari, Francis V

    2015-10-01

    Hepatitis B virus (HBV) is a noncytopathic, hepatotropic, double-stranded DNA virus that causes acute and chronic hepatitis. Although HBV does not induce a measurable innate immune response in the infected liver, the outcome of infection is determined by the kinetics, breadth, vigor, trafficking, and effector functions of HBV-specific adaptive T cell responses, and the development of neutralizing antibodies. Dysregulation of one or more of these events leads to persistent HBV infection and a variably severe chronic necroinflammatory liver disease that fosters the development of hepatocellular carcinoma. Deeper understanding of the mechanisms responsible for immunological tolerance to HBV is needed in order to devise immunotherapeutic strategies to cure chronic HBV infection and prevent its life-threatening sequelae. PMID:26186123

  10. 9 CFR 113.206 - Wart Vaccine, Killed Virus.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Wart Vaccine, Killed Virus. 113.206... AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart Vaccine, Killed Virus. Wart Vaccine, Killed Virus, shall be...

  11. Blueberry latent virus: An Amalgam of the Totiviridae and Partitiviridae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new, symptomless virus was identified in blueberry. The dsRNA genome of the virus, provisionally named Blueberry latent virus (BBLV), codes for two putative proteins and lacks a movement protein, a property only shared with cryptic viruses. More than 35 isolates of the virus from different cultiv...

  12. 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...

  13. Recombination in Eukaryotic Single Stranded DNA Viruses

    PubMed Central

    Martin, Darren P.; Biagini, Philippe; Lefeuvre, Pierre; Golden, Michael; Roumagnac, Philippe; Varsani, Arvind

    2011-01-01

    Although single stranded (ss) DNA viruses that infect humans and their domesticated animals do not generally cause major diseases, the arthropod borne ssDNA viruses of plants do, and as a result seriously constrain food production in most temperate regions of the world. Besides the well known plant and animal-infecting ssDNA viruses, it has recently become apparent through metagenomic surveys of ssDNA molecules that there also exist large numbers of other diverse ssDNA viruses within almost all terrestrial and aquatic environments. The host ranges of these viruses probably span the tree of life and they are likely to be important components of global ecosystems. Various lines of evidence suggest that a pivotal evolutionary process during the generation of this global ssDNA virus diversity has probably been genetic recombination. High rates of homologous recombination, non-homologous recombination and genome component reassortment are known to occur within and between various different ssDNA virus species and we look here at the various roles that these different types of recombination may play, both in the day-to-day biology, and in the longer term evolution, of these viruses. We specifically focus on the ecological, biochemical and selective factors underlying patterns of genetic exchange detectable amongst the ssDNA viruses and discuss how these should all be considered when assessing the adaptive value of recombination during ssDNA virus evolution. PMID:21994803

  14. West Nile virus: North American experience

    USGS Publications Warehouse

    Hofmeister, Erik K.

    2011-01-01

    West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico, Central America and, more recently, South America. West Nile virus has been reported in over 300 species of birds in the USA and has caused the deaths of thousands of birds, local population declines of some avian species, the clinical illness and deaths of thousands of domestic horses, and the clinical disease in over 30 000 Americans and the deaths of over 1000. Prior to the emergence of West Nile virus in North America, St. Louis encephalitis virus and Dengue virus were the only other known mosquito-transmitted flaviviruses in North America capable of causing human disease. This review will discuss the North American experience with mosquito-borne flavivirus prior to the arrival of West Nile virus, the entry and spread of West Nile virus in North America, effects on wild bird populations, genetic changes in the virus, and the current state of West Nile virus transmission.

  15. Avian influenza virus transmission to mammals.

    PubMed

    Herfst, S; Imai, M; Kawaoka, Y; Fouchier, R A M

    2014-01-01

    Influenza A viruses cause yearly epidemics and occasional pandemics. In addition, zoonotic influenza A viruses sporadically infect humans and may cause severe respiratory disease and fatalities. Fortunately, most of these viruses do not have the ability to be efficiently spread among humans via aerosols or respiratory droplets (airborne transmission) and to subsequently cause a pandemic. However, adaptation of these zoonotic viruses to humans by mutation or reassortment with human influenza A viruses may result in airborne transmissible viruses with pandemic potential. Although our knowledge of factors that affect mammalian adaptation and transmissibility of influenza viruses is still limited, we are beginning to understand some of the biological traits that drive airborne transmission of influenza viruses among mammals. Increased understanding of the determinants and mechanisms of airborne transmission may aid in assessing the risks posed by avian influenza viruses to human health, and preparedness for such risks. This chapter summarizes recent discoveries on the genetic and phenotypic traits required for avian influenza viruses to become airborne transmissible between mammals. PMID:25048542

  16. [Epidemiological characteristics of Zika virus disease].

    PubMed

    Li, J D; Li, D X

    2016-03-10

    Zika virus disease is an emerging mosquito-borne acute infectious disease caused by Zika virus, so far there have been no available vaccine or specific treatment. Currently, the outbreaks of Zika virus disease mainly occurs in the Americas, but the regional distribution of the disease is in rapid expansion, 34 countries and territories have reported autochthonous transmission of the virus. The illness is usually mild with very rarely death, but increased reports of birth defects and neurologic disorders in the areas affected by Zika virus has caused extensive concern worldwide. In China, the competent vectors for Zika virus are widely distributed, imported viraemic cases may become a source of local transmission of the virus. However, Zika virus disease is preventable, the spread of virus could be stopped when the effective prevention measures are taken. This paper summarizes the retrieval results from Medline database and the information from the reports of the governments of countries affected or health organizations about the epidemiological characteristics of Zika virus disease. PMID:27005530

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

    SciTech Connect

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

    2014-05-15

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

  18. 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

  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. 40 CFR 174.514 - Coat Protein of Watermelon Mosaic Virus-2 and Zucchini Yellow Mosaic Virus; exemption from the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Virus-2 and Zucchini Yellow Mosaic Virus; exemption from the requirement for a tolerance. 174.514... Coat Protein of Watermelon Mosaic Virus-2 and Zucchini Yellow Mosaic Virus; exemption from the requirement for a tolerance. Residues of Coat Protein of Watermelon Mosaic Virus-2 and Zucchini Yellow...

  1. Evolution and ecology of influenza A viruses.

    PubMed Central

    Webster, R G; Bean, W J; Gorman, O T; Chambers, T M; Kawaoka, Y

    1992-01-01

    In this review we examine the hypothesis that aquatic birds are the primordial source of all influenza viruses in other species and study the ecological features that permit the perpetuation of influenza viruses in aquatic avian species. Phylogenetic analysis of the nucleotide sequence of influenza A virus RNA segments coding for the spike proteins (HA, NA, and M2) and the internal proteins (PB2, PB1, PA, NP, M, and NS) from a wide range of hosts, geographical regions, and influenza A virus subtypes support the following conclusions. (i) Two partly overlapping reservoirs of influenza A viruses exist in migrating waterfowl and shorebirds throughout the world. These species harbor influenza viruses of all the known HA and NA subtypes. (ii) Influenza viruses have evolved into a number of host-specific lineages that are exemplified by the NP gene and include equine Prague/56, recent equine strains, classical swine and human strains, H13 gull strains, and all other avian strains. Other genes show similar patterns, but with extensive evidence of genetic reassortment. Geographical as well as host-specific lineages are evident. (iii) All of the influenza A viruses of mammalian sources originated from the avian gene pool, and it is possible that influenza B viruses also arose from the same source. (iv) The different virus lineages are predominantly host specific, but there are periodic exchanges of influenza virus genes or whole viruses between species, giving rise to pandemics of disease in humans, lower animals, and birds. (v) The influenza viruses currently circulating in humans and pigs in North America originated by transmission of all genes from the avian reservoir prior to the 1918 Spanish influenza pandemic; some of the genes have subsequently been replaced by others from the influenza gene pool in birds. (vi) The influenza virus gene pool in aquatic birds of the world is probably perpetuated by low-level transmission within that species throughout the year. (vii) There is evidence that most new human pandemic strains and variants have originated in southern China. (viii) There is speculation that pigs may serve as the intermediate host in genetic exchange between influenza viruses in avian and humans, but experimental evidence is lacking. (ix) Once the ecological properties of influenza viruses are understood, it may be possible to interdict the introduction of new influenza viruses into humans. Images PMID:1579108

  2. The pros and cons of hospital employment.

    PubMed

    Bert, Jack M

    2013-09-01

    The pros and cons of hospital employment vary significantly in today's economic environment. This chapter summarizes the advantages and disadvantages of hospital employment with an emphasis on the critical aspect of formalizing an agreement with the hospital employer to prevent future salary reductions and/or termination. PMID:23924751

  3. InterCon Travel Health: Case B

    ERIC Educational Resources Information Center

    Truman, Gregory E.; Pachamanova, Dessislava A.; Goldstein, Michael A.

    2010-01-01

    InterCon provides services to health insurers of foreign tourists who travel to the United States and Canada. Management wants to implement a new information system that will deal with several operational problems, but it is having difficulty securing the capital resources to fund the system's development. After an initial failure, the chief

  4. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses

    PubMed Central

    Holm, Christian K.; Rahbek, Stine H.; Gad, Hans Henrik; Bak, Rasmus O.; Jakobsen, Martin R.; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K.; Sun, Chenglong; Thomsen, Martin K.; Laustsen, Anders; Nielsen, Camilla G.; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L.; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A.; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Søren R.

    2016-01-01

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV. PMID:26893169

  5. Impact of anti-virus software on computer virus dynamical behavior

    NASA Astrophysics Data System (ADS)

    Sun, Mei; Li, Dandan; Han, Dun; Jia, Changsheng

    2014-11-01

    The impact of anti-virus software on the spreading of computer virus is investigated via developing a mathematical model in this paper. Considering the anti-virus software may not be effective, as it may be an outdated version, and then the computers may be infected with a reduced incidence rate. According to the method of next generation matrix, the basic reproduction number is derived. By introducing appropriate Lyapunov function and the Routh stability criterion, acquiring the stability conditions of the virus-free equilibrium and virus equilibrium. The effect of anti-virus software and disconnecting rate on the spreading of virus are also analyzed. When combined with the numerical results, a set of suggestions are put forward for eradicating virus effectively.

  6. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses.

    PubMed

    Holm, Christian K; Rahbek, Stine H; Gad, Hans Henrik; Bak, Rasmus O; Jakobsen, Martin R; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K; Sun, Chenglong; Thomsen, Martin K; Laustsen, Anders; Nielsen, Camilla G; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Sren R

    2016-01-01

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV. PMID:26893169

  7. Pseudotyping of vesicular stomatitis virus with the envelope glycoproteins of highly pathogenic avian influenza viruses.

    PubMed

    Zimmer, Gert; Locher, Samira; Berger Rentsch, Marianne; Halbherr, Stefan J

    2014-08-01

    Pseudotype viruses are useful for studying the envelope proteins of harmful viruses. This work describes the pseudotyping of vesicular stomatitis virus (VSV) with the envelope glycoproteins of highly pathogenic avian influenza viruses. VSV lacking the homotypic glycoprotein (G) gene (VSV?G) was used to express haemagglutinin (HA), neuraminidase (NA) or the combination of both. Propagation-competent pseudotype viruses were only obtained when HA and NA were expressed from the same vector genome. Pseudotype viruses containing HA from different H5 clades were neutralized specifically by immune sera directed against the corresponding clade. Fast and sensitive reading of test results was achieved by vector-mediated expression of GFP. Pseudotype viruses expressing a mutant VSV matrix protein showed restricted spread in IFN-competent cells. This pseudotype system will facilitate the detection of neutralizing antibodies against virulent influenza viruses, circumventing the need for high-level biosafety containment. PMID:24814925

  8. Processing Strategies to Inactivate Enteric Viruses in Shellfish: Limitations of Surrogate Viruses and Molecular Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Noroviruses, hepatitis A and E viruses, sapovirus, astrovirus, rotavirus, Aichi virus, enteric adenoviruses, poliovirus, and other enteroviruses enter shellfish through contaminated seawater or by contamination during handling and processing, resulting in outbreaks ranging from isolated to epidemic....

  9. Detection of sweet potato virus C, sweet potato virus 2 and sweet potato feathery mottle virus in Portugal.

    PubMed

    Varanda, Carla M R; Santos, Susana J; Oliveira, Mnica D M; Clara, Maria Ivone E; Flix, Maria Rosrio F

    2015-06-01

    Field sweet potato plants showing virus-like symptoms, as stunting, leaf distortion, mosaic and chlorosis, were collected in southwest Portugal and tested for the presence of four potyviruses, sweet potato virus C(SPVC), sweet potato virus 2 (SPV2), sweet potato feathery mottle virus (SPFMV), sweet potato virus G(SPVG), and the crinivirus sweet potato chlorotic stunt virus (SPCSV). DsRNA fractions were extracted from symptomatic leaves and used as templates in single and multiplex RT-PCR assays using previously described specific primers for each analyzed virus. The amplified reaction products for SPVC, SPV2 and SPFMV were of expected size, and direct sequencing of PCR products revealed that they correspond to the coat protein gene (CP) and showed 98%, 99% and 99% identity, respectively, to those viruses. Comparison of the CP genomic and amino acid sequences of the Portuguese viral isolates recovered here with those of ten other sequences of isolates obtained in different countries retrieved from the GenBank showed very few differences. The application of the RT-PCR assays revealed for the first time the presence of SPVC and SPFMV in the sweet potato crop in Portugal, the absence of SPVG and SPCSV in tested plants, as well as the occurrence of triple virus infections under field conditions. PMID:26104336

  10. Physical Chemistry of DNA Viruses

    NASA Astrophysics Data System (ADS)

    Knobler, Charles M.; Gelbart, William M.

    2009-05-01

    The relative simplicity of viruses makes it possible to apply generic physical approaches to the understanding of their structure and function. We focus here on viruses that have double-stranded (ds)DNA genomes that are enclosed in a protein container called the capsid. Their structures are now known in precise detail from cryo-electron microscopy. dsDNA is a stiff, highly charged polymer, and typical viral DNAs have contour lengths 1000 times longer than the radius of the capsid into which they are introduced in the assembly process, which is driven by a biological motor. As a result, the confined DNA is highly stressed. The energy stored in the dsDNA, which is compressed to crystalline densities, drives the ejection of the genome into the host at the start of an infection. Experiments have examined the packaging and ejection of the genomes, which have also been the subject of analytic theories and simulations.

  11. Viruses and the autophagy machinery.

    PubMed

    Dreux, Marlne; Chisari, Francis V

    2010-04-01

    Autophagy is a major intracellular pathway for degradation and recycling of long-lived proteins and cytoplasmic organelles that plays an essential role in maintenance of homeostasis in response to starvation and other cellular stresses. Autophagy is also important for a variety of other processes including restriction of intracellular pathogen replication. Our understanding of the fascinating relationship between viruses and the autophagy machinery is still in its infancy but it is clear that autophagy is a newly recognized facet of innate and adaptive immunity against viral infection. Although the autophagy pathway is emerging as a component of host defense, certain viruses have developed strategies to counteract these antiviral mechanisms, and others appear to have co-opted the autophagy machinery as proviral host factors favoring viral replication. The complex interplay between autophagy and viral infection will be discussed in this review. PMID:20305376

  12. 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

  13. West Nile Virus in California

    PubMed Central

    Lothrop, Hugh; Chiles, Robert; Madon, Minoo; Cossen, Cynthia; Woods, Leslie; Husted, Stan; Kramer, Vicki; Edman, John

    2004-01-01

    West Nile virus (WNV) was first isolated in California during July 2003 from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV transmission then increased and spread in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside to San Diego County. WNV was reported concurrently from Arizona in mid-August and from Baja, Mexico, in mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed. PMID:15496236

  14. Genetic resistance to avian viruses.

    PubMed

    Bumstead, N

    1998-04-01

    Viral infections of poultry can be catastrophic in terms of both welfare and economics, and although vaccines have been very successful in combating these diseases, new forms of viruses have evolved which present increasing difficulties for vaccine control. Differences in genetic susceptibility are known to exist for many of the major viral pathogens of poultry. Consequently, an increase in the level of genetic resistance provides a possible means of enhancing protection of flocks. This is particularly feasible where specific resistance genes have been identified, as in the case of avian leukosis and Marek's disease, and the development of genetic maps of the chicken has offered new possibilities for the identification of further resistance genes. It has also become clear that there are genetic differences in the response to live attenuated vaccine viruses, and new possibilities exist to manipulate the genetics of host flocks so that the effect of vaccination can be optimised. PMID:9638814

  15. Variable transcription of pro- and anti-inflammatory cytokines in phocine lymphocytes following canine distemper virus infection.

    PubMed

    Seibel, H; Siebert, U; Rosenberger, T; Baumgrtner, W

    2014-10-15

    Canine distemper virus (CDV) is a highly contagious viral pathogen. Domesticated dogs are the main reservoir of CDV. Although phocine distemper virus was responsible for the recent epidemics in seals in the North and Baltic Seas, most devastating epidemics in seals were also caused by CDV. To further study the pathogenesis of CDV infection in seals, it was the aim of the present study to investigate the mechanisms of CDV induced immunosuppression in seals by analyzing the gene transcription of different pro- and anti-inflammatory cytokines in Concanavalin A (Con A) stimulated and non-stimulated phocine lymphocytes in vitro following infection with the CDV Onderstepoort (CDV-OND) strain. Phocine lymphocytes were isolated via density gradient centrifugation. The addition of 1 ?g/ml Con A and virus was either performed simultaneously or lymphocytes were stimulated for 48 h with Con A prior to virus infection. Gene transcription of interleukin (IL)-6, IL-12 and tumor necrosis factor alpha (TNF?) as pro-inflammatory cytokines and IL-4, IL-10 and transforming growth factor beta (TGF?) as anti-inflammatory cytokines were determined by using RT-qPCR. CDV-OND infection caused an initial increase of pro-inflammatory phocine cytokines mRNA 24h after infection, followed by a decrease in gene transcription after 48 h. A strong increase in the transcription of IL-4 and TGF? was detected after 48 h when virus and mitogen were added simultaneously. An increased IL-10 production occurred only when stimulation and infection were performed simultaneously. Furthermore, an inhibition of IL-12 on IL-4 was noticed in phocine lymphocytes which were stimulated for 48 h prior to infection. In summary, the duration of the stimulation or the lymphocytes seem to have an important influence on the cytokine transcription and indicates that the outcome of CDV infection is dependent on various factors that might sensitize lymphocytes or make them more susceptible or reactive to CDV infection. PMID:25190509

  16. Innate immune evasion strategies of influenza viruses

    PubMed Central

    Hale, Benjamin G; Albrecht, Randy A; Garca-Sastre, Adolfo

    2010-01-01

    Influenza viruses are globally important human respiratory pathogens. These viruses cause seasonal epidemics and occasional worldwide pandemics, both of which can vary significantly in disease severity. The virulence of a particular influenza virus strain is partly determined by its success in circumventing the host immune response. This article briefly reviews the innate mechanisms that host cells have evolved to resist virus infection, and outlines the plethora of strategies that influenza viruses have developed in order to counteract such powerful defences. The molecular details of this virushost interplay are summarized, and the ways in which research in this area is being applied to the rational design of protective vaccines and novel antivirals are discussed. PMID:20020828

  17. Genetic regulation of human immunodeficiency virus.

    PubMed Central

    Steffy, K; Wong-Staal, F

    1991-01-01

    Human immunodeficiency virus (HIV) has a complex life cycle in which both cellular and virus-encoded factors participate to determine the level of virus production. Two of the viral genes, tat and rev, are essential for virus replication and encode novel trans-activators that interact specifically with their cognate RNA target elements. Elucidation of their mechanisms of action is likely to expand our knowledge of gene regulation at transcriptional and posttranscriptional levels in the eukaryotic cell. Several viral genes (vif, vpu, and vpr) facilitate virus infection and/or release and may play a role in target cell tropism and infection in vivo. The functions of yet other viral genes (nef, vpt) remain unclear. Recent data also suggest that the tat gene product may have a role in HIV pathogenesis that goes beyond trans-activating virus expression. It can potentially impact on uninfected cells as a diffusible molecule and alter the growth of different cell types. PMID:1886517

  18. Study of virus by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Moor, K.; Kitamura, H.; Hashimoto, K.; Sawa, M.; Andriana, B. B.; Ohtani, K.; Yagura, T.; Sato, H.

    2013-02-01

    Problem of viruses is very actual for nowadays. Some viruses, which are responsible for human of all tumors, are about 15 %. Main purposes this study, early detection virus in live cell without labeling and in the real time by Raman spectroscopy. Micro Raman spectroscopy (mRs) is a technique that uses a Raman spectrometer to measure the spectra of microscopic samples. According to the Raman spectroscopy, it becomes possible to study the metabolites of a live cultured cell without labeling. We used mRs to detect the virus via HEK 293 cell line-infected adenovirus. We obtained raman specters of lives cells with viruses in 24 hours and 7 days after the infection. As the result, there is some biochemical changing after the treatment of cell with virus. One of biochemical alteration is at 1081 cm-1. For the clarification result, we use confocal fluorescent microscopy and transmission electron microscopy (TEM).

  19. Control of virus diseases of citrus.

    PubMed

    Lee, Richard F

    2015-01-01

    Citrus is thought to have originated in Southeast Asia and horticulturally desirable clonal selections have been clonally cultivated for hundreds of years. While some citrus species have nucellar embryony, most cultivation of citrus has been by clonal propagation to ensure that propagated plants have the same traits as the parent selection. Clonal propagation also avoids juvenility, and the propagated plants produce fruit sooner. Because of the clonal propagation of citrus, citrus has accumulated a large number of viruses; many of these viruses are asymptomatic until a susceptible rootstock and/or scion is encountered. The viruses reported to occur in citrus will be summarized in this review. Methods of therapy to clean selected clones from viruses will be reviewed; the use of quarantine, clean stock, and certification programs for control of citrus viruses and other strategies to control insect spread citrus viruses, such as mild strain cross-protection and the use of pest management areas will be discussed. PMID:25591879

  20. Whitefly transmission of sweet potato viruses.

    PubMed

    Valverde, Rodrigo A; Sim, Jeonggu; Lotrakul, Pongtharin

    2004-03-01

    Three genera of plant viruses, Begomovirus (Geminiviridae), Crinivirus (Closteroviridae) and Ipomovirus (Potyviridae), contain members that infect sweet potato (Ipomoea batatas) and are transmitted by whiteflies. The begomoviruses, Sweet potato leaf curl virus (SPLCV) and Ipomoea leaf curl virus (ILCV), and the ipomovirus Sweet potato mild mottle virus are transmitted by Bemisia tabaci, the sweet potato whitefly. The crinivirus, Sweet potato chlorotic stunt virus (SPCSV), is transmitted by B. tabaci and Trialeurodes abutilonea, the bandedwinged whitefly. Transmission experiments were done with three of these viruses using laboratory-reared whiteflies and 2-day acquisition and transmission feeding periods. SPLCV and ILCV were transmitted from single and double infections by B. tabaci at rates of 5-10%. Transmission rates for SPLCV by B. tabaci were 15-20%. T. abutilonea transmitted SPCSV at a rate of ca. 3% but did not transmit ILCV or SPLCV. PMID:15036843

  1. Impacts of West Nile Virus on wildlife

    USGS Publications Warehouse

    Saito, E.K.; Wild, M.A.

    2004-01-01

    The recent epidemic of West Nile virus in the United States proved to be unexpectedly active and was the largest epidemic of the virus ever recorded. Much remains to be discovered about the ecology and epidemiology of West Nile virus in the United States, including which species are important in maintaining the virus in nature, why some species are more susceptible to lethal infection, and what environmental factors are important in predicting future epidemics. These factors will likely vary regionally, depending on local ecological characteristics. Until scientists better understand the virus and factors influencing its activity, predicting its effects for future seasons is impossible. However, experts are certain about one thing: West Nile virus is here to stay.

  2. Cross-protection against drifted influenza viruses

    PubMed Central

    Orsi, Andrea; Ansaldi, Filippo; de Florentiis, Daniela; Ceravolo, Antonella; Parodi, Valentina; Canepa, Paola; Coppelli, Martina; Icardi, Giancarlo; Durando, Paolo

    2013-01-01

    Antigenic drift, the evolutionary mechanism of influenza viruses, results in an increased susceptibility of vaccinated subjects against circulating viruses. New vaccines able to grant a broader and cross-reactive immune response against drifted influenza variants are needed. Several strategies were explored to enhance the immunogenicity of plain vaccines: adjuvants, carriers and intradermal administration of influenza vaccine emerge as a promising options. To evaluate the ability of a MF59-adjuvanted and intradermal influenza vaccine to elicit an effective antibody response against circulating viruses presenting antigenic patterns different from those of the vaccine strains, we compared antibody responses elicited by implemented vaccines and conventional intramuscular trivalent inactivated vaccine against heterologous circulating influenza A viruses. Different studies, simulating different epidemiological pictures produced by the natural antigenic drift of seasonal influenza viruses, highlighted the superior cross-reactivity of the antibodies elicited by MF59 and intradermal vaccines, compared with subunit or split vaccine against heterologous viruses. PMID:23295230

  3. Virus-Based Chemical and Biological Sensing

    PubMed Central

    Mao, Chuanbin; Liu, Aihua; Cao, Binrui

    2009-01-01

    Viruses have recently proven useful for the detection of target analytes such as explosives, proteins, bacteria, viruses, spores, and toxins with high selectivity and sensitivity. Bacteriophages (often shortened to phages), viruses that specifically infect bacteria, are currently the most studied viruses, mainly because target-specific nonlytic phages (and the peptides and proteins carried by them) can be identified by using the well-established phage display technique, and lytic phages can specifically break bacteria to release cell-specific marker molecules such as enzymes that can be assayed. In addition, phages have good chemical and thermal stability, and can be conjugated with nanomaterials and immobilized on a transducer surface in an analytical device. This Review focuses on progress made in the use of phages in chemical and biological sensors in combination with traditional analytical techniques. Recent progress in the use of virusnanomaterial composites and other viruses in sensing applications is also high-lighted. PMID:19662666

  4. Water quality indicators: bacteria, coliphages, enteric viruses.

    PubMed

    Lin, Johnson; Ganesh, Atheesha

    2013-12-01

    Water quality through the presence of pathogenic enteric microorganisms may affect human health. Coliform bacteria, Escherichia coli and coliphages are normally used as indicators of water quality. However, the presence of above-mentioned indicators do not always suggest the presence of human enteric viruses. It is important to study human enteric viruses in water. Human enteric viruses can tolerate fluctuating environmental conditions and survive in the environment for long periods of time becoming causal agents of diarrhoeal diseases. Therefore, the potential of human pathogenic viruses as significant indicators of water quality is emerging. Human Adenoviruses and other viruses have been proposed as suitable indices for the effective identification of such organisms of human origin contaminating water systems. This article reports on the recent developments in the management of water quality specifically focusing on human enteric viruses as indicators. PMID:23438312

  5. Chloroviruses: not your everyday plant virus.

    PubMed

    Van Etten, James L; Dunigan, David D

    2012-01-01

    Viruses infecting higher plants are among the smallest viruses known and typically have four to ten protein-encoding genes. By contrast, many viruses that infect algae (classified in the virus family Phycodnaviridae) are among the largest viruses found to date and have up to 600 protein-encoding genes. This brief review focuses on one group of plaque-forming phycodnaviruses that infect unicellular chlorella-like green algae. The prototype chlorovirus PBCV-1 has more than 400 protein-encoding genes and 11 tRNA genes. About 40% of the PBCV-1 encoded proteins resemble proteins of known function including many that are completely unexpected for a virus. In many respects, chlorovirus infection resembles bacterial infection by tailed bacteriophages. PMID:22100667

  6. Suppression of Drug Resistance in Dengue Virus

    PubMed Central

    Mateo, Roberto; Nagamine, Claude M.

    2015-01-01

    ABSTRACT Dengue virus is a major human pathogen responsible for 400 million infections yearly. As with other RNA viruses, daunting challenges to antiviral design exist due to the high error rates of RNA-dependent RNA synthesis. Indeed, treatment of dengue virus infection with a nucleoside analog resulted in the expected genetic selection of resistant viruses in tissue culture and in mice. However, when the function of the oligomeric core protein was inhibited, no detectable selection of drug resistance in tissue culture or in mice was detected, despite the presence of drug-resistant variants in the population. Suppressed selection of drug-resistant virus correlated with cooligomerization of the targeted drug-susceptible and drug-resistant core proteins. The concept of “dominant drug targets,” in which inhibition of oligomeric viral assemblages leads to the formation of drug-susceptible chimeras, can therefore be used to prevent the outgrowth of drug resistance during dengue virus infection. PMID:26670386

  7. 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

  8. Resistant Pathogens, Fungi, and Viruses

    PubMed Central

    Guidry, Christopher A.; Mansfield, Sara A.; Sawyer, Robert G.; Cook, Charles H.

    2014-01-01

    The first reports of antibiotic pathogens occurred a few short years after the introduction of these powerful new agents, heralding a new kind of war between medicine and pathogens. Although originally described in Staphylococcus aureus, resistance among bacteria has now become a grim race to determine which classes of bacteria will become more resistant, pitting the Gram positive staphylococci, enterococci, and streptococci against the increasingly resistant Gram negative pathogens, e. g., carbapenemase-resistant enterobacteriaceae. In addition, the availability of antibacterial agents has allowed the development of whole new kinds of diseases caused by non-bacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. All of these organisms are becoming more prevalent and, ultimately, more clinically relevant for surgeons. It is ironic that despite their ubiquity in our communities, there is seldom a second thought given to viral infections in patients with surgical illness. The extent of most surgeon’s interest in viral infections ends with hepatitis and HIV, no doubt related to transmissibility as well as the implications that these viruses might have in a patient’s hepatic or immune functions. There are chapters and even textbooks written about these viruses so these will not be considered here. Instead, we will present the growing body of knowledge of the herpes family viruses and their occurrence and consequences in patients with concomitant surgical disease or critical illness. We have also chosen to focus this chapter on previously immune competent patients, as the impact of herpes family viruses in immunosuppressed patients such as transplant or AIDS patients has received thorough treatment elsewhere. PMID:25440119

  9. Oncolytic virus immunotherapy for melanoma.

    PubMed

    Dharmadhikari, Neal; Mehnert, Janice M; Kaufman, Howard L

    2015-03-01

    Melanoma is a type of skin cancer arising from melanocytes and is increasing in incidence. Although complete surgical excision of early stage lesions may be curative, metastatic melanoma continues to be a major therapeutic challenge. Advances in understanding the molecular pathways that promote tumorigenesis and the interactions between melanoma cells and the immune system have resulted in the approval of several newly targeted agents and immunotherapy strategies for the treatment of advanced disease. Oncolytic virus immunotherapy is a new approach that uses native or attenuated live viruses to selectively kill melanoma cells and induce systemic tumor-specific immune responses. A variety of viruses are now in clinical development with the attenuated oncolytic herpesvirus encoding granulocyte-macrophage colony stimulating factor, known as talimogene laherparepvec, recently demonstrating an improvement in durable response rate in patients with advanced melanoma compared with granulocyte-macrophage colony stimulating factor alone. A major advantage of talimogene laherparepvec and related agents is the limited toxicity and ability to use each individual tumor as a source of antigen to generate a highly specific antitumor immune response. These agents are easily administered in the out-patient setting and may be a reasonable option for patients with limited metastatic tumor burden, those with a good performance status and without extensive prior treatment, and in those who cannot tolerate more difficult therapeutic regimens. Further investigation into the impact on overall survival as monotherapy and combination of oncolytic virus immunotherapy with other forms of immunotherapy merit high priority for further clinical application of these novel agents for the treatment of melanoma and perhaps other cancers as well. PMID:25777572

  10. 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

  11. 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

  12. Satellite Tobacco Mosaic Virus Structure

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The structure of the Satellite Tobacco Mosaic Viurus (STMV)--one of the smallest viruses known--has been successfully reduced using STMV crystals grown aboard the Space Shuttle in 1992 and 1994. The STMV crystals were up to 30 times the volume of any seen in the laboratory. At the time they gave the best resolution data ever obtained on any virus crystal. STMV is a small icosahedral plant virus, consisting of a protein shell made up of 60 identical protein subunits of molecular weight 17,500. Particularly noteworthy is the fact that, in contrast to the crystals grown on Earth, the crystals grown under microgravity conditions were visually perfect, with no striations or clumping of crystals. Furthermore, the x-ray diffraction data obtained from the space-grown crystals was of a much higher quality than the best data available at that time from ground-based crystals. This stylized ribbon model shows the protein coat in white and the nucleic acid in yellow. STMV is used because it is a simple protein to work with; studies are unrelated to tobacco. Credit: Dr. Alex McPherson, University of California at Irvin.

  13. 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

  14. West Nile Virus and wildlife

    USGS Publications Warehouse

    Marra, P.P.; Griffing, S.; Caffrey, C.; Kilpatrick, A.M.; McLean, R.; Brand, C.; Saito, E.; Dupuis, A.P.; Kramer, L.; Novak, R.

    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, few regionwide declines can be attributed to WNV. Predicting future impacts of WNV on wildlife, and pinpointing what drives epidemics, will require substantial additional research into host susceptibility, reservoir competency, and linkages between climate, mosquitoes, and disease. Such work will entail a collaborative effort between scientists in governmental research groups, in surveillance and control programs, and in nongovernmental organizations. West Nile virus was not the first, and it will not be the last, exotic disease to be introduced to the New World. Its spread in North America highlights the need to strengthen animal monitoring programs and to integrate them with research on disease ecology.

  15. Virus removal by biogenic cerium.

    PubMed

    De Gusseme, Bart; Du Laing, Gijs; Hennebel, Tom; Renard, Piet; Chidambaram, Dev; Fitts, Jeffrey P; Bruneel, Els; Van Driessche, Isabel; Verbeken, Kim; Boon, Nico; Verstraete, Willy

    2010-08-15

    The rare earth element cerium has been known to exert antifungal and antibacterial properties in the oxidation states +III and +IV. This study reports on an innovative strategy for virus removal in drinking water by the combination of Ce(III) on a bacterial carrier matrix. The biogenic cerium (bio-Ce) was produced by addition of aqueous Ce(III) to actively growing cultures of either freshwater manganese-oxidizing bacteria (MOB) Leptothrix discophora or Pseudomonas putida MnB29. X-ray absorption spectroscopy results indicated that Ce remained in its trivalent state on the bacterial surface. The spectra were consistent with Ce(III) ions associated with the phosphoryl groups of the bacterial cell wall. In disinfection assays using a bacteriophage as model, it was demonstrated that bio-Ce exhibited antiviral properties. A 4.4 log decrease of the phage was observed after 2 h of contact with 50 mg L(-1) bio-Ce. Given the fact that virus removal with 50 mg L(-1) Ce(III) as CeNO(3) was lower, the presence of the bacterial carrier matrix in bio-Ce significantly enhanced virus removal. PMID:20704235

  16. Virus Removal by Biogenic Cerium

    SciTech Connect

    De Gusseme, B.; Du Laing, G; Hennebel, T; Renard, P; Chidambaram, D; Fitts, J; Bruneel, E; Van Driessche, I; Verbeken, K; et. al.

    2010-01-01

    The rare earth element cerium has been known to exert antifungal and antibacterial properties in the oxidation states +III and +IV. This study reports on an innovative strategy for virus removal in drinking water by the combination of Ce(III) on a bacterial carrier matrix. The biogenic cerium (bio-Ce) was produced by addition of aqueous Ce(III) to actively growing cultures of either freshwater manganese-oxidizing bacteria (MOB) Leptothrix discophora or Pseudomonas putida MnB29. X-ray absorption spectroscopy results indicated that Ce remained in its trivalent state on the bacterial surface. The spectra were consistent with Ce(III) ions associated with the phosphoryl groups of the bacterial cell wall. In disinfection assays using a bacteriophage as model, it was demonstrated that bio-Ce exhibited antiviral properties. A 4.4 log decrease of the phage was observed after 2 h of contact with 50 mg L{sup -1} bio-Ce. Given the fact that virus removal with 50 mg L{sup -1} Ce(III) as CeNO{sub 3} was lower, the presence of the bacterial carrier matrix in bio-Ce significantly enhanced virus removal.

  17. Binding of egg white proteins to viruses.

    PubMed

    Tsuge, Y; Shimoyamada, M; Watanabe, K

    1996-09-01

    The binding of some egg white proteins to bovine rotavirus, hen new castle disease virus (NDV), and human influenza virus (IV) was investigated by using the hemagglutination inhibition (HI) test and supplemented by an enzyme-linked immunosorbent assay (ELISA). In comparison with other egg white proteins, ovomucin showed the highest affinity for the three viruses, while ovomucoid showed only slight affinity for NDV in the HI test and ELISA. PMID:8987603

  18. Dating the emergence of pandemic influenza viruses

    PubMed Central

    Smith, Gavin J. D.; Bahl, Justin; Vijaykrishna, Dhanasekaran; Zhang, Jinxia; Poon, Leo L. M.; Chen, Honglin; Webster, Robert G.; Peiris, J. S. Malik; Guan, Yi

    2009-01-01

    Pandemic influenza viruses cause significant mortality in humans. In the 20th century, 3 influenza viruses caused major pandemics: the 1918 H1N1 virus, the 1957 H2N2 virus, and the 1968 H3N2 virus. These pandemics were initiated by the introduction and successful adaptation of a novel hemagglutinin subtype to humans from an animal source, resulting in antigenic shift. Despite global concern regarding a new pandemic influenza, the emergence pathway of pandemic strains remains unknown. Here we estimated the evolutionary history and inferred date of introduction to humans of each of the genes for all 20th century pandemic influenza strains. Our results indicate that genetic components of the 1918 H1N1 pandemic virus circulated in mammalian hosts, i.e., swine and humans, as early as 1911 and was not likely to be a recently introduced avian virus. Phylogenetic relationships suggest that the A/Brevig Mission/1/1918 virus (BM/1918) was generated by reassortment between mammalian viruses and a previously circulating human strain, either in swine or, possibly, in humans. Furthermore, seasonal and classic swine H1N1 viruses were not derived directly from BM/1918, but their precursors co-circulated during the pandemic. Mean estimates of the time of most recent common ancestor also suggest that the H2N2 and H3N2 pandemic strains may have been generated through reassortment events in unknown mammalian hosts and involved multiple avian viruses preceding pandemic recognition. The possible generation of pandemic strains through a series of reassortment events in mammals over a period of years before pandemic recognition suggests that appropriate surveillance strategies for detection of precursor viruses may abort future pandemics. PMID:19597152

  19. Cell killing by avian leukosis viruses.

    PubMed Central

    Weller, S K; Temin, H M

    1981-01-01

    Infection of chicken cells with a cytopathic avian leukosis virus resulted in the detachment of killed cells from the culture dish. The detached, dead cells contained more unintegrated viral DNA than the attached cells. These results confirm the hypothesis that cell killing after infection with a cytopathic avian leukosis virus is associated with accumulation of large amounts of unintegrated viral DNA. No accumulation of large amounts of integrated viral DNA was found in cells infected with cytopathic avian leukosis viruses. Images PMID:6270346

  20. Imported Mayaro virus infection in the Netherlands.

    PubMed

    Hassing, Robert-Jan; Leparc-Goffart, Isabelle; Blank, Sybrandus N; Thevarayan, Subashini; Tolou, Hugues; van Doornum, Gerard; van Genderen, Perry J

    2010-10-01

    A Dutch couple, presenting with persisting arthralgias, temporary fever and rash after a stay in Surinam were diagnosed with Mayaro virus infection. Mayaro virus is a relatively unknown South American Alphavirus responsible for dengue-like clinical features and persisting arthralgias. An important, but probably underappreciated cross-reactivity with other Alphaviruses like Chikungunya virus is present, which may become of clinical importance in the event the various Alphaviruses will have overlapping geographical distributions and in seroprevalence studies. PMID:20600300

  1. Modeling Transport of Viruses in Fractured Rock

    NASA Astrophysics Data System (ADS)

    Sleep, B. E.; Mondal, P. K.

    2011-12-01

    Fractured rock aquifers are frequently used for water supply for human consumption. In many instances the fractured rock aquifers are vulnerable to contamination by pathogens, including viruses, due to co-location of on-site septic systems, wastewater discharges, biosolids and agricultural activities. Approximately half of the illnesses associated with groundwater consumption in the Unites States have been attributed to viral contamination. A number of these cases have been related to transport of viruses from septic systems to drinking water wells. Despite the potential for rapid transport of viruses through rock fractures to drinking water wells, the understanding of virus transport in fractured rock is limited. In particular, the impacts of virus size, fracture aperture variability and roughness, matrix porosity, groundwater velocity, and geochemical conditions have not been well studied. In this study, a multidimensional model for virus transport in variable aperture fractures is presented. The model is applied to laboratory experiments on transport of virus-sized latex microspheres (0.02 and 0.2 microns) and bacteriophages (MS2 and PR772) in artificially fractured dolomite rocks. In these experiments significant impacts of particle size, fracture characteristics, groundwater velocity, and geochemistry were observed. Given the variability in aperture distribution and associated spatial variation in groundwater flow field, one-dimensional models were not suitable for a comprehensive evaluation of the mechanisms governing the microsphere and bacteriophage transport. Various relationships for virus retention (attachment and detachment) are evaluated to provide insight into the governing processes in virus transport in fractured rock. In addition, the role of virus size, fracture aperture variability, fracture roughness, fracture surface charge, matrix porosity, groundwater velocity, and ionic strength in virus transport are evaluated. Scale-up to the field is addressed to evaluate the potential travel distances of viruses in various fractured rock settings.

  2. 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

  3. 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

  4. Virion nucleic acid of Ebola virus.

    PubMed Central

    Regnery, R L; Johnson, K M; Kiley, M P

    1980-01-01

    The virion nucleic acid of Ebola virus consists of a single-stranded RNA with a molecular weight of approximately 4.0 x 10(6). The virion RNA did not bind to oligodeoxythymidylic acid-cellulose under conditions known to bind RNAs rich in polyadenylic acid and was not infectious under conditions which yielded infectious RNA from Sindbis virus, suggesting that Ebola virus virion nucleic acid is a negative-stranded RNA. PMID:7431486

  5. 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

  6. A case of Powassan virus encephalitis

    PubMed Central

    Rossier, Edmond; Harrison, Robert J.; Lemieux, Bernard

    1974-01-01

    A case of encephalitis due to Powassan virus, probably transmitted through tick-bite, is reported in an 8-year-old boy. There was a 50-fold increase in neutralization titre against Powassan virus, but the virus could not be isolated. Other virological investigations were negative. The patient survived and early physiotherapy and speech re-education could be instituted. Nine months after onset of illness the patient showed moderate sequelae, despite a very severe illness. PMID:4829843

  7. Lipid interactions during virus entry and infection

    PubMed Central

    Mazzon, Michela; Mercer, Jason

    2014-01-01

    Summary For entry and infection viruses have developed numerous strategies to subjugate indispensable cellular factors and functions. Host cell lipids and cellular lipid synthesis machinery are no exception. Not only do viruses exploit existing lipid signalling and modifications for virus entry and trafficking, they also reprogram lipid synthesis, metabolism, and compartmentalization for assembly and egress. Here we review these various concepts and highlight recent progress in understanding viral interactions with host cell lipids during entry and assembly. PMID:25131438

  8. Stability at systems of usual differential equations in virus dynamics

    NASA Astrophysics Data System (ADS)

    Schrer, H.

    In this paper we discuss different models of differential equations systems, that describe virus dynamics in different situations (HIV-virus and Hepatitis B-virus). We inquire the stability of differential equations. We use theorems of the stability theory.

  9. Worries Over Computer "Viruses" Lead Campuses to Issue Guidelines.

    ERIC Educational Resources Information Center

    Turner, Judith Axler

    1987-01-01

    Computer viruses are programs that propagate themselves from disk to disk and destroy programs or information files. Several universities have recently reported virus outbreaks. Some suggestions for avoiding the viruses are provided. (MLW)

  10. Question and Answers: Zika Virus Infection (Zika) and Pregnancy

    MedlinePLUS

    ... Search The CDC Cancel Submit Search The CDC Zika Virus Note: Javascript is disabled or is not supported ... message, please visit this page: About CDC.gov . Zika Virus Home What CDC is doing About Zika Virus ...

  11. 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...

  12. Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus (Genus Potyvirus; Potyviridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV) are species within the genus Potyvirus, family Potyviridae and cause some of the most economically important diseases of legume crops worldwide. Both viruses occur essentially wherever bean and cowpea (including Phaseolus...

  13. Association of Tobacco ringspot virus and Tomato ringspot virus with declining blueberry in New York

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey of highbush blueberry (Vaccinium corymbosum L.) cultivars Patriot and Bluecrop showing virus-like symptoms and decline in vigor in New York was conducted to assess the occurrence of viruses. Leaf samples from symptomatic and asymptomatic bushes reacted positively to Tobacco ringspot virus ...

  14. Detection of influenza C virus but not influenza D virus in Scottish respiratory samples

    PubMed Central

    Smith, Donald B.; Gaunt, Eleanor R.; Digard, Paul; Templeton, Kate; Simmonds, Peter

    2016-01-01

    Background A newly proposed genus of influenza virus (influenza D) is associated with respiratory disease in pigs and cattle. The novel virus is most closely related to human influenza C virus and can infect ferrets but infection has not been reported in humans. Objectives To ascertain if influenza D virus can be detected retrospectively in patient respiratory samples. Study design 3300 human respiratory samples from Edinburgh, Scotland, covering the period 2006–2008, were screened in pools of 10 by RT-PCR using primers capable of detecting both influenza C and D viruses. Results Influenza D was not detected in any sample. Influenza C was present in 6 samples (0.2%), compared with frequencies of 3.3% and 0.9% for influenza A and B viruses from RT-PCR testing of respiratory samples over the same period. Influenza C virus was detected in samples from individuals <2 years or >45 years old, with cases occurring throughout the year. Phylogenetic analysis of nearly complete sequences of all seven segments revealed the presence of multiple, reassortant lineages. Conclusion We were unable to detect viruses related to influenza D virus in human respiratory samples. Influenza C virus was less prevalent than influenza A and B viruses, was associated with mild disease in the young (<2 years) and old (>45 years) and comprised multiple, reassortant lineages. Inclusion of influenza C virus as part of a diagnostic testing panel for respiratory infections would be of limited additional value. PMID:26655269

  15. 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

  16. 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 ...

  17. 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...

  18. 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...

  19. 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...

  20. 9 CFR 113.215 - Bovine Virus Diarrhea Vaccine, Killed Virus.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Bovine Virus Diarrhea Vaccine, Killed Virus. 113.215 Section 113.215 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS...