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1

Influenza A(H1N1)pdm09 Virus Infection in Giant Pandas, China  

PubMed Central

We confirmed infection with influenza A(H1N1)pdm09 in giant pandas in China during 2009 by using virus isolation and serologic analysis methods. This finding extends the host range of influenza viruses and indicates a need for increased surveillance for and control of influenza viruses among giant pandas. PMID:24565026

Li, Desheng; Zhu, Ling; Cui, Hengmin; Ling, Shanshan; Fan, Shengtao; Yu, Zhijun; Zhou, Yuancheng; Wang, Tiecheng; Qian, Jun; Xia, Xianzhu; Xu, Zhiwen; Wang, Chengdong

2014-01-01

2

Epidermal multinucleated giant cells are not always a histopathologic clue to a herpes virus infection: multinucleated epithelial giant cells in the epidermis of lesional skin biopsies from patients with acantholytic dermatoses can histologically mimic a herpes virus infection  

PubMed Central

Background: Multinucleated giant cells in the epidermis can either be epithelial or histiocytic. Epithelial multinucleated giant cells are most often associated with herpes virus infections. Purpose: To review the histologic differential diagnosis of conditions with epithelial and histiocytic multinucleated giant cells—since multinucleated giant cells in the epidermis are not always pathognomonic of a cutaneous herpes virus infection—and to summarize dermatoses in which herpes virus infection has been observed to coexist. Methods: Two individuals with acantholytic dermatoses whose initial lesional skin biopsies showed multinucleated epithelial giant cells suggestive of a herpes virus infection are reported. Using the PubMed database, an extensive literature search was performed on multinucleated giant cell (and epidermis, epithelial, and histiocytic) and herpes virus infection. Relevant papers were reviewed to discover the skin conditions with either multinucleated giant cells in the epidermis or coincident cutaneous herpes virus infection. Results: Initial skin biopsies from patients with either pemphigus vulgaris or transient acantholytic dermatosis mimicked herpes virus infection; however, laboratory studies and repeat biopsies established the correct diagnosis of their acantholytic dermatosis. Hence, epidermal multinucleated giant cells are not always a histopathologic clue to a herpes virus infection. Indeed, epithelial multinucleated giant cells in the epidermis can be observed not only in the presence of infection (herpes virus), but also acantholytic dermatoses and tumors (trichoepithelioma and pleomorphic basal cell carcinoma). Histiocytic multinucleated giant cells in the epidermis can be observed in patients with either giant cell lichenoid dermatitis or lichen nitidus of the palms. Conclusions: Epithelial and histiocytic multinucleated giant cell can occur in the epidermis. Keratinocyte-derived multinucleated giant cells are most commonly associated with herpes virus infection; yet, they can also be observed in patients with skin tumors or acantholytic dermatoses. Cutaneous herpes simplex virus infection can coexist in association with other conditions such as acantholytic dermatoses, benign skin tumors, bullous disorders, hematologic malignancies, inflammatory dermatoses, and physical therapies. However, when a herpes virus infection is suspected based upon the discovery of epithelial multinucleated giant cells in the epidermis, but either the clinic presentation or lack of response to viral therapy or absence of confirmatory laboratory studies does not support the diagnosis of a viral infection, the possibility of a primary acantholytic dermatosis should be considered and additional lesional skin biopsies performed. Also, because hematoxylin and eosin staining is not the golden standard for confirmation of autoimmune bullous dermatoses, skin biopsies for direct immunofluorescence should be performed when a primary bullous dermatosis is suspected since the histopathology observed on hematoxylin and eosin stained sections can be misleading. PMID:25396080

Cohen, Philip R.; Paravar, Taraneh; Lee, Robert A.

2014-01-01

3

Plant genomes enclose footprints of past infections by giant virus relatives.  

PubMed

Nucleocytoplasmic large DNA viruses (NCLDVs) are eukaryotic viruses with large genomes (100 kb-2.5 Mb), which include giant Mimivirus, Megavirus and Pandoravirus. NCLDVs are known to infect animals, protists and phytoplankton but were never described as pathogens of land plants. Here, we show that the bryophyte Physcomitrella patens and the lycophyte Selaginella moellendorffii have open reading frames (ORFs) with high phylogenetic affinities to NCLDV homologues. The P. patens genes are clustered in DNA stretches (up to 13 kb) containing up to 16 NCLDV-like ORFs. Molecular evolution analysis suggests that the NCLDV-like regions were acquired by horizontal gene transfer from distinct but closely related viruses that possibly define a new family of NCLDVs. Transcriptomics and DNA methylation data indicate that the NCLDV-like regions are transcriptionally inactive and are highly cytosine methylated through a mechanism not relying on small RNAs. Altogether, our data show that members of NCLDV have infected land plants. PMID:24969138

Maumus, Florian; Epert, Aline; Nogué, Fabien; Blanc, Guillaume

2014-01-01

4

Plant genomes enclose footprints of past infections by giant virus relatives  

PubMed Central

Nucleocytoplasmic large DNA viruses (NCLDVs) are eukaryotic viruses with large genomes (100?kb–2.5?Mb), which include giant Mimivirus, Megavirus and Pandoravirus. NCLDVs are known to infect animals, protists and phytoplankton but were never described as pathogens of land plants. Here, we show that the bryophyte Physcomitrella patens and the lycophyte Selaginella moellendorffii have open reading frames (ORFs) with high phylogenetic affinities to NCLDV homologues. The P. patens genes are clustered in DNA stretches (up to 13?kb) containing up to 16 NCLDV-like ORFs. Molecular evolution analysis suggests that the NCLDV-like regions were acquired by horizontal gene transfer from distinct but closely related viruses that possibly define a new family of NCLDVs. Transcriptomics and DNA methylation data indicate that the NCLDV-like regions are transcriptionally inactive and are highly cytosine methylated through a mechanism not relying on small RNAs. Altogether, our data show that members of NCLDV have infected land plants. PMID:24969138

Maumus, Florian; Epert, Aline; Nogue, Fabien; Blanc, Guillaume

2014-01-01

5

Evolutionary dynamics of giant viruses and their virophages.  

PubMed

Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested. PMID:23919155

Wodarz, Dominik

2013-07-01

6

Evolutionary dynamics of giant viruses and their virophages  

PubMed Central

Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested. PMID:23919155

Wodarz, Dominik

2013-01-01

7

Provirophages and transpovirons as the diverse mobilome of giant viruses.  

PubMed

A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ~7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer. PMID:23071316

Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V; Raoult, Didier

2012-10-30

8

Viruses Infecting Reptiles  

PubMed Central

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

Marschang, Rachel E.

2011-01-01

9

The Giant Cafeteria roenbergensis Virus That Infects a Widespread Marine Phagocytic Protist Is a New Member of the Fourth Domain of Life  

PubMed Central

Background A recent work has provided strong arguments in favor of a fourth domain of Life composed of nucleo-cytoplasmic large DNA viruses (NCLDVs). This hypothesis was supported by phylogenetic and phyletic analyses based on a common set of proteins conserved in Eukarya, Archaea, Bacteria, and viruses, and implicated in the functions of information storage and processing. Recently, the genome of a new NCLDV, Cafeteria roenbergensis virus (CroV), was released. The present work aimed to determine if CroV supports the fourth domain of Life hypothesis. Methods A consensus phylogenetic tree of NCLDVs including CroV was generated from a concatenated alignment of four universal proteins of NCLDVs. Some features of the gene complement of CroV and its distribution along the genome were further analyzed. Phylogenetic and phyletic analyses were performed using the previously identified common set of informational genes present in Eukarya, Archaea, Bacteria, and NCLDVs, including CroV. Findings Phylogenetic reconstructions indicated that CroV is clearly related to the Mimiviridae family. The comparison between the gene repertoires of CroV and Mimivirus showed similarities regarding the gene contents and genome organization. In addition, the phyletic clustering based on the comparison of informational gene repertoire between Eukarya, Archaea, Bacteria, and NCLDVs unambiguously classified CroV with other NCLDVs and clearly included it in a fourth domain of Life. Taken together, these data suggest that Mimiviridae, including CroV, may have inherited a common gene content probably acquired from a common Mimiviridae ancestor. Conclusions This further analysis of the gene repertoire of CroV consolidated the fourth domain of Life hypothesis and contributed to outline a functional pan-genome for giant viruses infecting phagocytic protistan grazers. PMID:21559486

Colson, Philippe; Gimenez, Gregory; Boyer, Mickael; Fournous, Ghislain; Raoult, Didier

2011-01-01

10

Yellow Fever Virus Infection  

PubMed Central

A sequential and quantitative survey of brain and liver of suckling mice for infective virus and complement-fixing antigen, after infection with yellow fever virus, showed that while there was progressive increase of infective virus content in both organs, only the brain showed a corresponding rise in CF antigen. Histopathological examination revealed that the liver was not significantly involved. The target organ was the brain, where the progressive pathological changes culminated in an acute encephalitis by the 3rd day of experiment. Organ destruction began with the molecular layer of the grey matter. But by the 4th day after infection the entire cerebral cortex was involved. At the initial stages the hippocampus was particularly affected. Tissue damage did not appear to be entirely due to the differential quantitative localization of infective virus. It was hypothesized that the CF antigen acting singly or in conjunction with some hypothetical proteins may be principally involved in the pathological outcome of the disease. ImagesFigs. 7-9Figs. 3-6 PMID:5582071

David-West, Tam. S.; Smith, J. A.

1971-01-01

11

Avian Influenza A Virus Infections in Humans  

MedlinePLUS

... What's this? Submit What's this? Submit Button Avian Influenza A Virus Infections in Humans Language: English Español Share ... Human Infection with Avian Influenza A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses ...

12

Reactive lymphoid hyperplasia of the lymph nodes with giant follicles: a clinicopathologic study of 14 Japanese cases, with special reference to Epstein-Barr virus infection.  

PubMed

To clarify the clinicopathologic and immunohistochemical features of reactive lymphoid hyperplasia with giant follicles (RHGF) among Japanese, 14 patients were studied. The subjects consisted of 9 males and 5 females, ranging in age from 9 to 61 years, with a mean age of 30 years and a median age of 24 years. None of the patients exhibited systemic symptoms. The affected lymph nodes were located in the head and neck area except in 1 case. At the time of lymph node biopsy, 1 patient was diagnosed as having acute infectious mononucleosis (IM) and 2 patients had a recent history of acute IM. One each with myelogenous leukemia or diffuse large B-cell lymphoma had a history of peripheral blood stem cell transplantation. There were no recurrences during follow-up periods ranging from 3 to 50 months. Histologically, 14 lesions were characterized by numerous enlarged, coalescing lymphoid follicles with distortion rather than effacement of the lymph node architecture. By in situ hybridization, Epstein-Barr virus (EBV) genomes were demonstrated in 5 (36%) of 14 cases. The present study indicates that a portion of RHGF appears to represent a histologic finding of acute IM. Moreover, as previously stated, RHGF should be differentiated from follicular lymphoma, particularly the floral variant. PMID:16086082

Kojima, Masaru; Nakamura, Shigeo; Shimizu, Kazuhiko; Iijima, Misa; Murayama, Kayoko; Ohno, Yoshihiro; Itoh, Hideaki; Sakata, Noriyuki; Masawa, Nobuhide

2005-07-01

13

West Nile virus infection  

Microsoft Academic Search

West Nile virus was discovered in 1937 in the West Nile region of Uganda. The virus was found only in the Eastern Hemisphere until 1999. In 1999, West Nile virus was first identified in the Western Hemisphere in New York City. Since 1999, viremic birds have continued to spread the disease across the United States. West Nile virus is an

Patricia A Devine

2003-01-01

14

Neonatal herpes simplex virus infections.  

PubMed

Neonatal herpes simplex virus infections are uncommon, but because of the morbidity and mortality associated with the infection they are often considered in the differential diagnosis of ill neonates. The use of polymerase chain reaction for diagnosis of central nervous system infections and the development of safe and effective antiviral therapy has revolutionized the diagnosis and management of these infants. Initiation of long-term antiviral suppressive therapy in these infants has led to significant improvement in morbidity. This article summarizes the epidemiology of neonatal herpes simplex virus infections and discusses clinical presentation, diagnosis, management, and follow up of infants with neonatal herpes disease. PMID:23481105

Pinninti, Swetha G; Kimberlin, David W

2013-04-01

15

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 ...

16

Human Infection with Foamy Viruses  

Microsoft Academic Search

\\u000a Virtually all nonhuman primate species investigated thus far including prosimians, New World and Old World monkeys and apes\\u000a all harbor distinct and species-specific clades of simian foamy virus (SFV). However, evidence supporting the existence of\\u000a a human-specific foamy virus (FV) is not yet available. Early reports describing widespread infection of healthy and sick\\u000a humans with FV could not be confirmed.

W. Heneine; M. Schweizer; P. Sandstrom; T. Folks

17

MEDLINEPlus: Monkeypox Virus Infections  

NSDL National Science Digital Library

Readers can keep up with the latest developments in the Monkeypox outbreak with this straightforward Web site from MEDLINEplus. The site features the latest Monkeypox news as well as links to authoritative sites for background information about the virus. Readers will also find information on prevention and screening, updated statistics on the outbreak from the Center for Disease Control and Prevention, and more. The site also includes a downloadable electron micrograph of the Monkeypox virus.

18

Samba virus: a novel mimivirus from a giant rain forest, the Brazilian Amazon  

PubMed Central

Background The identification of novel giant viruses from the nucleocytoplasmic large DNA viruses group and their virophages has increased in the last decade and has helped to shed light on viral evolution. This study describe the discovery, isolation and characterization of Samba virus (SMBV), a novel giant virus belonging to the Mimivirus genus, which was isolated from the Negro River in the Brazilian Amazon. We also report the isolation of an SMBV-associated virophage named Rio Negro (RNV), which is the first Mimivirus virophage to be isolated in the Americas. Methods/results Based on a phylogenetic analysis, SMBV belongs to group A of the putative Megavirales order, possibly a new virus related to Acanthamoeba polyphaga mimivirus (APMV). SMBV is the largest virus isolated in Brazil, with an average particle diameter about 574 nm. The SMBV genome contains 938 ORFs, of which nine are ORFans. The 1,213.6 kb SMBV genome is one of the largest genome of any group A Mimivirus described to date. Electron microscopy showed RNV particle accumulation near SMBV and APMV factories resulting in the production of defective SMBV and APMV particles and decreasing the infectivity of these two viruses by several logs. Conclusion This discovery expands our knowledge of Mimiviridae evolution and ecology. PMID:24886672

2014-01-01

19

Ebola virus infection: an overview.  

PubMed

The current outbreak of the Ebola virus infection in Africa has yet again proven that highly dangerous diseases that are transmitted via the blood-borne route may be endemic in some parts of the world and may emerge as sporadic outbreaks causing worldwide concern. Health care professionals are at the forefront of combatting these diseases and treating infected individuals. Though dental professionals are unlikely to be directly involved in the management of such acute infections, with very high mortality rates, they may encounter patients seeking dental treatment who are either from, or who have recently toured the endemic disease areas. This overview, therefore, is a thumb nail sketch of the Ebola virus infection and its implications for dentistry. PMID:8935292

Samaranayake, L P; Peiris, J S; Scully, C

1996-04-01

20

Influenza virus infections  

Microsoft Academic Search

Ninety-six strains of influenza A and 113 influenza B were found in the two MRC\\/PHLS surveys. In the general practitioner survey the majority of strains were isolated from cases diagnosed as influenza but in hospital most came from cases diagnosed as having other respiratory infections. In the latter survey isolation rates were higher in upper respiratory tract infection than in

N. R. Grist

1973-01-01

21

Neonatal herpes simplex virus infection  

PubMed Central

Neonatal herpes, seen roughly in 1 of 3,000 live births in the United States, is the most serious manifestation of herpes simplex virus (HSV) infection in the perinatal period. Although acyclovir therapy decreases infant mortality associated with perinatal HSV transmission, development of permanent neurologic disabilities is not uncommon. Mother-to-neonate HSV transmission is most efficient when maternal genital tract HSV infection is acquired proximate to the time of delivery, signifying that neonatal herpes prevention strategies need to focus on decreasing the incidence of maternal infection during pregnancy and more precisely identifying infants most likely to benefit from prophylactic antiviral therapy. PMID:23090462

Cherpes, Thomas L.; Matthews, Dean B.; Maryak, Samantha A.

2012-01-01

22

Neonatal herpes simplex virus infection.  

PubMed

Neonatal herpes, seen roughly in 1 of 3000 live births in the United States, is the most serious manifestation of herpes simplex virus (HSV) infection in the perinatal period. Although acyclovir therapy decreases infant mortality associated with perinatal HSV transmission, development of permanent neurological disabilities is not uncommon. Mother-to-neonate HSV transmission is most efficient when maternal genital tract HSV infection is acquired proximate to the time of delivery, signifying that neonatal herpes prevention strategies need to focus on decreasing the incidence of maternal infection during pregnancy and more precisely identifying infants most likely to benefit from prophylactic antiviral therapy. PMID:23090462

Cherpes, Thomas L; Matthews, Dean B; Maryak, Samantha A

2012-12-01

23

Giant viruses in the oceans : the 4th Algal Virus Workshop  

E-print Network

Paramecium bursaria chlorella virus (PBCV-1), the prototype of the Phycodnaviridae, was isolated more than 20 bursaria chlorella viruses: NY-2A (infecting PBCV-1 host Chlorella species NC64A) and Chlorella Pbi virus MT325. NY-2A genome contains 368,683 bp, making it the largest chlorella virus sequenced to date

Boyer, Edmond

24

Pediatric human immunodeficiency virus infection.  

PubMed Central

In the past decade, an increase in pediatric human immunodeficiency virus (HIV) infection has had a substantial impact on childhood morbidity and mortality worldwide. The vertical transmission of HIV from mother to infant accounts for the vast majority of these cases. Identification of HIV-infected pregnant women needs to be impoved so that appropriate therapy can be initiated for both mothers and infants. While recent data demonstrate a dramatic decrease in HIV transmission from a subset of women treated with zidovudine during pregnancy, further efforts at reducing transmission are desperately needed. This review focuses on vertically transmitted HIV infection in children, its epidemiology, diagnostic criteria, natural history, and clinical manifestations including infectious and noninfectious complications. An overview of the complex medical management of these children ensues, including the use of antiretroviral therapy. Opportunistic infection prophylaxis is reviewed, along with the important role of other supportive therapies. PMID:8894346

Domachowske, J B

1996-01-01

25

Human Immunodeficiency Virus (HIV) Primary Infection  

MedlinePLUS

newsletter | contact Share | Human Immunodeficiency Virus (HIV) Primary Infection Information for adults A A A When HIV is first contracted, there may be ... 1–6 weeks following exposure to HIV (the human immunodeficiency virus). Chronic infection with this virus can ...

26

Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology  

PubMed Central

The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 ?m in diameter and adenine–thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 ?m in length and guanine–cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 ?m in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health. PMID:24591590

Legendre, Matthieu; Bartoli, Julia; Shmakova, Lyubov; Jeudy, Sandra; Labadie, Karine; Adrait, Annie; Lescot, Magali; Poirot, Olivier; Bertaux, Lionel; Bruley, Christophe; Coute, Yohann; Rivkina, Elizaveta; Abergel, Chantal; Claverie, Jean-Michel

2014-01-01

27

Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology.  

PubMed

The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 ?m in diameter and adenine-thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 ?m in length and guanine-cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 ?m in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health. PMID:24591590

Legendre, Matthieu; Bartoli, Julia; Shmakova, Lyubov; Jeudy, Sandra; Labadie, Karine; Adrait, Annie; Lescot, Magali; Poirot, Olivier; Bertaux, Lionel; Bruley, Christophe; Couté, Yohann; Rivkina, Elizaveta; Abergel, Chantal; Claverie, Jean-Michel

2014-03-18

28

Gene repertoire of amoeba-associated giant viruses.  

PubMed

Acanthamoeba polyphaga mimivirus, Marseillevirus, and Sputnik, a virophage, are intra-amoebal viruses that have been isolated from water collected in cooling towers. They have provided fascinating data and have raised exciting questions about viruses definition and evolution. Mimivirus and Marseillevirus have been classified in the nucleo-cytoplasmic large DNA viruses (NCLDVs) class. Their genomes are the largest and fifth largest viral genomes sequenced so far. The gene repertoire of these amoeba-associated viruses can be divided into four groups: the core genome, genes acquired by lateral gene transfer, duplicated genes, and ORFans. Open reading frames (ORFs) that have homologs in the NCLDVs core gene set represent 2.9 and 6.1% of the Mimivirus and Marseillevirus gene contents, respectively. A substantial proportion of the Mimivirus, Marseillevirus and Sputnik ORFs exhibit sequence similarities to homologs found in bacteria, archaea, eukaryotes or viruses. The large amount of chimeric genes in these viral genomes might have resulted from acquisitions by lateral gene transfers, implicating sympatric bacteria and viruses with an intra-amoebal lifestyle. In addition, lineage-specific gene expansion may have played a major role in the genome shaping. Altogether, the data so far accumulated on amoeba-associated giant viruses are a powerful incentive to isolate and study additional strains to gain better understanding of their pangenome. PMID:20551685

Colson, Philippe; Raoult, Didier

2010-01-01

29

Therapy of Herpes Virus Infections in Children  

Microsoft Academic Search

Rapid advances have been achieved in the therapy of herpes virus infections of children over the past 25 years. Following\\u000a the demonstration that vidarabine was an efficacious treatment for neonatal herpes simplex virus (HSV) infections, herpes\\u000a simplex encephalitis, and varicella zoster virus (VZV) infections of children, significant advances were achieved with the\\u000a development of second generation anti-viral drugs. The second

Richard J. Whitley

30

[Giant branchial cyst with infection in newborn infant: case report].  

PubMed

Branchial cyst is a rarely seen inheritent cyst commonly located in the lateral face and neck.A giant branchial cyst with infection in a newborn infant was reported in this paper. Surgical enucleate of the cyst was performed at 17 days of the infant with good result. The patient has been followed up for 2 years without recurrence. PMID:15133556

Luo, Xian-feng; Chen, Guo-ying

2004-04-01

31

Immunology of hepatitis B virus and hepatitis C virus infection  

Microsoft Academic Search

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

Michelina Nascimbeni; Barbara Rehermann

2005-01-01

32

West Nile Virus Infection and Pregnancy  

MedlinePLUS

... a virus that can infect humans, birds, mosquitoes, horses and some other mammals. It is commonly found ... States. You cannot get WNV from birds or horses. If an infected mosquito bites a human, the ...

33

CELLULAR PATHOLOGY OF A GRANULOSIS VIRUS INFECTION  

EPA Science Inventory

Nuclear and cytoplasmic ultrastructural changes were examined in Spodoptera frugiperda (SF) larval fat body cells infected with granulosis virus (GV). Soon after infection necleocapsidlike structures were observed within the nucleus associated with nuclear pores. The earliest cel...

34

Influenza A Virus Infections in Land  

E-print Network

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

Clayton, Dale H.

35

Genetic resistance to Infectious Bronchitis Virus infection  

E-print Network

was the most resistant, followed by B2/B12, B2/B2, B19/B19, and B12/B12. Low levels of virus were recovered in the lungs of only the infected B2/B2 and B12/B12 haplotypes. Virus was easily detected in infected kidneys of all groups examined and levels...

Dzielawa, Jennifer Ann

2012-06-07

36

Persistent Seoul virus infection in Lewis rats  

Microsoft Academic Search

Summary. Mechanistic studies of hantavirus persistence in rodent reservoirs have been limited by the lack of a versatile animal model. This report describes findings from experimental infection of inbred Lewis rats with Seoul virus strain 80–39. Rats inoculated with virus intraperitoneally at 6 days of age became persistently infected without clinical signs. Tissues from Seoul virus-inoculated 6-day-old rats were assessed

S. R. Compton; R. O. Jacoby; F. X. Paturzo; A. L. Smith

2004-01-01

37

Influenza A virus infections in Chinese landbirds  

E-print Network

Infl uenza A Virus Infections in Land Birds, People’s Republic of China A. Townsend Peterson, Sarah E. Bush, Erica Spackman, David E. Swayne, and Hon S. Ip Water birds are considered the reservoir for avian in- fl uenza viruses. We examined... this assumption by sampling and real-time reverse transcription–PCR testing of 939 Asian land birds of 153 species. Infl uenza A infection was found, particularly among migratory species. Surveillance programs for monitoring spread of these viruses need...

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

2009-10-01

38

Virus-Induced Aggregates in Infected Cells  

PubMed Central

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

Moshe, Adi; Gorovits, Rena

2012-01-01

39

Mimiviridae: clusters of orthologous genes, reconstruction of gene repertoire evolution and proposed expansion of the giant virus family  

PubMed Central

Background The family Mimiviridae belongs to the large monophyletic group of Nucleo-Cytoplasmic Large DNA Viruses (NCLDV; proposed order Megavirales) and encompasses giant viruses infecting amoeba and probably other unicellular eukaryotes. The recent discovery of the Cafeteria roenbergensis virus (CroV), a distant relative of the prototype mimiviruses, led to a substantial expansion of the genetic variance within the family Mimiviridae. In the light of these findings, a reassessment of the relationships between the mimiviruses and other NCLDV and reconstruction of the evolution of giant virus genomes emerge as interesting and timely goals. Results Database searches for the protein sequences encoded in the genomes of several viruses originally classified as members of the family Phycodnaviridae, in particular Organic Lake phycodnaviruses and Phaeocystis globosa viruses (OLPG), revealed a greater number of highly similar homologs in members of the Mimiviridae than in phycodnaviruses. We constructed a collection of 898 Clusters of Orthologous Genes for the putative expanded family Mimiviridae (MimiCOGs) and used these clusters for a comprehensive phylogenetic analysis of the genes that are conserved in most of the NCLDV. The topologies of the phylogenetic trees for these conserved viral genes strongly support the monophyly of the OLPG and the mimiviruses. The same tree topology was obtained by analysis of the phyletic patterns of conserved viral genes. We further employed the mimiCOGs to obtain a maximum likelihood reconstruction of the history of genes losses and gains among the giant viruses. The results reveal massive gene gain in the mimivirus branch and modest gene gain in the OLPG branch. Conclusions These phylogenomic results reported here suggest a substantial expansion of the family Mimiviridae. The proposed expanded family encompasses a greater diversity of viruses including a group of viruses with much smaller genomes than those of the original members of the Mimiviridae. If the OLPG group is included in an expanded family Mimiviridae, it becomes the only family of giant viruses currently shown to host virophages. The mimiCOGs are expected to become a key resource for phylogenomics of giant viruses. PMID:23557328

2013-01-01

40

The Epidemiology of Human Immunodeficiency Virus Infection.  

ERIC Educational Resources Information Center

Reviews epidemiology and natural history of human immunodeficiency virus-Type 1 (HIV-1) infection. Discusses early and late clinical manifestations, diagnosis of infection, incubation and latency periods, and survival time. Reviews data from published literature on distribution of HIV infection in adult United States population and factors that…

Glasner, Peter D.; Kaslow, Richard A.

1990-01-01

41

Epidemiology of hepatitis C virus infection  

Microsoft Academic Search

Globally, hepatitis C virus (HCV) has infected an estimated 130 million people, most of whom are chronically infected. HCV-infected people serve as a reservoir for transmission to others and are at risk for developing chronic liver disease, cirrhosis, and primary hepatocellular carcinoma (HCC). It has been estimated that HCV accounts for 27% of cirrhosis and 25% of HCC worldwide. HCV

Miriam J Alter

2007-01-01

42

Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells  

SciTech Connect

Dengue virus causes {approx}50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture.

Perera, Rushika M.; Riley, Catherine; Isaac, Georgis; Hopf- Jannasch, Amber; Moore, Ronald J.; Weitz, Karl K.; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Adamec, Jiri; Kuhn, Richard J.

2012-03-22

43

Multifocal VZV vasculopathy with temporal artery infection mimics giant cell arteritis  

PubMed Central

Objective: To address the incidence of varicella-zoster virus (VZV) infection in patients with biopsy-negative giant cell arteritis (GCA), we examined archived biopsy-negative temporal arteries from subjects with clinically suspected GCA for the presence of VZV antigen. Methods: Formalin-fixed, paraffin-embedded temporal arteries that were pathologically negative for GCA and normal temporal arteries were analyzed immunohistochemically for VZV and herpes simplex virus-1 (HSV-1) antigen. Results: Five (21%) of 24 temporal arteries from patients who were clinically suspect but biopsy negative for GCA revealed VZV but not HSV-1 by immunohistochemical analysis. Thirteen normal temporal arteries did not contain VZV or HSV-1 antigen. All 5 subjects whose temporal arteries contained VZV antigen presented with clinical and laboratory features of GCA and early visual disturbances. Conclusion: Multifocal VZV vasculopathy can present with the full spectrum of clinical features and laboratory abnormalities characteristically seen in GCA. PMID:23635966

Nagel, Maria A.; Bennett, Jeffrey L.; Khmeleva, Nelly; Choe, Alexander; Rempel, April; Boyer, Philip J.

2013-01-01

44

Innate immunity to influenza virus infection  

PubMed Central

Influenza viruses are a major pathogen of both humans and animals. Recent studies using gene-knockout mice have led to an in-depth understanding of the innate sensors that detect influenza virus infection in a variety of cell types. Signalling downstream of these sensors induces distinct sets of effector mechanisms that block virus replication and promote viral clearance by inducing innate and adaptive immune responses. In this Review, we discuss the various ways in which the innate immune system uses pattern recognition receptors to detect and respond to influenza virus infection. We consider whether the outcome of innate sensor stimulation promotes antiviral resistance or disease tolerance, and propose rational treatment strategies for the acute respiratory disease that is caused by influenza virus infection. PMID:24762827

Iwasaki, Akiko; Pillai, Padmini S.

2014-01-01

45

Akabane and bovine ephemeral fever virus infections.  

PubMed

Akabane and bovine ephemeral fever viruses are exotic to the American continent. Both viruses are spread by insect vectors, and each causes disease of varying severity in food-producing animals. However, there are few other similarities between the agents and the diseases that they cause. They do not share the same insect vectors, the mammalian host range is different, and the clinical manifestations of virus infection vary markedly. Akabane virus is a cause of severe congenital defects, but adult animals show no signs of infection. In contrast, bovine ephemeral fever virus causes a febrile illness affecting mainly mature animals. If introduced to North America, it is probable that there would be significant economic losses, at least until endemic virus transmission patterns were established. Subsequently, it is likely that there would be patterns of alternate disease outbreaks followed by interepidemic periods in which there is a minor clinical effect. PMID:12442580

Kirkland, Peter D

2002-11-01

46

Human immunodeficiency virus infection and pneumothorax  

PubMed Central

Pneumothorax is a serious and relatively frequent complication of human immunodeficiency virus (HIV) infection that may associate with increased morbidity and mortality and may prove difficult to manage, especially in patients with acquired immunodeficiency syndrome (AIDS). PMID:25337392

Terzi, Eirini; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros

2014-01-01

47

METHODS USED TO STUDY RESPIRATORY VIRUS INFECTION  

PubMed Central

This unit describes protocols for infecting the mouse respiratory tract, and assaying virus replication and host response in the lung. Respiratory infections are the leading cause of acute illness worldwide, affecting mostly infants and children in developing countries. The purpose of this unit is to provide the readers with a basic strategy and protocols to study the pathogenesis and immunology of respiratory virus infection using the mouse as an animal model. The procedures include: (i) basic techniques for mouse infection, tissue sampling and preservation, (ii) determination of viral titers, isolation and analysis of lymphocytes and dendritic cells using flow-cytometry, and (iii) lung histology, immunohistochemistry and in situ hybridization. PMID:19499505

Flano, Emilio; Jewell, Nancy A.; Durbin, Russell K.; Durbin, Joan E.

2009-01-01

48

Cytomorphological changes during Nariva virus infection  

Microsoft Academic Search

Summary Fatal encephalitis developed in newborn Swiss mice following intracerebral inoculation with Nariva virus. By light microscopic examination Nariva virus encephalitis is characterized by a discreete astrogliosis, lymphocytic perivascular infiltrations and diffused microglial proliferation which occurred in form of nodules. Electron microscopic examination of infected mouse brain tissues revealed marked morphological damage to the neurons and the astroglial cells and

R. Walder; A. C. Dominguez; J. G. Tamayo

1971-01-01

49

Postexposure Treatment of Marburg Virus Infection  

PubMed Central

Rhesus monkeys are protected from disease when a recombinant vesicular stomatitis virus–based vaccine is administered 20–30 min after infection with Marburg virus. We protected 5/6 monkeys when this vaccine was given 24 h after challenge; 2/6 animals were protected when the vaccine was administered 48 h postinfection. PMID:20587184

Hensley, Lisa E.; Geisbert, Joan B.; Leung, Anders; Johnson, Joshua C.; Grolla, Allen; Feldmann, Heinz

2010-01-01

50

DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS  

EPA Science Inventory

Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

51

The Pathology of Influenza Virus Infections  

PubMed Central

Influenza viruses are significant human respiratory pathogens that cause both seasonal, endemic infections and periodic, unpredictable pandemics. The worst pandemic on record, in 1918, killed approximately 50 million people worldwide. Human infections caused by H5N1 highly pathogenic avian influenza viruses have raised concern about the emergence of another pandemic. The histopathology of fatal influenza virus pneumonias as documented over the past 120 years is reviewed here. Strikingly, the spectrum of pathologic changes described in the 1918 influenza pandemic is not significantly different from the histopathology observed in other less lethal pandemics or even in deaths occurring during seasonal influenza outbreaks. PMID:18039138

Taubenberger, Jeffery K.; Morens, David M.

2008-01-01

52

DNA-dependent RNA polymerase detects hidden giant viruses in published databanks.  

PubMed

Environmental metagenomic studies show that there is a "dark matter," composed of sequences not linked to any known organism, as determined mainly using ribosomal DNA (rDNA) sequences, which therefore ignore giant viruses. DNA-dependent RNA polymerase (RNAP) genes are universal in microbes and conserved in giant viruses and may replace rDNA for identifying microbes. We found while reconstructing RNAP subunit 2 (RNAP2) phylogeny that a giant virus sequenced together with the genome of a large eukaryote, Hydra magnipapillata, has been overlooked. To explore the dark matter, we used viral RNAP2 and reconstructed putative ancestral RNAP2, which were significantly superior in detecting distant clades than current sequences, and we revealed two additional unknown mimiviruses, misclassified as an euryarchaeote and an oomycete plant pathogen, and detected unknown putative viral clades. We suggest using RNAP systematically to decipher the black matter and identify giant viruses. PMID:24929085

Sharma, Vikas; Colson, Philippe; Giorgi, Roch; Pontarotti, Pierre; Raoult, Didier

2014-07-01

53

Human Immunodeficiency Virus Type 1 Infection of Neural Xenografts  

NASA Astrophysics Data System (ADS)

Human immunodeficiency virus type 1 (HIV-1) infection is highly specific for its human host. To study HIV-1 infection of the human nervous system, we have established a small animal model in which second-trimester (11 to 17.5 weeks) human fetal brain or neural retina is transplanted to the anterior chamber of the eye of immunosuppressed adult rats. The human xenografts vascularized, formed a blood-brain barrier, and differentiated, forming neurons and glia. The xenografts were infected with cell-free HIV-1 or with HIV-1-infected human monocytes. Analysis by polymerase chain reaction revealed HIV-1 sequences in DNA from xenograft tissue exposed to HIV-1 virions, and in situ hybridization demonstrated HIV-1 mRNA localized in macrophages and multinucleated giant cells. Pathological damage was observed only in neural xenografts containing HIV-1-infected human monocytes, supporting the hypothesis that these cells mediate neurotoxicity. This small animal model allows the study of direct and indirect effects of HIV-1 infection on developing human fetal neural tissues, and it should prove useful in evaluating antiviral therapies, which must ultimately target HIV-1 infection of the brain.

Cvetkovich, Therese A.; Lazar, Eliot; Blumberg, Benjamin M.; Saito, Yoshihiro; Eskin, Thomas A.; Reichman, Richard; Baram, David A.; del Cerro, Coca; Gendelman, Howard E.; del Cerro, Manuel; Epstein, Leon G.

1992-06-01

54

Experimental Schmallenberg virus infection of pigs.  

PubMed

Schmallenberg virus (SBV) is a newly emerged virus responsible for an acute non-specific syndrome in adult cattle including high fever, decrease in milk production and severe diarrhea. It also causes reproductive problems in cattle, sheep and goat including abortions, stillbirths and malformations. The role of pigs in the epidemiology of SBV has not yet been evaluated while this could be interesting seen their suggested role in the epidemiology of the closely related Akabane virus. To address this issue, four 12 week old seronegative piglets were subcutaneously infected with 1 ml of SBV infectious serum (FLI) and kept into contact with four non-infected piglets to examine direct virus transmission. Throughout the experiment blood, swabs and feces samples were collected and upon euthanasia at 28 dpi different organs (cerebrum, cerebellum, brain stem, lung, liver, iliac lymph nodes, kidney and spleen) were sampled. No clinical impact was observed and all collected samples tested negative for SBV in rRT-PCR. Despite the absence of viremia and virus transmission, low and short lasting amounts of neutralizing antibodies were found in 2 out of 4 infected piglets. The limited impact of SBV infection in pigs was further supported by the absence of neutralizing anti-SBV antibodies in field collected sera from indoor housed domestic pigs (n=106). In conclusion, SBV infection of pigs can induce seroconversion but is ineffective in terms of virus replication and transmission indicating that pigs have no obvious role in the SBV epidemiology. PMID:24679959

Poskin, Antoine; Van Campe, Willem; Mostin, Laurent; Cay, Brigitte; De Regge, Nick

2014-06-01

55

Visualizing infection of individual influenza viruses  

Microsoft Academic Search

Influenza is a paradigm for understanding viral infections. As an opportunistic pathogen exploiting the cellular endocytic machinery for infection, influenza is also a valuable model system for exploring the cell's constitutive endocytic pathway. We have studied the transport, acidification, and fusion of single influenza viruses in living cells by using real-time fluorescence microscopy and have dissected individual stages of the

Melike Lakadamyali; Michael J. Rust; Hazen P. Babcock; Xiaowei Zhuang

2003-01-01

56

Hepatitis E Virus Mixed Infection in Immunocompetent Patient  

PubMed Central

We detected 2 hepatitis E virus (HEV) strains in an acutely infected immunocompetent patient. Two populations of genotype 3 virus were observed in the hypervariable regions and open reading frames 2 and 3, indicating multiple infection with hepatitis E virus. Persons with mixed infections may provide the opportunity for virus recombination. PMID:23621890

Vanek, Jeff; Wellington, Louise; Johannessen, Ingolfur; Ramalingam, Sandeep; Simmonds, Peter

2013-01-01

57

Inhibition of enveloped viruses infectivity by curcumin.  

PubMed

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

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

2013-01-01

58

Inhibition of Enveloped Viruses Infectivity by Curcumin  

PubMed Central

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

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

2013-01-01

59

Management of Neonatal herpes simplex virus infections  

Microsoft Academic Search

As many as 2,500 infants develop neonatal herpes each year, most of whom are born to women with no history or physical findings\\u000a suggestive of genital herpes. Infection usually takes one of three forms: 1) disease localized to skin, eyes, and mucous membranes,\\u000a 2) localized central nervous system infection, or 3) disseminated infection. Exposure to the virus occurs during passage

Bishara J. Freij

2004-01-01

60

Plant growth regulators and virus infection: A critical review  

Microsoft Academic Search

Virus infection can severely inhibit plant growth and distort development. This article reviews changes in plant growth regulator metabolism caused by infection. In general, virus infection decreases auxin and gibberellin concentrations and increases abscisic acid concentration. Ethylene production is stimulated in necrotic or chlorotic reactions to infection, but not where the virus spreads systemically without necrosis. While these broad trends

R. S. S. Fraser; R. J. Whenham

1982-01-01

61

Hantaan virus infection of human endothelial cells.  

PubMed Central

The primary pathophysiologic finding of the viral disease known as Korean hemorrhagic fever, the etiological agent of which is Hantaan virus (HTV), is vascular instability. To investigate whether HTV was able to infect cells derived from human vascular tissue and alter their behavior, we infected in vitro primary adult human endothelial cells from saphenous veins (HSVEC). We were able to detect the presence of viral antigens in infected cells both by immunofluorescence and by Western blot (immunoblot) analysis as early as day 1 postinfection. HSVEC infected with HTV produce infectious virus during the first 3 days of infection but, at later times (days 4 to 8), show decreasing yields of virus. This contrasts with the HTV growth pattern observed for the permissive simian CV-7 cell line, which generates infectious virus up to day 12 after infection. Further investigation showed that the late decrease in viral production in HSVEC is the result of the induction of beta interferon and can be reversed by the addition of anti-beta interferon serum to the culture medium. At no time during the course of infection of HSVEC with HTV was any obvious cytopathic effect observed. When tests for changes in mRNA levels of other cytokines and endothelial cell gene products following HTV infection of HSVEC were done by reverse transcription and polymerase chain reaction methods, no significant changes were observed in the levels of interleukin 1, interleukin 6, or von Willebrand factor mRNA. We hypothesize that, while HTV can replicate in human vascular endothelial cells, the mechanism of microvascular damage seen with Korean hemorrhagic fever is not likely to be a direct effect of virus replication but may conceivably be the consequence of an immune-mediated endothelial injury triggered by viral infection. Images PMID:1356160

Pensiero, M N; Sharefkin, J B; Dieffenbach, C W; Hay, J

1992-01-01

62

Virus infections in type 1 diabetes.  

PubMed

The precise etiology of type 1 diabetes (T1D) is still unknown, but viruses have long been suggested as a potential environmental trigger for the disease. However, despite decades of research, the body of evidence supporting a relationship between viral infections and initiation or acceleration of islet autoimmunity remains largely circumstantial. The most robust association with viruses and T1D involves enterovirus species, of which some strains have the ability to induce or accelerate disease in animal models. Several hypotheses have been formulated to mechanistically explain how viruses may affect islet autoimmunity and ?-cell decay. The recent observation that certain viral infections, when encountered at the right time and infectious dose, can prevent autoimmune diabetes illustrates that potential relationships may be more complex than previously thought. Here, we provide a concise summary of data obtained in mouse models and humans, and identify future avenues toward a better characterization of the association between viruses and T1D. PMID:22315719

Coppieters, Ken T; Boettler, Tobias; von Herrath, Matthias

2012-01-01

63

MULTIPLE VIRUS INFECTION OF SINGLE HOST CELLS  

PubMed Central

Evidence is presented to show that two or more viruses can simultaneously manifest their characteristic activities within individual epithelial cells of the normal rabbit's cornea. This evidence, together with that previously presented (1, 5, 6), makes plain that multiple virus infection of a single host cell can take place in corneal cells, in the cells of chick embryos, and in those of rabbit tumors, both benign (Shope's papilloma) and malignant. Certain implications of the findings are discussed. PMID:19871662

Syverton, Jerome T.; Berry, George Packer

1947-01-01

64

Human Immunology of Measles Virus Infection  

Microsoft Academic Search

Measles is a highly contagious disease, which was responsible for high infant mortality before the advent of an effective\\u000a vaccine in 1963. In immuno-competent individuals, measles virus (MV) infection triggers an effective immune response that\\u000a starts with innate responses and then leads to successful adaptive immunity, including cell-mediated immunity and humoral\\u000a immunity. The virus is cleared and lifelong protection is

D. Naniche

65

Postexposure Treatment of Marburg Virus Infection  

E-print Network

Rhesus monkeys are protected from disease when a recombinant vesicular stomatitis virus–based vaccine is administered 20–30 min after infection with Marburg virus. We protected 5/6 monkeys when this vaccine was given 24 h after challenge; 2/6 animals were protected when the vaccine was administered 48 h postinfection. The filoviruses, Marburg virus (MBGV) and Ebola virus (EBOV), have been associated with sporadic episodes of hemorrhagic fever (HF) in Central Africa that produce severe disease and high mortality rates among infected patients (1). MBGV and EBOV are also considered potential biological weapons. No approved active or passive therapeutic modalities exist for filovirus infections. Although much progress has been made in developing preventive vaccines that can protect nonhuman primates against lethal challenge with MBGV and EBOV, advances in development of postexposure interventions against the filoviruses have not kept pace. Some degree of success has been achieved by using strategies that mitigate the coagulation abnormalities characterizing filoviral infection (2,3). Also, new postexposure treatment approaches, based on small interfering RNA (4) and antisense oligomers (5,6), have shown promising results in rodent models, but no reports have been published of evaluations of either strategy in the more stringent macaque models. Recently, we showed the first complete postexposure protection of nonhuman primates against a filovirus by administering a live-attenuated recombinant vesicular stomatitis virus (rVSV) vaccine vector expressing the MBGV glycoprotein (GP) (VSV?G MBGV GP) shortly after a

Thomas W. Geisbert; Lisa E. Hensley; Joan B. Geisbert; Anders Leung; Heinz Feldmann

66

Maternal and neonatal herpes simplex virus infections.  

PubMed

Genital herpes infections are extremely common worldwide and ~22% of pregnant women are infected with herpes simplex virus. Eighty percent of those affected with genital herpes are unaware of being infected. The most devastating consequence of maternal genital herpes is neonatal herpes disease. Fortunately, neonatal herpes simplex infections are uncommon but due to the morbidity and mortality associated with the infection are often considered in the differential diagnosis of ill neonates. The use of polymerase chain reaction assay for diagnosis of central nervous system infections and the development of safe and effective antiviral therapy have revolutionized the diagnosis and management of these infants. Most recently, the initiation of long-term antiviral suppressive therapy in these infants has led to significant improvement in morbidity. This review will summarize the epidemiology of maternal and neonatal herpes infections and discuss clinical presentation, diagnosis, management, and follow-up of infants with neonatal herpes disease. PMID:23303485

Pinninti, Swetha G; Kimberlin, David W

2013-02-01

67

Immune Responses and Lassa Virus Infection  

PubMed Central

Lassa fever is a hemorrhagic fever endemic to West Africa and caused by Lassa virus, an Old World arenavirus. It may be fatal, but most patients recover from acute disease and some experience asymptomatic infection. The immune mechanisms associated with these different outcomes have not yet been fully elucidated, but considerable progress has recently been made, through the use of in vitro human models and nonhuman primates, the only relevant animal model that mimics the pathophysiology and immune responses induced in patients. We discuss here the roles of the various components of the innate and adaptive immune systems in Lassa virus infection and in the control of viral replication and pathogenesis. PMID:23202504

Russier, Marion; Pannetier, Delphine; Baize, Sylvain

2012-01-01

68

Pathogenesis of human immunodeficiency virus infection.  

PubMed Central

The lentivirus human immunodeficiency virus (HIV) causes AIDS by interacting with a large number of different cells in the body and escaping the host immune response against it. HIV is transmitted primarily through blood and genital fluids and to newborn infants from infected mothers. The steps occurring in infection involve an interaction of HIV not only with the CD4 molecule on cells but also with other cellular receptors recently identified. Virus-cell fusion and HIV entry subsequently take place. Following virus infection, a variety of intracellular mechanisms determine the relative expression of viral regulatory and accessory genes leading to productive or latent infection. With CD4+ lymphocytes, HIV replication can cause syncytium formation and cell death; with other cells, such as macrophages, persistent infection can occur, creating reservoirs for the virus in many cells and tissues. HIV strains are highly heterogeneous, and certain biologic and serologic properties determined by specific genetic sequences can be linked to pathogenic pathways and resistance to the immune response. The host reaction against HIV, through neutralizing antibodies and particularly through strong cellular immune responses, can keep the virus suppressed for many years. Long-term survival appears to involve infection with a relatively low-virulence strain that remains sensitive to the immune response, particularly to control by CD8+ cell antiviral activity. Several therapeutic approaches have been attempted, and others are under investigation. Vaccine development has provided some encouraging results, but the observations indicate the major challenge of preventing infection by HIV. Ongoing research is necessary to find a solution to this devastating worldwide epidemic. Images PMID:8464405

Levy, J A

1993-01-01

69

Epstein-Barr virus infection mechanisms.  

PubMed

Epstein-Barr virus (EBV) infection occurs by distinct mechanisms across different cell types. EBV infection of B cells in vitro minimally requires 5 viral glycoproteins and 2 cellular proteins. By contrast, infection of epithelial cells requires a minimum of 3 viral glycoproteins, which are capable of interacting with one or more of 3 different cellular proteins. The full complement of proteins involved in entry into all cell types capable of being infected in vivo is unknown. This review discusses the events that occur when the virus is delivered into the cytoplasm of a cell, the players known to be involved in these events, and the ways in which these players are thought to function. PMID:25322867

Chesnokova, Liudmila S; Hutt-Fletcher, Lindsey M

2014-11-01

70

Epstein-Barr virus infection mechanisms  

PubMed Central

Epstein-Barr virus (EBV) infection occurs by distinct mechanisms across different cell types. EBV infection of B cells in vitro minimally requires 5 viral glycoproteins and 2 cellular proteins. By contrast, infection of epithelial cells requires a minimum of 3 viral glycoproteins, which are capable of interacting with one or more of 3 different cellular proteins. The full complement of proteins involved in entry into all cell types capable of being infected in vivo is unknown. This review discusses the events that occur when the virus is delivered into the cytoplasm of a cell, the players known to be involved in these events, and the ways in which these players are thought to function. PMID:25322867

Chesnokova, Liudmila S.; Hutt-Fletcher, Lindsey M.

2014-01-01

71

Apoptosis in virus infection dynamics models  

PubMed Central

In this paper, on the basis of the simplified two-dimensional virus infection dynamics model, we propose two extended models that aim at incorporating the influence of activation-induced apoptosis which directly affects the population of uninfected cells. The theoretical analysis shows that increasing apoptosis plays a positive role in control of virus infection. However, after being included the third population of cytotoxic T lymphocytes immune response in HIV-infected patients, it shows that depending on intensity of the apoptosis of healthy cells, the apoptosis can either promote or comfort the long-term evolution of HIV infection. Further, the discrete-time delay of apoptosis is incorporated into the pervious model. Stability switching occurs as the time delay in apoptosis increases. Numerical simulations are performed to illustrate the theoretical results and display the different impacts of a delay in apoptosis. PMID:24963975

Fan, Ruili; Dong, Yueping; Huang, Gang; Takeuchi, Yasuhiro

2014-01-01

72

Pseudorabies Virus Infection Alters Neuronal Activity and Connectivity In Vitro  

Microsoft Academic Search

Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV), infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat

Kelly M. McCarthy; David W. Tank; Lynn W. Enquist

2009-01-01

73

Pathogeneses of respiratory infections with virulent and attenuated vaccinia viruses  

Microsoft Academic Search

BACKGROUND: Respiratory infection with the neurovirulent vaccinia virus (VV) strain Western Reserve (WR) results in an acute infection of the lung followed by dissemination of the virus to other organs and causes lethality in mice. The mechanisms of lethality are not well-understood. In this study, we analyzed virus replication and host immune responses after intranasal infection with lethal and non-lethal

Daisuke Hayasaka; Francis A Ennis; Masanori Terajima

2007-01-01

74

Swine Workers and Swine Influenza Virus Infections  

PubMed Central

In 2004, 803 rural Iowans from the Agricultural Health Study were enrolled in a 2-year prospective study of zoonotic influenza transmission. Demographic and occupational exposure data from enrollment, 12-month, and 24-month follow-up encounters were examined for association with evidence of previous and incident influenza virus infections. When proportional odds modeling with multivariable adjustment was used, upon enrollment, swine-exposed participants (odds ratio [OR] 54.9, 95% confidence interval [CI] 13.0–232.6) and their nonswine-exposed spouses (OR 28.2, 95% CI 6.1–130.1) were found to have an increased odds of elevated antibody level to swine influenza (H1N1) virus compared with 79 nonexposed University of Iowa personnel. Further evidence of occupational swine influenza virus infections was observed through self-reported influenza-like illness data, comparisons of enrollment and follow-up serum samples, and the isolation of a reassortant swine influenza (H1N1) virus from an ill swine farmer. Study data suggest that swine workers and their nonswine-exposed spouses are at increased risk of zoonotic influenza virus infections. PMID:18258038

McCarthy, Troy; Capuano, Ana W.; Setterquist, Sharon F.; Olsen, Christopher W.; Alavanja, Michael C.; Lynch, Charles F.

2007-01-01

75

Hepatitis C virus infection and renal transplantation  

Microsoft Academic Search

With the success of organ transplantation, liver disease has emerged as an important cause of morbidity and mortality of renal transplant (RT) recipients. Numerous studies performed during the 1990s have shown that hepatitis C virus (HCV) infection is the leading cause of chronic liver disease among RT recipients. The transmission of HCV by renal transplantation of a kidney from an

Fabrizio Fabrizi; Paul Martin; Claudio Ponticelli

2001-01-01

76

Hepatitis C virus infection: An enigma continues  

Microsoft Academic Search

Hepatitis C, caused by hepatitis C virus (HCV), has emerged as a major health problem not only in developing world but also in developed countries. HCV infects approximately 170 million people worldwide. HCV is the most efficiently transmitted through percutaneous exposure to blood, intravenous drug abuse, haemodialysis, nosocomial incidents (colonoscopy), inadequately sterilised medical instruments, high-risk sexual behaviour, body piercing, tattooing

Nadeem Sajjad Raja; Nishi Nihar Singh; Khalid Abbas Janjua

2006-01-01

77

A case of Ebola virus infection.  

PubMed Central

In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community. PMID:890413

Emond, R T; Evans, B; Bowen, E T; Lloyd, G

1977-01-01

78

A case of Ebola virus infection.  

PubMed

In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community. PMID:890413

Emond, R T; Evans, B; Bowen, E T; Lloyd, G

1977-08-27

79

Simian virus infections of humans are an increasing public health concern. Simian foamy virus (SFV) infections  

E-print Network

RESEARCH Simian virus infections of humans are an increasing public health concern. Simian foamy in the human host. Alarge proportion of viral pathogens that have recently emerged in humans have originated in various ani- mals. After initial interspecies transmission, these viruses have evolved and disseminated

Paris-Sud XI, Université de

80

Approach to chronic hepatitis B virus infection.  

PubMed

Hepatitis B virus (HBV) infection constitutes one of the major global public health problems. Not only India and Nepal, East Asia is fighting with the same. About 30 percent of the world's population has serological evidence of current or past infection with HBV. By virtue of its different stage of presentation in different age groups of patients and the rapid mutation in the virus, the treatment of HBV requires thorough work-up and regular monitoring. Many new concepts have evolved in last decade in managing these patients, such as HBV Genotype, HBV DNA quantification and mutation analysis. The introduction of oral antivirals in the treatment of HBV infection has revolutionized the treatment. PMID:22916521

Tyagi, P; Arora, A

2011-01-01

81

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

SciTech Connect

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.

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

1981-06-01

82

Paramecium bursaria Chlorella Virus 1 Proteome Reveals Novel Architectural and Regulatory Features of a Giant Virus  

PubMed Central

The 331-kbp chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) genome was resequenced and annotated to correct errors in the original 15-year-old sequence; 40 codons was considered the minimum protein size of an open reading frame. PBCV-1 has 416 predicted protein-encoding sequences and 11 tRNAs. A proteome analysis was also conducted on highly purified PBCV-1 virions using two mass spectrometry-based protocols. The mass spectrometry-derived data were compared to PBCV-1 and its host Chlorella variabilis NC64A predicted proteomes. Combined, these analyses revealed 148 unique virus-encoded proteins associated with the virion (about 35% of the coding capacity of the virus) and 1 host protein. Some of these proteins appear to be structural/architectural, whereas others have enzymatic, chromatin modification, and signal transduction functions. Most (106) of the proteins have no known function or homologs in the existing gene databases except as orthologs with proteins of other chloroviruses, phycodnaviruses, and nuclear-cytoplasmic large DNA viruses. The genes encoding these proteins are dispersed throughout the virus genome, and most are transcribed late or early-late in the infection cycle, which is consistent with virion morphogenesis. PMID:22696644

Cerny, Ronald L.; Bauman, Andrew T.; Roach, Jared C.; Lane, Leslie C.; Agarkova, Irina V.; Wulser, Kurt; Yanai-Balser, Giane M.; Gurnon, James R.; Vitek, Jason C.; Kronschnabel, Bernard J.; Jeanniard, Adrien; Blanc, Guillaume; Upton, Chris; Duncan, Garry A.; McClung, O. William; Ma, Fangrui

2012-01-01

83

Paramecium bursaria chlorella virus 1 proteome reveals novel architectural and regulatory features of a giant virus.  

PubMed

The 331-kbp chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) genome was resequenced and annotated to correct errors in the original 15-year-old sequence; 40 codons was considered the minimum protein size of an open reading frame. PBCV-1 has 416 predicted protein-encoding sequences and 11 tRNAs. A proteome analysis was also conducted on highly purified PBCV-1 virions using two mass spectrometry-based protocols. The mass spectrometry-derived data were compared to PBCV-1 and its host Chlorella variabilis NC64A predicted proteomes. Combined, these analyses revealed 148 unique virus-encoded proteins associated with the virion (about 35% of the coding capacity of the virus) and 1 host protein. Some of these proteins appear to be structural/architectural, whereas others have enzymatic, chromatin modification, and signal transduction functions. Most (106) of the proteins have no known function or homologs in the existing gene databases except as orthologs with proteins of other chloroviruses, phycodnaviruses, and nuclear-cytoplasmic large DNA viruses. The genes encoding these proteins are dispersed throughout the virus genome, and most are transcribed late or early-late in the infection cycle, which is consistent with virion morphogenesis. PMID:22696644

Dunigan, David D; Cerny, Ronald L; Bauman, Andrew T; Roach, Jared C; Lane, Leslie C; Agarkova, Irina V; Wulser, Kurt; Yanai-Balser, Giane M; Gurnon, James R; Vitek, Jason C; Kronschnabel, Bernard J; Jeanniard, Adrien; Blanc, Guillaume; Upton, Chris; Duncan, Garry A; McClung, O William; Ma, Fangrui; Van Etten, James L

2012-08-01

84

Epidemiology of hepatitis C virus infection  

PubMed Central

Globally, hepatitis C virus (HCV) has infected an estimated 130 million people, most of whom are chronically infected. HCV-infected people serve as a reservoir for transmission to others and are at risk for developing chronic liver disease, cirrhosis, and primary hepatocellular carcinoma (HCC). It has been estimated that HCV accounts for 27% of cirrhosis and 25% of HCC worldwide. HCV infection has likely been endemic in many populations for centuries. However, the wave of increased HCV-related morbidity and mortality that we are now facing is the result of an unprecedented increase in the spread of HCV during the 20th century. Two 20th century events appear to be responsible for this increase; the widespread availability of injectable therapies and the illicit use of injectable drugs. PMID:17552026

Alter, Miriam J

2007-01-01

85

Rabies virus infection of cultured rat sensory neurons.  

PubMed Central

The axonal transport of rabies virus (challenge virus strain of fixed virus) was studied in differentiated rat embryonic dorsal root ganglion cells. In addition, we observed the attachment of rabies virus to neuronal extensions and virus production by infected neurons. A compartmentalized cell culture system was used, allowing infection and manipulation of neuronal extensions without exposing the neural soma to the virus. The cultures consisted of 60% large neuronal cells whose extensions exhibited neurofilament structures. Rabies virus demonstrated high binding affinity to unmyelinated neurites, as suggested by assays of virus adsorption and immunofluorescence studies. The rate of axoplasmic transport of virus was 12 to 24 mm/day, including the time required for internalization of the virus into neurites. The virus transport could be blocked by cytochalasin B, vinblastine, and colchicine, none of which negatively affected the production of virus in cells once the infection was established. It was concluded that, for the retrograde transfer of rabies virus by neurites from the periphery to the neuronal soma, the integrity of tubulin- and actin-containing structures is essential. The rat sensory neurons were characterized as permissive, moderately susceptible, but low producers of rabies virus. These neurons were capable of harboring rabies virus for long periods of time and able to release virus into the culture medium without showing any morphological alterations. The involvement of sensory neurons in rabies virus pathogenesis, both in viral transport and as a site for persistent viral infection, is discussed. Images PMID:2441076

Lycke, E; Tsiang, H

1987-01-01

86

Host Species Barriers to Influenza Virus Infections  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required: Most emerging infectious diseases in humans originate from animal reservoirs; to contain and eradicate these diseases we need to understand how and why some pathogens become capable of crossing host species barriers. Influenza virus illustrates the interaction of factors that limit the transmission and subsequent establishment of an infection in a novel host species. Influenza species barriers can be categorized into virus-host interactions occurring within individuals and host-host interactions, either within or between species, that affect transmission between individuals. Viral evolution can help surmount species barriers, principally by affecting virus-host interactions; however, evolving the capability for sustained transmission in a new host species represents a major adaptive challenge because the number of mutations required is often large.

Thijs Kuiken (Erasmus Medical Center;Department of Virology); Edward C. Holmes (Pennsylvania State University;Department of Biology); John McCauley (Compton Laboratory;Institute for Animal Health); Guus F. Rimmelzwaan (Erasmus Medical Center;Department of Virology); Catherine S. Williams (Pennsylvania State University;Department of Biology); Bryan T. Grenfell (National Institutes of Health, Pennsylvania State University;Fogarty International Center)

2006-04-21

87

Hepatitis B virus and hepatitis C virus dual infection  

PubMed Central

Hepatitis B virus (HBV) and hepatitis C virus (HCV) share common mode of transmission and both are able to induce a chronic infection. Dual HBV/HCV chronic coinfection is a fairly frequent occurrence, especially in high endemic areas and among individuals at high risk of parenterally transmitted infections. The intracellular interplay between HBV and HCV has not yet been sufficiently clarified, also due to the lack of a proper in vitro cellular model. Longitudinal evaluation of serum HBV DNA and HCV RNA amounts has revealed that complex virological profiles may be present in coinfected patients. Dual HBV/HCV infection has been associated to a severe course of the liver disease and to a high risk of developing hepatocellular carcinoma. Despite the clinical importance, solid evidence and clear guidelines for treatment of this special population are still lacking. This review summarizes the available data on the virological and clinical features as well as the therapeutic options of the dual HBV/HCV infection, and highlights the aspects that need to be better clarified. PMID:25356020

Caccamo, Gaia; Saffioti, Francesca; Raimondo, Giovanni

2014-01-01

88

Prevention of respiratory syncytial virus infection  

PubMed Central

Respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract infection in young children, with significant numbers of premature infants and those with other risk factors requiring hospitalization in Canada each year. Palivizumab, an RSV-specific monoclonal antibody, can reduce the hospitalization rate and severity of illness for a small group of high-risk or premature infants during their first RSV season. The present statement reviews the published literature and provides recommendations regarding its use in premature and other at-risk infants, for Canadian physicians. PMID:20885804

Samson, L

2009-01-01

89

Animal Models of Varicella Zoster Virus Infection  

PubMed Central

Primary infection with varicella zoster virus (VZV) results in varicella (chickenpox) followed by the establishment of latency in sensory ganglia. Declining T cell immunity due to aging or immune suppressive treatments can lead to VZV reactivation and the development of herpes zoster (HZ, shingles). HZ is often associated with significant morbidity and occasionally mortality in elderly and immune compromised patients. There are currently two FDA-approved vaccines for the prevention of VZV: Varivax® (for varicella) and Zostavax® (for HZ). Both vaccines contain the live-attenuated Oka strain of VZV. Although highly immunogenic, a two-dose regimen is required to achieve a 99% seroconversion rate. Zostavax vaccination reduces the incidence of HZ by 51% within a 3-year period, but a significant reduction in vaccine-induced immunity is observed within the first year after vaccination. Developing more efficacious vaccines and therapeutics requires a better understanding of the host response to VZV. These studies have been hampered by the scarcity of animal models that recapitulate all aspects of VZV infections in humans. In this review, we describe different animal models of VZV infection as well as an alternative animal model that leverages the infection of Old World macaques with the highly related simian varicella virus (SVV) and discuss their contributions to our understanding of pathogenesis and immunity during VZV infection.

Haberthur, Kristen; Messaoudi, Ilhem

2013-01-01

90

Influenza A virus infections in swine: pathogenesis and diagnosis.  

PubMed

Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 "Spanish flu" human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Influenza viruses infect epithelial cells lining the surface of the respiratory tract, inducing prominent necrotizing bronchitis and bronchiolitis and variable interstitial pneumonia. Cell death is due to direct virus infection and to insult directed by leukocytes and cytokines of the innate immune system. The most virulent viruses consistently express the following characteristics of infection: (1) higher or more prolonged virus replication, (2) excessive cytokine induction, and (3) replication in the lower respiratory tract. Nearly all the viral proteins contribute to virulence. Pigs are susceptible to infection with both human and avian viruses, which often results in gene reassortment between these viruses and endemic swine viruses. The receptors on the epithelial cells lining the respiratory tract are major determinants of infection by influenza viruses from other hosts. The polymerases, especially PB2, also influence cross-species infection. Methods of diagnosis and characterization of influenza viruses that infect swine have improved over the years, driven both by the availability of new technologies and by the necessity of keeping up with changes in the virus. Testing of oral fluids from pigs for virus and antibody is a recent development that allows efficient sampling of large numbers of animals. PMID:24363301

Janke, B H

2014-03-01

91

Ebola virus (EboV) infection causes fatal  

E-print Network

Ebola virus (EboV) infection causes fatal haemorrhagic fever with mortality rates exceeding 75 Carette, J. E. et al. Ebola virus entry requires the cholesterol transporter Niemann­Pick C1. Nature 24 is essential for Ebola virus infection. Nature 24 Aug 2011 (doi:10.1038/nature10380) ANTIVIRALS Achilles heel

Chandran, Kartik

92

Systemic and intraocular manifestations of West Nile virus infection  

Microsoft Academic Search

Since the introduction of West Nile virus in the Western Hemisphere in 1999, the incidence of human infection has increased dramatically. As this virus spreads westward across the United States, ophthalmologists should be aware of this presently uncommon but important condition. Systemic features of West Nile virus infection are well characterized; however, the ophthalmic presentations are not widely known. Intraocular

Seema Garg; Lee M. Jampol

2005-01-01

93

Hepatitis C Virus Population Dynamics During Infection  

Microsoft Academic Search

Hepatitis C virus (HCV) behaves as an evolving viral quasispecies in its continuously changing environment. The study of HCV\\u000a quasispecies population dynamics in experimental models and infected patients can provide useful information on factors involved\\u000a in the HCV life cycle and pathogenicity. HCV quasispecies variability also has therapeutic implications, as the continuous\\u000a generation and selection of fitter or truly resistant

J.-M. Pawlotsky

94

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

SciTech Connect

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.

Straus, S.E. (National Institute of Allergy and Infectious Diseases, Bethesda, MD (USA))

1989-12-01

95

Structural Insight into African Horsesickness Virus Infection  

PubMed Central

African horsesickness (AHS) is a devastating disease of horses. The disease is caused by the double-stranded RNA-containing African horsesickness virus (AHSV). Using electron cryomicroscopy and three-dimensional image reconstruction, we determined the architecture of an AHSV serotype 4 (AHSV-4) reference strain. The structure revealed triple-layered AHS virions enclosing the segmented genome and transcriptase complex. The innermost protein layer contains 120 copies of VP3, with the viral polymerase, capping enzyme, and helicase attached to the inner surface of the VP3 layer on the 5-fold axis, surrounded by double-stranded RNA. VP7 trimers form a second, T=13 layer on top of VP3. Comparative analyses of the structures of bluetongue virus and AHSV-4 confirmed that VP5 trimers form globular domains and VP2 trimers form triskelions, on the virion surface. We also identified an AHSV-7 strain with a truncated VP2 protein (AHSV-7 tVP2) which outgrows AHSV-4 in culture. Comparison of AHSV-7 tVP2 to bluetongue virus and AHSV-4 allowed mapping of two domains in AHSV-4 VP2, and one in bluetongue virus VP2, that are important in infection. We also revealed a protein plugging the 5-fold vertices in AHSV-4. These results shed light on virus-host interactions in an economically important orbivirus to help the informed design of new vaccines. PMID:22593166

Manole, Violeta; Laurinmaki, Pasi; Van Wyngaardt, Wouter; Potgieter, Christiaan A.; Wright, Isabella M.; Venter, Gert J.; van Dijk, Alberdina A.; Sewell, B. Trevor

2012-01-01

96

Ebola Virus Defective Interfering Particles and Persistent Infection  

Microsoft Academic Search

Ebola virus (Zaire subtype) is associated with high mortality disease outbreaks that commonly involve human to human transmission. Surviving patients can show evidence of prolonged virus persistence. The potential for Ebola virus to generate defective interfering (DI) particles and establish persistent infections in tissue culture was investigated. It was found that serial undiluted virus passages quickly resulted in production of

Philippe Calain; Martha C. Monroe; Stuart T. Nichol

1999-01-01

97

West Nile Virus: Biology, Transmission, and Human Infection  

PubMed Central

Summary: West Nile Virus was introduced into the Western Hemisphere during the late summer of 1999 and has been causing significant and sometimes severe human diseases since that time. This article briefly touches upon the biology of the virus and provides a comprehensive review regarding recent discoveries about virus transmission, virus acquisition, and human infection and disease. PMID:23034323

Colpitts, Tonya M.; Conway, Michael J.; Montgomery, Ruth R.

2012-01-01

98

Herpes simplex virus and Epstein-Barr virus infections in pregnancy: consequences of neonatal or intrauterine infection  

Microsoft Academic Search

Herpes simplex virus (HSV) type 1\\/2 and Epstein-Barr virus (EBV) belong to the human herpes viruses and are among the most ubiquitous viruses in the adult population. In spite of the fact that a large proportion of women at childbearing age are seropositive to these viruses, especially to HSV, primary or secondary infections with these viruses may occur during pregnancy.Genital

Meytal Avgil; Asher Ornoy

2006-01-01

99

Frequent Occult Hepatitis B Virus Infection in Patients Infected with Human Immunodeficiency Virus Type 1  

Microsoft Academic Search

  \\u000a The presence of hepatitis B virus (HBV) serological markers was investigated in 170 patients (137 male, 33 female) infected\\u000a with human immunodeficiency virus (HIV) type 1. Antibodies to the hepatitis B core antigen (anti-HBc antibodies) were detected\\u000a in 115 (68%) patients. Of these 115, 14 (12%) were hepatitis B surface antigen (HBsAg) positive, 60 (52%) presented anti-HBs\\u000a antibodies, and

E. A. Santos; C. F. T. Yoshida; V. C. Rolla; J. M. Mendes; I. F. Vieira; J. Arabe; S. A. Gomes

2003-01-01

100

Global control of hepatitis B virus infection.  

PubMed

Worldwide about 350 million people are chronic carriers of the hepatitis B virus (HBV). The infection can cause acute and chronic liver disease including cirrhosis and hepatocellular carcinoma (HCC). Hepatocellular injuries of HBV infection are predominantly immune-mediated, and the natural history of chronic infection can be divided into three phases based on virus-host interactions-namely, immune tolerance, immune clearance, and viral integration phases. Four serotypes (adw, ayw, adr, and ayr) and seven genotypes (A to G) of HBV have been identified, and they show some distinct geographic distributions. The HBV genotypes may have clinical relevance and are currently under investigation. On the basis of disease burden and the availability of safe and effective vaccines, the WHO recommended that by the end of the 20th century hepatitis B vaccine be incorporated into routine infant and childhood immunisation programmes for all countries. The efficacy of universal immunisation has been shown in different countries, with striking reductions of the prevalence of HBV carriage in children. Most important, hepatitis B vaccination can protect children against HCC and fulminant hepatitis, as has been shown in Taiwan. Nevertheless, the implementation of worldwide vaccination against HBV requires greater effort to overcome the social and economic hurdles. Safe and effective antiviral treatments are available but are still far from ideal, a situation that, hopefully, will be improved soon. With hepatitis B immunisation, the global control of HBV infection is possible by the end of the first half of 21st century. PMID:12127351

Kao, Jia-Horng; Chen, Ding-Shinn

2002-07-01

101

ANALYSIS OF HEPATITIS C VIRUS INFECTION MODELS WITH HEPATOCYTE HOMEOSTASIS  

E-print Network

ANALYSIS OF HEPATITIS C VIRUS INFECTION MODELS WITH HEPATOCYTE HOMEOSTASIS TIMOTHY C. RELUGA virus (HCV) infection that explicitly includes proliferation of infected and uninfected hepatocytes of the target cell population. Since it has been suggested that hepatocytes, the major cell type in the liver

Reluga, Tim

102

Antibody-Dependent Enhancement of Ebola Virus Infection  

Microsoft Academic Search

Most strains of Ebola virus cause a rapidly fatal hemorrhagic disease in humans, yet there are still no biologic explanations that adequately account for the extreme virulence of these emerging pathogens. Here we show that Ebola Zaire virus infection in humans induces antibodies that enhance viral infectivity. Plasma or serum from convalescing patients enhanced the infection of primate kidney cells

Ayato Takada; Heinz Feldmann; Thomas G. Ksiazek; Yoshihiro Kawaoka

2003-01-01

103

KINETIC PROFILE OF INFLUENZA VIRUS INFECTION IN THREE RAT STRAINS  

EPA Science Inventory

Abstract Influenza infection is a respiratory disease of viral origin that can cause major epidemics in man. The influenza virus infects and damages epithelial cells of the respiratory tract and causes pneumonia. Lung lesions of mice infected with influenza virus resembl...

104

Euphorbia thymifolia suppresses herpes simplex virus-2 infection by directly inactivating virus infectivity.  

PubMed

1. The ethyl acetate (EtOAc) extract and 3-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-d-glucose (3OG46HG) of Euphorbia thymifolia Linnea have been shown to exhibit anti-herpes simplex virus (HSV)-2 activity in vitro. In the present study, we investigated the mode of action of these two compounds in suppressing HSV-2 multiplication. 2. The results demonstrated that the EtOAc extract and 3OG46HG affected virus infectivity in a dose-dependent manner. The EtOAc extract significantly reduced virus infectivity at a concentration of 4.0 microg/mL, whereas 3OG46HG obviously diminished virus infectivity at concentration of a 0.5 microg/mL. The virucidal ability of the EtOAc extract was affected by the incubation period, but not by the incubation temperature. In the case of the action of 3OG46HG against HSV-2, the effects of incubation time and temperature were negligible. 3. In summary, the EtOAc extract and 3OG46HG of E. thymifolia are concluded to inhibit HSV-2 multiplication by reducing virus infectivity. PMID:15854140

Yang, Chien-Min; Cheng, Hua-Yew; Lin, Ta-Chen; Chiang, Lien-Chai; Lin, Chun-Ching

2005-01-01

105

Previously Unknown Virus Infects Marine Diatom  

PubMed Central

Diatoms are a major phytoplankton group that play important roles in maintaining oxygen levels in the atmosphere and sustaining the primary nutritional production of the aquatic environment. Among diatoms, the genus Chaetoceros is one of the most abundant and widespread. Temperature, climate, salinity, nutrients, and predators were regarded as important factors controlling the abundance and population dynamics of diatoms. Here we show that a viral infection can occur in the genus Chaetoceros and should therefore be considered as a potential mortality source. Chaetoceros salsugineum nuclear inclusion virus (CsNIV) is a 38-nm icosahedral virus that replicates within the nucleus of C. salsugineum. The latent period was estimated to be between 12 and 24 h, with a burst size of 325 infectious units per host cell. CsNIV has a genome structure unlike that of other viruses that have been described. It consists of a single molecule of covalently closed circular single-stranded DNA (ssDNA; 6,005 nucleotides), as well as a segment of linear ssDNA (997 nucleotides). The linear segment is complementary to a portion of the closed circle creating a partially double-stranded genome. Sequence analysis reveals a low but significant similarity to the replicase of circoviruses that have a covalently closed circular ssDNA genome. This new host-virus system will be useful for investigating the ecological relationships between bloom-forming diatoms and other viruses in the marine system. Our study supports the view that, given the diversity and abundance of plankton, the ocean is a treasury of undiscovered viruses. PMID:16000758

Nagasaki, Keizo; Tomaru, Yuji; Takao, Yoshitake; Nishida, Kensho; Shirai, Yoko; Suzuki, Hidekazu; Nagumo, Tamotsu

2005-01-01

106

Infectivity of Aphids after Several Hours on Tobacco infected with Potato Virus Y  

Microsoft Academic Search

WATSON showed that fasted Myzus persicoe (Sulz.) were more than 60 per cent infective after 5 min. on tobacco infected with potato virus Y, but after 4 hr. on infected plants only about 10 per cent of the aphids were infective1. During investigations on the aphid transmission of potato virus Y, it was observed that, after several hours on tobacco,

R. H. E. Bradley

1953-01-01

107

[Human immunodeficiency virus type 2 infection].  

PubMed

The isolation of a second retrovirus, HIV-2, led to fears that a second AIDS pandemic, similar in scope and magnitude to that caused by HIV-1, might ensue. However, the peculiar biologic properties of HIV-2, namely the lower transmissibility of this virus through both sexual and vertical routes, contributed to a more regionalized distribution of the virus, which became endemic in West Africa. HIV-2 is genetically more closely related to SIV than to HIV-1. When it comes to clinical disease, the spectrum of opportunistic infections and tumors (except for Kaposi sarcoma) are similar to that observed with HIV-1. Controlled longitudinal studies suggest that the rate of progression to advanced HIV related disease and mortality are far lower for HIV-2 than for HIV-1. Understanding how, immunologically and virologically, HIV-2 behaves differently from HIV-1 may provide some insight into the mechanisms governing HIV-1 pathogenesis. PMID:10892439

Mansinho, K

1999-12-01

108

Therapy and prophylaxis of Ebola virus infections.  

PubMed

The first cases of Ebola hemorrhagic fever were reported from Sudan and Zaire (now Democratic Republic of the Congo) in 1976, but the virus has only received significant attention since 1995. Until recently, the development of therapeutics or vaccines was not considered a priority. The knowledge gained during the past decade on the biology and pathogenesis of Ebola virus has led to the development of therapeutic strategies that are currently being investigated. Considering the aggressive nature of Ebola infections, in particular the rapid and overwhelming viral burdens, early diagnosis will play a significant role in determining the success of any intervention strategy. Advanced understanding of the immune response has produced several vaccine candidates of which a few can be considered for further evaluation. This review will summarize and discuss the current therapeutic and prophylactic strategies for Ebola hemorrhagic fever. PMID:16121689

Feldmann, Heinz; Jones, Steven M; Schnittler, Hans-Joachim; Geisbert, Thomas

2005-08-01

109

Immunological alterations in hepatitis C virus infection  

PubMed Central

A higher prevalence of immunological processes has recently been reported in patients with hepatitis C virus (HCV) infection, focusing the attention of physicians and researchers on the close association between HCV and immune disorders. HCV lymphotropism represents the most important step in the pathogenesis of virus-related immunological diseases and experimental, virologic, and clinical evidence has demonstrated a trigger role for HCV both in systemic autoimmune diseases, such as rheumatoid arthritis, Sjögren syndrome, hemolytic anemia and severe thrombocytopenia, and in organ-specific autoimmune diseases, such as autoimmune hepatitis, thyroid disorders and diabetes. This review will outline the principal aspects of such HCV-induced immunological alterations, focusing on the prevalence of these less characterized HCV extrahepatic manifestations. PMID:24379616

Calvaruso, Vincenza; Craxi, Antonio

2013-01-01

110

Animal Models of Dengue Virus Infection  

PubMed Central

The development of animal models of dengue virus (DENV) infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs) can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines. PMID:22355452

Zompi, Simona; Harris, Eva

2012-01-01

111

Silymarin for hepatitis C virus infection  

PubMed Central

Silymarin, an extract of milk thistle seeds, and silymarin-derived compounds have been considered hepatoprotective since the plant was first described in ancient times. Hepatoprotection is defined as several non-mutually exclusive biological activities including antiviral, antioxidant, anti-inflammatory and immunomodulatory functions. Despite clear evidence for silymarin-induced hepatoprotection in cell culture and animal models, evidence for beneficial effects in humans has been equivocal. This review will summarize the current state of knowledge on silymarin in the context of hepatitis C virus infection. The information was collated from a recent workshop on silibinin in Germany. PMID:23011959

Polyak, Stephen J; Oberlies, Nicholas H; Pécheur, Eve-Isabelle; Dahari, Harel; Ferenci, Peter; Pawlotsky, Jean-Michel

2014-01-01

112

ROLE OF MONOCYTES IN RESPIRATORY SYNCTIAL VIRUS (RSV) INFECTION.  

EPA Science Inventory

ROLE OF MONOCYTES IN RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION. Joleen M. Soukup and Susanne Becker, National Health and Environmental Effects Research Laboratory, US EPA, Research Traingle Park, NC USA. RSV infection in airway epithelial cells (EC) results i...

113

The ecology of viruses that infect eukaryotic algae.  

PubMed

Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560?kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies will provide keys to unlocking our understanding of algal virus ecology specifically, and aquatic ecosystems generally. PMID:22360532

Short, Steven M

2012-09-01

114

ANALYSIS OF HEPATITIS C VIRUS INFECTION MODELS WITH HEPATOCYTE HOMEOSTASIS‡  

PubMed Central

Recently, we developed a model for hepatitis C virus (HCV) infection that explicitly includes proliferation of infected and uninfected hepatocytes. The model predictions agree with a large body of experimental observations on the kinetics of HCV RNA change during acute infection, under antiviral therapy, and after the cessation of therapy. Here we mathematically analyze and characterize both the steady state and dynamical behavior of this model. The analyses presented here are important not only for HCV infection but should also be relevant for modeling other infections with hepatotropic viruses, such as hepatitis B virus. PMID:19183708

RELUGA, TIMOTHY C.; DAHARI, HAREL; PERELSON, ALAN S.

2008-01-01

115

Hepatitis C virus infection protein network  

PubMed Central

A proteome-wide mapping of interactions between hepatitis C virus (HCV) and human proteins was performed to provide a comprehensive view of the cellular infection. A total of 314 protein–protein interactions between HCV and human proteins was identified by yeast two-hybrid and 170 by literature mining. Integration of this data set into a reconstructed human interactome showed that cellular proteins interacting with HCV are enriched in highly central and interconnected proteins. A global analysis on the basis of functional annotation highlighted the enrichment of cellular pathways targeted by HCV. A network of proteins associated with frequent clinical disorders of chronically infected patients was constructed by connecting the insulin, Jak/STAT and TGF? pathways with cellular proteins targeted by HCV. CORE protein appeared as a major perturbator of this network. Focal adhesion was identified as a new function affected by HCV, mainly by NS3 and NS5A proteins. PMID:18985028

de Chassey, B; Navratil, V; Tafforeau, L; Hiet, M S; Aublin-Gex, A; Agaugue, S; Meiffren, G; Pradezynski, F; Faria, B F; Chantier, T; Le Breton, M; Pellet, J; Davoust, N; Mangeot, P E; Chaboud, A; Penin, F; Jacob, Y; Vidalain, P O; Vidal, M; Andre, P; Rabourdin-Combe, C; Lotteau, V

2008-01-01

116

Microglia in the giant cell encephalitis of acquired immune deficiency syndrome: proliferation, infection and fusion  

Microsoft Academic Search

The autopsied brains of three homosexual men with acquired immune deficiency syndrome (AIDS), progressive encephalopathy and widespread multinucleated giant cell encephalitis were investigated by lectin and immunohistochemical methods to ascertain the cellular distribution of a human immunodeficiency virus (HIV) core protein, p25. Abundant viral antigen was present in all brains, limited to perivascular macrophages, microglial and multinucleated cells, some bearing

J. Michaels; R. W. Price; M. K. Rosenblum

1988-01-01

117

Hepatitis C virus infection in hemodialyzed patients.  

PubMed

In spite of our present improved knowledge of the epidemiology and pathways of contamination of the hepatitis C virus (HCV), infection still remains a public health problem. One category of patients who have suffered greatly from the consequences of HCV infection is certainly that of hemodialysis patients. In the past, in fact, their need for transfusions exposed these patients to infection and, as a result, subjects on dialysis for over 15 years are today paying the price for those inevitable transfusions, as the virus and its pathways of contagion were unknown then. However, still today, albeit at a much lower prevalence, even subjects with a shorter dialysis age present a higher prevalence of anti-HCV than the general population, suggesting that other factors of contamination than the classical ones contribute to keeping this prevalence high. Its clinical course is generally asymptomatic and the biological and virological progression of the disease is quite particular and apparently benign. The mortality rate of infected patients is higher than in noninfected subjects and this is not only due to the liver disease itself but also to cardiovascular disorders. Even anti-viral therapy, after its first timid steps, is now routinely used in patients with a certain degree of liver damage and kidney transplant candidates. The appropriate use of pegylated interferons is expected to improve the percentage of eradication and limit side effects, in parallel with what has been observed in non-dialysis patients. Ribavirin, however, is at present contraindicated due to its toxic effects on red blood cells as hemoglobin content could be dangerously reduced in these patients. PMID:17377904

Li Vecchi, M; La Spada, E; Li Vecchi, V; Montalto, G

2007-02-01

118

Update on hepatitis B virus infection  

PubMed Central

Chronic infection with hepatitis B virus (HBV) leads to the development of hepatocellular carcinoma and/or chronic liver failure. Despite extensive research, the immunopathogenesis is not completely understood. Viral persistence and clinical outcomes following HBV infection depend on viral factors and host factors; including genetic factors that determine a host’s immune mechanisms. The primary goal of chronic hepatitis B (CHB) treatment is to eradicate HBV or to at least maintain suppression of HBV replication. Despite recent advances in anti-viral agents for chronic HBV infection, complete eradication of the virus has been difficult to achieve. Agents for the treatment of CHB are divided mainly into two groups: immunomodulating agents and antiviral nucleos(t)ide analogues (NAs). Although NAs are safe, effective and easily administered orally, their long-term use poses the risk of drug resistance. Currently, international evidence-based guidelines have been developed to support physicians in managing CHB patients. However, treatment of patients with drug resistance is still challenging, as only a few classes of anti-HBV drugs are available and cross-resistance between drugs can occur. In addition, as the currently available genotypic test for detection of drug resistance still has limitations in identifying the different substitutions present in the same viral genome, the development of a new virologic test to overcome this limitation is necessary. Among the predictive factors associated with response to pegylated interferon (PEG-IFN) therapy, hepatitis B surface antigen quantification is considered to be a surrogate marker for monitoring response to PEG-IFN. Current practice guidelines stress the importance of profound and durable HBV viral suppression in the treatment of CHB patients. To this end, it is essential to choose a potent antiviral drug with a low risk of resistance for initial treatment of CHB to achieve sustained virological response. This review highlights recent advances in the understanding of the immunopathogenesis of HBV and currently available and developing treatment strategies against HBV infection. PMID:25309066

You, Chan Ran; Lee, Sung Won; Jang, Jeong Won; Yoon, Seung Kew

2014-01-01

119

Hepatitis C virus infection in the human immunodeficiency virus infected patient.  

PubMed

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same transmission routes; therefore, coinfection is frequent. An estimated 5-10 million individuals alone in the western world are infected with both viruses. The majority of people acquire HCV by injection drug use and, to a lesser extent, through blood transfusion and blood products. Recently, there has been an increase in HCV infections among men who have sex with men. In the context of effective antiretroviral treatment, liver-related deaths are now more common than Acquired Immune Deficiency Syndrome-related deaths among HIV-HCV coinfected individuals. Morbidity and mortality rates from chronic HCV infection will increase because the infection incidence peaked in the mid-1980s and because liver disease progresses slowly and is clinically silent to cirrhosis and end-stage-liver disease over a 15-20 year time period for 15%-20% of chronically infected individuals. HCV treatment has rapidly changed with the development of new direct-acting antiviral agents; therefore, cure rates have greatly improved because the new treatment regimens target different parts of the HCV life cycle. In this review, we focus on the epidemiology, diagnosis and the natural course of HCV as well as current and future strategies for HCV therapy in the context of HIV-HCV coinfection in the western world. PMID:25232248

Clausen, Louise Nygaard; Lundbo, Lene Fogt; Benfield, Thomas

2014-09-14

120

Hepatitis C virus infection in the human immunodeficiency virus infected patient  

PubMed Central

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same transmission routes; therefore, coinfection is frequent. An estimated 5-10 million individuals alone in the western world are infected with both viruses. The majority of people acquire HCV by injection drug use and, to a lesser extent, through blood transfusion and blood products. Recently, there has been an increase in HCV infections among men who have sex with men. In the context of effective antiretroviral treatment, liver-related deaths are now more common than Acquired Immune Deficiency Syndrome-related deaths among HIV-HCV coinfected individuals. Morbidity and mortality rates from chronic HCV infection will increase because the infection incidence peaked in the mid-1980s and because liver disease progresses slowly and is clinically silent to cirrhosis and end-stage-liver disease over a 15-20 year time period for 15%-20% of chronically infected individuals. HCV treatment has rapidly changed with the development of new direct-acting antiviral agents; therefore, cure rates have greatly improved because the new treatment regimens target different parts of the HCV life cycle. In this review, we focus on the epidemiology, diagnosis and the natural course of HCV as well as current and future strategies for HCV therapy in the context of HIV-HCV coinfection in the western world.

Clausen, Louise Nygaard; Lundbo, Lene Fogt; Benfield, Thomas

2014-01-01

121

Ebola virus defective interfering particles and persistent infection.  

PubMed

Ebola virus (Zaire subtype) is associated with high mortality disease outbreaks that commonly involve human to human transmission. Surviving patients can show evidence of prolonged virus persistence. The potential for Ebola virus to generate defective interfering (DI) particles and establish persistent infections in tissue culture was investigated. It was found that serial undiluted virus passages quickly resulted in production of an evolving population of virus minireplicons possessing both deletion and copyback type DI genome rearrangements. The tenth undiluted virus passage resulted in the establishment of virus persistently infected cell lines. Following one or two crises, these cells were stably maintained for several months with continuous shedding of infectious virus. An analysis of the estimated genome lengths of a selected set of the Ebola virus minireplicons and standard filoviruses revealed no obvious genome length rule, such as "the rule of six" found for the phylogenetically related Paramyxovirinae subfamily viruses. Minimal promoters for Ebola virus replication were found to be contained within 156 and 177 nucleotide regions of the genomic and antigenomic RNA 3' termini, respectively, based on the length of authentic termini retained in the naturally occurring minireplicons analyzed. In addition, using UV-irradiated preparations of virus released from persistently infected cells, it was demonstrated that Ebola virus DI particles could potentially be used as natural minireplicons to assay standard virus support functions. PMID:10489346

Calain, P; Monroe, M C; Nichol, S T

1999-09-15

122

Effect of adenovirus and influenza virus infection on obesity.  

PubMed

The purpose of this review is to provide an overview of the effects of adenovirus and influenza virus infections on obesity in various experimental models. We reviewed studies that were conducted within the past 10 years and were related to virus infection and obesity prevalence. Here, we discuss a different causal relationship between adenovirus and influenza infections with obesity. Adenovirus infection can cause obesity, whereas obesity can be a risk factor for increasing influenza virus infection and increases the risk of morbidity and mortality. The prevalence of obesity due to adenovirus infections may be due to an increase in glucose uptake and reduction in lipolysis caused by an increase in corticosterone secretion. Adenovirus infections may lead to increases in appetite by decreasing norepinephrine and leptin levels and also cause immune dysfunction. The relationship between obesity and influenza virus infection could be summarized by the following features: decreases in memory T-cell functionality and interferon (IFN)-?, IFN-?, and IFN-? mRNA expression, increases in viral titer and infiltration, and impaired dendritic cell function in obese individuals. Moreover, leptin resistance may play an important role in increasing influenza virus infections in obese individuals. In conclusion, prevention of adenovirus infections could be a good approach for reducing obesity prevalence, and prevention of obesity could reduce influenza virus infections from the point of view of viral infections and obesity. PMID:24007799

Hur, Sun Jin; Kim, Doo Hwan; Chun, Se Chul; Lee, Si Kyung

2013-10-11

123

Peptide inhibitors against herpes simplex virus infections.  

PubMed

Herpes simplex virus (HSV) is a significant human pathogen causing mucocutaneous lesions primarily in the oral or genital mucosa. Although acyclovir (ACV) and related nucleoside analogs provide successful treatment, HSV remains highly prevalent worldwide and is a major cofactor for the spread of human immunodeficiency virus. Encephalitis, meningitis, and blinding keratitis are among the most severe diseases caused by HSV. ACV resistance poses an important problem for immunocompromised patients and highlights the need for new safe and effective agents; therefore, the development of novel strategies to eradicate HSV is a global public health priority. Despite the continued global epidemic of HSV and extensive research, there have been few major breakthroughs in the treatment or prevention of the virus since the introduction of ACV in the 1980s. A therapeutic strategy at the moment not fully addressed is the use of small peptide molecules. These can be either modeled on viral proteins or derived from antimicrobial peptides. Any peptide that interrupts protein-protein or viral protein-host cell membrane interactions is potentially a novel antiviral drug and may be a useful tool for elucidating the mechanisms of viral entry. This review summarizes current knowledge and strategies in the development of synthetic and natural peptides to inhibit HSV infectivity. PMID:23389903

Galdiero, Stefania; Falanga, Annarita; Tarallo, Rossella; Russo, Luigi; Galdiero, Emilia; Cantisani, Marco; Morelli, Giancarlo; Galdiero, Massimiliano

2013-03-01

124

Hepatitis C virus infection and autoimmunity.  

PubMed

Hepatitis C virus (HCV) infection has been associated with a plethora of immune and autoimmune perturbations. We review serological and clinical autoimmune manifestations associated with HCV infection, discuss treatment regimens for HCV-related autoimmune diseases, and present a framework for understanding HCV-associated autoimmune disease by performing a computerized literature search from which representative articles were used and referenced. The immune response to HCV may include the development of cryoglobulins, rheumatoid factor, antinuclear antibodies (ANA), anticardiolipin, antithyroid, anti-liver/kidney/microsomal antibodies (anti-LKM), as well as HCV/anti-HCV immune complex formation and deposition. HCV infection is a significant cause of mixed essential cryoglobulinemia, which may then be complicated by cryoglobulinemic glomerulonephritis, vasculitis, or neuropathy. It has also been associated with membranous and membranoproliferative glomerulonephritis. Subsets of autoimmune hepatitis patients are infected with HCV and evidence suggests that HCV is a causative agent of antithyroid antibodies and autoimmune thyroid disease. Although cause-and-effect remain to be proved, there are reports of HCV infection preceding or coincident with polyarthritis, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and polymyositis/dermatomyositis (PM/DM). HCV-infected patients also have a high incidence of sialoadenitis, and reports of low-grade lymphoproliferative malignancies have emerged. However, HCV is not a major causative factor for most autoimmune diseases. Optimal treatment for HCV-related autoimmune disease remains to be determined. Interferon alpha (IFN alpha) has successfully reduced viremia/transaminitis, cryoglobulins, proteinuria, and nephritis, but recurrent disease manifestations are frequent after discontinuation of therapy. Moreover, IFN alpha may precipitate or exacerbate autoimmune disease symptoms. HCV-related autoimmune disease also has been treated successfully with corticosteroids, azathioprine, and cyclophosphamide, although HCV viremia persists and may worsen. PMID:9062950

McMurray, R W; Elbourne, K

1997-02-01

125

Characterization of a ranavirus isolated from the Chinese giant salamander (Andrias davidianus, Blanchard, 1871) in China  

E-print Network

-offs of farmed Chinese giant salamanders (Andrias davidianus) in Leshan, Sichuan Province, China. The farmed to the natural infections. Our data suggested that the virus isolate was a novel member of the genus Ranavirus, family Iridoviridae. We tentatively named the virus as Chinese giant salamander virus (CGSV-L). CGSV

Gray, Matthew

126

Hepatitis B Virus Infection in Cultured Human Lymphoblastoid Cells  

Microsoft Academic Search

Since it has been postulated that liver hepatocytes may become infected by hepatitis B virus (HBV) in vivo through direct contact with infected macrophages, the possibility that a circulating cell of hematopoietic origin might be susceptible to infection with HBV was investigated. Cells positive for HBV surface antigen were identified in aspirates of bone marrow cells from people infected with

Jean-Loup Romet-Lemonne; Mary Frances McLane; Emile Elfassi; William A. Haseltine; Jose Azocar; Myron Essex

1983-01-01

127

Pathogenesis of Respiratory Syncytial Virus Infection in the Murine Model  

Microsoft Academic Search

There is a wide spectrum of illness caused by respiratory syncytial virus (RSV) infection that is caused in large part by host-related factors, such as age of the patient and degree of host immunocom- petency. Although the vast majority of persons infected with RSV experience symptoms of mild upper respiratory tract infection, in some people these infections cause significant morbidity

R. Stokes Peebles; Barney S. Graham

2005-01-01

128

Exacerbation of Mycoplasma gallisepticum infection in Turkeys by rhinotracheitis virus  

Microsoft Academic Search

Groups of 1?day?old turkey poults from a parent flock free of antibodies to turkey rhinotracheitis virus (TRTV) and the pathogenic mycoplasmas, were infected by eyedrop with virulent TRTV, with Mycoplasma gallisepticum (Mg) or with both agents together. Dual infection resulted in increased morbidity compared with those groups given single infections. The presence of the Mg in the dual infection had

C. J. Naylor; J. M. Bradbury; R. C. Jones

1992-01-01

129

ENHANCED AND PROLONGED PULMONARY INFLUENZA VIRUS INFECTION FOLLOWING PHOSGENE INHALATION  

EPA Science Inventory

Animal infectivity models have been important in the demonstration of enhanced susceptibility to viral and bacterial infection as a result of low level toxicant exposure. his study demonstrated an enhanced and prolonged viral infection using an influenza virus infectivity model i...

130

Evidence that hepatitis C virus genome partly controls infection outcome  

PubMed Central

Infection by hepatitis C virus (HCV) leads to one of two outcomes; either the infection resolves within approximately 6 months or the virus can persist indefinitely. Host genetics are known to affect the likelihood of clearance or persistence. By contrast, the importance of the virus genotype in determining infection outcome is unknown, as quantifying this effect traditionally requires well-characterized transmission networks, which are rare. Extending phylogenetic approaches previously developed to estimate the virus control over set-point viral load in HIV-1 infections, we simulate inheritance of a binary trait along a phylogenetic tree, use this data to quantify how infection outcomes cluster and ascertain the effect of virus genotype on these. We apply our method to the Hepatitis C Incidence and Transmission Study in prisons (HITS-p) data set from Australia, as this cohort prospectively identified incident cases including viraemic subjects who ultimately clear the virus, thus providing us with a unique collection of sequences from clearing infections. We detect significant correlations between infection outcome and virus distance in the phylogeny for viruses of Genotype 1, with estimates lying at around 67%. No statistically significant estimates were obtained for viruses of Genotype 3a. PMID:24944567

Hartfield, Matthew; Bull, Rowena; White, Peter A; Lloyd, Andrew; Luciani, Fabio; Alizon, Samuel

2014-01-01

131

RESEARCH ARTICLE Open Access Modelling Marek's Disease Virus (MDV) infection  

E-print Network

RESEARCH ARTICLE Open Access Modelling Marek's Disease Virus (MDV) infection: parameter estimates Renz3 , Stephen W Walkden-Brown3 and Mark EJ Woolhouse1 Abstract Background: Marek's disease virus (MDV simpler and cheaper approaches to comparing the virulence of MDV strains. Background Marek's Disease Virus

Read, Andrew

132

Highly pathogenic avian influenza virus infection in feral raccoons, Japan.  

PubMed

Although raccoons (Procyon lotor) are susceptible to influenza viruses, highly pathogenic avian influenza virus (H5N1) infection in these animals has not been reported. We performed a serosurvey of apparently healthy feral raccoons in Japan and found specific antibodies to subtype H5N1 viruses. Feral raccoons may pose a risk to farms and public health. PMID:21470469

Horimoto, Taisuke; Maeda, Ken; Murakami, Shin; Kiso, Maki; Iwatsuki-Horimoto, Kiyoko; Sashika, Mariko; Ito, Toshihiro; Suzuki, Kazuo; Yokoyama, Mayumi; Kawaoka, Yoshihiro

2011-04-01

133

Infectivity-Enhancing Antibodies to Ebola Virus Glycoprotein  

Microsoft Academic Search

Ebola virus causes severe hemorrhagic fever in primates, resulting in mortality rates of up to 100%, yet there are no satisfactory biologic explanations for this extreme virulence. Here we show that antisera produced by DNA immunization with a plasmid encoding the surface glycoprotein (GP) of the Zaire strain of Ebola virus enhances the infectivity of vesicular stomatitis virus pseudotyped with

AYATO TAKADA; SHINJI WATANABE; KATSUNORI OKAZAKI; HIROSHI KIDA; Y. Kawaoka

2001-01-01

134

Agents for treating human immunodeficiency virus infection.  

PubMed

The replicative cycle of the human immunodeficiency virus (HIV) is reviewed, and currently used and investigational agents directed against the virus are discussed. The first step in the replication of HIV is selective binding of the envelope glycoprotein to CD4 receptors located on T lymphocytes. The virion is then uncoated within the cytoplasm, yielding viral genomic RNA. Reverse transcriptase uses the viral RNA as a template to form single-stranded DNA, which is duplicated to form proviral DNA through the activity of ribonuclease H. Host RNA polymerases transcribe the integrated proviral DNA into messenger RNA, and there is subsequent translation to viral proteins. After translation, further modification of precursor polyproteins is necessary to produce functional peptides. The assembled virus then buds from the cell surface and invades other cells. Targets of drug intervention in the replicative cycle include (1) binding and entry, (2) reverse transcriptase, (3) transcription and translation, and (4) viral maturation and budding. Inhibitors of binding and entry include recombinant soluble CD4, immunoadhesins, peptide T, and hypericin. Nucleoside reverse-transcriptase inhibitors include zidovudine, didanosine, zalcitabine, and stavudine. Foscarnet, tetrahydroimidazobenzo-diazepinthione compounds, and nevirapine are some nonnucleoside reverse-transcriptase inhibitors. Inhibitors of transcription and translation include antagonists of the tat gene and GLQ223. Castanospermine, N-butyldeoxynojirimycin, and protease inhibitors interfere with viral maturation and budding. Drug combinations that have been or are being investigated include zidovudine plus interferon alfa, zidovudine plus zalcitabine, and zidovudine plus didanosine. Four agents currently have approved labeling for use against HIV infection: zidovudine, didanosine, zalcitabine, and stavudine. Monotherapy with zidovudine remains the treatment of first choice. Although progress has been made in developing drug therapies for HIV infection, more selective and more potent drugs are urgently needed. The best approach at present is to optimize the use of available agents, continue to investigate new therapies, and educate the public about prevention. PMID:7801986

Acosta, E P; Fletcher, C V

1994-09-15

135

Antibody-Dependent Enhancement of Hepatitis C Virus Infection  

Microsoft Academic Search

Hepatitis C virus (HCV) often causes a persistent infection associated with hypergammaglobulinemia, high levels of antiviral antibody and circulating immune complexes, and immune complex disease. We previously reported that only a limited neutralizing activity to vesicular stomatitis virus or HCV pseudotype is generated in animals immunized with recombinant HCV envelope proteins and chronically infected HCV patient sera. Interestingly, when some

Keith Meyer; Malika Ait-Goughoulte; Zhen-Yong Keck; Steven Foung; Ranjit Ray

2008-01-01

136

Virus infection causes specific learning deficits in honeybee foragers  

Microsoft Academic Search

In both mammals and invertebrates, virus infections can impair a broad spectrum of physiological functions including learning and memory formation. In contrast to the knowledge on the conserved mechanisms underlying learning, the effects of virus infection on different aspects of learning are barely known. We use the honeybee (Apis mellifera), a well-established model system for studying learning, to investigate the

Javaid Iqbal; Uli Mueller

2007-01-01

137

Mayaro Virus Infection, Amazon Basin Region, Peru, 2010-2013  

PubMed Central

During 2010–2013, we recruited 16 persons with confirmed Mayaro virus infection in the Peruvian Amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. Mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses. PMID:24210165

Siles, Crystyan; Guevara, Carolina; Vilcarromero, Stalin; Jhonston, Erik J.; Ramal, Cesar; Aguilar, Patricia V.; Ampuero, Julia S.

2013-01-01

138

Subclinical Infections with Crimean-Congo Hemorrhagic Fever Virus, Turkey  

PubMed Central

To investigate Crimean-Congo hemorrhagic fever virus in Turkey, we conducted a seroepidemiologic survey during January–April 2009. Seroprevalence of infection was 10% in a sample from an outbreak region and increased with patient age, indicating that the virus had been previously present in Turkey. We also estimated that 88% of infections were subclinical. PMID:22469474

Akinci, Esragul; Ascioglu, Sibel; Onguru, Pinar; Uyar, Yavuz

2012-01-01

139

Virus-specific responses of Heterosigma akashiwo to infection.  

PubMed

We used flow cytometry to examine the process of cell death in the bloom-forming alga Heterosigma akashiwo during infection by a double-stranded DNA virus (OIs1) and a single-stranded RNA virus (H. akashiwo RNA virus [HaRNAV]). These viruses were isolated from the same geographic area and infect the same strain of H. akashiwo. By use of the live/dead stains fluorescein diacetate and SYTOX green as indicators of cellular physiology, cells infected with OIs1 showed signs of infection earlier than HaRNAV-infected cultures (6 to 17 h versus 23 to 29 h). Intracellular esterase activity was lost prior to increased membrane permeability during infection with OIs1, while the opposite was seen with HaRNAV-infected cultures. In addition, OIs1-infected cells accumulated in the cultures while HaRNAV-infected cells rapidly disintegrated. Progeny OIs1 viruses consisted of large and small morphotypes with estimated latent periods of 11 and 17 h, respectively, and about 1,100 and 16,000 viruses produced per cell, respectively. In contrast, HaRNAV produced about 21,000 viruses per cell and had a latent period of 29 h. This study reveals that the characteristics of viral infection in algae are virus dependent and therefore are variable among viruses infecting the same species. This is an important consideration for ecosystem modeling exercises; calculations based on in situ measurements of algal physiology must be sensitive to the diverse responses of algae to viral infection. PMID:17041155

Lawrence, Janice E; Brussaard, Corina P D; Suttle, Curtis A

2006-12-01

140

The epidemiology and clinical presentation of herpes virus infections.  

PubMed

The chief characters of infection by the human herpes viruses are considered with particular reference to herpes simplex viruses, types 1 and 2. Infection with type 1 virus is acquired very early in life though infrequently as a true congenital transmission of virus. Primary infections result from direct contact usually with infected saliva or skin vesicles. Kerato-conjunctivitis, when primary, may be severe yet superficial in extent. Vulvo-vaginitis, often acquired in adults as a result of type 2 infection by sexual transmission, can give extensive but superficial ulceration and discharge. Recurrent infections located on the dermatome with the same nerve supply as that of the organ affected primarily occur throughout life and at relatively short intervals. Sensory nerve ganglia harbour the virus particles as latent infection and when reactivation occurs virus spreads along nerve fibres to the skin. The most serious infections occur as disseminated disease with liver involvement in the neonatal period, in infants suffering from malnutrition or those undergoing immunosuppression for malignancies. Eczematous children are then at particular risk from spreading haemorrhagic skin lesions (Kaposi's eruption). Herpes encephalitis, commoner in adults than children, is an insidious severe disease with mortality related to the depth of coma. Antiviral therapy though successful may lead to chronic neurological sequelae. The success of antiviral therapy in herpes partly turns on the ability to bring the drug into close contact with the infected tissues. Latent virus is relatively unaffected by acyclovir and thus far recurrences have continued to occur. PMID:6355045

Stuart-Harris, C

1983-09-01

141

Experimental infection of prairie dogs with monkeypox virus.  

PubMed

Studies of experimental infection of prairie dogs (Cynomys ludovicianus) with monkeypox virus are described. After intraperitoneal infection, all of the animals died within 11 days. Virus was cultured from their blood and oropharynx several days before death; at necropsy, most of the organs tested contained monkeypox virus. Marked hepatic and splenic necrosis were observed, along with mild inflammatory changes in the lungs. After intranasal (IN) infection, the primary pathologic changes were in the lungs and pleural cavity. Some of the IN infected animals (40%) survived, and monkeypox virus could be cultured from their nasal discharge and oropharynx for <22 days. Ulcerative lesions also developed on the lips, tongue, and buccal mucosa of the surviving animals. Our findings support an earlier report, which suggested that infected prairie dogs can transmit monkeypox virus by respiratory and mucocutaneous contact with susceptible animals and persons. PMID:15829191

Xiao, Shu-Yuan; Sbrana, Elena; Watts, Douglas M; Siirin, Marina; da Rosa, Amelia P A Travassos; Tesh, Robert B

2005-04-01

142

Immunomodulatory activity of red ginseng against influenza A virus infection.  

PubMed

Ginseng herbal medicine has been known to have beneficial effects on improving human health. We investigated whether red ginseng extract (RGE) has preventive effects on influenza A virus infection in vivo and in vitro. RGE was found to improve survival of human lung epithelial cells upon influenza virus infection. Also, RGE treatment reduced the expression of pro-inflammatory genes (IL-6, IL-8) probably in part through interference with the formation of reactive oxygen species by influenza A virus infection. Long-term oral administration of mice with RGE showed multiple immunomodulatory effects such as stimulating antiviral cytokine IFN-? production after influenza A virus infection. In addition, RGE administration in mice inhibited the infiltration of inflammatory cells into the bronchial lumens. Therefore, RGE might have the potential beneficial effects on preventing influenza A virus infections via its multiple immunomodulatory functions. PMID:24473234

Lee, Jong Seok; Hwang, Hye Suk; Ko, Eun-Ju; Lee, Yu-Na; Kwon, Young-Man; Kim, Min-Chul; Kang, Sang-Moo

2014-01-01

143

Immunomodulatory Activity of Red Ginseng against Influenza A Virus Infection  

PubMed Central

Ginseng herbal medicine has been known to have beneficial effects on improving human health. We investigated whether red ginseng extract (RGE) has preventive effects on influenza A virus infection in vivo and in vitro. RGE was found to improve survival of human lung epithelial cells upon influenza virus infection. Also, RGE treatment reduced the expression of pro-inflammatory genes (IL-6, IL-8) probably in part through interference with the formation of reactive oxygen species by influenza A virus infection. Long-term oral administration of mice with RGE showed multiple immunomodulatory effects such as stimulating antiviral cytokine IFN-? production after influenza A virus infection. In addition, RGE administration in mice inhibited the infiltration of inflammatory cells into the bronchial lumens. Therefore, RGE might have the potential beneficial effects on preventing influenza A virus infections via its multiple immunomodulatory functions. PMID:24473234

Lee, Jong Seok; Hwang, Hye Suk; Ko, Eun-Ju; Lee, Yu-Na; Kwon, Young-Man; Kim, Min-Chul; Kang, Sang-Moo

2014-01-01

144

GB virus type C infection in hemodialysis patients considering co-infection with hepatitis C virus.  

PubMed

GB virus type C is a well-known viral agent with capability of infecting patients undergoing hemodialysis. Liver enzyme levels in infected individuals have been reported to remain within the normal range. Simultaneous infection of GBV-C and other viral agents may occur due to common routes of transmission. A total of 104 hemodialysis patients living in Tehran were included in this case-control study (53 patients with HCV infection, group I; and 51 with no HCV infection, group II). Diagnosis was made by detection Anti-E(2) protein using ELISA and HCV-RNA using RT-PCR. History of HBV-infection, organ transplantation, depression, malignancies, chemotherapy, diabetes mellitus, thyroid disorders and chronic cutaneous disorders were considered. Patients were evaluated for high- risk behaviors such as intravenous drug injection, addiction or substance abuse. A total of 14 patients (13.6%) were GBV-C-infected. Four of them were co-infected with HCV. All patients with GBV-C infection had viral genotype 2. Thirteen patients (12%) had a history of multiple blood transfusions. Mean (+/-SD) age of GBV-C-infected patients was 48.7+/-13.8 years. Among GBV-C infected patients, three patients had a history of organ transplantation and three had a co-morbidity of diabetes mellitus. This study as the first case-control study to evaluate the association between GBV-C and HCV infection, to our knowledge, shows hemodialysis patients living in Tehran are infected with GBV-C with intermediate level of frequency. The association of GBV-C transmission with other viral blood-borne agents might be necessary. PMID:18461616

Hosseini-Moghaddam, S M; Keyvani, H; Samadi, M; Alavian, S M; Mahdavimazdeh, M; Daneshvar, S; Razzaghi, Z

2008-07-01

145

Roles of Target Cells and Virus-Specific Cellular Immunity in Primary Simian Immunodeficiency Virus Infection  

PubMed Central

There is an ongoing debate on whether acute human immunodeficiency virus infection is controlled by target cell limitation or by virus-specific cellular immunity. To resolve this question, we developed a novel mathematical modeling scheme which allows us to incorporate measurements of virus load, target cells, and virus-specific immunity and applied it to a comprehensive data set generated in an experiment involving rhesus macaques infected with simian immunodeficiency virus. Half of the macaques studied were treated during the primary infection period with reagents which block T-cell costimulation and as a result displayed severely impaired virus-specific immune responses. Our results show that early viral replication in normal infection is controlled to a large extent by virus-specific CD8+ T cells and not by target cell limitation. PMID:15078967

Regoes, Roland R.; Antia, Rustom; Garber, David A.; Silvestri, Guido; Feinberg, Mark B.; Staprans, Silvija I.

2004-01-01

146

Facilitative and antagonistic interactions between plant viruses in mixed infections.  

PubMed

Mixed infections of plant viruses are common in nature, and a number of important virus diseases of plants are the outcomes of interactions between causative agents. Multiple infections lead to a variety of intrahost virus-virus interactions, many of which may result in the generation of variants showing novel genetic features, and thus change the genetic structure of the viral population. Hence, virus-virus interactions in plants may be of crucial significance for the understanding of viral pathogenesis and evolution, and consequently for the development of efficient and stable control strategies. The interactions between plant viruses in mixed infections are generally categorized as synergistic or antagonistic. Moreover, mixtures of synergistic and antagonistic interactions, creating usually unpredictable biological and epidemiological consequences, are likely to occur in plants. The mechanisms of some of these are still unknown. This review aims to bring together the current knowledge on the most commonly occurring facilitative and antagonistic interactions between related or unrelated viruses infecting the same host plant. The best characterized implications of these interactions for virus-vector-host relationships are included. The terms 'synergism' and 'helper dependence' for facilitative virus-virus interactions, and 'cross-protection' and 'mutual exclusion' for antagonistic interactions, are applied in this article. PMID:21726401

Syller, Jerzy

2012-02-01

147

[Research progress of prevention and treatment of Ebola virus infection].  

PubMed

Starting from February 2014, the Ebola virus outbreak had spread across West African countries within a few months and caused great concerns of the World Health Organization. Currently no effective vaccines or drugs have been available for prevention and treatment of Ebola virus infection. This paper gives a brief review of the epidemics and pandemics, the biological characteristics of Ebola virus, the potential antiviral drug targets, and research progress of vaccine and drug development against the virus. PMID:25345954

Wu, Wen-Jiao; Liu, Shu-Wen

2014-10-01

148

Human immunodeficiency virus infection and pregnancy.  

PubMed

Human immunodeficiency virus infection profoundly affects the medical community and is spreading rapidly in women of childbearing age worldwide. Transmission of HIV from mother to child can occur in utero, during labor, or after delivery through breast-feeding. Most of the infants are infected during delivery. We focus on the factors affecting the transmission of HIV, diagnostic and resistance tests, strategies to prevent mother-to-child transmission with special reference to mode of delivery, infant feeding, and use of antiretroviral therapy. The risk of infection for the infant can be decreased by reducing maternal viral load, by elective cesarean delivery, and by avoidance of breast-feeding. The efficacy of antiretroviral treatment should be balanced against the possibility of embryonic or fetal toxicity. The choice of therapy should be based on the woman's treatment history, the clinical status, and the available prognostic markers, which are related to the progression of disease in the mother and the risk of mother-to-child transmission HIV transmission. PMID:17113971

Petropoulou, Haritini; Stratigos, Alexander J; Katsambas, Andreas D

2006-01-01

149

Effect of Human Immunodeficiency Virus on Hepatitis B Virus Serologic Status in Co-Infected Adults.  

National Technical Information Service (NTIS)

Background: Factors associated with serologic hepatitis B virus (HBV) outcomes in HIV-infected individuals remain incompletely understood, yet such knowledge may lead to improvements in the prevention and treatment of chronic HBV infection. Methods and Fi...

A. M. Fieberg, H. M. Chun, M. L. Landrum, N. F. Crum- Cianflone, V. C. Marconi

2010-01-01

150

Cellular localization of human immunodeficiency virus infection within the brains of acquired immune deficiency syndrome patients.  

PubMed Central

Dysfunction of the central nervous system (CNS) is a prominent feature of the acquired immune deficiency syndrome (AIDS). Many of these patients have a subacute encephalitis consistent with a viral infection of the CNS. We studied the brains of 12 AIDS patients using in situ hybridization to identify human immunodeficiency virus [HIV, referred to by others as human T-cell lymphotropic virus type III (HTLV-III), lymphadenopathy-associated virus (LAV), AIDS-associated retrovirus (ARV)] nucleic acid sequences and immunocytochemistry to identify viral and cellular proteins. Nine patients had significant HIV infection in the CNS. In all examined brains, the white matter was more severely involved than the grey matter. In most cases the infection was restricted to capillary endothelial cells, mononuclear inflammatory cells, and giant cells. In a single case with severe CNS involvement, a low-level infection was seen in some astrocytes and neurons. These results suggest that CNS dysfunction is due to indirect effects rather than neuronal or glial infection. Images PMID:3018755

Wiley, C A; Schrier, R D; Nelson, J A; Lampert, P W; Oldstone, M B

1986-01-01

151

Amoebae as Battlefields for Bacteria, Giant Viruses, and Virophages  

PubMed Central

When amoebae are simultaneously infected with Acanthamoeba polyphaga Mimivirus (APM) and the strictly intracellular BABL1 bacterium, the latter is always lost after serial subculturing. We showed that the virophage Sputnik 1, by reducing APM fitness, preserved BABL1 growth in acute and chronic models. This capability of a virophage to modulate the virulence of mimiviruses highlights the competition that occurs between them during natural host infection. PMID:23388714

Slimani, Meriem; Pagnier, Isabelle; Raoult, Didier

2013-01-01

152

Amoebae as battlefields for bacteria, giant viruses, and virophages.  

PubMed

When amoebae are simultaneously infected with Acanthamoeba polyphaga Mimivirus (APM) and the strictly intracellular BABL1 bacterium, the latter is always lost after serial subculturing. We showed that the virophage Sputnik 1, by reducing APM fitness, preserved BABL1 growth in acute and chronic models. This capability of a virophage to modulate the virulence of mimiviruses highlights the competition that occurs between them during natural host infection. PMID:23388714

Slimani, Meriem; Pagnier, Isabelle; Raoult, Didier; La Scola, Bernard

2013-04-01

153

Unfolded protein response in hepatitis C virus infection  

PubMed Central

Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus of clinical importance. The virus establishes a chronic infection and can progress from chronic hepatitis, steatosis to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The mechanisms of viral persistence and pathogenesis are poorly understood. Recently the unfolded protein response (UPR), a cellular homeostatic response to endoplasmic reticulum (ER) stress, has emerged to be a major contributing factor in many human diseases. It is also evident that viruses interact with the host UPR in many different ways and the outcome could be pro-viral, anti-viral or pathogenic, depending on the particular type of infection. Here we present evidence for the elicitation of chronic ER stress in HCV infection. We analyze the UPR signaling pathways involved in HCV infection, the various levels of UPR regulation by different viral proteins and finally, we propose several mechanisms by which the virus provokes the UPR. PMID:24904547

Chan, Shiu-Wan

2014-01-01

154

Frog virus 3-like infections in aquatic amphibian communities.  

PubMed

Frog virus 3 (FV3) and FV3-like viruses, are members of the genus Ranavirus (family Iridoviridae), and they have been associated with infectious diseases that may be contributing to amphibian population declines. We examined the mode of transmission of an FV3-like virus, and potential hosts and reservoirs of the virus in a local amphibian community. Using the polymerase chain reaction to detect infected animals, we found an FV3-like virus in south-central Ontario, Canada, amphibian communities, where it infects sympatric amphibian species, including ranid and hylid tadpoles (Rana sylvatica, Hyla versicolor, and Pseudacris spp.), larval salamanders (Ambystoma spp.), and adult eastern-spotted newts (Notophthalmus viridescens). The high prevalence of FV3-like infections in caudate larvae suggests that salamanders are likely to be both hosts and reservoirs. In laboratory FV3 challenges of R. sylvatica, the rate of infection was dependent on the amount of virus to which the animals were exposed. In addition, although vertical transmission was suspected, horizontal transmission through exposure to infected pond water is the most likely route of infection in tadpoles. Based on our observations, a simple model of FV3/FV3-like virus transmission postulates that, in aquatic amphibian communities, transmission of the virus occurs between anuran and urodele species, with ambystomatid salamanders the most likely reservoir for the ranavirus in our study. PMID:18263826

Duffus, A L J; Pauli, B D; Wozney, K; Brunetti, C R; Berrill, M

2008-01-01

155

Antibody dependent enhancement of frog virus 3 infection  

PubMed Central

Background Viruses included in the family Iridoviridae are large, icosahedral, dsDNA viruses that are subdivided into 5 genera. Frog virus 3 (FV3) is the type species of the genus Ranavirus and the best studied iridovirus at the molecular level. Typically, antibodies directed against a virus act to neutralize the virus and limit infection. Antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it. Results Here we show that anti-FV3 serum present at the time of FV3 infection enhances infectivity of the virus in two non-immune teleost cell lines. We found that antibody dependent enhancement of FV3 was dependent on the Fc portion of anti-FV3 antibodies but not related to complement. Furthermore, the presence of anti-FV3 serum during an FV3 infection in a non-immune mammalian cell line resulted in neutralization of the virus. Our results suggest that a cell surface receptor specific to teleost cell lines is responsible for the enhancement. Conclusions This report represents the first evidence of antibody dependent enhancement in iridoviruses. The data suggests that anti-FV3 serum can either neutralize or enhance viral infection and that enhancement is related to a novel antibody dependent enhancement pathway found in teleosts that is Fc dependent. PMID:20167100

2010-01-01

156

Clustering of giant virus-DNA based on variations in local entropy.  

PubMed

We present a method for clustering genomic sequences based on variations in local entropy. We have analyzed the distributions of the block entropies of viruses and plant genomes. A distinct pattern for viruses and plant genomes is observed. These distributions, which describe the local entropic variability of the genomes, are used for clustering the genomes based on the Jensen-Shannon (JS) distances. The analysis of the JS distances between all genomes that infect the chlorella algae shows the host specificity of the viruses. We illustrate the efficacy of this entropy-based clustering technique by the segregation of plant and virus genomes into separate bins. PMID:24887142

Bose, Ranjan; Thiel, Gerhard; Hamacher, Kay

2014-06-01

157

Effects of influenza A virus infection on migrating mallard ducks  

PubMed Central

The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002–2007, we collected faecal samples (n=10?918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20?g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales. PMID:19129127

Latorre-Margalef, Neus; Gunnarsson, Gunnar; Munster, Vincent J.; Fouchier, Ron A.M.; Osterhaus, Albert D.M.E.; Elmberg, Johan; Olsen, Bjorn; Wallensten, Anders; Haemig, Paul D.; Fransson, Thord; Brudin, Lars; Waldenstrom, Jonas

2008-01-01

158

Effects of influenza A virus infection on migrating mallard ducks.  

PubMed

The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002-2007, we collected faecal samples (n=10918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales. PMID:19129127

Latorre-Margalef, Neus; Gunnarsson, Gunnar; Munster, Vincent J; Fouchier, Ron A M; Osterhaus, Albert D M E; Elmberg, Johan; Olsen, Björn; Wallensten, Anders; Haemig, Paul D; Fransson, Thord; Brudin, Lars; Waldenström, Jonas

2009-03-22

159

Respiratory syncytial virus infections in pediatric renal transplant recipients  

Microsoft Academic Search

Immunocompromised patients are considered at increased risk from respiratory syncytial virus (RSV) infection. We examined the incidence and outcome of RSV infection in pediatric renal transplant (Tx) recipients on chronic immunosuppressive therapy. Of 173 recipients transplanted between November 1985 and April 1993, 5 (3%) developed RSV infection (age range 11–39 months). Initial immunosuppression included prednisone, azathioprine, cyclosporine, and polyclonal antibody

Robert B. Miller; Blanche M. Chavers

1996-01-01

160

Behçet's disease in a patient with immunodeficiency virus infection  

Microsoft Academic Search

A patient with human immunodeficiency virus (HIV) infection who developed Behçet's disease is described. As various vasculitis syndromes have been encountered recently in association with HIV infection it is suggested that Behçet's disease may be related to the HIV infection in this patient.

D Buskila; D D Gladman; J Gilmore; I E Salit

1991-01-01

161

Human Immunodeficiency Virus Type 2 Infection in Spain  

Microsoft Academic Search

SummaryThe first cases of human immunodeficiency virus type 2 (HIV-2) infection in Spain were identified in 1988, in 3 African immigrants living in Barcelona. Since then, up to December 1998, 92 individuals with HIV-2 infection have been reported in Spain. Most are adult men, infected through heterosexual contacts, originating from West African countries, and currently living in the largest urban

Ana Machuca; Vincent Soriano; Mayte Gutiérrez; Africa Holguín; Antonio Aguilera; Estrella Caballero; Gustavo Cilla

1999-01-01

162

Host Defence Mechanisms Against Japanese Encephalitis Virus Infection in Mice  

Microsoft Academic Search

SUMMARY The role of antibody and cell-mediated immunity in the resistance to Japanese encephalitis virus (JEV) infection was studied in adult mice. Passively transferred antibodies obtained up to 2 weeks after primary infection protected the recipient mice against a challenge infection with JEV. Antibody obtained at 4 or 5 weeks failed to protect despite the presence of high titres of

ASHA MATHUR; KAMLESH L. ARORA; U. C. Chaturvedi

1983-01-01

163

The Epidemiology of Herpes Simplex Virus Infections in Adolescents  

Microsoft Academic Search

SUMMARY Herpes simplex virus type 1 and type 2 (HSV-1 and -2) infections are common among adolescents. HSV-1 can cause either oral or genital infections, whereas HSV-2 causes predominantly genital herpes. Therefore, HSV-2 seroprevalence can be used as a marker of genital herpes. As in adults, genital infections in adolescents are often unrecognized; consequently the magnitude of the problem of

Susan L Rosenthal

1999-01-01

164

Herpes simplex Virus Infection in Pregnancy: Diagnosis and Significance  

Microsoft Academic Search

SummaryHerpes simplex viruses (HSV) cause genital infections, and HSV infection during pregnancy can result in infection of the neonate. Here HSV structure and replication,viral pathogenesis, human immune responses to HSV, the epidemiology, details of HSV diagnosis with emphasis on typing, clinical features and antiviral treatment are reviewed. The importance of appropriate diagnostic procedures in relation to correct risk assessment of

Ulrich Desselberger

1998-01-01

165

Hepatitis C virus infection in the United States  

Microsoft Academic Search

Hepatitis C virus (HCV) infection is the most common chronic bloodborne infection in the United States, and most infected persons are younger than 50 years old. The relative importance of the two most common exposures associated with transmission of HCV, blood transfusion and intravenous drug use (IVDU), has changed over time. Blood transfusion, which accounted for a substantial proportion of

Miriam J. Alter

1999-01-01

166

First isolation of a giant virus from wild Hirudo medicinalis leech: Mimiviridae isolation in Hirudo medicinalis.  

PubMed

Giant viruses and amoebae are common in freshwater, where they can coexist with other living multicellular organisms. We screened leeches from the species Hirudo medicinalis for giant viruses. We analyzed five H. medicinalis obtained from Tunisia (3) and France (2). The leeches were decontaminated and then dissected to remove internal parts for co-culture with Acanthamoeba polyphaga. The genomes of isolated viruses were sequenced on a 454 Roche instrument, and a comparative genomics analysis was performed. One Mimivirus was isolated and the strain was named Hirudovirus. The genome assembly generated two scaffolds, which were 1,155,382 and 25,660 base pairs in length. Functional annotations were identified for 47% of the genes, which corresponds to 466 proteins. The presence of Mimividae in the same ecological niche as wild Hirudo may explain the presence of the mimivirus in the digestive tract of the leech, and several studies have already shown that viruses can persist in the digestive tracts of leeches fed contaminated blood. As leeches can be used medically and Mimiviruses have the potential to be an infectious agent in humans, patients treated with leeches should be surveyed to investigate a possible connection. PMID:24287596

Boughalmi, Mondher; Pagnier, Isabelle; Aherfi, Sarah; Colson, Philippe; Raoult, Didier; La Scola, Bernard

2013-12-01

167

First Isolation of a Giant Virus from Wild Hirudo medicinalis Leech: Mimiviridae isolation in Hirudo medicinalis  

PubMed Central

Giant viruses and amoebae are common in freshwater, where they can coexist with other living multicellular organisms. We screened leeches from the species Hirudo medicinalis for giant viruses. We analyzed five H. medicinalis obtained from Tunisia (3) and France (2). The leeches were decontaminated and then dissected to remove internal parts for co-culture with Acanthamoeba polyphaga. The genomes of isolated viruses were sequenced on a 454 Roche instrument, and a comparative genomics analysis was performed. One Mimivirus was isolated and the strain was named Hirudovirus. The genome assembly generated two scaffolds, which were 1,155,382 and 25,660 base pairs in length. Functional annotations were identified for 47% of the genes, which corresponds to 466 proteins. The presence of Mimividae in the same ecological niche as wild Hirudo may explain the presence of the mimivirus in the digestive tract of the leech, and several studies have already shown that viruses can persist in the digestive tracts of leeches fed contaminated blood. As leeches can be used medically and Mimiviruses have the potential to be an infectious agent in humans, patients treated with leeches should be surveyed to investigate a possible connection. PMID:24287596

Boughalmi, Mondher; Pagnier, Isabelle; Aherfi, Sarah; Colson, Philippe; Raoult, Didier; La Scola, Bernard

2013-01-01

168

Protective effect of an oral infection with Herpes simplex virus type 1 against subsequent genital infection with Herpes simplex virus type 2  

Microsoft Academic Search

The problem of whether oral Herpes simplex virus type 1 (HSV-1) infection provides protection against subsequent genital infection by Herpes simplex virus type 2 (HSV-2) was investigated. Mice were used as models. Following conditions in man, both the oral and genital infections applied were noninjurious. Mice infected orally with HSV-1 were weakly protected against virus ‘take’ following vaginal challenge with

Bernhard Sturn; Karl-Eduard Schneweis

1978-01-01

169

Proteolysis of the Ebola Virus Glycoproteins Enhances Virus Binding and Infectivity  

Microsoft Academic Search

Cellular cathepsins are required for Ebola virus infection and are believed to proteolytically process the Ebola virus glycoprotein (GP) during entry. However, the significance of cathepsin cleavage during infection remains unclear. Here we demonstrate a role for cathepsin L (CatL) cleavage of Ebola virus GP in the generation of a stable 18-kDa GP1 viral intermediate that exhibits increased binding to

Rachel L. Kaletsky; Graham Simmons; Paul Bates

2007-01-01

170

Hepatitis C virus infection in hemodialysis patients.  

PubMed

Hepatitis C virus (HCV) infection is observed in around 20% of dialysis patients and in allograft recipients and results in a significant morbidity and mortality, especially after transplantation. Its prevalence has markedly decreased in patients who are candidates for transplantation since the introduction of screening, hygiene and prevention measures, including systematic screening of blood and organ donations, use of erythropoietin, and compliance with universal hygiene rules. A liver biopsy is preferable to non-invasive biochemical and/or morphological tests of fibrosis to evaluate liver fibrosis before and even after transplantation. In HCV-infected dialyzed patients who are not candidates for renal transplantation, the indication for antiviral therapy is limited to significant fibrosis (fibrosis ? 2 on the METAVIR scale). Antiviral treatment should be proposed to any HCV-infected candidate for renal transplantation, whatever the baseline histopathology. The recommendation is to use standard interferon-? as monotherapy, but pegylated interferon can be used, resulting in sustained virological response, while low doses of combined ribavirin may enhance the antiviral efficacy. After transplantation, interferon-? is contra-indicated but may be used in patients for whom the benefits of antiviral treatment clearly outweigh the risks, especially that of allograft rejection. All cirrhotic patients should be screened for hepatocellular carcinoma, whose risk is enhanced by immunosuppressive regimens. Sustained suppression of necro-inflammation may result in the reversal of cirrhosis, which reduces liver-related morbidity and improves patient and allograft survival. Finally, due to the high mortality after renal transplantation, active cirrhosis must be considered to be a contraindication to kidney transplantation, but an indication to combined liver-kidney transplantation; on the contrary, inactive compensated cirrhosis may permit renal transplantation alone. PMID:23933193

Vallet-Pichard, Anais; Pol, Stanislas

2013-09-01

171

Reference gene selection for quantitative real-time PCR analysis in virus infected cells: SARS corona virus, Yellow fever virus, Human Herpesvirus-6, Camelpox virus and Cytomegalovirus infections  

PubMed Central

Ten potential reference genes were compared for their use in experiments investigating cellular mRNA expression of virus infected cells. Human cell lines were infected with Cytomegalovirus, Human Herpesvirus-6, Camelpox virus, SARS coronavirus or Yellow fever virus. The expression levels of these genes and the viral replication were determined by real-time PCR. Genes were ranked by the BestKeeper tool, the GeNorm tool and by criteria we reported previously. Ranking lists of the genes tested were tool dependent. However, over all, ?-actin is an unsuitable as reference gene, whereas TATA-Box binding protein and peptidyl-prolyl-isomerase A are stable reference genes for expression studies in virus infected cells. PMID:15705200

Radonic, Aleksandar; Thulke, Stefanie; Bae, Hi-Gung; Muller, Marcel A; Siegert, Wolfgang; Nitsche, Andreas

2005-01-01

172

Ebola virus-like particles prevent lethal Ebola virus infection  

E-print Network

... successfully immunized mice against Ebola virus using virus-like particles ... exposed to lethal doses of Ebola . The work could serve as ... basis for developing countermeasures to Ebola , which causes hemorrhagic fever with ...

173

Prevalence of Hepatitis Virus Infections in an Institution for Persons with Developmental Disabilities.  

ERIC Educational Resources Information Center

A study involving 1,235 residents of Sonoma Developmental Center found 3 residents had hepatitis C virus infections, and 633 had past or current hepatitis B virus infections. The prevalence of hepatitis B virus infection rose rapidly with longer residence in institutions. Hepatitis A virus infection had occurred in 494 residents. (Contains…

Woodruff, Bradley A.; Vazquez, Elizabeth

2002-01-01

174

Role of interleukin-12 in primary influenza virus infection.  

PubMed

The effect of endogenous interleukin-12 (IL-12) on the influenza virus immune response in BALB/c mice was evaluated. Following primary influenza virus infection, IL-12 mRNA and protein are detected in the lung, with live virus being required for cytokine induction. Endogenous IL-12 contributes to early NK cell-dependent gamma interferon (IFN-gamma) production (days 3 and 5) but not late T-cell-dependent IFN-gamma secretion (day 7). IL-12 contributes to the inhibition of early virus replication but is not required for virus clearance. IL-12 also modestly contributes to the activation of cytotoxic T lymphocytes. Thus, in this model of experimental influenza virus infection, endogenous IL-12 contributes primarily to the early development and activation of the innate immune response. PMID:9573248

Monteiro, J M; Harvey, C; Trinchieri, G

1998-06-01

175

Auxiliary metabolic genes in viruses infecting marine cyanobacteria  

E-print Network

Marine viruses shape the diversity and biogeochemical role of their microbial hosts. Cyanophages that infect the cyanobacteria Prochlorococcus and Synechococcus often carry metabolic genes not found in other bacteriophages. ...

Thompson, Luke Richard

2010-01-01

176

Update on Human Immunodeficiency Virus (HIV)-2 Infection  

PubMed Central

Infection with human immunodeficiency virus type 2 (HIV-2) occurs mainly in West Africa, but an increasing number of cases have been recognized in Europe, India, and the United States. In this era of global integration, clinicians must be aware of when to consider the diagnosis of HIV-2 infection and how to test for this virus. Although there is debate regarding when therapy should be initiated and which regimen should be chosen, recent trials have provided important information on treatment options for HIV-2 infection. In this review, we present information on recent clinical advances in our understanding of HIV-2 infection and highlight remaining diagnostic and therapeutic challenges. PMID:21367732

Campbell-Yesufu, Omobolaji T.

2011-01-01

177

Respiratory Syncytial Virus Infects the Bonnet Monkey, Macaca radiata  

Microsoft Academic Search

The Bonnet monkey model of respiratory syncytial virus (RSV) infection may be a useful nonhuman primate model for studying\\u000a RSV disease in humans because Bonnet monkeys can predictably be infected to obtain an orderly sequence of morphologic, cytologic,\\u000a virologic, serologic, and inflammatory changes related to time of infection. Young feral Bonnet monkeys, Macaca radiata, were infected endotracheally with 106 plaque-forming

Eric A. F. Simoes; Anthony R. Hayward; Esther M. Ponnuraj; John P. Straumanis; Kurt R. Stenmark; Harry L. Wilson; P. George Babu

1999-01-01

178

Role of Interleukin12 in Primary Influenza Virus Infection  

Microsoft Academic Search

The effect of endogenous interleukin-12 (IL-12) on the influenza virus immune response in BALB\\/c mice was evaluated. Following primary influenza virus infection, IL-12 mRNA and protein are detected in the lung, with live virus being required for cytokine induction. Endogenous IL-12 contributes to early NK cell-dependent gamma interferon (IFN-g) production (days 3 and 5) but not late T-cell-dependent IFN-g secretion

JUANITA M. MONTEIRO; CATHERINE HARVEY; GIORGIO TRINCHIERI

1998-01-01

179

Release of Viral Glycoproteins during Ebola Virus Infection  

Microsoft Academic Search

Maturation and release of the Ebola virus glycoprotein GP were studied in cells infected with either Ebola or recombinant vaccinia viruses. Significant amounts of GP were found in the culture medium in nonvirion forms. The major form represented the large subunit GP1that was shed after release of its disulfide linkage to the smaller transmembrane subunit GP2. The minor form were

Viktor E. Volchkov; Valentina A. Volchkova; Werner Slenczka; Hans-Dieter Klenk; Heinz Feldmann

1998-01-01

180

EFFECT OF CHLORINE TREATMENT ON INFECTIVITY OF HEPATITIS A VIRUS  

EPA Science Inventory

This study examined the effect of chlorine treatment on the infectivity of hepatitis A virus (HAV). Prodromal chimpanzee feces, shown to induce hepatitis in marmosets (Saguinus sp.), was clarified, and the virus was precipitated with 7% polyethylene glycol 6000, harvested and res...

181

Lethal Experimental Infections of Rhesus Monkeys by Aerosolized Ebola Virus.  

National Technical Information Service (NTIS)

The potential of aerogenic infection by Ebola virus was established by using a head-only exposure aerosol system. Virus-containing droplets of 0.8-1.2 urn were generated and administered into the respiratory tract of rhesus monkeys via inhalation. Inhalat...

E. Johnson, N. Jaax, J. White, P. Jahrling

1994-01-01

182

First report of Chikungunya virus infection in Nepal.  

PubMed

Chikungunya virus is an emerging arboviral disease that has been spreading rapidly across south Asia in recent years. Until recently, no chikungunya cases have been reported in Nepal. For the first time, we report three cases of chikungunya virus infection in Nepal. PMID:24916880

Pun, Sher Bahadur; Bastola, Anup; Shah, Rajesh

2014-01-01

183

Mixed infection and the genesis of influenza virus diversity.  

PubMed

The emergence of viral infections with potentially devastating consequences for human health is highly dependent on their underlying evolutionary dynamics. One likely scenario for an avian influenza virus, such as A/H5N1, to evolve to one capable of human-to-human transmission is through the acquisition of genetic material from the A/H1N1 or A/H3N2 subtypes already circulating in human populations. This would require that viruses of both subtypes coinfect the same cells, generating a mixed infection, and then reassort. Determining the nature and frequency of mixed infection with influenza virus is therefore central to understanding the emergence of pandemic, antigenic, and drug-resistant strains. To better understand the potential for such events, we explored patterns of intrahost genetic diversity in recently circulating strains of human influenza virus. By analyzing multiple viral genome sequences sampled from individual influenza patients we reveal a high level of mixed infection, including diverse lineages of the same influenza virus subtype, drug-resistant and -sensitive strains, those that are likely to differ in antigenicity, and even viruses of different influenza virus types (A and B). These results reveal that individuals can harbor influenza viruses that differ in major phenotypic properties, including those that are antigenically distinct and those that differ in their sensitivity to antiviral agents. PMID:19553313

Ghedin, Elodie; Fitch, Adam; Boyne, Alex; Griesemer, Sara; DePasse, Jay; Bera, Jayati; Zhang, Xu; Halpin, Rebecca A; Smit, Marita; Jennings, Lance; St George, Kirsten; Holmes, Edward C; Spiro, David J

2009-09-01

184

Toscana Virus Central Nervous System Infections in Southern Italy  

Microsoft Academic Search

Toscana virus was detected by reverse transcription-nested PCR in 5.6% of cerebrospinal fluid (CSF) samples from patients with meningitis and encephalitis during the summer in southern Italy. The central nervous system infections were associated with young adults and with a substantially benign clinical course. Presenting features and CSF findings are also discussed in the present report. Toscana virus (TOSV) is

G. Di Nicuolo; P. Pagliano; S. Battisti; M. Starace; V. Mininni; V. Attanasio; F. S. Faella

2005-01-01

185

Protective efficacy of neutralizing antibodies against Ebola virus infection  

Microsoft Academic Search

Ebola virus causes lethal hemorrhagic fever in humans and nonhuman primates, but no effective antiviral compounds are available for the treatment of this infection. The surface glycoprotein (GP) of Ebola virus is an important target of neutralizing antibodies. Although passive transfer of GP-specific antibodies has been evaluated in mouse and guinea pig models, protection was achieved only by treatment shortly

Ayato Takada; Hideki Ebihara; Steven Jones; Heinz Feldmann; Yoshihiro Kawaoka

2007-01-01

186

Molecular and cellular biology of Borna disease virus infection  

Microsoft Academic Search

Borna disease virus (BDV) is a noncytolytic, neurotropic RNA virus that causes neurobehavioral disorders in a wide variety of warm-blooded animals. Recent evidence has revealed that BDV uses a unique strategy in its transcription and replication and directly affects cellular functions of infected central nervous systems. BDV research will provide new insights not only into the biology of neurotropic RNA

Keizo Tomonaga; Takeshi Kobayashi; Kazuyoshi Ikuta

2002-01-01

187

Persistent Infection with Ebola Virus under Conditions of Partial Immunity  

Microsoft Academic Search

Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed

Manisha Gupta; Siddhartha Mahanty; Patricia Greer; Jonathan S. Towner; Wun-Ju Shieh; Sherif R. Zaki; Rafi Ahmed; Pierre E. Rollin

2004-01-01

188

Severe Thrombocytopenia Associated with Acute Hepatitis E Virus Infection ?  

PubMed Central

We describe here what is, to the best of our knowledge, the third reported case of severe thrombocytopenia associated with acute hepatitis E virus infection. The patient was a 72-year-old French woman. It seems likely that the cause of the thrombocytopenia was acute hepatitis E virus infection, possibly occurring via an immune mechanism. No complications were noted, in contrast to the two previous reports. PMID:18480231

Colson, P.; Payraudeau, E.; Leonnet, C.; De Montigny, S.; Villeneuve, L.; Motte, A.; Tamalet, C.

2008-01-01

189

Production of temperature-sensitive and pathogenic virus from Aedes albopictus cells (Singh) persistently infected with chikungunya virus  

Microsoft Academic Search

Summary WhenA. albopictus, clone C6\\/36, cells were infected with chikungunya (CHIK) virus, high virus yield accompanied by a cytopathic effect in the acute stage of infection was followed by a relatively low yield of virus over a long period of time. Virus produced from persistently infected cultures became gradually of smaller plaque size and more temperature-sensitive; however, such virus still

A. Igarashi

1979-01-01

190

The effect of infection with bovine viral diarrhea virus on the fertility of Swiss dairy cattle  

Microsoft Academic Search

Bovine viral diarrhea virus is a major cattle pathogen with a worldwide distribution. Animals may be infected with BVD virus transiently or persistently. Transient infection leads to protective immunity. Persistent infection is unique because it is associated with an immunotolerance that is specific to the infecting strain of BVD virus. Persistent infection results from viral invasion of fetuses between the

J. Rüfenacht; P. Schaller; L. Audigé; B. Knutti; U. Küpfer; E. Peterhans

2001-01-01

191

Recombinant vesicular stomatitis virus-based vaccines against Ebola and Marburg virus infections.  

PubMed

The filoviruses, Marburg virus and Ebola virus, cause severe hemorrhagic fever with a high mortality rate in humans and nonhuman primates. Among the most-promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (rVSV) that expresses a single filovirus glycoprotein (GP) in place of the VSV glycoprotein (G). Importantly, a single injection of blended rVSV-based filovirus vaccines was shown to completely protect nonhuman primates against Marburg virus and 3 different species of Ebola virus. These rVSV-based vaccines have also shown utility when administered as a postexposure treatment against filovirus infections, and a rVSV-based Ebola virus vaccine was recently used to treat a potential laboratory exposure. Here, we review the history of rVSV-based vaccines and pivotal animal studies showing their utility in combating Ebola and Marburg virus infections. PMID:21987744

Geisbert, Thomas W; Feldmann, Heinz

2011-11-01

192

Viral MicroRNAs Targeting Virus Genes Promote Virus Infection in Shrimp In Vivo  

PubMed Central

Viral microRNAs (miRNAs), most of which are characterized in cell lines, have been found to play important roles in the virus life cycle to avoid attack by the host immune system or to keep virus in the latency state. Viral miRNAs targeting virus genes can inhibit virus infection. In this study, in vivo findings in Marsupenaeus japonicus shrimp revealed that the viral miRNAs could target virus genes and further promote the virus infection. The results showed that white spot syndrome virus (WSSV)-encoded miRNAs WSSV-miR-66 and WSSV-miR-68 were transcribed at the early stage of WSSV infection. When the expression of WSSV-miR-66 and WSSV-miR-68 was silenced with sequence-specific anti-miRNA oligonucleotides (AMOs), the number of copies of WSSV and the WSSV-infected shrimp mortality were significantly decreased, indicating that the two viral miRNAs had a great effect on virus infection. It was revealed that the WSSV wsv094 and wsv177 genes were the targets of WSSV-miR-66 and that the wsv248 and wsv309 genes were the targets of WSSV-miR-68. The data demonstrate that the four target genes play negative roles in the WSSV infection. The targeting of the four virus genes by WSSV-miR-66 and WSSV-miR-68 led to the promotion of virus infection. Therefore, our in vivo findings show a novel aspect of viral miRNAs in virus-host interactions. PMID:24198431

He, Yaodong; Yang, Kai

2014-01-01

193

Effect of Cell Physiological State on Infection by Rat Virus  

PubMed Central

Infection by rat virus has been studied in cultures of rat embryo cells to evaluate the Margolis-Kilham hypothesis that the virus preferentially infects tissues with actively dividing cells. An enhancement of infection was seen in cultures infected 10 hr after fresh medium was added as compared to infection of stationary cultures (infected before addition of fresh medium). Since addition of fresh medium stimulates deoxyribonucleic acid (DNA) synthesis, the number of cells per culture synthesizing DNA at the time of infection was compared with the proportion of cells which synthesized viral protein. Cells were infected before the medium change and 10 or 24 hr after the medium change and were pulse-labeled with 3H-thymidine at the time virus was added. The cells were allowed to initiate viral protein synthesis before they were fixed and stained with fluorescein-conjugated anti-rat virus serum. Fluorescence microscopy permitted both labels to be counted simultaneouly and showed that the greatest proportion of cells synthesizing viral protein were those which had incorporated 3H-thymidine at the time of infection. Images PMID:16789120

Tennant, Raymond W.; Layman, Kenneth R.; Hand, Russell E.

1969-01-01

194

Senescence Affects Endothelial Cells Susceptibility to Dengue Virus Infection  

PubMed Central

Alteration in the endothelium leading to increased vascular permeability contributes to plasma leakage seen in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). An earlier study showed that senescent endothelial cells (ECs) altered the ECs permeability. Here we investigated the susceptibility of senescing human umbilical vein endothelial cells (HUVECs) to dengue virus infection and determined if dengue virus infection induces HUVECs senescence. Our results suggest that DENV type-2 (DENV-2) foci forming unit (FFU) and extracellular virus RNA copy number were reduced by at least 35% and 85% in infection of the intermediate young and early senescent HUVECs, respectively, in comparison to infection of young HUVECs. No to low infectivity was recovered from infection of late senescent HUVECs. DENV infection also increases the percentage of HUVECs expressing senescence-associated (SA)-?-gal, cells arrested at the G2/M phase or 4N DNA content stage and cells with enlarged morphology, indicative of senescing cells. Alteration of HUVECs morphology was recorded using impedance-based real-time cell analysis system following DENV-2 infection. These results suggest that senescing HUVECs do not support DENV infection and DENV infection induces HUVECs senescence. The finding highlights the possible role of induction of senescence in DENV infection of the endothelial cells. PMID:24782642

AbuBakar, Sazaly; Shu, Meng-Hooi; Johari, Jefree; Wong, Pooi-Fong

2014-01-01

195

Preference by a virus vector for infected plants is reversed after virus acquisition.  

PubMed

Pathogens and their vectors can interact either directly or indirectly via their shared hosts, with implications for the persistence and spread of the pathogen in host populations. For example, some plant viruses induce changes in host plants that cause the aphids that carry these viruses to settle preferentially on infected plants. Furthermore, relative preference by the vector for infected plants can change to a preference for noninfected plants after virus acquisition by the vector, as has recently been demonstrated in the wheat-Rhopalosiphum padi-Barley yellow dwarf virus pathosystem. Here we document a similar dynamic in the potato-Myzus persicae (Sulzer)-Potato leaf roll virus (PLRV) pathosystem. Specifically, in a dual choice bioassay, nonviruliferous apterous M. persicae settled preferentially on or near potato plants infected with PLRV relative to noninfected (sham-inoculated) control plants, whereas viruliferous M. persicae (carrying PLRV) preferentially settled on or near sham-inoculated potato plants relative to infected plants. The change in preference after virus acquisition also occurred in response to trapped headspace volatiles, and to synthetic mimics of headspace volatile blends from PLRV-infected and sham-inoculated potato plants. The change in preference we document should promote virus spread by increasing rates of virus acquisition and transmission by the vector. PMID:24269348

Rajabaskar, Dheivasigamani; Bosque-Pérez, Nilsa A; Eigenbrode, Sanford D

2014-06-24

196

Protection against filovirus infection: virus-like particle vaccines.  

PubMed

Significant progress has been made in vaccine development against infection by Ebola and Marburg viruses, members of the Filoviridae, which cause severe hemorrhagic fevers in humans with no effective treatment and a mortality rate of up to 90%. Several vaccine strategies have been shown to effectively protect immunized animals against filovirus infection. Among these candidate vaccine strategies, virus-like particles represent a promising approach and have been shown to protect small laboratory animals as well as nonhuman primates against lethal challenge by Ebola and/or Marburg viruses. This review briefly summarizes filovirus epidemiology and pathogenesis, and focuses on the discussion of recent advances in filovirus vaccine development and the current understanding of protective immune responses against filovirus infection with an emphasis on the progress and challenge of filovirus virus-like particle vaccine development. PMID:18393603

Yang, Chinglai; Ye, Ling; Compans, Richard W

2008-04-01

197

Spectroscopic detection and identification of infected cells with herpes viruses.  

PubMed

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and Fourier transform infrared (FTIR) microspectroscopy were previously applied for the identification of various biological samples. In the present study, normal cells in culture and cells infected with herpes simplex virus type 2 (HSV-2) or varicella-zoster virus (VZV) were analyzed by MALDI-TOF and FTIR microscopy. Specific spectral biomarkers for rapid and reliable monitoring and identification of infected cells and probably for the discrimination between these viruses were searched. The results show consistent spectral peaks in all examined normal uninfected human fibroblast cells both in MALDI-T0F and FTIR microscopy. In HSV-2- or VZV-infected cells, two unique peaks for each appeared at m/z 5397 and 5813 or at m/z 3501 and 4951, respectively, in MALDI-TOF spectra. In addition, several peaks that appeared in control uninfected cells at the region m/z 13,000-20,000 disappeared completely in all examined infected samples. When these infected cells were examined by FTIR microscopy, a band at 859 cm(-1) in control uninfected cells was significantly shifted to 854 cm(-1) in both HSV2- and VZV-infected cells. In addition, phosphate levels were considerably increased in all infected cells compared to normal uninfected cells. These parameters could be used as a basis for developing a spectral method for the detection and identification of cells infected with herpes viruses. PMID:18932269

Erukhimovitch, Vitaly; Karpasasa, Mark; Huleihel, Mahmoud

2009-01-01

198

Natural Intrauterine Infection with Schmallenberg Virus in Malformed Newborn Calves  

PubMed Central

We surveyed morphologic alterations in calves in Belgium that were naturally infected in utero by Schmallenberg virus (SBV) and born with deformities during January–March 2012. SBV-specific RNA was distributed unevenly in different tissues. Natural intrauterine SBV infection of calves might cause serious damage to the central nervous system and muscles. PMID:25062351

Bayrou, Calixte; Garigliany, Mutien-Marie; Sarlet, Michael; Sartelet, Arnaud; Cassart, Dominique

2014-01-01

199

Natural intrauterine infection with Schmallenberg virus in malformed newborn calves.  

PubMed

We surveyed morphologic alterations in calves in Belgium that were naturally infected in utero by Schmallenberg virus (SBV) and born with deformities during January-March 2012. SBV-specific RNA was distributed unevenly in different tissues. Natural intrauterine SBV infection of calves might cause serious damage to the central nervous system and muscles. PMID:25062351

Bayrou, Calixte; Garigliany, Mutien-Marie; Sarlet, Michael; Sartelet, Arnaud; Cassart, Dominique; Desmecht, Daniel

2014-08-01

200

Outbreak of West Nile Virus Infection in Greece, 2010  

PubMed Central

During 2010, an outbreak of West Nile virus infection occurred in Greece. A total of 197 patients with neuroinvasive disease were reported, of whom 33 (17%) died. Advanced age and a history of heart disease were independently associated with death, emphasizing the need for prevention of this infection in persons with these risk factors. PMID:22000357

Papa, Anna; Theocharopoulos, George; Dougas, Georgios; Athanasiou, Maria; Detsis, Marios; Baka, Agoritsa; Lytras, Theodoros; Mellou, Kassiani; Bonovas, Stefanos; Panagiotopoulos, Takis

2011-01-01

201

Risk factors for hepatitis C virus infection among street youths  

Microsoft Academic Search

Background: The relative contributions to risk of hepatitis C virus (HCV) infection resulting from unsafe sexual behaviours and exposures to blood (e.g., tattooing, body piercing and injection drug use) among youths at risk are not well known. We interviewed street youths about risk factors for HCV infection and docu- mented their HCV antibody status. Methods: From December 1995 to September

Élise Roy; Nancy Haley; Pascale Leclerc; Jean-François Boivin; Lyne Cédras; Jean Vincelette

202

Gamma Interferon Primes Productive Human Immunodeficiency Virus Infection in Astrocytes  

Microsoft Academic Search

Considerable controversy exists over whether astrocytes can support human immunodeficiency virus (HIV) infection. We evaluated the impact of three cytokines critical to the development of HIV neuropathogenesis, gamma interferon (IFN-), granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor alpha, on priming astrocytes for HIV infection. We demonstrate that IFN- was the most potent in its ability to facilitate substantial productive HIV

Deborah Carroll-Anzinger; Lena Al-Harthi

2006-01-01

203

[Immunosuppression in dogs and pigs infected with canine distemper virus].  

PubMed

Immunosuppression manifesting itself as leukopenia and a considerably lower lymphocyte proliferative response to T- and B-cell mitogens develops in pigs and dogs within 2-3 weeks after intramuscular or oral infection with canine distemper virus (CDV). CDV antigens are detectable in the oral secretions of the animals within 2-2.5 week after infection. PMID:22171479

Sereda, A D; Nogina, I V

2011-01-01

204

Risk of Serious Bacterial Infection in Young Febrile Infants With Respiratory Syncytial Virus Infections  

Microsoft Academic Search

Background. The evaluation of young fe- brile infants is controversial, in part because it is unclear whether clinical evidence of a viral infection signifi- cantly reduces the risk of serious bacterial infections (SBIs). Specifically, it remains unclear whether the risk of SBI is altered in a meaningful way in the presence of respiratory syncytial virus (RSV) infections. Objective. The objective

Deborah A. Levine; Shari L. Platt; Peter S. Dayan; Charles G. Macias; Joseph J. Zorc; William Krief; Jeffrey Schor; David Bank; Nancy Fefferman; Kathy N. Shaw; Nathan Kuppermann

2004-01-01

205

Neurovirulent simian immunodeficiency virus infection induces neuronal, endothelial, and glial apoptosis.  

PubMed Central

BACKGROUND: Studies of human immunodeficiency virus type 1 (HIV-1) associated dementia have shown neuronal loss in discrete areas. The presence and mechanism of neuronal death, however, has remained quite elusive. One mechanism of cell death, apoptosis, has been clearly demonstrated outside the central nervous system (CNS) in HIV-1 infection but has not been firmly established within the CNS. Therefore, we set out to ascertain whether neuronal cell loss in simian immunodeficiency virus (SIV) encephalitis, an animal model of HIV-1-associated dementia, is a result of apoptosis. MATERIALS AND METHODS: With the aid of an in situ technique for identifying the 3'-OH ends of newly fragmented DNA characteristic of apoptosis, in conjunction with specific detected morphological criteria via light microscopy, we have examined encephalitic and nonencephalitic brains of macaques infected with a neurovirulent, neuroendotheliotropic strain of SIV to see if virus is spatially associated with apoptosis of neurons and non-neuronal cell types. RESULTS: We demonstrate the presence of DNA damage, indicative of apoptosis, in neurons, endothelial cells, and glial cells of the CNS of SIV-infected macaques. Furthermore, we observe an association between the localization of cells with significant DNA fragmentation and perivascular inflammatory cell infiltrates containing SIV-infected macrophages and multinucleated giant cells. Quantitative analysis reveals significantly more cells with DNA fragmentation in the CNS of macaques infected with neurovirulent, neuroendotheliotropic SIV strains as compared with strictly lymphocyte-tropic SIV strains and SIV negative controls. CONCLUSIONS: Our findings of apoptosis in SIV-infected CNS may potentially lead to a better understanding of the AIDS dementia complex, ultimately providing a basis for better treatments. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 PMID:8827712

Adamson, D. C.; Dawson, T. M.; Zink, M. C.; Clements, J. E.; Dawson, V. L.

1996-01-01

206

Innate immune control and regulation of influenza virus infections  

PubMed Central

Adaptive immune responses are critical for the control and clearance of influenza A virus (IAV) infection. However, in recent years, it has become increasingly apparent that innate immune cells, including natural killer cells, alveolar macrophages (aM?), and dendritic cells (DC) are essential following IAV infection in the direct control of viral replication or in the induction and regulation of virus-specific adaptive immune responses. This review will discuss the role of these innate immune cells following IAV infection, with a particular focus on DC and their ability to induce and regulate the adaptive IAV-specific immune response. PMID:19643736

McGill, Jodi; Heusel, Jonathan W.; Legge, Kevin L.

2009-01-01

207

Acute hepatitis A virus infections in British Gurkha soldiers.  

PubMed

Hepatitis A virus (HAV) and hepatitis E virus (HEV) infections are endemic in most developing countries, including Nepal and Afghanistan, and may cause outbreaks in military personnel. Previously, more than 99% of new British Gurkha recruits were already immune to HAV because of prior infection, but this may be declining due to improved living conditions in their countries of origin. Acute HAV infections have occurred in Gurkha soldiers serving in Afghanistan, which made them unfit for duty for 2-3 months. In one case, early serological diagnosis was impeded by IgM results against both HAV and HEV that were caused by cross-reactivity or persistence from a previous infection. These cases have led to a policy change whereby all Gurkha recruits are now tested for previous HAV infection and if negative they are offered vaccination. Meanwhile, HEV infection remains a significant threat in Nepal and Afghanistan with low levels of background immunity and no commercially available vaccine. PMID:23720504

Green, Chris A; Ross, D A; Bailey, M S

2013-09-01

208

Immune Modulation in Primary Vaccinia virus Zoonotic Human Infections  

PubMed Central

In 2010, the WHO celebrated the 30th anniversary of the smallpox eradication. Ironically, infections caused by viruses related to smallpox are being increasingly reported worldwide, including Monkeypox, Cowpox, and Vaccinia virus (VACV). Little is known about the human immunological responses elicited during acute infections caused by orthopoxviruses. We have followed VACV zoonotic outbreaks taking place in Brazil and analyzed cellular immune responses in patients acutely infected by VACV. Results indicated that these patients show a biased immune modulation when compared to noninfected controls. Amounts of B cells are low and less activated in infected patients. Although present, T CD4+ cells are also less activated when compared to noninfected individuals, and so are monocytes/macrophages. Similar results were obtained when Balb/C mice were experimentally infected with a VACV sample isolated during the zoonotic outbreaks. Taking together, the data suggest that zoonotic VACVs modulate specific immune cell compartments during an acute infection in humans. PMID:22229039

Gomes, Juliana Assis Silva; de Araújo, Fernanda Fortes; Trindade, Giliane de Souza; Quinan, Bárbara Resende; Drumond, Betânia Paiva; Ferreira, Jaqueline Maria Siqueira; Mota, Bruno Eduardo Fernandes; Nogueira, Maurício Lacerda; Kroon, Erna Geessien; Abrahão, Jônatas Santos; Côrrea-Oliveira, Rodrigo; da Fonseca, Flávio Guimarães

2012-01-01

209

Molecular diagnosis of Baylisascaris schroederi infections in giant panda (Ailuropoda melanoleuca) feces using PCR.  

PubMed

The helminth Baylisascaris schroederi is one of the most harmful parasites infecting giant pandas (Ailuropoda melanoleuca). It is therefore important to develop an exact diagnostic technique to detect this parasite. Using a known number (1, 2, 3, 4, 5, 10, 25, 50, 100) of feces-isolated B. schroederi egg and adult DNA, we developed a PCR to detect a portion of the mitochondrial 12S rRNA and applied it to giant panda fecal samples. The method was sufficiently sensitive to detect B. schroederi DNA from isolated eggs in a fecal sample with a detection threshold of one egg. We detected B. schroederi in 88% of fecal samples, 30% higher than the conventional flotation technique. No cross-reactivity with other common nematode DNA was detected. Our PCR assay may constitute a valuable alternative for the diagnosis of B. schroederi infections. PMID:24502740

Zhou, Xuan; Yu, Hua; Wang, Ning; Xie, Yue; Liang, Yi-nan; Li, De-sheng; Wang, Cheng-dong; Chen, Si-jie; Yan, Yu-bo; Gu, Xiao-bin; Wang, Shu-xian; Peng, Xue-rong; Yang, Guang-you

2013-10-01

210

Management of neonatal herpes simplex virus infection and exposure.  

PubMed

Neonatal herpes simplex virus (HSV) infections are rare but are associated with significant morbidity and mortality. Advances in diagnostic modalities to identify these infants, as well as the development of safe and effective antiviral therapy, have revolutionised the management of affected infants. This review will summarise the epidemiology of neonatal HSV infections and discuss the management of infants with HSV exposure and infection. PMID:24589428

Pinninti, Swetha G; Kimberlin, David W

2014-05-01

211

Risk of Lymphoma Increases with Hepatitis C Virus Infection  

Cancer.gov

People infected with the hepatitis C virus (HCV) are at an increased risk of developing certain lymphomas (cancers of the lymphatic system). Researchers found that HCV infection increased the risk of developing non-Hodgkin's lymphoma by 20 percent to 30 percent. The risk of developing Waldenström's macroglobulinemia (a rare type of non-Hodgkin's lymphoma) went up by 300 percent and the risk for cryoglobulinemia, a form of blood vessel inflammation, was also elevated for those with HCV infections.

212

Multiple Epstein-Barr virus infections in healthy individuals  

NASA Technical Reports Server (NTRS)

We employed a newly developed genotyping technique with direct representational detection of LMP-1 gene sequences to study the molecular epidemiology of Epstein-Barr virus (EBV) infection in healthy individuals. Infections with up to five different EBV genotypes were found in two of nine individuals studied. These results support the hypothesis that multiple EBV infections of healthy individuals are common. The implications for the development of an EBV vaccine are discussed.

Walling, Dennis M.; Brown, Abigail L.; Etienne, Wiguins; Keitel, Wendy A.; Ling, Paul D.; Butel, J. S. (Principal Investigator)

2003-01-01

213

Vaccination of chimpanzees against infection by the hepatitis C virus.  

PubMed Central

A high incidence of community-acquired hepatitis C virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. A vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. Seven chimpanzees (Pan troglodytes) have been immunized with both putative envelope glycoproteins [E1 (gp33) and E2 (gp72)] that were copurified from HeLa cells infected with a recombinant vaccinia virus expression vector. Despite the induction of a weak humoral immune response to these viral glycoproteins in experimentally infected chimpanzees, a strong humoral immune response was obtained in all vaccines. The five highest responders showed complete protection against an i.v. challenge with homologous hepatitis C virus 1. The remaining two vaccines became infected, but both infection and disease may have been ameliorated in comparison with four similarly challenged control chimpanzees, all of which developed acute hepatitis and chronic infections. These results provide considerable encouragement for the eventual control of hepatitis C virus infection by vaccination. PMID:7509068

Choo, Q L; Kuo, G; Ralston, R; Weiner, A; Chien, D; Van Nest, G; Han, J; Berger, K; Thudium, K; Kuo, C

1994-01-01

214

Immune response of lambs to experimental infection with Orf virus.  

PubMed

A group of six specific pathogen free (SPF) lambs were infected epidermally with Orf virus. Seven weeks later they were reinfected. For a period of 4 weeks after each inoculation they were observed clinically and blood was collected for analysis of virus specific antibody measured by ELISA and peripheral blood lymphocyte (PBL) proliferative response to various viral antigens. After the primary infection all animals showed clinical signs of Orf, namely vesicle formation which became pustular followed by scabbing; this steadily became heavier prior to shedding and the resolution of the infection by about 4 weeks. The severity of infection varied within the group. Little lymphoproliferative activity was recorded during the primary infection, although five/six test animals had positive lymphoproliferative responses to an sodium dodecyl sulphate (SDS) solubilised scab purified Orf virus preparation at some point between days 7 and 14 after inoculation. All animals seroconverted to Orf virus, lymphoproliferative activity always preceding specific antibody detection. Resolution of the secondary infection was very rapid. Vesicles were visible by day 2 after inoculation which became pustular followed by scab formation and resolution in the majority of animals by day 8. All animals showed a significant (greater than four-fold) rise in specific antibody titre following secondary inoculation. The proliferative activity of PBL's was much greater than that recorded for the primary infection although the magnitude of this response varied greatly between individuals. PMID:2534005

Yirrell, D L; Reid, H W; Norval, M; Howie, S E

1989-11-15

215

Metabolic stress in infected cells may represent a therapeutic target for human immunodeficiency virus infection.  

PubMed

Worldwide, there are thousands of new cases of human immunodeficiency virus-1 (HIV-1) infection per day. The effectiveness of current combination antiretroviral therapy (ART) is relative; to prioritize finding vaccines and/or cure-oriented initiatives should be reinforced because there is little room, if any, for procrastination. Basic and clinical findings on HIV-1 reservoirs suggest that disruption of virus latency is feasible. Because the goal is curing HIV-1 infection, we should be aware that the challenge is to eradicate the viruses of every single infected cell and consequently acting upon virus latency is necessary but not sufficient. The large majority of the virus reservoir, CD4(+) T lymphocytes, is readily accessible but other minor reservoirs, where ART does not diffuse, require innovative strategies. The situation closely resembles that currently faced in the treatment of cancer. Exploiting the fact that histone deacetylase inhibitors, mainly vorinostat, may disrupt the latency of HIV-1, we propose to supplement this effect with a programmed interference in the metabolic stress of infected cells. Metformin and chloroquine are cheap and accessible modulators of pro-survival mechanisms to which viruses are constantly confronted to generate alternative energy sources and maximize virus production. Metformin restrains the use of the usurped cellular biosynthetic machinery by viral genes and chloroquine contributes to death of infected cells. We suggest that the combination of vorinostat, chloroquine and metformin should be combined with ART to pursue viral eradication in infected cells. PMID:23639282

Alonso-Villaverde, Carlos; Menéndez, Javier A; Joven, Jorge

2013-07-01

216

Virus and target cell evolution in human immunodeficiency virus type 1 infection  

Microsoft Academic Search

Human immunodeficiency virus (HIV) infection lead to a prolonged struggle between a rapidly evolving viral population and\\u000a a potent immune response. In the vast majority of infected individuals, the virus wins this struggle. In my laboratory, we\\u000a focus on understanding both the viral and immune factors that contribute to this outcome. The results of our studies and those\\u000a of many

Donald E. Mosier

2000-01-01

217

Secondary dengue virus type 4 infections in Vietnam.  

PubMed

This study was designated to describe clinical and biological features of patients with a suspected diagnosis of dengue fever/dengue hemorrhagic fever during an outbreak in Central Vietnam. One hundred and twenty-five consecutive patients hospitalized at Khanh Hoa and Binh Thuan Provincial hospitals between November 2001 and January 2002 with a diagnosis of suspected dengue infection were included in the present study. Viruses were isolated in C6/36 and VERO E6 cell cultures or detected by RT-PCR. A hemagglutination-inhibition test (HI) was done on each paired sera using dengue antigens type 1-4, Japanese encephalitis (JE) virus antigen, Chickungunya virus antigen and Sindbis virus antigen. Anti-dengue and anti-JE virus IgM were measured by a capture enzyme-linked immunosorbent assay (MAC-ELISA). Anti-dengue and anti-JE virus IgG were measured by an ELISA test. Dengue viruses were isolated in cell culture and/or detected by RT-PCR in 20.8% of blood samples. DEN-4 and DEN-2 serotypes were found in 18.4% and 2.4% of the patients, respectively. A total of 86.4% of individuals had a diagnosis of acute dengue fever by using the HI test and/or dengue virus-specific IgM capture-ELISA and/or virus isolation and/or RT-PCR. The prevalence of primary and secondary acute dengue infection was 4% and 78.4%, respectively. Anti-dengue IgG ELISA test was positive in 88.8% of the patients. In 5 cases (4%), Japanese encephalitis virus infection was positive by serology but the cell culture was negative. No Chickungunya virus or Sindbis virus infection was detected by the HI test. In patients with acute dengue virus infection, the most common presenting symptom was headache, followed by conjunctivitis, petechial rash, muscle and joint pain, nausea and abdominal pain. Four percent of hospitalized patients were classified as dengue hemorrhagic fever. The clinical presentation and blood cell counts were similar between patients hospitalized with acute dengue fever and patients with other febrile illnesses. PMID:15906664

Buchy, Philippe; Vo, Van Luong; Bui, Khanh Toan; Trinh, Thi Xuan Mai; Glaziou, Philippe; Le, Thi Thu Ha; Le, Viet Lo; Bui, Trong Chien

2005-01-01

218

Herpes simplex virus glycoprotein D mediates interference with herpes simplex virus infection.  

PubMed

We showed that the expression of a single protein, glycoprotein D (gD-1), specified by herpes simplex virus type 1 (HSV-1) renders cells resistant to infection by HSV but not to infection by other viruses. Mouse (LMtk-) and human (HEp-2) cell lines containing the gene for gD-1 under control of the human metallothionein promoter II expressed various levels of gD-1 constitutively and could be induced to express higher levels with heavy metal ions. Radiolabeled viruses bound equally well to gD-1-expressing and control cell lines. Adsorbed viruses were unable to penetrate cells expressing sufficient levels of gD-1, based on lack of any cytopathic effects of the challenge virus and on failure to detect either the induction of viral protein synthesis or the shutoff of host protein synthesis normally mediated by a virion-associated factor. The resistance to HSV infection conferred by gD-1 expression was not absolute and depended on several variables, including the amount of gD-1 expressed, the dosage of the challenge virus, the serotype of the challenge virus, and the properties of the cells themselves. The interference activity of gD-1 is discussed in relation to the role of gD-1 in virion infectivity and its possible role in permitting escape of progeny HSV from infected cells. PMID:2536105

Johnson, R M; Spear, P G

1989-02-01

219

Prevalence of hepatitis E virus infection in regular hemodialysis patients.  

PubMed

The percentage of patients infected with blood-borne diseases, including hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, is high in patients undergoing hemodialysis regularly. Hepatitis E virus (HEV) is transmitted via the fecal-oral route, and blood-borne HEV infection has also been reported recently. On the basis of these findings, we investigated the actual status of HEV infection in regular hemodialysis patients. Out of 1077 patients undergoing hemodialysis at two key hospitals and three outpatient hemodialysis clinics, 300 were randomly selected as the subjects. Among these 300 hemodialysis patients, 19.0% were IgG-type anti-HEV antibody-positive. The percentage of HEV-infected patients increased with patient age and it was particularly high in patients 40 years of age or older. The percent IgG-type anti-HEV antibody positivity was not significantly different (P = 0.14) between anti-HCV antibody-positive patients (27.8%) and anti-HCV antibody-negative patients (17.8%). The percentage of HEV-infected patients among the hemodialysis patients was higher than that previously reported among patients with healthy kidneys. No correlation was observed between the percentage of HEV-infected patients and HCV infection incidence or a history of blood transfusion. The percent IgG-type anti-HEV antibody positivities were significantly different among the facilities. It was impossible to specify the route of infection, and the correlation between the incidence of infection and hemodialysis therapy was not clear. Because more routes of infection are possible for patients undergoing dialysis than for persons with normal kidney function, it seems necessary to analyze the significance of infection incidence, the route of infection and infection prevention measures. PMID:16684223

Kikuchi, Kan; Yoshida, Takumi; Kimata, Naoki; Sato, Chifumi; Akiba, Takashi

2006-04-01

220

Infectivity-enhancing antibodies to Ebola virus glycoprotein.  

PubMed

Ebola virus causes severe hemorrhagic fever in primates, resulting in mortality rates of up to 100%, yet there are no satisfactory biologic explanations for this extreme virulence. Here we show that antisera produced by DNA immunization with a plasmid encoding the surface glycoprotein (GP) of the Zaire strain of Ebola virus enhances the infectivity of vesicular stomatitis virus pseudotyped with the GP. Substantially weaker enhancement was observed with antiserum to the GP of the Reston strain, which is much less pathogenic in humans than the Ebola Zaire and Sudan viruses. The enhancing activity was abolished by heat but was increased in the presence of complement system inhibitors, suggesting that heat-labile factors other than the complement system are required for this effect. We also generated an anti-Zaire GP monoclonal antibody that enhanced viral infectivity and another that neutralized it, indicating the presence of distinct epitopes for these properties. Our findings suggest that antibody-dependent enhancement of infectivity may account for the extreme virulence of the virus. They also raise issues about the development of Ebola virus vaccines and the use of passive prophylaxis or therapy with Ebola virus GP antibodies. PMID:11160735

Takada, A; Watanabe, S; Okazaki, K; Kida, H; Kawaoka, Y

2001-03-01

221

Dissecting the Role of COPI Complexes in Influenza Virus Infection  

PubMed Central

As an obligate pathogen, influenza virus requires host cell factors and compartments to mediate productive infection and to produce infectious progeny virus. Recently, several small interfering RNA (siRNA) knockdown screens revealed influenza virus host dependency proteins, all of which identified at least two subunits of the coat protein I (COPI) complex. COPI proteins oligomerize to form coated vesicles that transport contents between the Golgi apparatus and the endoplasmic reticulum, and they have also been reported to mediate endosomal trafficking. However, it remains unclear which steps in the influenza virus infection cycle rely on the COPI complex. Upon systematic dissection of the influenza virus infection cycle, from entry to progeny virion production, we found that prolonged exposure to COPI complex disruption through siRNA depletion resulted in significant defects in virus internalization and trafficking to late endosomes. Acute inhibition of COPI complex recruitment to the Golgi apparatus with pharmacological compounds failed to recapitulate the same entry defects as observed with the COPI-depleted cells but did result in specific decreases in viral membrane protein expression and assembly, leading to defects in progeny virion production. Taken together, our findings suggest that COPI complexes likely function indirectly in influenza virus entry but play direct roles in viral membrane protein expression and assembly. PMID:23255804

Sun, Eileen; He, Jiang

2013-01-01

222

Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance  

PubMed Central

Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is effectiveness and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data has suggested that influenza B virus infections are of specific concern to pediatric patients because of the increased risk of severe disease. Treatment of influenza B is a challenging task for the following reasons: NAIs (e.g., oseltamivir and zanamivir) are the only FDA-approved class of antivirals available for treatment;the data suggest that oseltamivir is less effective than zanamivir in pediatric patients;zanamivir is not prescribed to patients younger than 7;influenza B viruses are less susceptible than influenza A viruses to NAIs in vitro;although the level of resistance to NAIs is low, the number of different molecular markers of resistance is higher than for influenza A viruses, and they are not well defined;the relationship between levels of NAI phenotypic resistance and known molecular markers, frequency of emergence, transmissibility, and fitness of NAI-resistant variants are not well established. This review presents current knowledge of the effectiveness of NAIs for influenza B virus and antiviral resistance in clinical, surveillance, and experimental studies. PMID:24013000

Burnham, Andrew J.; Baranovich, Tatiana; Govorkova, Elena A.

2013-01-01

223

Infection of cells by Sindbis virus at low temperature  

SciTech Connect

Sindbis virus, which belongs to the family Togaviridae genus Alphavirus infects a variety of vertebrate and invertebrate cells. The initial steps of Sindbis virus infection involve attachment, penetration and uncoating. Two different pathways of infection have been proposed for Alphaviruses. One proposed mechanism involves receptor mediated virion endocytosis followed by membrane fusion triggered by endosome acidification. This virus-host membrane fusion model, well established by influenza virus, has been applied to other unrelated membrane-containing viruses including Alphaviruses. The other mechanism proposes direct penetration of the cell plasma membrane by the virus glycoproteins in the absence of membrane fusion. This alternate model is supported by both ultrastructural [Paredes, A.M., Ferreira, D., Horton, M., Saad, A., Tsuruta, H., Johnston, R., Klimstra, W., Ryman, K., Hernandez, R., Chiu, W., Brown, D.T., 2004. Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion. Virology 324(2), 373-386] and biochemical [Koschinski, A., Wengler, G., Wengler, G., and Repp, H., 2005. Rare earth ions block the ion pores generated by the class II fusion proteins of alphaviruses and allow analysis of the biological functions of these pores. J. Gen. Virol. 86(Pt. 12), 3311-3320] studies. We have examined the ability of Sindbis virus to infect Baby Hamster Kidney (BHK) cells at temperatures which block endocytosis. We have found that under these conditions Sindbis virus infects cells in a temperature- and time-dependent fashion.

Wang Gongbo [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695 (United States); Hernandez, Raquel [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695 (United States); Weninger, Keith [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Brown, Dennis T. [Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695 (United States)]. E-mail: dennis_brown@ncsu.edu

2007-06-05

224

A case of Ebola virus infection  

Microsoft Academic Search

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

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

1977-01-01

225

Molecular Investigations of an Outbreak of Parainfluenza Virus Type 3 and Respiratory Syncytial Virus Infections in a Hematology Unit  

Microsoft Academic Search

A large simultaneous outbreak of respiratory syncytial virus (RSV) and parainfluenza type 3 (PIV-3) infections occurred on an adult hematology unit. Implementation of enhanced infection control was compli- cated by cocirculation of the two different viruses, with prolonged viral shedding from infected patients, and placed great pressure on health care staff; of 27 infected hematopoietic stem cell transplant patients, 9

Hamid Jalal; David F. Bibby; Julie Bennett; Rebecca E. Sampson; Nicola S. Brink; Stephen MacKinnon; Richard S. Tedder; Katherine N. Ward

226

Pathogenesis of Lassa Fever Virus Infection: I. Susceptibility of Mice to Recombinant Lassa Gp/LCMV Chimeric Virus  

PubMed Central

Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8+ T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. PMID:23684417

Lee, Andrew M.; Cruite, Justin; Welch, Megan J.; Sullivan, Brian; Oldstone, Michael B.A.

2013-01-01

227

Eastern Equine Encephalomyelitis Virus Infection in a Horse from California  

PubMed Central

A yearling quarter horse, which was raised in southern California, received routine vaccinations for prevention of infection by Eastern equine encephalomyelitis virus (EEEV). One week later, severe neurologic signs developed, and the horse was humanely destroyed because vaccine-related encephalomyelitis was suspected. A final diagnosis of EEEV infection was established on the basis of acute onset of the neurologic signs, histopathologic and serologic testing, and isolation and molecular characterization of EEEV from brain tissue. The vaccine was extensively tested for viral inactivation. Nucleotide sequences from the vaccine and the virus isolated in the affected horse were also compared. In California, arboviral encephalomyelitides are rarely reported, and EEEV infection has not previously been documented. This report describes the occurrence of EEEV infection in the horse and the investigation to determine the source of infection, which was not definitively identified. PMID:11927026

Kinde, Hailu; Jay, Michele T.; Kramer, Laura D.; Green, Emily-Gene N.; Chiles, Robert E.; Ostlund, Eileen; Husted, Stan; Smith, Jonathan; Parker, Michael D.

2002-01-01

228

Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients  

PubMed Central

AIM: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico. METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson’s ?2 and/or Fisher’s exact test. RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio (OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIV-antiretroviral treatment with drugs that interfere with HBV replication (lamivudine, tenofovir or emtricitabine) (OR = 0.25; P = 0.05; 95%CI: 0.08-1.05). CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV. PMID:25309083

Alvarez-Munoz, Ma Teresa; Maldonado-Rodriguez, Angelica; Rojas-Montes, Othon; Torres-Ibarra, Rocio; Gutierrez-Escolano, Fernanda; Vazquez-Rosales, Guillermo; Gomez, Alejandro; Munoz, Onofre; Torres, Javier; Lira, Rosalia

2014-01-01

229

78 FR 63218 - Draft Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting...  

Federal Register 2010, 2011, 2012, 2013

...Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting...industry entitled ``Chronic Hepatitis C Virus Infection: Developing Direct-Acting...industry entitled ``Chronic Hepatitis C Virus Infection: Developing...

2013-10-23

230

Host Cell Cathepsins Potentiate Moloney Murine Leukemia Virus Infection  

Microsoft Academic Search

The roles of cellular proteases in Moloney murine leukemia virus (MLV) infection were investigated using MLV particles pseudotyped with vesicular stomatitis virus (VSV) G glycoprotein as a control for effects on core MLV particles versus effects specific to Moloney MLV envelope protein (Env). The broad-spectrum inhibitors cathepsin inhibitor III and E-64d gave comparable dose-dependent inhibition of Moloney MLV Env and

Pankaj Kumar; Deepa Nachagari; Carolyn Fields; John Franks; Lorraine M. Albritton

2007-01-01

231

Endocrinopathies in children infected with human immunodeficiency virus.  

PubMed

Endocrine changes (including adrenal insufficiency, disorders of growth and puberty, thyroid dysfunction, metabolic abnormalities and osteopenia) accompany human immunodeficiency virus (HIV) infection in pediatric patients. The cause of these changes is multifactorial and includes direct viral effects of HIV, and effects of antiretroviral therapy. These effects may be of particular importance in childhood given the critical developmental processes that occur during this time period and the likelihood of prolonged exposure to the virus and medications. PMID:25169569

Loomba-Albrecht, Lindsey A; Bregman, Thea; Chantry, Caroline J

2014-09-01

232

Human immunodeficiency viruses: SIV infection in wild gorillas  

Microsoft Academic Search

Chimpanzees (Pan troglodytes troglodytes) from west central Africa are recognized as the reservoir of simian immunodeficiency viruses (SIVcpzPtt) that have crossed at least twice to humans: this resulted in the AIDS pandemic (from human immunodeficiency virus HIV-1 group M) in one instance and infection of just a few individuals in Cameroon (by HIV-1 group N) in another. A third HIV-1

Fran van Heuverswyn; Yingying Li; Cecile Neel; Elizabeth Bailes; Brandon F. Keele; Weimin Liu; Severin Loul; Christelle Butel; Florian Liegeois; Yanga Bienvenue; Eitel Mpoudi Ngolle; Paul M. Sharp; George M. Shaw; Eric Delaporte; Beatrice H. Hahn; Martine Peeters

2006-01-01

233

Low risk of TT virus (TTV) infection in medical workers  

Microsoft Academic Search

The rate of infection with TT virus (TTV), a novel single-strand DNA virus was evaluated and the clinical and laboratory features in affected Japanese medical workers were analysed. TTV DNA was measured in 356 medical workers and in 150 age-matched controls using a semi-nested polymerase chain reaction. TTV DNA was detected in 62 of 356 medical workers (17·4%). There were

K. Nagano; Y. Fukuda; S. Yokozaki; K. Okada; K. Tanaka; K. Funahashi; T. Hayakawa

1999-01-01

234

Diagnosis of Oropouche virus infection by RT-nested-PCR.  

PubMed

Using the RT-PCR with primers that anneal to the 5' and the 3' extremities of the genome segments of bunyaviruses and internal primers that anneal to the S segment of Simbu serogroup viruses in a nested PCR it was possible to amplify the Oropouche virus (ORO) genome from the sera of three patients. These results show that this RT-nested-PCR is a useful tool for rapid diagnosis of Oropouche fever infections. PMID:11748670

Moreli, Marcos Lázaro; Aquino, Victor Hugo; Cruz, Ana Cecília R; Figueiredo, Luiz Tadeu M

2002-01-01

235

Cohabitation reaction-diffusion model for virus focal infections  

NASA Astrophysics Data System (ADS)

The propagation of virus infection fronts has been typically modeled using a set of classical (noncohabitation) reaction-diffusion equations for interacting species. However, for some single-species systems it has been recently shown that noncohabitation reaction-diffusion equations may lead to unrealistic descriptions. We argue that previous virus infection models also have this limitation, because they assume that a virion can simultaneously reproduce inside a cell and diffuse away from it. For this reason, we build a several-species cohabitation model that does not have this limitation. Furthermore, we perform a sensitivity analysis for the most relevant parameters of the model, and we compare the predicted infection speed with observed data for two different strains of the T7 virus.

Amor, Daniel R.; Fort, Joaquim

2014-12-01

236

Antibody landscapes after influenza virus infection or vaccination.  

PubMed

We introduce the antibody landscape, a method for the quantitative analysis of antibody-mediated immunity to antigenically variable pathogens, achieved by accounting for antigenic variation among pathogen strains. We generated antibody landscapes to study immune profiles covering 43 years of influenza A/H3N2 virus evolution for 69 individuals monitored for infection over 6 years and for 225 individuals pre- and postvaccination. Upon infection and vaccination, titers increased broadly, including previously encountered viruses far beyond the extent of cross-reactivity observed after a primary infection. We explored implications for vaccination and found that the use of an antigenically advanced virus had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters. These results indicate that preemptive vaccine updates may improve influenza vaccine efficacy in previously exposed individuals. PMID:25414313

Fonville, J M; Wilks, S H; James, S L; Fox, A; Ventresca, M; Aban, M; Xue, L; Jones, T C; Le, N M H; Pham, Q T; Tran, N D; Wong, Y; Mosterin, A; Katzelnick, L C; Labonte, D; Le, T T; van der Net, G; Skepner, E; Russell, C A; Kaplan, T D; Rimmelzwaan, G F; Masurel, N; de Jong, J C; Palache, A; Beyer, W E P; Le, Q M; Nguyen, T H; Wertheim, H F L; Hurt, A C; Osterhaus, A D M E; Barr, I G; Fouchier, R A M; Horby, P W; Smith, D J

2014-11-21

237

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

E-print Network

1y Z TA24S.7 8873 NO.1708 IS 8-1708 July 1992 THE TEXAS AGRICULTURAL EXPERIMENT STATION J. Charles Lee, Interim Director ? The Texas A&M University System ? College Station, Texas T~XAS A&M UNIVERSfTY Lf'BRARV Pathogenic Interactions... Between Sorghum Yellow Banding Virus and Other Viruses Infecting Sorghum M.P.K.J. Theu and R. W. Toler1 Abstract A pathogenic interaction between sorghum yel low banding virus (SYBV) and maize dwarf mosaic (MDMV-A) virus was proved. Inoculation...

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

1992-01-01

238

Infection of influenza virus neuraminidase-vaccinated mice with homologous influenza virus leads to strong protection against heterologous influenza viruses.  

PubMed

Vaccination is the best measure to prevent influenza pandemics. Here, we studied the protective effect against heterologous influenza viruses, including A/reassortant/NYMC X-179A (pH1N1), A/Chicken/Henan/12/2004 (H5N1), A/Chicken/Jiangsu/7/2002 (H9N2) and A/Guizhou/54/89×A/PR/8/34 (A/Guizhou-X) (H3N2), in mice first vaccinated with a DNA vaccine of haemagglutinin (HA) or neuraminidase (NA) of A/PR/8/34 (PR8) and then infected with the homologous virus. We showed that PR8 HA or NA vaccination both protected mice against a lethal dose of the homologous virus; PR8 HA or NA DNA vaccination and then PR8 infection in mice offered poor or excellent protection, respectively, against a second, heterologous influenza virus challenge. In addition, before the second heterologous influenza infection, the highest antibody level against nucleoprotein (NP) and matrix (M1 and M2) proteins was found in the PR8 NA-vaccinated and PR8-infected group. The level of induced cellular immunity against NP and M1 showed a trend consistent with that seen in antibody levels. However, PR8 HA+NA vaccination and then PR8 infection resulted in limited protection against heterologous influenza virus challenge. Results of the present study demonstrated that infection of the homologous influenza virus in mice already immunized with a NA vaccine could provide excellent protection against subsequent infection of a heterologous influenza virus. These findings suggested that NA, a major antigen of influenza virus, could be an important candidate antigen for universal influenza vaccines. PMID:25170051

He, Biao; Chang, Haiyan; Liu, Zhihua; Huang, Chaoyang; Liu, Xueying; Zheng, Dan; Fang, Fang; Sun, Bing; Chen, Ze

2014-12-01

239

Marburg virus infection detected in a common African bat.  

PubMed

Marburg and Ebola viruses can cause large hemorrhagic fever (HF) outbreaks with high case fatality (80-90%) in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus) in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus. PMID:17712412

Towner, Jonathan S; Pourrut, Xavier; Albariño, César G; Nkogue, Chimène Nze; Bird, Brian H; Grard, Gilda; Ksiazek, Thomas G; Gonzalez, Jean-Paul; Nichol, Stuart T; Leroy, Eric M

2007-01-01

240

Analysis of in vivo dynamics of influenza virus infection in mice using a GFP reporter virus  

E-print Network

of Pathology and Animal Health, School of Biotechnological Sciences, University of Naples "Federico II", 80137 on human and animal health. However, the dynamics of influenza virus infection and the cell types infected of Medicine, New York, NY 10029; c Emory Vaccine Center, Emory University, Atlanta, GA 30329; and d Department

241

Dicer is involved in protection against influenza A virus infection.  

PubMed

In mammals the interferon (IFN) system is a central innate antiviral defence mechanism, while the involvement of RNA interference (RNAi) in antiviral response against RNA viruses is uncertain. Here, we tested whether RNAi is involved in the antiviral response in mammalian cells. To investigate the role of RNAi in influenza A virus-infected cells in the absence of IFN, we used Vero cells that lack IFN-alpha and IFN-beta genes. Our results demonstrate that knockdown of a key RNAi component, Dicer, led to a modest increase of virus production and accelerated apoptosis of influenza A virus-infected cells. These effects were much weaker in the presence of IFN. The results also show that in both Vero cells and the IFN-producing alveolar epithelial A549 cell line influenza A virus targets Dicer at mRNA and protein levels. Thus, RNAi is involved in antiviral response, and Dicer is important for protection against influenza A virus infection. PMID:17872512

Matskevich, Alexey A; Moelling, Karin

2007-10-01

242

Neurobiology of simian and feline immunodeficiency virus infections.  

PubMed

Experimental and clinical evidence indicates that all lentiviruses of animals and humans are neurotropic and potentially neurovirulent. The prototypic animal lentiviruses, visna virus in sheep and caprine arthritis encephalitis virus in goats have been known for decades to induce neurologic disease. More recently, infection of the brain with the human immunodeficiency virus (HIV) has been linked to an associated encephalopathy and cognitive/motor complex. While the visna virus and caprine arthritis encephalitis virus are important models of neurologic disease they are not optimal for the study of HIV encephalitis because immune deficiency is only a minor component of the disease they induce. By contrast, the recently isolated lentiviruses from monkeys and cats, the simian and feline immunodeficiency viruses (SIV and FIV respectively), are profoundly immunosuppressive as well as neurotropic. SIV infection of the central nervous system of macaques now provides the best animal model for HIV infection of the human brain due to the close evolutionary relationship between monkeys and man, the genetic relatedness of their respective lentiviruses, and the similarities in the neuropathology. This chapter will compare and contrast the neurobiology of SIV and FIV with HIV. PMID:1669709

Lackner, A A; Dandekar, S; Gardner, M B

1991-04-01

243

Cowpea viruses: effect of single and mixed infections on symptomatology and virus concentration.  

PubMed

Natural multiple viral infections of cultivated cowpeas have been reported in Nigeria. In this study, three Nigerian commercial cowpea cultivars ("Olo 11", "Oloyin" and "White") and two lines from the IITA (IT86D- 719 and TVU 76) were mechanically inoculated with Cowpea aphid-borne mosaic virus (CABMV), Bean southern mosaic virus (SBMV) and Cowpea mottle virus (CMeV) singly, as well as in all possible combinations at 10, 20 and 30 days after planting (DAP). Samples of leaves or stems were collected at 10, 20 and 30 days after inoculation (DAI) and analyzed for relative virus concentration by Enzyme-Linked Immunosrbent Assay. All the cultivars and lines {CVS/L} were susceptible to the viruses but the commercial CVS showed more severe symptoms and had relatively higher viral concentration. In single virus infections, CABMV which induced the most severe symptoms had absorbance values (at 405 nm) of 0.11 to 0.46 while SBMV and CMeV which induced moderate symptoms had virus titre of 0.74 to 1.99 and 0.11 to 0.90 respectively. Plants inoculated 10 DAP had significantly higher virus concentration than those inoculated 30 DAP. In mixed infections involving CABMV (10 DAP) apical necrosis and death were observed in commercial cultivars "Olo 11" and "White". Enhancement of CMeV titers were observed in plants infected with CMeV + CABMV. Multiple viral infections of cowpeas may result in complete yield loss, hence, the availability of seeds of cultivars with a high level of multiple virus resistance is recommended as a means of control. PMID:17900355

Taiwo, Moni A; Kareem, Kehinde T; Nsa, Imade Y; D'A Hughes, Jackies

2007-01-01

244

Role of Phosphatidylserine Receptors in Enveloped Virus Infection  

PubMed Central

ABSTRACT We recently demonstrated that a soluble protein, Gas6, can facilitate viral entry by bridging viral envelope phosphatidylserine to Axl, a receptor tyrosine kinase expressed on target cells. The interaction between phosphatidylserine, Gas6, and Axl was originally shown to be a molecular mechanism through which phagocytes recognize phosphatidylserine exposed on dead cells. Since our initial report, several groups have confirmed that Axl/Gas6, as well as other phosphatidylserine receptors, facilitate entry of dengue, West Nile, and Ebola viruses. Virus binding by viral envelope phosphatidylserine is now a viral entry mechanism generalized to many families of viruses. In addition to Axl/Gas6, various molecules are known to recognize phosphatidylserine; however, the effects of these molecules on virus binding and entry have not been comprehensively evaluated and compared. In this study, we examined most of the known human phosphatidylserine-recognizing molecules, including MFG-E8, TIM-1, -3, and -4, CD300a, BAI1, and stabilin-1 and -2, for their abilities to facilitate virus binding and infection. Using pseudotyped lentiviral vectors, we found that a soluble phosphatidylserine-binding protein, MFG-E8, enhances transduction. Cell surface receptors TIM-1 and -4 also enhance virus binding/transduction. The extent of enhancement by these molecules varies, depending on the type of pseudotyping envelope proteins. Mutated MFG-E8, which binds viral envelope phosphatidylserine without bridging virus to cells, but, surprisingly, not annexin V, which has been used to block phagocytosis of dead cells by concealing phosphatidylserine, efficiently blocks these phosphatidylserine-dependent viral entry mechanisms. These results provide insight into understanding the role of viral envelope phosphatidylserine in viral infection. IMPORTANCE Envelope phosphatidylserine has previously been shown to be important for replication of various envelope viruses, but details of this mechanism(s) were unclear. We were the first to report that a bifunctional serum protein, Gas6, bridges envelope phosphatidylserine to a cell surface receptor, Axl. Recent studies demonstrated that many envelope viruses, including vaccinia, dengue, West Nile, and Ebola viruses, utilize Axl/Gas6 to facilitate their entry, suggesting that the phosphatidylserine-mediated viral entry mechanism can be shared by various enveloped viruses. In addition to Axl/Gas6, various molecules are known to recognize phosphatidylserine; however, the effects of these molecules on virus binding and entry have not been comprehensively evaluated and compared. In this study, we examined most human phosphatidylserine-recognizing molecules for their abilities to facilitate viral infection. The results provide insights into the role(s) of envelope phosphatidylserine in viral infection, which can be applicable to the development of novel antiviral reagents that block phosphatidylserine-mediated viral entry. PMID:24478428

Chen, Irvin S. Y.

2014-01-01

245

Wesselsbron virus infection in West African dwarf goats (Fouta djallon): virological and immunological studies.  

PubMed

West African dwarf goats were experimentally infected with Nigerian strain of Wesselsbron virus. Viraemia was detected in infected goats 2 days after infection and lasted for one day. A 100% mortality was observed among the infected animals; the virus was reisolated in mice from almost every tissue obtained from the bodies of infected goats. In addition, the infected goats developed complement-fixing and haemagglutination inhibiting antibodies to Wesselsbron virus. PMID:2565679

Baba, S S; Fagbami, A H; Omilabu, S A

1989-01-01

246

Insights into Head-Tailed Viruses Infecting Extremely Halophilic Archaea  

PubMed Central

Extremophilic archaea, both hyperthermophiles and halophiles, dominate in habitats where rather harsh conditions are encountered. Like all other organisms, archaeal cells are susceptible to viral infections, and to date, about 100 archaeal viruses have been described. Among them, there are extraordinary virion morphologies as well as the common head-tailed viruses. Although approximately half of the isolated archaeal viruses belong to the latter group, no three-dimensional virion structures of these head-tailed viruses are available. Thus, rigorous comparisons with bacteriophages are not yet warranted. In the present study, we determined the genome sequences of two of such viruses of halophiles and solved their capsid structures by cryo-electron microscopy and three-dimensional image reconstruction. We show that these viruses are inactivated, yet remain intact, at low salinity and that their infectivity is regained when high salinity is restored. This enabled us to determine their three-dimensional capsid structures at low salinity to a ?10-Å resolution. The genetic and structural data showed that both viruses belong to the same T-number class, but one of them has enlarged its capsid to accommodate a larger genome than typically associated with a T=7 capsid by inserting an additional protein into the capsid lattice. PMID:23283946

Pietila, Maija K.; Laurinmaki, Pasi; Russell, Daniel A.; Ko, Ching-Chung; Jacobs-Sera, Deborah; Butcher, Sarah J.

2013-01-01

247

Respiratory viruses in acute respiratory tract infections in Western India  

Microsoft Academic Search

Objective  To study the circulation pattern of respiratory viruses in out patients department (OPD) and hospitalized children with acute\\u000a respiratory tract infection.\\u000a \\u000a \\u000a \\u000a Methods  Nasopharyngeal aspirates were collected from 385 children with acute respiratory tract infections attending the OPD (n=199,\\u000a 51.7%) and admitted to pediatric ward (n=186, 43.2%). Specimens were screened for seven respiratory viruses by immunofluoresence\\u000a test (IFT) using Respiratory panel 1

Leena Ravindra Yeolekar; Rekha Gangadhar Damle; Aarti Nilesh Kamat; Madhukar Ramchandra Khude; Vijay Simha; Anand Neelkanth Pandit

2008-01-01

248

Ribavirin aerosol treatment of influenza B virus infection.  

PubMed

In a randomized, controlled study, ribavirin small-particle aerosol was found to be effective in the treatment of influenza B virus infection in a group of college students. Eleven treated patients experienced significantly more rapid defervescence, disappearance of systemic illness, and reduction of virus shedding in nasal secretions than ten control patients treated with a saline aerosol. Antibody response to infection was similar in both groups. The treatment was well tolerated, and hematologic and clinical chemical tests demonstrated no toxicity. The estimated dose of ribavirin aerosol retained was about 2 g in 39 hours of treatment during the first 60 hours in the hospital. PMID:6341642

McClung, H W; Knight, V; Gilbert, B E; Wilson, S Z; Quarles, J M; Divine, G W

1983-05-20

249

Ribavirin aerosol treatment of influenza B virus infection.  

PubMed

In a randomized, controlled study, ribavirin small particle aerosol was found to be effective in the treatment of influenza B virus infection in a group of college students. Eleven treated patients experienced significantly more rapid defervescence, disappearance of systemic illness, and reduction of virus shedding in nasal secretions than 10 control patients treated with a saline aerosol. Antibody response to infection was similar in both groups. The treatment was well tolerated and hematologic and clinical chemical tests revealed no toxicity. The estimated dose of ribavirin aerosol retained was about 2 g in 35.5 hr of treatment during the first 60 hr in the hospital. PMID:6093312

McClung, H W; Knight, V; Gilbert, B E; Wilson, S Z; Quarles, J M; Couch, R B; Divine, G W; Gordon, W H; Thurston, J M; Atmar, R L

1983-01-01

250

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

PubMed Central

Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. We found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), are completely restricted in their replication after entry into Lepidopteran cells. This restriction is overcome when cells are co-infected with vaccinia virus (VACV), a vertebrate DNA virus. Using RNAi screening, we show that Lepidopteran RNAi, Nuclear Factor-?B, and ubiquitin-proteasome pathways restrict RNA virus infection. Surprisingly, a highly conserved, uncharacterized VACV protein, A51R, can partially overcome this virus restriction. We show that A51R is also critical for VACV replication in vertebrate cells and for pathogenesis in mice. Interestingly, A51R colocalizes with, and stabilizes, host microtubules and also associates with ubiquitin. We show that A51R promotes viral protein stability, possibly by preventing ubiquitin-dependent targeting of viral proteins for destruction. Importantly, our studies reveal exciting new opportunities to study virus-host interactions in experimentally-tractable Lepidopteran systems. DOI: http://dx.doi.org/10.7554/eLife.02910.001 PMID:24966209

Gammon, Don B; Duraffour, Sophie; Rozelle, Daniel K; Hehnly, Heidi; Sharma, Rita; Sparks, Michael E; West, Cara C; Chen, Ying; Moresco, James J; Andrei, Graciela; Connor, John H; Conte, Darryl; Gundersen-Rindal, Dawn E; Marshall, William L; Yates, John R; Silverman, Neal; Mello, Craig C

2014-01-01

251

Mice with Different Susceptibility to Japanese Encephalitis Virus Infection Show Selective Neutralizing  

E-print Network

Mice with Different Susceptibility to Japanese Encephalitis Virus Infection Show Selective, Shanghai, China Abstract Background: Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus. Citation: Wang K, Deubel V (2011) Mice with Different Susceptibility to Japanese Encephalitis Virus

Boyer, Edmond

252

Tahyna virus genetics, infectivity, and immunogenicity in mice and monkeys  

PubMed Central

Background Tahyna virus (TAHV) is a human pathogen of the California encephalitis virus (CEV) serogroup (Bunyaviridae) endemic to Europe, Asia, and Africa. TAHV maintains an enzootic life cycle with several species of mosquito vectors and hares, rabbits, hedgehogs, and rodents serving as small mammal amplifying hosts. Human TAHV infection occurs in summer and early fall with symptoms of fever, headache, malaise, conjunctivitis, pharyngitis, and nausea. TAHV disease can progress to CNS involvement, although unlike related La Crosse virus (LACV), fatalities have not been reported. Human infections are frequent with neutralizing antibodies present in 60-80% of the elderly population in endemic areas. Results In order to determine the genomic sequence of wild-type TAHV, we chose three TAHV isolates collected over a 26-year period from mosquitoes. Here we present the first complete sequence of the TAHV S, M, and L segments. The three TAHV isolates maintained a highly conserved genome with both nucleotide and amino acid sequence identity greater than 99%. In order to determine the extent of genetic relatedness to other members of the CEV serogroup, we compared protein sequences of TAHV with LACV, Snowshoe Hare virus (SSHV), Jamestown Canyon virus (JCV), and Inkoo virus (INKV). By amino acid comparison, TAHV was most similar to SSHV followed by LACV, JCV, and INKV. The sequence of the GN protein is most conserved followed by L, N, GC, NSS, and NSM. In a weanling Swiss Webster mouse model, all three TAHV isolates were uniformly neurovirulent, but only one virus was neuroinvasive. In rhesus monkeys, the virus was highly immunogenic even in the absence of viremia. Cross neutralization studies utilizing monkey immune serum demonstrated that TAHV is antigenically distinct from North American viruses LACV and JCV. Conclusions Here we report the first complete sequence of TAHV and present genetic analysis of new-world viruses, LACV, SSHV, and JCV with old-world viruses, TAHV and INKV. Using immune serum generated in monkeys against TAHV, LACV, and JCV, we have demonstrated cross-neutralization within the CEV serogroup. Such cross reactivity may complicate virus identification, especially following JCV infection which elicited antibodies that cross neutralized both LACV and TAHV. These data also suggest that a single vaccine could generate a cross-neutralizing antibody response which may provide protection against CEV serogroup viruses from a wide geographic range. PMID:21435229

2011-01-01

253

Tranylcypromine Reduces Herpes Simplex Virus 1 Infection in Mice  

PubMed Central

Herpes simplex virus 1 (HSV-1) infects the majority of the human population and establishes latency by maintaining viral genomes in neurons of sensory ganglia. Latent virus can undergo reactivation to cause recurrent infection. Both primary and recurrent infections can cause devastating diseases, including encephalitis and corneal blindness. Acyclovir is used to treat patients, but virus resistance to acyclovir is frequently reported. Recent in vitro findings reveal that pretreatment of cells with tranylcypromine (TCP), a drug widely used in the clinic to treat neurological disorders, restrains HSV-1 gene transcription by inhibiting the histone-modifying enzyme lysine-specific demethylase 1. The present study was designed to examine the anti-HSV-1 efficacy of TCP in vivo because of the paucity of reports on this issue. Using the murine model, we found that TCP decreased the severity of wild-type-virus-induced encephalitis and corneal blindness, infection with the acyclovir-resistant (thymidine kinase-negative) HSV-1 mutant, and tissue viral loads. Additionally, TCP blocked in vivo viral reactivation in trigeminal ganglia. These results support the therapeutic potential of TCP for controlling HSV-1 infection. PMID:24590478

Yao, Hui-Wen; Lin, Pin-Hung; Shen, Fang-Hsiu; Perng, Guey-Chuen; Tung, Yuk-Ying

2014-01-01

254

Review: Occult hepatitis C virus infection: still remains a controversy.  

PubMed

Occult hepatitis C virus (HCV) infection is characterized by the presence of HCV RNA in the liver cells or peripheral blood mononuclear cells of the patients whose serum samples test negative for HCV RNA, with or without presence of HCV antibodies. The present study reviews the existing literature on the persistence of occult hepatitis C virus infection, with description of the clinical characteristics and methods for identification of occult hepatitis C. Occult hepatitis C virus infection was detected in patients with abnormal results of liver function tests of unknown origin, with HCV antibodies and HCV RNA negativity in serum, and also in patients with spontaneous or treatment-induced recovery from hepatitis C. The viral replication in the liver cells and/or peripheral blood mononuclear cells was present in all clinical presentations of occult hepatitis C. The peripheral blood mononuclear cells represent an extra-hepatic site of HCV replication. The reason why HCV RNA was not detectable in the serum of patients with occult hepatitis C, could be the low number of circulating viral particles not detectable by the diagnostic tests with low sensitivity. It is uncertain whether occult hepatitis C is a different clinical entity or just a form of chronic hepatitis C virus infection. Data accumulated over the last decade demonstrated that an effective approach to the diagnosis of HCV infection would be the implementation of more sensitive HCV RNA diagnostic assays, and also, examination of the presence of viral particles in the cells of the immune system. PMID:24895180

Vidimliski, Pavlina Dzekova; Nikolov, Igor; Geshkovska, Nadica Matevska; Dimovski, Aleksandar; Rostaing, Lionel; Sikole, Aleksandar

2014-09-01

255

Adaptive immune response during hepatitis C virus infection  

PubMed Central

Hepatitis C virus (HCV) infection affects about 170 million people worldwide and it is a major cause of liver cirrhosis and hepatocellular carcinoma. HCV is a hepatotropic non-cytopathic virus able to persist in a great percentage of infected hosts due to its ability to escape from the immune control. Liver damage and disease progression during HCV infection are driven by both viral and host factors. Specifically, adaptive immune response carries out an essential task in controlling non-cytopathic viruses because of its ability to recognize infected cells and to destroy them by cytopathic mechanisms and to eliminate the virus by non-cytolytic machinery. HCV is able to impair this response by several means such as developing escape mutations in neutralizing antibodies and in T cell receptor viral epitope recognition sites and inducing HCV-specific cytotoxic T cell anergy and deletion. To impair HCV-specific T cell reactivity, HCV affects effector T cell regulation by modulating T helper and Treg response and by impairing the balance between positive and negative co-stimulatory molecules and between pro- and anti-apoptotic proteins. In this review, the role of adaptive immune response in controlling HCV infection and the HCV mechanisms to evade this response are reviewed. PMID:24707125

Larrubia, Juan Ramon; Moreno-Cubero, Elia; Lokhande, Megha Uttam; Garcia-Garzon, Silvia; Lazaro, Alicia; Miquel, Joaquin; Perna, Cristian; Sanz-de-Villalobos, Eduardo

2014-01-01

256

Experimental rabies virus infection of big brown bats (Eptesicus fuscus).  

PubMed

A captive colony of adult Big Brown Bats (Eptesicus fuscus) was experimentally infected with a rabies virus (RABV) variant isolated from the salivary glands of a naturally infected Big Brown Bat and passaged once through murine neuroblastoma cell culture. Bats were divided into 11 groups, which were composed of one to three noninfected and one to three infected individuals each. Twenty of 38 animals were infected intramuscularly into both left and right masseter muscles; they received a total of 10(3.2) median mouse intracerebral lethal dose (MICLD50) of Big Brown Bat RABV variant. Experimental outcome after viral exposure was followed in the bats for 140 days postinoculation (PI). Of 20 infected bats, 16 developed clinical rabies, and the mean incubation period was 24 days (range: 13-52 days). Three infected bats never seroconverted and succumbed early to infection (13 days). Four infected bats that survived until the end of the experiment without any signs of disease maintained detectable antibody titers until the third month PI, peaking between days 13 and 43, and consequent drop-off below the threshold for detection occurred by day 140. Limited excretion of virus in saliva of infected bats during the clinical course of disease was observed in two individuals on days 13 and 15 PI (<24 hr prior to onset of clinical illness). No bat-to-bat transmission of RABV to noninfected bats was detected. PMID:18689646

Jackson, Felix R; Turmelle, Amy S; Farino, David M; Franka, Richard; McCracken, Gary F; Rupprecht, Charles E

2008-07-01

257

A defect in carbohydrate metabolism ameliorates symptom severity in virus-infected Arabidopsis thaliana .  

E-print Network

??Altered starch accumulation is a characteristic biochemical symptom of virus infection in plants. To assess its biological importance, infection of Arabidopsis thaliana with Turnip vein-clearing… (more)

Handford, Michael

2006-01-01

258

Protection from lethal infection is determined by innate immune responses in a mouse model of Ebola virus infection  

Microsoft Academic Search

A mouse-adapted strain of Ebola Zaire virus produces a fatal infection when BALB\\/cj mice are infected intraperitoneally (ip) but subcutaneous (sc) infection with the same virus fails to produce illness and confers long-term protection from lethal ip rechallenge. To identify immune correlates of protection in this model, we compared viral replication and cytokine\\/chemokine responses to Ebola virus in mice infected

Siddhartha Mahanty; Manisha Gupta; Jason Paragas; Mike Bray; Rafi Ahmed; Pierre E Rollin

2003-01-01

259

Antigen-Specific Expansion of Cytotoxic T Lymphocytes in Acute Measles Virus Infection  

Microsoft Academic Search

Skewing of the T-cell receptor repertoire of CD81 T cells has been shown in some persistent infections with viruses, such as human immunodeficiency virus, simian immunodeficiency virus, and Epstein-Barr virus. We have demonstrated that similar distortions also occur in nonpersistent measles virus infection. In addition, two of four children immunized with live, attenuated measles virus showed larger and more persistent

JUTHATHIP MONGKOLSAPAYA; ASSAN JAYE; MARGARET F. C. CALLAN; ALBERT F. MAGNUSEN; ANDREW J. MCMICHAEL

1999-01-01

260

Prevalence of Serious Bacterial Infections in Febrile Infants With Respiratory Syncytial Virus Infection  

Microsoft Academic Search

Objective. Neonates with fever gener- ally undergo a full, invasive septic evaluation to exclude serious bacterial infection (SBI). The risk of SBI in fe- brile older infants and children with documented respi- ratory syncytial virus (RSV) infection has been found to be negligible. The purpose of this study was to investi- gate the prevalence of SBI in febrile infants who

M. Olivia Titus; Seth W. Wright

2003-01-01

261

Experimental infection of vertebrates of the Pocomoke Cypress Swamp, Maryland with Keystone and Jamestown Canyon viruses.  

PubMed

Experimental studies were conducted to assess the susceptibility of white-tailed deer (Odocoileus virginianus), gray squirrels (Sciurus carolinensis), and cottontail rabbits (Sylvilagus floridanus) to Jamestown Canyon (JC) and/or Keystone (KEY) virus infection. Viremia occurred in 5 of 6 deer inoculated with JC virus; however, all deer developed KEY virus neutralizing antibody. Based on the observation that antibody elicited by primary infection of deer with either KEY or JC virus exhibited partial heterologous neutralization in vitro, cross-challenge experiments were performed in these animals. Keystone virus failed to infect deer 30 days post primary JC virus infection; however, deer became infected when challenged with KEY virus 80 days after the initial JC virus infection as indicated by a substantial increase in antibody titer. Similarly, JC virus failed to produce viremia in immune animals infected with KEY virus 80 days previously, although 2 of the 3 animals challenged had serological evidence of infection. Three field-collected cottontail rabbits with no evidence of KEY antibody were readily susceptible to KEY virus infection and developed viremias of 1-4 days' duration; rabbits with KEY virus antibody did not develop viremia upon KEY virus challenge. Eight antibody-negative field-collected gray squirrels became viremic following injection with KEY virus; however, a comparable group of squirrels did not become viremic when injected with JC virus. PMID:453437

Watts, D M; Tammariello, R F; Dalrymple, J M; Eldridge, B F; Russell, P K; Top, F H

1979-03-01

262

Therapy for respiratory tract infections caused by respiratory syncytial virus  

Microsoft Academic Search

Respiratory syncytial virus (RSV) is the most common viral cause of lower respiratory tract infection (LRTI) in infancy and\\u000a young children. No effective treatment for RSV lower respiratory tract infection (RSV-LRTI) exists. Ribavirin initially proved\\u000a to be an effective anti-viral drug for RSV-LTRI. However, subsequently performed trials could not reproduce these positive\\u000a results and, based on the current available evidence,

Job van Woensel; Jan Kimpen

2000-01-01

263

Bird movement predicts Buggy Creek virus infection in insect vectors.  

PubMed

Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host for the virus, between nesting colonies. The prevalence of BCRV in bugs was also directly correlated with the number of swallows immigrating into a site. Birds that move into a site are often transient individuals that may have more often encountered virus elsewhere. These results indicate that the magnitude and direction of daily bird movement in a local area can accurately predict transmission foci for this virus and provide rare quantitative evidence that birds can play a critical role in the dispersal of certain vector-borne viruses. PMID:17760513

Brown, Charles R; Brown, Mary Bomberger; Moore, Amy T; Komar, Nicholas

2007-01-01

264

The Role of IKK? in Venezuelan Equine Encephalitis Virus Infection  

PubMed Central

Venezuelan equine encephalitis virus (VEEV) belongs to the genus Alphavirus, family Togaviridae. VEEV infection is characterized by extensive inflammation and studies from other laboratories implicated an involvement of the NF-?B cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-?B complex was activated in cells infected with the TC-83 strain of VEEV. One upstream kinase that contributes to the phosphorylation of p65 is the IKK? component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-?B cascade in infected cells, had indicated that the IKK? component underwent macromolecular reorganization to form a novel low molecular weight form unique to infected cells. This prompted us to investigate if the IKK complex undergoes a comparable macromolecular reorganization in VEEV infection. Size-fractionated VEEV infected cell extracts indicated a macromolecular reorganization of IKK? in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKK? function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKK? function was required for the production of infectious progeny virus. A decrease in infectious viral particles and viral RNA copies was observed with inhibitor treatment in the attenuated and virulent strains of VEEV infection. In order to further validate the requirement of IKK? for VEEV replication, we over-expressed IKK? in cells and observed an increase in viral titers. In contrast, studies carried out using IKK??/? cells demonstrated a decrease in VEEV replication. In vivo studies demonstrated that inhibitor treatment of TC-83 infected mice increased their survival. Finally, proteomics studies have revealed that IKK? may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKK? protein may be critically involved in VEEV replication. PMID:24586253

Amaya, Moushimi; Voss, Kelsey; Sampey, Gavin; Senina, Svetlana; de la Fuente, Cynthia; Mueller, Claudius; Calvert, Valerie; Kehn-Hall, Kylene; Carpenter, Calvin; Kashanchi, Fatah; Bailey, Charles; Mogelsvang, Soren; Petricoin, Emanuel; Narayanan, Aarthi

2014-01-01

265

Respiratory Syncytial Virus Infection (RSV): Infection and Incidence  

MedlinePLUS

... lower respiratory tract infections (such as bronchiolitis and pneumonia). In children under 1 year of age, RSV is the ... infection by their second birthday. When infants and children are exposed to ... bronchiolitis or pneumonia, and 0.5% to 2% will require hospitalization. ...

266

Ganjam virus/Nairobi sheep disease virus induces a pro-inflammatory response in infected sheep  

PubMed Central

Partly due to climate change, and partly due to changes of human habitat occupation, the impact of tick-borne viruses is increasing. Nairobi sheep disease virus (NSDV) and Ganjam virus (GV) are two names for the same virus, which causes disease in sheep and goats and is currently known to be circulating in India and East Africa. The virus is transmitted by ixodid ticks and causes a severe hemorrhagic disease. We have developed a real-time PCR assay for the virus genome and validated it in a pilot study of the pathogenicity induced by two different isolates of NSDV/GV. One isolate was highly adapted to tissue culture, grew in most cell lines tested, and was essentially apathogenic in sheep. The second isolate appeared to be poorly adapted to cell culture and retained pathogenicity in sheep. The real-time PCR assay for virus easily detected 4 copies or less of the viral genome, and allowed a quantitative measure of the virus in whole blood. Measurement of the changes in cytokine mRNAs showed similar changes to those observed in humans infected by the closely related virus Crimean Congo hemorrhagic fever virus. PMID:23083136

2012-01-01

267

Impact of Chikungunya Virus Infection on Health Status and Quality of Life: A Retrospective Cohort Study  

E-print Network

Impact of Chikungunya Virus Infection on Health Status and Quality of Life: A Retrospective Cohort several months after Chikungunya virus (CHIKV) infection. Their frequency and their impact on quality. (2009) Impact of Chikungunya Virus Infection on Health Status and Quality of Life: A Retrospective

Paris-Sud XI, Université de

268

Truncated Particles Produced in Fish Surviving Infectious Hematopoietic Necrosis Virus Infection: Mediators of Persistence?  

Microsoft Academic Search

Infectious hematopoietic necrosis virus (IHNV) is a rhabdovirus that produces an acute, lethal infection in rainbow trout (Oncorhynchus mykiss). Fish that survive infection cease to produce detectable infectious virus at approximately 46 days after infection, yet there is evidence that survivor fish continue to harbor virus particles (B. S. Drolet, P. P. Chiou, J. Heidel, and J. C. Leong, J.

CAROL H. KIM; DINA M. DUMMER; PINWEN P. CHIOU; JO-ANN C. LEONG

1999-01-01

269

Social status in relation to Sindbis virus infection clearance in greenfinches  

Microsoft Academic Search

The ability to resist infections can differ between individuals of different social rank. This study investigates if the clearance of an avian virus infection (Sindbis virus) was related to the social status of greenfinches ( Carduelis chloris) and if infected birds would decline in social status. The results showed that virus clearance patterns were related to social status. Within groups

Karin M. Lindström

2004-01-01

270

Handwashing and cohorting in prevention of hospital acquired infections with respiratory syncytial virus  

Microsoft Academic Search

Hospital acquired infections with respiratory syncytial virus are a major problem. The virus is spread predominantly by infected nasal secretions and we investigated whether we could reduce its incidence by cohorting babies on each ward into designated areas and encouraging staff and parents to wash their hands. We examined the incidence of hospital acquired infection due to respiratory syncytial virus

D Isaacs; H Dickson; C OCallaghan; R Sheaves; A Winter; E R Moxon

1991-01-01

271

Species-Specific, Postentry Barriers to Primate Immunodeficiency Virus Infection  

PubMed Central

By using replication-defective vectors derived from human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus (SIVmac), and murine leukemia virus (MuLV), all of which were pseudotyped with the vesicular stomatitis virus (VSV) G glycoprotein, the efficiency of postentry, early infection events was examined in target cells of several mammalian species. Titers of HIV-1 vectors were significantly lower than those of SIVmac and MuLV vectors in most cell lines and primary cells from Old World monkeys. By contrast, most New World monkey cells exhibited much lower titers for the SIVmac vector compared with those of the HIV-1 vector. Prosimian cells were resistant to both HIV-1 and SIVmac vectors, although the MuLV vector was able to infect these cells. Cells from other mammalian species were roughly equivalent in susceptibility to the three vectors, with the exception of rabbit cells, which were specifically resistant to the HIV-1 vector. The level of HIV-1 vector expression was very low in transduced cells of rodent, rabbit, cow, and pig origin. Early postentry restriction of primate immunodeficiency virus infection exhibits patterns largely coincident with species borders and applies to diverse cell types within an individual host, suggesting the involvement of species-specific, widely expressed cellular factors. PMID:10559316

Hofmann, Wolfgang; Schubert, David; LaBonte, Jason; Munson, Linda; Gibson, Susan; Scammell, Jonathan; Ferrigno, Paul; Sodroski, Joseph

1999-01-01

272

Relationships between A(H1N1)pdm09 influenza infection and infections with other respiratory viruses  

PubMed Central

Background A(H1N1)pdm09, a new influenza pandemic virus emerged in 2009. The A(H1N1)pdm09 infection had several unique characteristics which included rapid transmissibility and high morbidity in obese individuals, pregnant women and individuals suffering from chronic diseases. Objectives To study the relationships between A(H1N1)pdm09 influenza infection and infections with other respiratory viruses such as respiratory syncytial virus (RSV), human metapneumo virus (hMPV), adenovirus and seasonal influenza. Methods Samples (nasopharyngeal swabs or aspirates) collected between 2007 until 2012 from patients of various ages that were hospitalized due to respiratory virus infections were analyzed for the presence of various respiratory viruses, using qRT-PCR. Results In 2009–2010, when the pandemic influenza A(H1N1)pdm09 first appeared, two major infection peaks were noted and individuals of various ages were infected. Following the decline of the A(H1N1)pdm09 virus infection, the percentages of patients infected with adenovirus and hMPV increased, while infection frequency with RSV B and with seasonal influenza virus decreased. Furthermore, RSV infections were delayed and very few percentages of patients were co-infected with more than one virus. Interestingly, the A(H1N1)pdm09 virus lost its dominancy when it reappeared in the winter of 2010–2011, and at this time, only the incidence of RSV infections was affected by the A(H1N1)pdm09 virus. Conclusions The A(H1N1)pdm09 virus had distinct effects on other respiratory viruses when it first appeared versus later, when it evolved from being a pandemic to a seasonal virus. PMID:24698156

Meningher, Tal; Hindiyeh, Musa; Regev, Liora; Sherbany, Hilda; Mendelson, Ella; Mandelboim, Michal

2014-01-01

273

Lethal Nipah Virus Infection Induces Rapid Overexpression of CXCL10  

PubMed Central

Nipah virus (NiV) is a recently emerged zoonotic Paramyxovirus that causes regular outbreaks in East Asia with mortality rate exceeding 75%. Major cellular targets of NiV infection are endothelial cells and neurons. To better understand virus-host interaction, we analyzed the transcriptome profile of NiV infection in primary human umbilical vein endothelial cells. We further assessed some of the obtained results by in vitro and in vivo methods in a hamster model and in brain samples from NiV-infected patients. We found that NiV infection strongly induces genes involved in interferon response in endothelial cells. Among the top ten upregulated genes, we identified the chemokine CXCL10 (interferon-induced protein 10, IP-10), an important chemoattractant involved in the generation of inflammatory immune response and neurotoxicity. In NiV-infected hamsters, which develop pathology similar to what is seen in humans, expression of CXCL10 mRNA was induced in different organs with kinetics that followed NiV replication. Finally, we showed intense staining for CXCL10 in the brain of patients who succumbed to lethal NiV infection during the outbreak in Malaysia, confirming induction of this chemokine in fatal human infections. This study sheds new light on NiV pathogenesis, indicating the role of CXCL10 during the course of infection and suggests that this chemokine may serve as a potential new marker for lethal NiV encephalitis. PMID:22393386

Mathieu, Cyrille; Guillaume, Vanessa; Sabine, Amelie; Ong, Kien Chai; Wong, Kum Thong; Legras-Lachuer, Catherine; Horvat, Branka

2012-01-01

274

Persistent Infection with Ebola Virus under Conditions of Partial Immunity  

PubMed Central

Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed to subcutaneous infection and had high viral antigen titers in tissues, whereas mice deficient in B cells or CD4 T cells cleared infection and survived, suggesting that CD8 T cells, independent of CD4 T cells and antibodies, are critical to protection against subcutaneous Ebola virus infection. B-cell-deficient mice that survived the primary subcutaneous infection (vaccinated mice) transiently depleted or not depleted of CD4 T cells also survived lethal intraperitoneal rechallenge for ?25 days. However, all vaccinated B-cell-deficient mice depleted of CD8 T cells had high viral antigen titers in tissues following intraperitoneal rechallenge and died within 6 days, suggesting that memory CD8 T cells by themselves can protect mice from early death. Surprisingly, vaccinated B-cell-deficient mice, after initially clearing the infection, were found to have viral antigens in tissues later (day 120 to 150 post-intraperitoneal infection). Furthermore, following intraperitoneal rechallenge, vaccinated B-cell-deficient mice that were transiently depleted of CD4 T cells had high levels of viral antigen in tissues earlier (days 50 to 70) than vaccinated undepleted mice. This demonstrates that under certain immunodeficiency conditions, Ebola virus can persist and that loss of primed CD4 T cells accelerates the course of persistent infections. These data show that CD8 T cells play an important role in protection against acute disease, while both CD4 T cells and antibodies are required for long-term protection, and they provide evidence of persistent infection by Ebola virus suggesting that under certain conditions of immunodeficiency a host can harbor virus for prolonged periods, potentially acting as a reservoir. PMID:14694127

Gupta, Manisha; Mahanty, Siddhartha; Greer, Patricia; Towner, Jonathan S.; Shieh, Wun-Ju; Zaki, Sherif R.; Ahmed, Rafi; Rollin, Pierre E.

2004-01-01

275

Spatial Analysis of Feline Immunodeficiency Virus Infection in Cougars  

PubMed Central

The cougar (Puma concolor) is a large predatory feline found widely in the Americas that is susceptible to feline immunodeficiency virus (FIV), a fast-evolving lentivirus found in wild feline species that is analogous to simian immunodeficiency viruses in wild primates and belongs to the same family of viruses as human immunodeficiency virus. FIV infection in cougars can lead to a weakened immune system that creates opportunities for other infecting agents. FIV prevalence and lineages have been studied previously in several areas in the western United States, but typically without spatially explicit statistical techniques. To describe the distribution of FIV in a sample of cougars located in the northern Rocky Mountain region of North America, we first used kernel density ratio estimation to map the log relative risk of FIV. The risk surface showed a significant cluster of FIV in northwestern Montana. We also used Bayesian cluster models for genetic data to investigate the spatial structure of the feline immunodeficiency virus with virus genetic sequence data. A result of the models was two spatially distinct FIV lineages that aligned considerably with an interstate highway in Montana. Our results suggest that the use of spatial information and models adds novel insight when investigating an infectious animal disease. The results also suggest that the influence of landscape features likely plays an important role in the spatiotemporal spread of an infectious disease within wildlife populations. PMID:21197421

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

2010-01-01

276

Spatial analysis of feline immunodeficiency virus infection in cougars.  

PubMed

The cougar (Puma concolor) is a large predatory feline found widely in the Americas that is susceptible to feline immunodeficiency virus (FIV), a fast-evolving lentivirus found in wild feline species that is analogous to simian immunodeficiency viruses in wild primates and belongs to the same family of viruses as human immunodeficiency virus. FIV infection in cougars can lead to a weakened immune system that creates opportunities for other infecting agents. FIV prevalence and lineages have been studied previously in several areas in the western United States, but typically without spatially explicit statistical techniques. To describe the distribution of FIV in a sample of cougars located in the northern Rocky Mountain region of North America, we first used kernel density ratio estimation to map the log relative risk of FIV. The risk surface showed a significant cluster of FIV in northwestern Montana. We also used Bayesian cluster models for genetic data to investigate the spatial structure of the feline immunodeficiency virus with virus genetic sequence data. A result of the models was two spatially distinct FIV lineages that aligned considerably with an interstate highway in Montana. Our results suggest that the use of spatial information and models adds novel insight when investigating an infectious animal disease. The results also suggest that the influence of landscape features likely plays an important role in the spatiotemporal spread of an infectious disease within wildlife populations. PMID:21197421

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

2010-07-01

277

Cellular immune response in genital herpes simplex virus infection.  

PubMed

We studied the relations between the cellular immune response, pre-existing complement-fixing antibody and virus type with duration of virus excretion in genital herpes simplex virus (HSV) infection. Thirty-six patients (seven with HSV-1 and 29 with HSV-2) with genital herpes underwent serologic testing, sequential viral cultures and weekly determination of lymphocyte-transformation stimulation index with inactivated HSV antic n. The duration of virus excretion was shortest in those with pre-existing complement-fixing antibody, was unrelated to virus type, and was inversely correlated with the magnitude of the mean peak stimulation index (r = -0.69, P less than 0.001). Prolonged virus excretion occurred in patients with a delayed and diminished peak index. Recurrent episodes had a higher peak index (29.4 compared to 14.5) (P less than 0.02), an earlier development of the peak during recurrences (9.1 vs. 25.8 days) (P less than 0.01) and a briefer duration of viral shedding than initial episodes. Thus, the temporal course and magnitude of the stimulation index correlate with and may determine the duration of genital HSV infection. PMID:211414

Corey, L; Reeves, W C; Holmes, K K

1978-11-01

278

Epidemic of Sexually Transmitted Hepatitis C Virus Infection Among HIV-Infected Men  

Microsoft Academic Search

Sexual contact is thought to be an inefficient mode of hepatitis C virus (HCV) transmission. However, reports of sexually\\u000a transmitted HCV infection among HIV-infected men who have sex with men (MSM) began to appear in 2004. The patients were of\\u000a early middle age with well-controlled HIV infection, participated in unprotected receptive sex, and frequently used noninjection\\u000a recreational drugs. Molecular studies

Daniel Seth Fierer

2010-01-01

279

Persistent Infection of Cells in Culture by Measles Virus III. Comparison of Virus-Specific RNA Synthesized in Primary and Persistent Infection in HeLa Cells  

PubMed Central

The pattern of actinomycin D-resistant RNA synthesis was examined during primary infection of HeLa cells by virulent Edmonston measles virus and in two HeLa clones persistently infected by the same strain of virus. One of these clones, K11, produces infectious virus of low virulence for HeLa cells, and the other, K11A-HG-1, has thus far failed to yield infectious virus. The patterns of virus-specific RNA synthesized in these three types of infection are qualitatively similar to each other and to the patterns of virus-specific RNA synthesis in other paramyxovirus infections. There were, however, quantitative differences. In addition, virions of the virulent Edmonston strain of measles virus were found to contain high-molecular-weight RNA with a sedimentation constant identical to that of Newcastle disease virus. PMID:4576519

Winston, Stuart H.; Rustigian, Robert; Bratt, Michael A.

1973-01-01

280

Bovine Viral Diarrhea Virus Quasispecies during Persistent Infection  

Microsoft Academic Search

Analysis of viral genome sequences from two calves persistently infected with bovine viral diarrhea virus revealed a quasispecies distribution. The sequences encoding the glycoprotein E2 were variable, translating to a number of changes in predicted amino acid sequences. The NS3 region was found to be highly conserved in both animals. The number of E2 clones showing variant amino acids increased

Margaret E. Collins; Moira Desport; Joe Brownlie

1999-01-01

281

Depression after Infection with West Nile Virus1  

PubMed Central

Previous reports have noted depression after West Nile virus (WNV) infection. We further measured this outcome and found that 31% of patients reported new-onset depression and 75% of these had Center for Epidemiologic Studies Depression scores indicative of mild-to-severe depression. Physicians should be aware of neuropsychiatric consequences of WNV in patients. PMID:17552106

Resnick, Melissa; Miller, Vicki

2007-01-01

282

Sin Nombre Virus Infection in Field Workers, Colorado, USA  

PubMed Central

We report 2 cases of Sin Nombre virus (SNV) infection in field workers, possibly contracted through rodent bites. Screening for antibodies to SNV in rodents trapped in 2 seasons showed that 9.77% were seropositive. Quantitative real-time PCR showed that 2 of 79 deer mice had detectable titers of SNV RNA. PMID:20113567

Torres-Pérez, Fernando; Wilson, Linda; Collinge, Sharon K.; Harmon, Heath; Ray, Chris; Medina, Rafael A.

2010-01-01

283

Hepatitis E Virus Infection in Sheltered Homeless Persons, France  

PubMed Central

To determine the prevalence of hepatitis E virus (HEV) infection among sheltered homeless persons in Marseille, France, we retrospectively tested 490 such persons. A total of 11.6% had immunoglobulin (Ig) G and 2.5% had IgM against HEV; 1 person had HEV genotype 3f. Injection drug use was associated with IgG against HEV. PMID:21029538

Kaba, Mamadou; Brouqui, Philippe; Richet, Herve; Badiaga, Sekene; Gallian, Pierre; Raoult, Didier

2010-01-01

284

Outbreak of West Nile virus infection, Volgograd Region, Russia, 1999.  

PubMed Central

From July 25 to October 1, 1999, 826 patients were admitted to Volgograd Region, Russia, hospitals with acute aseptic meningoencephalitis, meningitis, or fever consistent with arboviral infection. Of 84 cases of meningoencephalitis, 40 were fatal. Fourteen brain specimens were positive in reverse transcriptase-polymerase chain reaction assays, confirming the presence of West Nile/Kunjin virus. PMID:11266303

Platonov, A. E.; Shipulin, G. A.; Shipulina, O. Y.; Tyutyunnik, E. N.; Frolochkina, T. I.; Lanciotti, R. S.; Yazyshina, S.; Platonova, O. V.; Obukhov, I. L.; Zhukov, A. N.; Vengerov, Y. Y.; Pokrovskii, V. I.

2001-01-01

285

Measles Virus Infections of the Central Nervous System  

Microsoft Academic Search

Summary Acute measles is a classic infectious disease of childhood with worldwide distribution. Its causative agent, measles virus (MV), is an efficent pathogen, persisting in nature in populations large enough to support it, even though it is able to cause an acute infection in any individual only once in his lifetime. The characteristic clinical hallmarks of measles, fever and rash,

Uwe G. Liebert

1997-01-01

286

[Epub ahead of print] Postexposure Treatment of Marburg Virus Infection  

E-print Network

Rhesus monkeys are protected from disease when a recombinant vesicular stomatitis virus–based vaccine is administered 20–30 min after infection with Marburg virus. We protected 5/6 monkeys when this vaccine was given 24 h after challenge; 2/6 animals were protected when the vaccine was administered 48 h postinfection. The filoviruses, Marburg virus (MBGV) and Ebola virus (EBOV), have been associated with sporadic episodes of hemorrhagic fever (HF) in Central Africa that produce severe disease and high mortality rates among infected patients (1). MBGV and EBOV are also considered potential biological weapons. No approved active or passive therapeutic modalities exist for filovirus infections. Although much progress has been made in developing preventive vaccines that can protect nonhuman primates against lethal challenge with MBGV and EBOV, advances in development of postexposure interventions against the filoviruses have not kept pace. Some degree of success has been achieved by using strategies that mitigate the coagulation abnormalities characterizing filoviral infection (2,3). Also, new postexposure treatment approaches, based on small interfering RNA (4) and antisense oligomers (5,6), have shown Page 1 of 8promising results in rodent models, but no reports have been published of evaluations of either

Thomas W. Geisbert; Lisa E. Hensley; Joan B. Geisbert; Anders Leung; Joshua C. Johnson; Allen Grolla; Heinz Feldmann

287

Cystic encephalomalacia and intrauterine herpes simplex virus infection  

Microsoft Academic Search

Cystic encephalomalacia occurred in two preterm infants who had proven intrauterine herpes simplex virus type 2 infection. Calcification was evident in the basal ganglia. Follow-up scans indicated that the cysts had resolved over a period of two months in one infant, while in the case of the other, the cysts became progressively larger with significant ventricular dilatation developing. While cystic

P. H. Gray; D. I. Tudehope; J. Masel

1992-01-01

288

Hsp70 Protein Positively Regulates Rabies Virus Infection  

PubMed Central

The Hsp70 chaperone plays a central role in multiple processes within cells, including protein translation, folding, intracellular trafficking, and degradation. This protein is implicated in the replication of numerous viruses. We have shown that rabies virus infection induced the cellular expression of Hsp70, which accumulated in Negri body-like structures, where viral transcription and replication take place. In addition, Hsp70 is present in both nucleocapsids purified from infected cells and in purified virions. Hsp70 has been shown to interact with the nucleoprotein N. The downregulation of Hsp70, using specific chaperone inhibitors, such as quercetin or RNA interference, resulted in a significant decrease of the amount of viral mRNAs, viral proteins, and virus particles. These results indicate that Hsp70 has a proviral function during rabies virus infection and suggest that Hsp70 is involved in at least one stage(s) of the viral life cycle, such as viral transcription, translation, and/or production. The mechanism by which Hsp70 controls viral infection will be discussed. PMID:22345440

Lahaye, Xavier; Vidy, Aurore; Fouquet, Baptiste

2012-01-01

289

Zinc status in human immunodeficiency virus infection  

SciTech Connect

Plasma zinc and copper concentrations, erythrocyte zinc concentration, copper-zinc superoxide dismutase activity and urinary zinc concentrations were determined for control subjects and individuals with AIDS, ARC, or asymptomatic HIV infection. Significant differences among the population groups were not noted for the above parameters with the exception of plasma copper which was higher in the AIDS group than in other patient groups. These results do not support the idea that zinc deficiency is a common contributory factor of HIV infectivity or clinical expression, nor that HIV infection induces a zinc deficiency.

Walter, R.M. Jr.; Oster, M.H.; Lee, T.J.; Flynn, N.; Keen, C.L. (Univ. of California, Davis (USA))

1990-01-01

290

A virus-like particle vaccine for epidemic Chikungunya virus protects nonhuman primates against infection.  

PubMed

Chikungunya virus (CHIKV) has infected millions of people in Africa, Europe and Asia since this alphavirus reemerged from Kenya in 2004. The severity of the disease and the spread of this epidemic virus present a serious public health threat in the absence of vaccines or antiviral therapies. Here, we describe a new vaccine that protects against CHIKV infection of nonhuman primates. We show that selective expression of viral structural proteins gives rise to virus-like particles (VLPs) in vitro that resemble replication-competent alphaviruses. Immunization with these VLPs elicited neutralizing antibodies against envelope proteins from alternative CHIKV strains. Monkeys immunized with VLPs produced high-titer neutralizing antibodies that protected against viremia after high-dose challenge. We transferred these antibodies into immunodeficient mice, where they protected against subsequent lethal CHIKV challenge, indicating a humoral mechanism of protection. Immunization with alphavirus VLP vaccines represents a strategy to contain the spread of CHIKV and related pathogenic viruses in humans. PMID:20111039

Akahata, Wataru; Yang, Zhi-Yong; Andersen, Hanne; Sun, Siyang; Holdaway, Heather A; Kong, Wing-Pui; Lewis, Mark G; Higgs, Stephen; Rossmann, Michael G; Rao, Srinivas; Nabel, Gary J

2010-03-01

291

Filarial infections increase susceptibility to human immunodeficiency virus infection in peripheral blood mononuclear cells in vitro.  

PubMed

Because helminth infections and human immunodeficiency virus (HIV) coexist in areas where the spread of AIDS is most dramatic, their in vitro interaction was explored. Cryopreserved peripheral blood mononuclear cells (PBMC) from patients with filarial infections (n=24) and from unexposed control subjects (n=12) were depleted of CD8 T cells and were infected with macrophage (M)- and T cell-tropic viruses. A trend toward increased HIV replication in PBMC from filaria-infected patients was observed. Furthermore, PBMC from 6 filaria-infected patients before antifilarial treatment were significantly more susceptible to replication of M-tropic virus than their posttreatment PBMC (P=.03). No intergroup differences were found in the surface expression of HLA-DR, CD25, CCR5, CXCR4, CCR3 on CD4 T cells, or monocytes before infection. PBMC from filaria-infected patients produced less RANTES (P=.02) but more intracellular interleukin-4 than those of control subjects. Thus, PBMC from persons with filarial infections appear to have enhanced susceptibility to HIV-1 infection mediated by an undetermined mechanism. PMID:11069260

Gopinath, R; Ostrowski, M; Justement, S J; Fauci, A S; Nutman, T B

2000-12-01

292

Occurrence of latent virus infection in visually-rated cowpea (Vigna unguiculata L. Walp) seedlings  

Microsoft Academic Search

The presence of latent infections was studied in five cowpeas varieties. Seeds of the varieties were planted and the seedlings inoculated with antigens from Cucumber mosaic virus (CMV) genus Cucumovirus, Bean common mosaic virus (BCMV) genus Potyvirus (Blackeye cowpea mosaic virus strain), Southern bean mosaic virus (SBMV) genus Sobemovirus and Cowpea mottle virus (CPMoV) genus Carmovirus seven days after planting.

Olusola O. Odedara; Jacqueline D A. Hughes; Babajide O. Odu

2009-01-01

293

Synchronized Infection of Cell Cultures by Magnetically Controlled Virus  

PubMed Central

To override the diffusion-limited adsorption step of viral infection, we magnetically synchronized cell attachment. Human immunodeficiency virus type 1-based lentivirus preparations were rendered magnetically reactive by association with magnetite nanoparticles, 50 nm in diameter. Application of a magnetic field resulted in immediate redistribution of the viral inoculum to the cell-associated state and completion of the productive adsorption process within 1 min. Independent of adsorption time, viral concentration, and diffusion rate, infection subsequently progressed by the receptor-mediated entry mechanism. Synchronization of this rate-limiting step of infection may now be applied to analyze isolated events in the viral replication sequence. PMID:15596857

Haim, Hillel; Steiner, Israel; Panet, Amos

2005-01-01

294

Agrobacterium-mediated infectivity of cloned digitaria streak virus DNA.  

PubMed

A monomeric clone of double-stranded DNA synthesized in vitro DNA of the geminivirus Digitaria streak (DSV) was subcloned as a tandem dimeric unit into a binary vector of Agrobacterium tumefaciens, creating a plasmid pDS2. Inoculation of digitaria sanguinalis with A. tumefaciens carrying pDS2 resulted in viral infection. The symptoms, virus particles, and DNA forms obtained were indistinguishable from those of a natural DSV infection of D. sanguinalis. Inoculations have also induced infections in Zea mays and Avena sativa. The sequence of the Agrobacterium-mediated infectious clone of DSV has been determined. PMID:3341112

Donson, J; Gunn, H V; Woolston, C J; Pinner, M S; Boulton, M I; Mullineaux, P M; Davies, J W

1988-01-01

295

Recent progress in antiviral chemotherapy for respiratory syncytial virus infections.  

PubMed

The recent progress in antiviral chemotherapy against respiratory syncytial virus (RSV) infections was reviewed. RSV infections among high risk individuals, such as premature babies, infants with congenital disease of cardiopulmonary system or immune system and the aged, hospitalised patients with immunosuppressed status are threatened, with high mortality rates and thus need anti-viral chemotherapy. Clinical efficacy of ribavirin and humanized monoclonal antibody (mAb) against RSV infections as well as experimental reports of novel anti-RSV compounds under investigation such as membrane fusion inhibitors were introduced. PMID:11060673

Shigeta, S

2000-02-01

296

Interactions between human immunodeficiency virus-1, hepatitis delta virus and hepatitis B virus infections in 260 chronic carriers of hepatitis B virus.  

PubMed

To evaluate the factors determining the severity of chronic hepatitis B virus infection and the interactions of human immunodeficiency virus and hepatitis delta virus infections, we retrospectively analyzed 260 patients, 146 of whom were followed for a mean of 31.4 +/- 1.8 mo. Human immunodeficiency virus, hepatitis B virus, and hepatitis delta virus status and aminotransferase activities, histological activity index, alcohol consumption and the prevalence of cirrhosis were investigated. The patients included 54 homosexuals, 19 parenteral drug abusers and 187 subjects with other or unidentified risk factors for exposure to hepatitis B virus. Thirty-five patients (13%) were positive for antibody to human immunodeficiency virus; 27 were homosexual and 8 were drug abusers. The mean aminotransferase activities, histological activity index and the prevalence of cirrhosis were similar in the human immunodeficiency virus-positive and human immunodeficiency virus-negative subgroups. Actuarial survival was significantly lower in the human immunodeficiency virus-negative subgroups. Actuarial survival was significantly lower in the human immunodeficiency virus-positive group than in the human immunodeficiency virus-negative subjects (p = 0.004); the cause of death was clearly related to liver failure in four of the five human immunodeficiency virus-positive patients and two of the six human immunodeficiency virus-negative subjects who died. To evaluate the factors determining the severity of liver disease, we compared homogeneous subgroups of subjects. Among the homosexual patients, the prevalence of HBeAg and hepatitis B virus DNA, aminotransferase activities and the histological activity index did not differ according to human immunodeficiency virus antibody status.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1551633

Housset, C; Pol, S; Carnot, F; Dubois, F; Nalpas, B; Housset, B; Berthelot, P; Brechot, C

1992-04-01

297

Structural aberrations in T-even bacteriophage. IX. Effect of mixed infection on the production of giant bacteriophage.  

PubMed Central

To date, the production of T-even bacteriophage with giant heads has been achieved in two ways: (i) by use of canavanine-arginine treatment of Escherichia coli B cultures infected by wild-type bacteriophage (Cummings and Bolin, Bacteriol. Rev. 40:314-359, 1976; Cummings et al., Virology 54:245-261, 1973), which give a size distribution of giants that is phage specific (Cummings et al., Virology 54:245-261, 1973); and (ii) by infection with certain missense mutants of T4D gene 23 (Doermann et al., J. Virol. 12:374-385, 1973; ICN-UCLA Symposium on Molecular Biology, p. 243-285, 1973) or temperature-sensitive mutants of gene 24 (Aebi et al., J. Supramol. Struct. 2:253-275, 1974; Biljenga et al., J. Mol. Biol. 103:469-498, 1976). We now report the effect of mixed infection with several mutants of T4D on both the production and the size of giant bacteriophage. We found that gene 24 mutant is a critical partner for the production of giants. Infection using T4.24 mutants together with either T4.23 mutants, T4B+ or T6+ led to the formation of giants with heads 10- to 14-fold longer than normal-length heads. Infection with amber 24-bypass 24 double mutants of T4D led to the production of giants when gene 23 mutant was used to co-infect. Addition of canavanine to the co-infected cultures could alter the size distribution of giants, depending on which phage were used to coinfect. Gene 22 mutants had a modifying effect on these results. In the absence of canavanine co-infection with gene 22 mutants prevented the production of giants, and in the presence of canavanine giants of 1.5 to 5 head lengths were found. We have interpreted these results to mean that critical concentrations of gene products 22, 23, and 24 interact to control head length in T-even bacteriophage. Images PMID:864836

Cummings, D J; Chapman, V A; DeLong, S S

1977-01-01

298

Cutaneous Co-infected Cytomegalovirus and Herpes Simplex Virus Perigenital Ulcers in Human Immunodeficiency Virus Patients.  

PubMed

There is uncertainty regarding the pathogenic nature of cytomegalovirus in cutaneous lesions co-infected with herpes simplex virus. It is widely believed that herpes simplex virus is the main pathogenic factor in such lesions and that cytomegalovirus plays little if any role. There are, however, isolated case reports that describe cytomegalovirus as an important driving pathogen in such lesions. The authors present two human immunodeficiency virus patients who have cytomegalovirus and herpes simplex virus co-infected perigenital ulcers, one of whom improved on valacyclovir, while the other, who was already on valacyclovir for chronic herpes simplex virus suppression, showed no improvement with a single dose of cidofovir. He only showed rapid improvement when treated with valganciclovir. The latter patient underscores the viewpoint that at least in some cases, cytomegalovirus may be an important driving force behind the formation of such lesions. The authors therefore recommend that clinicians be aware of the possible pathogenic role of cytomegalovirus in these ulcers, and, in nonhealing ulcers, use anti-cytomegalovirus agents to prevent the onset of systemic disease. These results warrant further study of the pathogenesis of cytomegalovirus in co-infected herpes simplex virus ulcers. PMID:24155993

Schoenfeld, Jason; Cannon, Sarah; Cam, Kristin; Keller, Matthew

2013-10-01

299

Bovine viral diarrhea virus infection induces autophagy in MDBK cells.  

PubMed

Bovine viral diarrhea virus (BVDV) is an enveloped, positive-sense, single-stranded RNA virus that belongs to the genus Pestivirus (Flaviviridae). The signaling pathways and levels of signaling molecules are altered in Madin-Darby Bovine Kidney (MDBK) cells infected with BVDV. Autophagy is a conservative biological degradation pathway that mainly eliminates and degrades damaged or superfluous organelles and macromolecular complexes for intracellular recycling in eukaryotic cells. Autophagy can also be induced as an effective response to maintain cellular homeostasis in response to different stresses, such as nutrient or growth factor deprivation, hypoxia, reactive oxygen species exposure and pathogen infection. However, the effects of BVDV infection on autophagy in MDBK cells remain unclear. Therefore, we performed an analysis of autophagic activity after BVDV NADL infection using real-time PCR, electron microscopy, laser confocal microscopy, and Western blotting analysis. The results demonstrated that BVDV NADL infection increased autophagic activity and significantly elevated the expression levels of the autophagy-related genes Beclin1 and ATG14 in MDBK cells. However, the knockdown of Beclin1 and ATG14 by RNA interference (RNAi) did not affect BVDV NADL infection-related autophagic activity. These findings provided a novel perspective to elaborate the effects of viral infection on the host cells. PMID:24972811

Fu, Qiang; Shi, Huijun; Ren, Yan; Guo, Fei; Ni, Wei; Qiao, Jun; Wang, Pengyan; Zhang, Hui; Chen, Chuangfu

2014-07-01

300

Role of macrophages and monocytes in hepatitis C virus infections  

PubMed Central

A number of studies conducted over many years have shown that hepatitis C virus (HCV) can infect a variety of cell types. In vivo infection of monocytes, macrophages, and dendritic cells by HCV has been frequently shown by a number of researchers. These studies have demonstrated replication of HCV by detecting the presence of both negative genomic strands and a variety of non-structural HCV proteins in infected cells. In addition, analyses of genome sequences have also shown that different cell types can harbor different HCV variants. Investigators have also done preliminary studies of which cellular genes are affected by HCV infection, but there have not yet been a sufficient number of these studies to understand the effects of infection on these cells. Analyses of in vitro HCV replication have shown that monocytes, macrophages and dendritic cells can be infected by HCV from patient sera or plasma. These studies suggest that entry and cellular locations may vary between different cell types. Some studies suggest that macrophages may preferentially allow HCV genotype 1 to replicate, but macrophages do not appear to select particular hypervariable regions. Overall, these studies agree with a model where monocytes and macrophages act as an amplification system, in which these cells are infected and show few cytopathic effects, but continuously produce HCV. This allows them to produce virus over an extended time and allows its spread to other cell types. PMID:24659871

Revie, Dennis; Salahuddin, Syed Zaki

2014-01-01

301

Endemic Lagos bat virus infection in Eidolon helvum.  

PubMed

Phylogenetic analyses suggest lyssaviruses, including Rabies virus, originated from bats. However, the role of bats in the maintenance, transmission and evolution of lyssaviruses is poorly understood. A number of genetically diverse lyssaviruses are present in Africa, including Lagos bat virus (LBV). A high seroprevalence of antibodies against LBV was detected in Eidolon helvum bats. Longitudinal seroprevalence and age-specific seroprevalence data were analysed and capture-mark-recapture (CMR) analysis used to follow 98 bats over 18 months. These data demonstrate endemic infection, with evidence of horizontal transmission, and force of infection was estimated for differing age categories. The CMR analysis found survival probabilities of seronegative and seropositive bats were not significantly different. The lack of increased mortality in seropositive animals suggests infection is not causing disease after extended incubation. These key findings point towards acute transmission of bat lyssaviruses in adapted bat hosts that occurs at a far higher rate than the occurrence of disease. PMID:22370126

Hayman, D T S; Fooks, A R; Rowcliffe, J M; McCrea, R; Restif, O; Baker, K S; Horton, D L; Suu-Ire, R; Cunningham, A A; Wood, J L N

2012-12-01

302

CD81 and Hepatitis C Virus (HCV) Infection  

PubMed Central

Hepatitis C Virus (HCV) infection is a global public health problem affecting over 160 million individuals worldwide. Its symptoms include chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped RNA virus mainly targeting liver cells and for which the initiation of infection occurs through a complex multistep process involving a series of specific cellular entry factors. This process is likely mediated through the formation of a tightly orchestrated complex of HCV entry factors at the plasma membrane. Among HCV entry factors, the tetraspanin CD81 is one of the best characterized and it is undoubtedly a key player in the HCV lifecycle. In this review, we detail the current knowledge on the involvement of CD81 in the HCV lifecycle, as well as in the immune response to HCV infection. PMID:24509809

Feneant, Lucie; Levy, Shoshana; Cocquerel, Laurence

2014-01-01

303

CD81 and hepatitis C virus (HCV) infection.  

PubMed

Hepatitis C Virus (HCV) infection is a global public health problem affecting over 160 million individuals worldwide. Its symptoms include chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped RNA virus mainly targeting liver cells and for which the initiation of infection occurs through a complex multistep process involving a series of specific cellular entry factors. This process is likely mediated through the formation of a tightly orchestrated complex of HCV entry factors at the plasma membrane. Among HCV entry factors, the tetraspanin CD81 is one of the best characterized and it is undoubtedly a key player in the HCV lifecycle. In this review, we detail the current knowledge on the involvement of CD81 in the HCV lifecycle, as well as in the immune response to HCV infection. PMID:24509809

Fénéant, Lucie; Levy, Shoshana; Cocquerel, Laurence

2014-02-01

304

Hepatitis E virus infections in humans and animals.  

PubMed

Hepatitis E has traditionally been considered an endemic disease of developing countries. It generally spreads through contaminated water. However, seroprevalence studies have shown that hepatitis E virus (HEV) infections are not uncommon in industrialized countries. In addition, the number of autochthonous hepatitis E cases in these countries is increasing. Most HEV infections in developed countries can be traced to the ingestion of contaminated raw or undercooked pork meat or sausages. Several animal species, including pigs, are known reservoirs of HEV that transmit the virus to humans. HEVs are now recognized as an emerging zoonotic agent. In this review, we describe the general characteristics of HEVs isolated from humans and animals, the risk factors for human HEV infection, and the current status of human vaccine development. PMID:24427760

Song, Young-Jo; Park, Woo-Jung; Park, Byung-Joo; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Nak-Hyung; Seo, Kun-Ho; Kang, Young-Sun; Choi, In-Soo

2014-01-01

305

Study of Giant Group A Marker Chromosome in Several Burkitt's Lymphoma and Lymphoblastoid Cell Lines with Epstein-Barr Virus from Different Origins.  

National Technical Information Service (NTIS)

Several Burkitt's lymphoma and lymphobiastoid cell lines with Epstein-Barr virus derived from different origins have been investigated cytogenetically. Giant group A marker chromosome was detected only in three lymphobiastoid cell lines from nasopharyngea...

W. Bing, W. Yuging, L. Yisen, Z. Yi W. Min

1980-01-01

306

Clinical Features of Adult Patients with Acute Hepatitis B Virus Infection Progressing to Chronic Infection  

PubMed Central

Background. Information regarding the progression of acute hepatitis B virus (HBV) infection to chronic infection in adults is scarce. Methods. Twenty-five adult patients with acute HBV infection (14 men and 11 women, 18–84 years old), whose clinical features progressed to those of chronic infection (group A) or did not (group B), were studied retrospectively. Results. There were 3 and 22 patients in groups A and B, respectively. Two of the 3 patients of group A lacked the typical symptoms of acute hepatitis. No differences were found between groups with respect to age, sex, or HBV genotypes. However, total bilirubin and alanine aminotransaminase levels were significantly lower in group A. Conclusions. Three of the 25 adult patients with acute HBV infection progressed to chronic infection. Hepatitis was mild in these patients. Patients with mild acute hepatitis B or unapparent HBV infection may have a higher risk of progressing to chronic infection. PMID:25349743

Michitaka, Kojiro; Hiraoka, Atsushi; Tokumoto, Yoshio; Ninomiya, Keiko; Ninomiya, Tomoyuki; Horiike, Norio

2014-01-01

307

Virus antibody dynamics in primary and secondary dengue infections.  

PubMed

Dengue viral infections show unique infection patterns arising from its four serotypes, (DENV-1,2,3,4). Its effects range from simple fever in primary infections to potentially fatal secondary infections. We analytically and numerically analyse virus dynamics and humoral response in a host during primary and secondary dengue infection for long periods using micro-epidemic models. The models presented here incorporate time delays, antibody dependent enhancement, a dynamic switch and a correlation factor between different DENV serotypes. We find that the viral load goes down to undetectable levels within 7-14 days as is observed for dengue infection, in both cases. For primary infection, the stability analysis of steady states shows interesting dependence on the time delay involved in the production of antibodies from plasma cells. We demonstrate the existence of a critical value for the immune response parameter, beyond which the infection gets completely cured. For secondary infections with a different serotype, the homologous antibody production is enhanced due to the influence of heterologous antibodies. The antibody production is also controlled by the correlation factor, which is a measure of similarities between the different DENV serotypes involved. Our results agree with clinically observed humoral responses for primary and secondary infections. PMID:24384697

Gujarati, Tanvi P; Ambika, G

2014-12-01

308

Disease course and viral shedding in experimental Norwalk virus and Snow Mountain virus infection.  

PubMed

Norovirus is the most common cause of acute infectious gastroenteritis, causing approximately 21 million cases annually in the USA. The virus is highly contagious and resistant to decontamination, making outbreaks difficult to control. To facilitate the development of better control methods, this study characterized the viral shedding patterns in stools from subjects experimentally infected with genogroup I or II norovirus. Viral stool titers were determined by quantitative real-time RT-PCR for all stools produced in the first 7 days post-challenge and representative stools through day 35 post-challenge. The shedding titers and disease course were analyzed with respect to virus type, illness, and subject demographics. Infection with GII.2 Snow Mountain (SMV) resulted in more symptoms and a higher frequency of painful symptoms compared to GI.1 Norwalk (NV) infection. However, NV infection produced stool viral titers approximately 2 logs higher than those seen in SMV infections. Both NV and SMV were shed in stools for up to 3 weeks after the resolution of symptoms, but long shedding durations were more common in NV infections. For each challenge virus, shedding titers and patterns were not correlated with subject demographics or clinical course. This is the first study to report shedding dynamics in experimental GII norovirus infection. J. Med. Virol. 86:2055-2064, 2014. © 2014 Wiley Periodicals, Inc. PMID:24531909

Kirby, A E; Shi, J; Montes, J; Lichtenstein, M; Moe, C L

2014-12-01

309

Mouse Models of Hepatitis B Virus Infection Comprising Host-Virus Immunologic Interactions  

PubMed Central

Hepatitis B virus (HBV) infection is one of the most prevalent infectious diseases associated with various human liver diseases, including acute, fulminant and chronic hepatitis; liver cirrhosis; and hepatocellular carcinoma. Despite the availability of an HBV vaccine and the development of antiviral therapies, there are still more than 350 million chronically infected people worldwide, approximately 5% of the world population. To understand the virus biology and pathogenesis in HBV-infected patients, several animal models have been developed to mimic hepatic HBV infection and the immune response against HBV, but the narrow host range of HBV infection and lack of a full immune response spectrum in animal models remain significant limitations. Accumulating evidence obtained from studies using a variety of mouse models that recapitulate hepatic HBV infection provides several clues for understanding host-virus immunologic interactions during HBV infection, whereas the determinants of the immune response required for HBV clearance are poorly defined. Therefore, adequate mouse models are urgently needed to elucidate the mechanism of HBV elimination and identify novel targets for antiviral therapies.

Inuzuka, Tadashi; Takahashi, Ken; Chiba, Tsutomu; Marusawa, Hiroyuki

2014-01-01

310

Antiviral activity of ginseng extract against respiratory syncytial virus infection  

PubMed Central

Panax ginseng has been known to have a number of immuno-modulatory effects. In this study, we investigated whether Panax Korean red ginseng extract (KRGE) has in vitro and in vivo antiviral effects on respiratory syncytial virus (RSV) infection. KRGE improved the survival of human lung epithelial cells against RSV infection and inhibited RSV replication. In addition, KRGE treatment suppressed the expression of RSV-induced inflammatory cytokine genes (IL-6 and IL-8) and the formation of reactive oxygen species in epithelial cell cultures. Oral administration of mice with KRGE resulted in lowering lung viral loads after RSV infection. Additionally, the in vivo effects of KRGE showed an enhanced level of interferon-? (IFN-?) producing dendritic cells subsequent to RSV infection. Taken together, these results suggested that KRGE has antiviral activity against RSV infection. PMID:24756136

LEE, JONG SEOK; KO, EUN-JU; HWANG, HYE SUK; LEE, YU-NA; KWON, YOUNG-MAN; KIM, MIN-CHUL; KANG, SANG-MOO

2014-01-01

311

Cutaneous manifestations of opportunistic infections in patients infected with human immunodeficiency virus.  

PubMed Central

Bacillary angiomatosis (BA) presents most commonly as a cutaneous disease and is caused by two organisms. Bartonella (Rochalimaea) henselae and Bartonella (Rochalimaea) quintana. Biopsy confirmation of cutaneous BA is essential because lesions can mimic nodular Kaposi's sarcoma in appearance. Although the vast majority of human immunodeficiency virus (HIV)-infected patients with BA have CD4 lymphocyte counts of less than 100 cells per mm3, the disease responds well to antimicrobial therapy. Staphylococcus aureus is the most common bacterial skin pathogen affecting HIV-infected patients. The prevalence of skin disease due to S. aureus may be explained by high nasal carriage rates for the organism ( > or = 50%) and altered immune function in conjunction with an impaired cutaneous barrier. Herpes simplex virus causes mucocutaneous disease early in the course HIV infection and ulcerative lesions at any site in advanced HIV infection. Herpes zoster is common early in the course of HIV infection; recurrent and disseminated herpes zoster infections are characteristic of patients with advanced HIV disease. Acyclovir resistance is usually seen in patients with large, untreated, ulcerative lesions of herpes simplex virus and in patients with chronic, verrucous lesions of varicella-zoster virus. Cutaneous cryptococcosis, histoplasmosis, and coccidiomycosis are markers of disseminated disease and require biopsy confirmation. Scabies is easily diagnosed but may be atypical in presentation and difficult to eradicate in advanced HIV disease. PMID:7553576

Tappero, J W; Perkins, B A; Wenger, J D; Berger, T G

1995-01-01

312

Bacterial vaginosis and human immunodeficiency virus infection  

PubMed Central

Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission. PMID:17953761

Spear, Gregory T; St John, Elizabeth; Zariffard, M Reza

2007-01-01

313

Response of white-tailed deer to infection with peste des petits ruminants virus.  

PubMed

White-tailed deer (Odocoileus virginianus) were infected experimentally with two strains of peste des petits ruminants virus. The response varied from fatal consequence to subclinical infection. The clinical signs and gross lesions were similar to those in goats. Virus was recovered from all the infected deer, and survivors developed specific antibodies demonstrated by complement fixation and virus neutralization tests. Survivors also resisted challenge with virulent rinderpest virus that was lethal to a control deer. PMID:16502689

Hamdy, F M; Dardiri, A H

1976-10-01

314

The ABC of Epstein-Barr virus infections.  

PubMed

The EBV has evolved mechanisms that allow it to take advantages of different aspects of the human immune system, resulting in evasion of the defense mechanisms of the host. The virus is capable of resting calmly in a "sea of tranquility". The virus has the unique ability among herpesviruses to transform infected B lymphocytes, thereby creating the potential for uncontrolled lymphoproliferation. Such lymphoproliferation occurs when the immune system is deregulated as a result of inborn defects or acquired defects (e.g., XLP syndrome and organ transplantation, respectively). Otherwise, EBV is kept in check by the surveillance activity of cytotoxic T lymphocytes and NK cells. PMID:16107064

Allen, Upton D

2005-01-01

315

Serological evidence of Ebola virus infection in Indonesian orangutans.  

PubMed

Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae and cause severe hemorrhagic fever in humans and nonhuman primates. Despite the discovery of EBOV (Reston virus) in nonhuman primates and domestic pigs in the Philippines and the serological evidence for its infection of humans and fruit bats, information on the reservoirs and potential amplifying hosts for filoviruses in Asia is lacking. In this study, serum samples collected from 353 healthy Bornean orangutans (Pongo pygmaeus) in Kalimantan Island, Indonesia, during the period from December 2005 to December 2006 were screened for filovirus-specific IgG antibodies using a highly sensitive enzyme-linked immunosorbent assay (ELISA) with recombinant viral surface glycoprotein (GP) antigens derived from multiple species of filoviruses (5 EBOV and 1 MARV species). Here we show that 18.4% (65/353) and 1.7% (6/353) of the samples were seropositive for EBOV and MARV, respectively, with little cross-reactivity among EBOV and MARV antigens. In these positive samples, IgG antibodies to viral internal proteins were also detected by immunoblotting. Interestingly, while the specificity for Reston virus, which has been recognized as an Asian filovirus, was the highest in only 1.4% (5/353) of the serum samples, the majority of EBOV-positive sera showed specificity to Zaire, Sudan, Cote d'Ivoire, or Bundibugyo viruses, all of which have been found so far only in Africa. These results suggest the existence of multiple species of filoviruses or unknown filovirus-related viruses in Indonesia, some of which are serologically similar to African EBOVs, and transmission of the viruses from yet unidentified reservoir hosts into the orangutan populations. Our findings point to the need for risk assessment and continued surveillance of filovirus infection of human and nonhuman primates, as well as wild and domestic animals, in Asia. PMID:22815803

Nidom, Chairul A; Nakayama, Eri; Nidom, Reviany V; Alamudi, Mohamad Y; Daulay, Syafril; Dharmayanti, Indi N L P; Dachlan, Yoes P; Amin, Mohamad; Igarashi, Manabu; Miyamoto, Hiroko; Yoshida, Reiko; Takada, Ayato

2012-01-01

316

Serological Evidence of Ebola Virus Infection in Indonesian Orangutans  

PubMed Central

Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae and cause severe hemorrhagic fever in humans and nonhuman primates. Despite the discovery of EBOV (Reston virus) in nonhuman primates and domestic pigs in the Philippines and the serological evidence for its infection of humans and fruit bats, information on the reservoirs and potential amplifying hosts for filoviruses in Asia is lacking. In this study, serum samples collected from 353 healthy Bornean orangutans (Pongo pygmaeus) in Kalimantan Island, Indonesia, during the period from December 2005 to December 2006 were screened for filovirus-specific IgG antibodies using a highly sensitive enzyme-linked immunosorbent assay (ELISA) with recombinant viral surface glycoprotein (GP) antigens derived from multiple species of filoviruses (5 EBOV and 1 MARV species). Here we show that 18.4% (65/353) and 1.7% (6/353) of the samples were seropositive for EBOV and MARV, respectively, with little cross-reactivity among EBOV and MARV antigens. In these positive samples, IgG antibodies to viral internal proteins were also detected by immunoblotting. Interestingly, while the specificity for Reston virus, which has been recognized as an Asian filovirus, was the highest in only 1.4% (5/353) of the serum samples, the majority of EBOV-positive sera showed specificity to Zaire, Sudan, Cote d’Ivoire, or Bundibugyo viruses, all of which have been found so far only in Africa. These results suggest the existence of multiple species of filoviruses or unknown filovirus-related viruses in Indonesia, some of which are serologically similar to African EBOVs, and transmission of the viruses from yet unidentified reservoir hosts into the orangutan populations. Our findings point to the need for risk assessment and continued surveillance of filovirus infection of human and nonhuman primates, as well as wild and domestic animals, in Asia. PMID:22815803

Nidom, Reviany V.; Alamudi, Mohamad Y.; Daulay, Syafril; Dharmayanti, Indi N. L. P.; Dachlan, Yoes P.; Amin, Mohamad; Igarashi, Manabu; Miyamoto, Hiroko; Yoshida, Reiko; Takada, Ayato

2012-01-01

317

In vivo infection of sheep by bovine leukemia virus mutants.  

PubMed Central

Direct inoculation of a cloned bovine leukemia virus (BLV) provirus into sheep has allowed study of the viral infectivity of genetic mutants in vivo. Three BLV variants cloned from BLV-induced tumors and 12 in vitro-modified proviruses were isolated and analyzed for viral expression in cell culture. The proviruses were then inoculated into sheep in order to assess viral infectivity in vivo. Of three variants cloned from BLV-induced tumors (344, 395, and 1345), one (344) was found infectious in vivo. This particular provirus was used to engineer 12 BLV mutants. A hybrid between the 5' region of the complete but noninfectious provirus 395 and the 3' end of mutant 344 was infectious in vivo, suggesting that the tax/rex sequences were altered in virus 395. As expected, several regions of the BLV genome appeared to be essential for viral infection: the protease, pol, and env genes. Even discrete modifications in the fusion peptide located at the NH2 end of the transmembrane gp30 glycoprotein destroyed the infectious potential. In contrast, mutations and deletions in the X3 region present between the env gene and the 3' tax/rex region did not interfere with viral infection in vivo. This region of unknown function could thus be used to introduce foreign sequences. A BLV recombinant carrying a ribozyme directed against the tax/rex sequences was still infectious in vivo. Cotransfection of two noninfectious mutants carrying deletions led to infection in two of four independent injections, the infectious virus being then a recombinant between the two deletants. The experimental approach described here should help to gain insight into essential mechanisms such as in vivo viral replication, cooperation between deletants for viral infectivity, and viral superinfections. The gene products in the X3 and X4 region which are dispensable for in vivo infection could be involved in leukemogenesis, and thus proviruses deleted in these sequences could constitute the basis for a live attenuated vaccine. Images PMID:8389918

Willems, L; Kettmann, R; Dequiedt, F; Portetelle, D; Voneche, V; Cornil, I; Kerkhofs, P; Burny, A; Mammerickx, M

1993-01-01

318

Genetics of natural resistance to Sendai virus infection in mice.  

PubMed Central

The genetics of resistance to a naturally occurring respiratory infection caused by Sendai virus was examined in F1, F2, and backcross progeny of resistant C57BL/6J and susceptible DBA/2J mice and in 25 recombinant inbred strains. An intranasal inoculum of 0.1 50% tissue culture infective dose (low dose) of Sendai virus caused 0% mortality in C57BL/6J and F1 mice and 73% mortality in DBA/2J mice. An inoculum of 1.0 50% tissue culture infective dose (high dose) caused 3, 0, and 89% mortality in C57BL/6J, F1, and DBA/2J mice, respectively. Low-dose infection caused 36% mortality in F1 X DBA/2J hybrids and 0% mortality in F2 hybrids. High-dose infection caused 29 and 32% mortality in F1 X DBA/2J and F2 hybrids, respectively. Resistance was not linked to H-2 haplotype, coat color, or sex. High-dose infection caused deaths in 12 recombinant inbred strains, and the strain distribution pattern was concordant with that of a chromosome 1 marker, Sas-1, in 20 of 25 strains (P less than 0.01). Resistance therefore behaved as a simple Mendelian dominant trait which presumptively mapped to chromosome 1. PMID:6305840

Brownstein, D G

1983-01-01

319

Woodchuck hepatitis virus: experimental infection and natural occurrence.  

PubMed

Sera from 588 woodchucks were assayed for woodchuck hepatitis virus (WHV) markers using hepatitis B virus (HBV) reagents which have cross-reactivity with WHV markers. Twenty per cent of these woodchucks, trapped in Delaware, Maryland and Pennsylvania, had WHsAg; 50% of these had DNA polymerase. There are areas of high and low endemicity within these states. Female woodchucks may have a higher incidence of WHV markers than do males. Woodchuck hepatitis surface antigen (WHsAg) and anti-WHc often occur together but less commonly than HBsAg and anti-HBc do in human HBV infection. Experimental infection of woodchucks with WHV produced a prolonged infection (up to 40 weeks). WHsAg and DNA polymerase appeared to be more reliable indicators of infectivity than anti-WHc, woodchuck hepatitis e antigen (WHeAg) or anti-WHe. WHeAg was not detected throughout this period of infection, while anti-WHe appeared late in two of three experimentally infected animals. Four male and four female woodchucks which developed primary hepatocellular carcinoma in captivity were analyzed for WHV markers throughout their period of confinement. Seven were WHsAg and anti-WHc positive when captured. The animal that was free of WHV markers on capture converted to the WHsAg and anti-WHc positive state prior to the development of primary hepatocellular carcinoma. One primary hepatocellular carcinoma animal produced WHeAg and none anti-WHs or anti-WHe. PMID:6383996

Millman, I; Southam, L; Halbherr, T; Simmons, H; Kang, C M

1984-01-01

320

Hepatitis during respiratory syncytial virus infection - a case report  

PubMed Central

Introduction: Respiratory syncytial virus (RSV) infection is the most common cause of hospitalization in infants and small children. The aim was to present a 13-months old boy diagnosed with acute airway infection, acute otitis media (AOM) and hepatitis during the RSV-infection. Material and methods: Serum catalytic activities of alkaline phosphatase (ALP), aspartate aminotranspherase (AST), alanine aminotranspherase (ALT), gamma glutamyl transpherase (GGT), lactate dehydrogenase (LD), and concentrations of bilirubin were monitored during hospitalization and at control examination. Results: The child had clinical signs and symptoms of respiratory failure, AOM, and laboratory findings of virus infection and liver disease. On admission, catalytic activities of enzymes were markedly increased, especially the activity of ALP (10333 U/L, i.e. 24-fold increase in comparison with the upper reference limit). The highest increased in AST (339 U/L, 4.5-fold), ALT (475 U/L, 10.3-fold) and LD (545 U/L, 1.5-fold) were registered on the 3rd day, and the highest increase in GGT (68 U/L, 3.1-fold) occurred on the 11th day. Seven weeks after discharge AST, ALT, GGT and LD decreased into reference range, and ALP remain mildly increased (478 U/L, 1.1 fold increase). RSV was confirmed in nasal lavage fluid. Conclusion: Laboratory results in patient with RSV infection needs to be interpreted in the light of both, respiratory and extrapulmonary manifestations of the infection, respectively. PMID:23457772

Kirin, Branka Kristic; Topic, Renata Zrinski; Dodig, Slavica

2013-01-01

321

Antiviral therapy for human immunodeficiency virus infections.  

PubMed Central

Depending on the stage of their intervention with the viral replicative cycle, human immunodeficiency virus inhibitors could be divided into the following groups: (i) adsorption inhibitors (i.e., CD4 constructs, polysulfates, polysulfonates, polycarboxylates, and polyoxometalates), (ii) fusion inhibitors (i.e., plant lectins, succinylated or aconitylated albumins, and betulinic acid derivatives), (iii) uncoating inhibitors (i.e., bicyclams), (iv) reverse transcription inhibitors acting either competitively with the substrate binding site (i.e., dideoxynucleoside analogs and acyclic nucleoside phosphonates) or allosterically with a nonsubstrate binding site (i.e., non-nucleoside reverse transcriptase inhibitors), (v) integration inhibitors, (vi) DNA replication inhibitors, (vii) transcription inhibitors (i.e., antisense oligodeoxynucleotides and Tat antagonists), (viii) translation inhibitors (i.e., antisense oligodeoxynucleotides and ribozymes), (ix) maturation inhibitors (i.e., protease inhibitors, myristoylation inhibitors, and glycosylation inhibitors), and finally, (x) budding (assembly/release) inhibitors. Current knowledge, including the therapeutic potential, of these various inhibitors is discussed. In view of their potential clinical the utility, the problem of virus-drug resistance and possible strategies to circumvent this problem are also addressed. PMID:7542558

De Clercq, E

1995-01-01

322

Inhibition of Bim Enhances Replication of Varicella-Zoster Virus and Delays Plaque Formation in Virus-Infected Cells  

PubMed Central

Programmed cell death (apoptosis) is an important host defense mechanism against intracellular pathogens, such as viruses. Accordingly, viruses have evolved multiple mechanisms to modulate apoptosis to enhance replication. Varicella-zoster virus (VZV) induces apoptosis in human fibroblasts and melanoma cells. We found that VZV triggered the phosphorylation of the proapoptotic proteins Bim and BAD but had little or no effect on other Bcl-2 family members. Since phosphorylation of Bim and BAD reduces their proapoptotic activity, this may prevent or delay apoptosis in VZV-infected cells. Phosphorylation of Bim but not BAD in VZV-infected cells was dependent on activation of the MEK/extracellular signal-regulated kinase (ERK) pathway. Cells knocked down for Bim showed delayed VZV plaque formation, resulting in longer survival of VZV-infected cells and increased replication of virus, compared with wild-type cells infected with virus. Conversely, overexpression of Bim resulted in earlier plaque formation, smaller plaques, reduced virus replication, and increased caspase 3 activity. Inhibition of caspase activity in VZV-infected cells overexpressing Bim restored levels of virus production similar to those seen with virus-infected wild-type cells. Previously we showed that VZV ORF12 activates ERK and inhibits apoptosis in virus-infected cells. Here we found that VZV ORF12 contributes to Bim and BAD phosphorylation. In summary, VZV triggers Bim phosphorylation; reduction of Bim levels results in longer survival of VZV-infected cells and increased VZV replication. PMID:24227856

Liu, XueQiao

2014-01-01

323

Experimental Lassa virus infection in the squirrel monkey.  

PubMed Central

Experimental Lassa virus infection was investigated in a nonhuman primate in order to elucidate the target organs of the viral infection and the course of pathologic events. Four squirrel monkeys (Saimiri scirreus) were inoculated intramuscularly with Lassa virus and sacrificed for organ titrations and histopathology, one each day, on Days 7, 12, 14, and 28 after inoculation. The animals showed a variable clinical course, with an incubation period of 8 to 18 days. The virus was demonstrated to be virtually pantropic; however, lymph node, liver, and kidney were key early targets. After the onset of overt disease, patterns of lymphoreticulotropism, hepatotropism, nephrotropism, adrenotropism, and persistent viremia were evident. Complement-fixing antibody failed to develop after 28 days of infection. Histopathologic findings included germinal center necrosis in spleen and lymph node; myocarditis; acute arteritis; renal tubular necrosis and regeneration; hepatocytic regeneration; chronic inflammation of choroid plexus, ependyma, and meninges; and cerebral perivascular cuffing. There is a relationship between many of these lesions and certain features of other arenavirus infections. The model offers the opportunity to pursue investigations of experimental pathogenesis, transmissibility, and efficacy of immunotherapy. Images Figure 1 Figure 2 Figure 9 Figure 10 Figure 11 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:1163630

Walker, D. H.; Wulff, H.; Murphy, F. A.

1975-01-01

324

High doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets.  

PubMed

High pathogenicity avian influenza viruses (HPAIV) have caused fatal infections in mammals through consumption of infected bird carcasses or meat, but scarce information exists on the dose of virus required and the diversity of HPAIV subtypes involved. Ferrets were exposed to different HPAIV (H5 and H7 subtypes) through consumption of infected chicken meat. The dose of virus needed to infect ferrets through consumption was much higher than via respiratory exposure and varied with the virus strain. In addition, H5N1 HPAIV produced higher titers in the meat of infected chickens and more easily infected ferrets than the H7N3 or H7N7 HPAIV. PMID:24894438

Bertran, Kateri; Swayne, David E

2014-01-01

325

High doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets  

PubMed Central

High pathogenicity avian influenza viruses (HPAIV) have caused fatal infections in mammals through consumption of infected bird carcasses or meat, but scarce information exists on the dose of virus required and the diversity of HPAIV subtypes involved. Ferrets were exposed to different HPAIV (H5 and H7 subtypes) through consumption of infected chicken meat. The dose of virus needed to infect ferrets through consumption was much higher than via respiratory exposure and varied with the virus strain. In addition, H5N1 HPAIV produced higher titers in the meat of infected chickens and more easily infected ferrets than the H7N3 or H7N7 HPAIV. PMID:24894438

2014-01-01

326

Hepatitis C virus (HCV) core serotypes in chronic HCV infection.  

PubMed Central

Recently, two distinct hepatitis C virus (HCV) serologic types have been identified on the basis of amino acid variations in the core region. The two serologic types can readily discriminate between genotypes I-II-V (serotype 1) and III-IV (serotype 2), according to the Okamoto classification. We compared HCV core serotyping with genotyping with sera from 363 anti-HCV-positive patients (309 HCV RNA positive by PCR) using a synthetic core peptide-based enzyme immunoassay and PCR amplification of core region sequences with type-specific primers, respectively. Serologic responses to HCV serotypes were successfully identified in 164 (45%) patients, of whom 153 were viremic. Eighty-nine patients had evidence of exposure to serotype 1: 8 of these were infected with genotype I, 50 were infected with genotype II, 2 were infected with genotype III, 7 were infected with genotype V, 13 had infections with mixed genotypes, 3 were infected with an indeterminate genotype, and 6 were nonviremic. Seventy-four patients had been exposed to serotype 2: 64 were infected with genotype III, 3 were infected with mixed genotypes, 2 were infected with an indeterminate genotype, and 5 were nonviremic. The serum of one patient, infected with genotype III, showed reactivity to both serotypes. Comparative evaluation of HCV core region serotyping and genotyping with sera from 294 viremic patients infected with a known HCV genotype showed a remarkable concordance between HCV core region genotyping and serotyping, with only 2 apparently discordant serum samples (both from patients with genotype III infection) of 148 (1.4%) successfully serotyped samples. Serotype 1 infection was more frequently observed in patients with overt chronic liver disease and accounted for all successfully serotyped samples from intravenous drug abusers. In contrast, serotype 2 was more prevalent in subjects with biochemically silent HCV infection (alanine aminotransferase, < 45 U/liter), in agreement with previous findings at the molecular level. HCV core serologic typing is a simple, inexpensive, and highly reproducible assay that can be applied to more than 50% of viremic HCV antibody carriers prior to the use of more sophisticated molecular typing techniques. Moreover, it may be helpful in tracking transmissions routes, particularly for incorrectly stored samples in which the RNA has degraded or for subjects who have cleared the virus and therefore have only antibodies remaining to testify to a remote infection. The lack of recognition of the core sequence from residues 67 to 81, which contains a minor B-cell epitope used to detect type-specific immunoreactivity, may explain the negative serologic findings for half of the patients. PMID:7814491

Mondelli, M U; Cerino, A; Bono, F; Cividini, A; Maccabruni, A; Arico, M; Malfitano, A; Barbarini, G; Piazza, V; Minoli, L

1994-01-01

327

Herpes Simplex Virus Type 1 Renders Infected Cells Resistant to Cytotoxic T-Lymphocyte-Induced Apoptosis  

Microsoft Academic Search

Many viruses interfere with apoptosis of infected cells, presumably preventing cellular apoptosis as a direct response to viral infection. Since cytotoxic T lymphocytes (CTL) induce apoptosis of infected cells as part of the \\

KEITH R. JEROME; JONATHAN F. TAIT; DAVID M. KOELLE; LAWRENCE COREY

1998-01-01

328

75 FR 55797 - Draft Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting...  

Federal Register 2010, 2011, 2012, 2013

...Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting...industry entitled ``Chronic Hepatitis C Virus Infection: Developing Direct-Acting...with specific steps in the hepatitis C virus (HCV) replication cycle. The...

2010-09-14

329

Lipoprotein Lipase Inhibits Hepatitis C Virus (HCV) Infection by Blocking Virus Cell Entry  

PubMed Central

A distinctive feature of HCV is that its life cycle depends on lipoprotein metabolism. Viral morphogenesis and secretion follow the very low-density lipoprotein (VLDL) biogenesis pathway and, consequently, infectious HCV in the serum is associated with triglyceride-rich lipoproteins (TRL). Lipoprotein lipase (LPL) hydrolyzes TRL within chylomicrons and VLDL but, independently of its catalytic activity, it has a bridging activity, mediating the hepatic uptake of chylomicrons and VLDL remnants. We previously showed that exogenously added LPL increases HCV binding to hepatoma cells by acting as a bridge between virus-associated lipoproteins and cell surface heparan sulfate, while simultaneously decreasing infection levels. We show here that LPL efficiently inhibits cell infection with two HCV strains produced in hepatoma cells or in primary human hepatocytes transplanted into uPA-SCID mice with fully functional human ApoB-lipoprotein profiles. Viruses produced in vitro or in vivo were separated on iodixanol gradients into low and higher density populations, and the infection of Huh 7.5 cells by both virus populations was inhibited by LPL. The effect of LPL depended on its enzymatic activity. However, the lipase inhibitor tetrahydrolipstatin restored only a minor part of HCV infectivity, suggesting an important role of the LPL bridging function in the inhibition of infection. We followed HCV cell entry by immunoelectron microscopy with anti-envelope and anti-core antibodies. These analyses demonstrated the internalization of virus particles into hepatoma cells and their presence in intracellular vesicles and associated with lipid droplets. In the presence of LPL, HCV was retained at the cell surface. We conclude that LPL efficiently inhibits HCV infection by acting on TRL associated with HCV particles through mechanisms involving its lipolytic function, but mostly its bridging function. These mechanisms lead to immobilization of the virus at the cell surface. HCV-associated lipoproteins may therefore be a promising target for the development of new therapeutic approaches. PMID:22039521

Meuleman, Philip; Roohvand, Farzin; Huby, Thierry; Le Goff, Wilfried; Leroux-Roels, Geert; Pecheur, Eve-Isabelle; Budkowska, Agata

2011-01-01

330

Hepatitis G virus infection in chronic liver disease  

PubMed Central

Background—The hepatitis G virus (HGV), a recently identified member of the Flaviviridae family, can cause chronic infection in man but the role of this agent in chronic liver disease is poorly understood. ?Aims—To evaluate the prevalence and meaning of HGV infection in a large series of patients with chronic liver disease. ?Subjects—Two hundred volunteer blood donors, 179 patients with chronic hepatitis C, 111 with chronic hepatitis B, 104 with alcoholic liver disease, 136 with hepatocellular carcinoma, and 24 with cryptogenic chronic liver disease were studied. ?Methods—HGV RNA was investigated in serum samples by reverse transcription and polymerase chain reaction amplification of the 5' non-coding region of HCV and hybridisation to a specific probe. The main features of HGV RNA seropositive and seronegative patients were compared. ?Results—The prevalence of HGV infection was 3% in blood donors, 7% in chronic hepatitis C, 8% in chronic hepatitis B, 2% in alcoholic liver disease, 4% in hepatocellular carcinoma, and 8% in cryptogenic chronic liver disease. HGV infected patients tended to be younger than non-infected patients but no differences concerning sex, possible source of infection, clinical manifestations, biochemical and virological parameters, or severity of liver lesions were found. ?Conclusions—The prevalence of HGV infection in chronic liver disease seems to be relatively low in our area. Infection with HGV does not seem to play a significant pathogenic role in patients with chronic liver disease related to chronic HBV or HCV infection or to increased alcohol consumption, or in those with cryptogenic chronic liver disease. ?? Keywords: chronic liver disease; hepatitis G virus PMID:9505895

Guilera, M; Saiz, J; Lopez-Labrador, F; Olmedo, E; Ampurdanes, S; Forns, X; Bruix, J; Pares, A; Sanchez-Tapias, J; de Anta, M T J.; Rodes, J

1998-01-01

331

Hepatitis G virus infection in hepatitis C virus-positive patients co-infected or not with hepatitis B virus and/or human immunodeficiency virus.  

PubMed

This was a retrospective study to evaluate the prevalence and impact of hepatitis G virus (HGV) infection in hepatitis C virus (HCV)-positive drug addicts, according to the serological status of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) coinfection. Two hundred and thirty-five randomly selected intravenous drug addicted patients (147 French, 88 Italian) were studied. All patients were positive for antibodies to HCV (anti-HCV). HGV RNA positivity was measured by reverse transcriptase-polymerase chain reaction (RT-PCR). Comparisons of HCV RNA positivity rate, and biological and histopathological variables, were made between HGV RNA-positive and negative patients, according to their HBV and HIV status. HGV prevalence was around 30% in both French and Italian groups. No clear association between HGV infection and a particular HCV genotype was observed. The rate of HCV RNA positivity did not differ between HGV-positive and HGV-negative patients after stratification for hepatitis B surface antigen (HBsAg) and HIV positivity. Histological severity of the underlying chronic hepatitis did not differ according to the HGV status; however, in HIV-positive HBsAg-negative patients, the hepatitis activity was moderately increased in HGV-positive patients. A striking negative influence of HBsAg positivity on HCV replication was observed in HIV-negative patients; an HCV RNA-positive rate of 25% was found in HBsAg-positive patients vs 86% in HBsAg-negative patients; similar significant results were observed in HIV-positive patients, although to a lesser extent. The underlying chronic hepatitis was significantly more severe in HBsAg-positive than in HBsAg-negative HIV-negative patients. Hence, HGV infection is highly prevalent in anti-HCV positive drug addicts but the co-infection with HCV does not seem to influence HCV replication nor to worsen the underlying chronic hepatitis, in HIV-negative patients at least. Reciprocal influence between HBV, HCV and HIV appears rather complex, HBsAg carriage seeming to exert per se a negative effect on HCV replication, particularly in HIV-negative patients, suggesting that interactions between hepatitis viruses should always be analysed in the light of HIV status. PMID:9572037

Thiers, V; Pol, S; Persico, T; Carnot, F; Zylberberg, H; Berthelot, P; Bréchot, C; Nalpas, B

1998-03-01

332

Dual infections of feeder pigs with porcine reproductive and respiratory syndrome virus followed by porcine respiratory coronavirus or swine influenza virus: a clinical and virological study  

Microsoft Academic Search

Dual infections of pigs with porcine reproductive and respiratory syndrome virus (PRRSV) followed by a second common respiratory virus, either porcine respiratory coronavirus (PRCV) or swine influenza virus (SIV), were studied. The aim was to determine if dual infections, as compared to single virus infections, result in enhanced clinical manifestations. It was also examined if PRRSV replication affects replication of

Kristien Van Reeth; Hans Nauwynck; Maurice Pensaert

1996-01-01

333

Giant magnetoimpedance-based microchannel system for quick and parallel genotyping of human papilloma virus type 16/18  

NASA Astrophysics Data System (ADS)

Quick and parallel genotyping of human papilloma virus (HPV) type 16/18 is carried out by a specially designed giant magnetoimpedance (GMI) based microchannel system. Micropatterned soft magnetic ribbon exhibiting large GMI ratio serves as the biosensor element. HPV genotyping can be determined by the changes in GMI ratio in corresponding detection region after hybridization. The result shows that this system has great potential in future clinical diagnostics and can be easily extended to other biomedical applications based on molecular recognition.

Yang, Hao; Chen, Lei; Lei, Chong; Zhang, Ju; Li, Ding; Zhou, Zhi-Min; Bao, Chen-Chen; Hu, Heng-Yao; Chen, Xiang; Cui, Feng; Zhang, Shuang-Xi; Zhou, Yong; Cui, Da-Xiang

2010-07-01

334

Articular manifestations of human immunodeficiency virus infection  

Microsoft Academic Search

Prospective studies of HIV-positive and HIV-negative individuals, longitudinal prospective studies of HIV-positive patients and the African experience with spondyloarthropathies have provided support for a direct role of HIV infection in producing a variety of articular manifestations. The most common manifestations are arthralgia and the spectrum of spondyloarthropathies, but distinct entities such as HIV-associated arthritis and the painful articular syndrome have

John D Reveille

2003-01-01

335

Hepatitis B virus coinfection in human immunodeficiency virus-infected patients: A review  

PubMed Central

Hepatitis B virus (HBV) infection is a leading cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma worldwide. Due to the shared modes of transmission, coinfection with HBV and human immunodeficiency virus (HIV) is not uncommon. It is estimated that 10% of HIV-infected patients worldwide are coinfected with HBV. In areas where an HBV vaccination program is implemented, the HBV seroprevalence has declined significantly. In HIV/HBV-coinfected patients, HBV coinfection accelerates immunologic and clinical progression of HIV infection and increases the risk of hepatotoxicity when combination antiretroviral therapy (cART) is initiated, while HIV infection increases the risk of hepatitis events, cirrhosis, and end-stage liver disease related to chronic HBV infection. With the advances in antiviral therapy, concurrent, successful long-term suppression of HIV and HBV replication can be achieved in the cART era. To reduce the disease burden of HBV infection among HIV-infected patients, adoption of safe sex practices, avoidance of sharing needles and diluent, HBV vaccination and use of cART containing tenofovir disoproxil fumarate plus emtricitabine or lamivudine are the most effective approaches. However, due to HIV-related immunosuppression, using increased doses of HBV vaccine and novel approaches to HBV vaccination are needed to improve the immunogenicity of HBV vaccine among HIV-infected patients.

Sun, Hsin-Yun; Sheng, Wang-Huei; Tsai, Mao-Song; Lee, Kuan-Yeh; Chang, Sui-Yuan; Hung, Chien-Ching

2014-01-01

336

West Nile Virus Infection of Birds, Mexico  

PubMed Central

West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006–2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths. PMID:22172633

Guerrero-Sanchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M.; Trujillo-Olivera, Maria Teresa Jesus; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C.; Kramer, Laura D.; Komar, Nicholas

2011-01-01

337

Diverse host-virus interactions following caprine arthritis-encephalitis virus infection in sheep and goats.  

PubMed

Interspecies transmissions substantially contribute to the epidemiology of small ruminant lentiviruses (SRLVs), including caprine arthritis encephalitis virus (CAEV) and visna-maëdi virus. However, comprehensive studies of host-virus interactions during SRLV adaptation to the new host are lacking. In this study, virological and serological features were analysed over a 6 month period in five sheep and three goats experimentally infected with a CAEV strain. Provirus load at the early stage of infection was significantly higher in sheep than in goats. A broad antibody reactivity against the matrix and capsid proteins was detected in goats, whereas the response to these antigens was mostly type-specific in sheep. The humoral response to the major immunodominant domain of the surface unit glycoprotein was type-specific, regardless of the host species. These species-specific immune responses were then confirmed in naturally infected sheep and goats using sera from mixed flocks in which interspecies transmissions were reported. Taken together, these results provide evidence that SRLV infections evolve in a host-dependent manner, with distinct host-virus interactions in sheep and goats, and highlight the need to consider both SRLV genotypes in diagnosis, particularly in sheep. PMID:23197577

Rachid, Antoine; Croisé, Benoit; Russo, Pierre; Vignoni, Michel; Lacerenza, Daniela; Rosati, Sergio; Kuzmak, Jacek; Valas, Stephen

2013-03-01

338

[Limbic encephalitis caused by herpes simplex virus infection after vaccination against the influenza virus].  

PubMed

Various causative factors, including viral infection, autoimmunity, and paraneoplasia, are considered to be involved in the pathomechanism of limbic encephalitis. We encountered a patient who developed limbic encephalitis after vaccination against the influenza virus. In Japan, an influenza epidemic occurs every winter, and vaccination against the influenza virus is recommended. However, there have been reports of serious side effects such as the development of Guillain-Barré syndrome and acute disseminated encephalomyelitis after influenza vaccination; these findings indicate the activation of an autoimmune pathomechanism after vaccination. Here, we discuss the relationship between limbic encephalitis and influenza vaccination from the perspective of viral infection and autoimmunity. We considered that limbic encephalitis was caused by the herpes simplex virus, and hypothesized that this clinical condition rarely develops as a sole consequence of influenza vaccination but rather develops because of the activation of an autoimmune pathomechanism after vaccination. PMID:20548122

Utumi, Yushi; Iseki, Eizo; Murayama, Norio; Ichimiya, Yosuke; Arai, Heii

2010-06-01

339

Prevention and management of neonatal herpes simplex virus infections  

PubMed Central

Human herpes simplex virus (HSV) infection in neonates can result in devastating outcomes, including mortality and significant morbidity. All infants are potentially at risk for neonatal HSV infection. This position statement reviews epidemiology, transmission and risk factors, with a focus on intrapartum infection. It considers diagnosis and prognosis according to infection category, along with testing modalities and limitations. Recommendations for managing newborns known to have been exposed intrapartum to HSV are based on expert opinion because a randomized trial to compare management options is not feasible. Guidance is provided for the empirical management of infants with suspected clinical sepsis, including those who do not respond to antibacterial therapy. The present statement replaces a 2006 position statement by the Canadian Paediatric Society. PMID:24855418

Allen, Upton D; Robinson, Joan L

2014-01-01

340

Systemic fungal infections in patients with human inmunodeficiency virus.  

PubMed

Histoplasmosis is a systemic infection caused by the dimorphic fungus Histoplasma capsulatum. In immunocompromised patients, primary pulmonary infection can spread to the skin and meninges. Clinical manifestations appear in patients with a CD4(+) lymphocyte count of less than 150 cells/?L. Coccidioidomycosis is a systemic mycosis caused by Coccidioides immitis and Coccidioides posadasii. It can present as diffuse pulmonary disease or as a disseminated form primarily affecting the central nervous system, the bones, and the skin. Cryptococcosis is caused by Cryptococcus neoformans (var. neoformans and var. grubii) and Cryptococcus gattii, which are members of the Cryptococcus species complex and have 5 serotypes: A, B, C, D, and AD. It is a common opportunistic infection in patients with human immunodeficiency virus (HIV)/AIDS, even those receiving antiretroviral therapy. Histopathologic examination and culture of samples from any suspicious lesions are essential for the correct diagnosis of systemic fungal infections in patients with HIV/AIDS. PMID:23107866

Rodríguez-Cerdeira, C; Arenas, R; Moreno-Coutiño, G; Vásquez, E; Fernández, R; Chang, P

2014-01-01

341

Broadly neutralizing antibodies abrogate established hepatitis C virus infection.  

PubMed

In most exposed individuals, hepatitis C virus (HCV) establishes a chronic infection; this long-term infection in turn contributes to the development of liver diseases such as cirrhosis and hepatocellular carcinoma. The role of antibodies directed against HCV in disease progression is poorly understood. Neutralizing antibodies (nAbs) can prevent HCV infection in vitro and in animal models. However, the effects of nAbs on an established HCV infection are unclear. We demonstrate that three broadly nAbs-AR3A, AR3B, and AR4A-delivered with adeno-associated viral vectors can confer protection against viral challenge in humanized mice. Furthermore, we provide evidence that nAbs can abrogate an ongoing HCV infection in primary hepatocyte cultures and in a human liver chimeric mouse model. These results showcase a therapeutic approach to interfere with HCV infection by exploiting a previously unappreciated need for HCV to continuously infect new hepatocytes to sustain a chronic infection. PMID:25232181

de Jong, Ype P; Dorner, Marcus; Mommersteeg, Michiel C; Xiao, Jing W; Balazs, Alejandro B; Robbins, Justin B; Winer, Benjamin Y; Gerges, Sherif; Vega, Kevin; Labitt, Rachael N; Donovan, Bridget M; Giang, Erick; Krishnan, Anuradha; Chiriboga, Luis; Charlton, Michael R; Burton, Dennis R; Baltimore, David; Law, Mansun; Rice, Charles M; Ploss, Alexander

2014-09-17

342

Systems biology unravels interferon responses to respiratory virus infections  

PubMed Central

Interferon production is an important defence against viral replication and its activation is an attractive therapeutic target. However, it has long been known that viruses perpetually evolve a multitude of strategies to evade these host immune responses. In recent years there has been an explosion of information on virus-induced alterations of the host immune response that have resulted from data-rich omics technologies. Unravelling how these systems interact and determining the overall outcome of the host response to viral infection will play an important role in future treatment and vaccine development. In this review we focus primarily on the interferon pathway and its regulation as well as mechanisms by which respiratory RNA viruses interfere with its signalling capacity. PMID:24600511

Kroeker, Andrea L; Coombs, Kevin M

2014-01-01

343

A unicellular algal virus, Emiliania huxleyi virus 86, exploits an animal-like infection strategy.  

PubMed

Emiliania huxleyi virus 86 (EhV-86) belongs to the family Phycodnaviridae, a group of viruses that infect a wide range of freshwater and marine eukaryotic algae. Phycodnaviridae is one of the five families that belong to a large and phylogenetically diverse group of viruses known as nucleocytoplasmic large dsDNA viruses (NCLDVs). To date, our understanding of algal NCLDV entry is based on the entry mechanisms of members of the genera Chlorovirus and Phaeovirus, both of which consist of non-enveloped viruses that 'inject' their genome into their host via a viral inner-membrane host plasma membrane fusion mechanism, leaving an extracellular viral capsid. Using a combination of confocal and electron microscopy, this study demonstrated for the first time that EhV-86 differs from its algal virus counterparts in two fundamental areas. Firstly, its capsid is enveloped by a lipid membrane, and secondly, EhV-86 enters its host via either an endocytotic or an envelope fusion mechanism in which an intact nucleoprotein core still encapsulated by its capsid is seen in the host cytoplasm. Real-time fluorescence microscopy showed that viral internalization and virion breakdown took place within the host on a timescale of seconds. At around 4.5 h post-infection, virus progeny were released via a budding mechanism during which EhV-86 virions became enveloped with host plasma membrane. EhV-86 therefore appears to have an infection mechanism different from that employed by other algal NCLDVs, with entry and exit strategies showing a greater analogy to animal-like NCLDVs. PMID:19474246

Mackinder, Luke C M; Worthy, Charlotte A; Biggi, Gaia; Hall, Matthew; Ryan, Keith P; Varsani, Arvind; Harper, Glenn M; Wilson, William H; Brownlee, Colin; Schroeder, Declan C

2009-09-01

344

Human papilloma virus and oral infections: an update.  

PubMed

Human papilloma virus (HPV) is one of the most common virus groups affecting the skin and mucosal areas of the body in the world today. It is also a known fact that HPV causes many lesions in the oral cavity. The most common conditions induced by oral HPV infection are usually benign-like oral papillomas, oral condylomas, and focal epithelial hyperplasia. Oral HPV infection has been found to be associated with some cases of oropharyngeal cancer, but it is not the main risk factor for this kind of cancer. HPV is been proved to be the causative agent in causation of cervical cancers without doubt, but its role as a etiologic agent in causing oral cancers needs to be evaluated and studied more to come into any conclusion. We have used review papers, case reports, cohort studies, case control studies, and various internet sources published from 1960 to 2011 to prepare this review of literature. PMID:21768696

Kumaraswamy, K L; Vidhya, M

2011-01-01

345

Peritoneal coccidioidomycosis associated with human immunodeficiency virus infection.  

PubMed

Peritoneal coccidioidomycosis is extremely rare. This report describes a patient infected with the human immunodeficiency virus who presented with unexplained ascites and was found to have peritoneal coccidioidomycosis. The ascites had a low serum-ascites albumin gradient, and laparoscopy showed peritoneal implants that grew Coccidioides immitis. This case is unique in several ways; this is the first case in which a patient's acquired immunodeficiency syndrome-defining illness was peritoneal coccidioidomycosis, and the serum-ascites albumin gradient determination as well as laparoscopy provided information critical to the diagnosis. This patient's dramatic response to systemic antifungal therapy, as evidenced by resolution of ascites and constitutional symptoms, underscores the importance of timely diagnosis and prompt therapy. In summary, this report reviews the previous cases of coccidioidal peritonitis and reports the first case in which localized peritoneal coccidioidomycosis was the acquired immunodeficiency syndrome-defining illness in a human immunodeficiency virus-infected patient. PMID:1531643

Jamidar, P A; Campbell, D R; Fishback, J L; Klotz, S A

1992-03-01

346

Metabolomic Profile of Hepatitis C Virus-Infected Hepatocytes  

PubMed Central

Hepatitis C virus (HCV) is capable of disrupting different facets of lipid metabolism and lipids have been shown to play a crucial role in the viral life cycle. The aim of this study was to examine the effect HCV infection has on the hepatocyte metabolome. Huh-7.5 cells were infected using virus produced by the HCV J6/JFH1 cell culture system and cells were harvested 24, 48, and 72-hours following infection. Metabolic profiling was performed using a non-targeted multiple platform methodology combining ultrahigh performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS2) and gas chromatography/mass spectrometry (GC/MS). There was a significant increase in a number of metabolites involved in nucleotide synthesis and RNA replication during early HCV infection. NAD levels were also significantly increased along with several amino acids. A number of lipid metabolic pathways were disrupted by HCV infection, resulting in an increase in cholesterol and sphingolipid levels, altered phospholipid metabolism and a possible disruption in mitochondrial fatty acid transport. Fluctuations in 5?-methylthioadenosine levels were also noted, along with alterations in the glutathione synthesis pathway. These results highlight a number of previously unreported metabolic interactions and give a more in depth insight into the effect HCV has on host cell biochemical processes. PMID:21853158

Roe, Barbara; Kensicki, Elizabeth; Mohney, Robert; Hall, William W.

2011-01-01

347

Lymphocytic Choriomeningitis Virus Infection in FVB Mouse Produces Hemorrhagic Disease  

PubMed Central

The viral family Arenaviridae includes a number of viruses that can cause hemorrhagic fever in humans. Arenavirus infection often involves multiple organs and can lead to capillary instability, impaired hemostasis, and death. Preclinical testing for development of antiviral or therapeutics is in part hampered due to a lack of an immunologically well-defined rodent model that exhibits similar acute hemorrhagic illness or sequelae compared to the human disease. We have identified the FVB mouse strain, which succumbs to a hemorrhagic fever-like illness when infected with lymphocytic choriomeningitis virus (LCMV). FVB mice infected with LCMV demonstrate high mortality associated with thrombocytopenia, hepatocellular and splenic necrosis, and cutaneous hemorrhage. Investigation of inflammatory mediators revealed increased IFN-?, IL-6 and IL-17, along with increased chemokine production, at early times after LCMV infection, which suggests that a viral-induced host immune response is the cause of the pathology. Depletion of T cells at time of infection prevented mortality in all treated animals. Antisense-targeted reduction of IL-17 cytokine responsiveness provided significant protection from hemorrhagic pathology. F1 mice derived from FVB×C57BL/6 mating exhibit disease signs and mortality concomitant with the FVB challenged mice, extending this model to more widely available immunological tools. This report offers a novel animal model for arenavirus research and pre-clinical therapeutic testing. PMID:23300439

Schnell, Frederick J.; Sundholm, Sarah; Crumley, Stacy; Iversen, Patrick L.; Mourich, Dan V.

2012-01-01

348

Analysis of Marek's Disease Virus Serotype 1-specific Phosphorylated Polypeptides in Virus-infected Cells and Marek's Disease Lymphoblastoid Cells  

Microsoft Academic Search

SUMMARY By use of monoclonal antibodies, a virus-specific cytoplasmic antigen related to phosphorylated polypeptides specific to serotype 1 of Marek's disease virus (MDV)- related viruses (MDV1) has been identified in all MD tumour cell lines examined, as well as in infected cells and in tumour lesions of chickens with MD. At least two phosphorylated polypeptides with mol. wt. 39000 (39K)

KAZUHIRO NAKAJIMA; KAZUYOSHI IKUTA; MATAO NAITO; SHIGEHARU UEDA; SHIRO KATO; KANJI HIRAI

1987-01-01

349

[An infected partially thrombosed giant aneurysm of the azygos anterior cerebral artery].  

PubMed

The authors report a case of partially thrombosed giant aneurysm which was secondarily infected with purulent meningitis. The relationship between the infection of the aneurysm, the rapid growth of the aneurysm and the development of severe cerebral edema was discussed. A 53 year-old man was admitted on September 1, 1986, with a diagnosis of bacterial meningitis. On his admission, his body temperature was 39 degrees C, and he showed mental confusion but no neurological deficits. Laboratory data revealed signs of infection in white blood cell count, CRP, and erythrocyte sedimentation rate. Computerized tomographic (CT) scan and magnetic resonance (MR) imaging showed a massive round mass with perifocal edema measuring 40mm in the maximum diameter in the left paramedian frontal region. T1 weighted MR image also showed the presence of pus accumulation in the left ventricle. Cerebral angiography demonstrated a giant aneurysm at the distal portion of the azygos anterior cerebral artery, and irregular narrowing of both the supraclinoid segment of the carotid artery and its main branches indicating arteritis due to purulent meningitis. The patient was treated with ventricular drainage and administration of antibiotics. Culture of the purulent CSF was negative. The patient's lab data, CSF finding and neurological status improved progressively. However, follow-up CT scan and angiogram a month later showed enlargement of the aneurysm, dilatation of the patent lumen and perifocal edema. On October 8, the patient suddenly became comatose with anisocoria. A CT scan showed massive edema with marked midline shift. Emergency bifrontal craniotomy was carried out, and clipping was completed after removal of the thrombosed portion of the aneurysm, and thromboendarterectomy of the aneurysmal neck.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2385324

Mishima, K; Watanabe, T; Sasaki, T; Saito, I; Takakura, K

1990-05-01

350

Multidisciplinary Prospective Study of Mother-to-Child Chikungunya Virus Infections  

E-print Network

Multidisciplinary Prospective Study of Mother-to-Child Chikungunya Virus Infections on the Island-to-child chikungunya virus infections on the Island of La Re´union. PLoS Med 5(3): e60. doi:10. 1371/journal, antepartum fetal death; CHIKV, chikungunya virus; CI, confidence interval; CNS, central nervous system; CSF

Paris-Sud XI, Université de

351

Infected mosquitoes transmit the virus to birds. Birds of some species get ill and die,  

E-print Network

Infected mosquitoes transmit the virus to birds. Birds of some species get ill and die, while Virus (WNV) 3 circulates and multiplies for several days in a mosquito's blood before penetrating its salivary glands. After an in- cubation period of 10 to 14 days, an infected mosquito can transmit the virus

Kaye, Jason P.

352

Potassium Ion Channels of Chlorella Viruses Cause Rapid Depolarization of Host Cells during Infection  

Microsoft Academic Search

Previous studies have established that chlorella viruses encode K channels with different structural and functional properties. In the current study, we exploit the different sensitivities of these channels to Cs to determine if the membrane depolarization observed during virus infection is caused by the activities of these channels. Infection of Chlorella NC64A with four viruses caused rapid membrane depolarization of

Florian Frohns; Anja Kasmann; Detlef Kramer; Britta Schafer; Mario Mehmel; Ming Kang; James L. Van Etten; Sabrina Gazzarrini; Anna Moroni; Gerhard Thiel

2006-01-01

353

Longitudinal study of herpes simplex virus type 2 infection using viral dynamic modelling  

E-print Network

HSV Longitudinal study of herpes simplex virus type 2 infection using viral dynamic modelling of herpes simplex virus type 2 (HSV-2) change over time and these changes affect transmission and clinical infection that cannot be obtained by other methods. H erpes simplex virus type 2 (HSV-2), the primary cause

Blower, Sally

354

Diagnosis of herpes simplex virus infection by immunofluorescence.  

PubMed

The utility of the indirect immunofluorescent antibody (IFA) technique for diagnosis of herpes simplex virus (HSV) infection was examined by testing specimens for this agent from 31 patients with encephalitis or meningitis, 17 with conjunctivitis, 19 with genital disease, and 1 with genital disease and meningitis. Brain biopsy tissue from four patients with encephalitis was positive by IFA and virus culture for HSV. Leukocytes in cerebrospinal fluid from these four patients and one with HSV meningitis were also positive by IFA, but virus isolation attempts on the fluid were all negative. Conjunctival scrapings from two patients with conjunctivitis were positive for HSV by both IFA and virus culture. Eleven of 12 culture-positive lesions of herpes progenitalis were positive by IFA, and 1 dark field-positive syphilitic chancre was also positive for HSV by both IFA and culture. Evidence for specificity of the results was provided by internal controls in each test and negative results from patients with other diagnoses. Thus, the IFA technique constituted a rapid, sensitive, and specific diagnostic method for the diagnosis of HSV infections. PMID:178689

Taber, L H; Brasier, F; Couch, R B; Greenberg, S B; Jones, D; Knight, V

1976-03-01

355

Regional Aggressive Root Resorption Caused by Neuronal Virus Infection  

PubMed Central

During orthodontic treatment, root resorption can occur unexplainably. No clear distinction has been made between resorption located within specific regions and resorption occurring generally in the dentition. The purpose is to present cases with idiopathic (of unknown origin) root resorption occurring regionally. Two cases of female patients, 26 and 28 years old, referred with aggressive root resorption were investigated clinically and radiographically. Anamnestic information revealed severe virus diseases during childhood, meningitis in one case and whooping cough in the other. One of the patients was treated with dental implants. Virus spreading along nerve paths is a possible explanation for the unexpected resorptions. In both cases, the resorptions began cervically. The extent of the resorption processes in the dentition followed the virus infected nerve paths and the resorption process stopped when reaching regions that were innervated differently and not infected by virus. In one case, histological examination revealed multinuclear dentinoclasts. The pattern of resorption in the two cases indicates that innervation is a factor, which under normal conditions may protect the root surface against resorption. Therefore, the normal nerve pattern is important for diagnostics and for predicting the course of severe unexpected root resorption. PMID:23097724

Kjaer, Inger; Str?m, Carsten; Worsaae, Nils

2012-01-01

356

Protective efficacy of neutralizing antibodies against Ebola virus infection.  

PubMed

Ebola virus causes lethal hemorrhagic fever in humans and nonhuman primates, but no effective antiviral compounds are available for the treatment of this infection. The surface glycoprotein (GP) of Ebola virus is an important target of neutralizing antibodies. Although passive transfer of GP-specific antibodies has been evaluated in mouse and guinea pig models, protection was achieved only by treatment shortly before or after virus challenge. Using these animal models, we evaluated the protective efficacy of two monoclonal antibodies whose epitopes are distinct from those of the antibodies tested by others. Treatment of mice with these antibodies 2 days after challenge completely protected most of the animals; even treatment 3 or 4 days after challenge was partially effective. Although antibody treatment in the guinea pig model was not as effective as in the mouse model, single-dose treatment of guinea pigs 1 day before, or 1 or 2 days after challenge did protect some animals. Interestingly, the protective effects seen in these animal models did not correlate with the in vitro neutralizing activity of the antibodies, suggesting different mechanisms of the neutralization by these antibodies. These results underscore the potential therapeutic utility of monoclonal antibodies for postexposure treatment of Ebola virus infections. PMID:17055127

Takada, Ayato; Ebihara, Hideki; Jones, Steven; Feldmann, Heinz; Kawaoka, Yoshihiro

2007-01-22

357

Rapid Hepatitis C Virus Divergence among Chronically Infected Individuals  

PubMed Central

Here, we analyze the viral divergence among hepatitis C virus (HCV) chronic cases infected with genotype 1. The intrahost viral evolution was assessed by deep sequencing using the 454 Genome Sequencer platform. The results showed a rapid nucleotide sequence divergence. This notorious short-term viral evolution is of the utmost importance for the study of HCV transmission, because direct links between related samples were virtually lost. Thus, rapid divergence of HCV significantly affects genetic relatedness studies and outbreak investigations. PMID:23224093

Cruz-Rivera, Mayra; Carpio-Pedroza, Juan Carlos; Escobar-Gutierrez, Alejandro; Lozano, Daniela; Vergara-Castaneda, Arely; Rivera-Osorio, Pilar; Martinez-Guarneros, Armando; Chacon, Carlos A. Vazquez; Fonseca-Coronado, Salvador

2013-01-01

358

Pathogenesis of infection with attenuated Marek's disease virus strains  

Microsoft Academic Search

Recently, attenuated Marek's disease virus (MDV) became of renewed interest as a component in bi? or polyvalent vaccines. The effect of attenuation on the pathogenesis of infection was investigated. Cloned preparations of the JM?16, BC?1A and RB?1B strains of MDV were attenuated by serial passage in chick kidney cells or chicken embryo fibroblasts. Subclones were obtained from the JM?16 strain

K. A. Schat; B. W. Calnek; J. Fabricant; D. L. Graham

1985-01-01

359

Epidemiology of hepatitis C virus infection in American veterans  

Microsoft Academic Search

OBJECTIVE:This study reports the findings of hepatitis C virus (HCV) infection in a large Department of Veterans Affairs Health Care System in suburban Northern California.METHODS:All veterans who had anti-HCV (EIA II) tested during a 6-yr period (7\\/92 to 6\\/98) were included in this study. To estimate the seroprevalence of anti-HCV among our population, 126 consecutive bloodborne pathogen exposure accidents were

Ramsey C. Cheung

2000-01-01

360

Rapid hepatitis C virus divergence among chronically infected individuals.  

PubMed

Here, we analyze the viral divergence among hepatitis C virus (HCV) chronic cases infected with genotype 1. The intrahost viral evolution was assessed by deep sequencing using the 454 Genome Sequencer platform. The results showed a rapid nucleotide sequence divergence. This notorious short-term viral evolution is of the utmost importance for the study of HCV transmission, because direct links between related samples were virtually lost. Thus, rapid divergence of HCV significantly affects genetic relatedness studies and outbreak investigations. PMID:23224093

Cruz-Rivera, Mayra; Carpio-Pedroza, Juan Carlos; Escobar-Gutiérrez, Alejandro; Lozano, Daniela; Vergara-Castaneda, Arely; Rivera-Osorio, Pilar; Martinez-Guarneros, Armando; Chacon, Carlos A Vazquez; Fonseca-Coronado, Salvador; Vaughan, Gilberto

2013-02-01

361

Hepatitis C virus infection in United States correctional institutions  

Microsoft Academic Search

In the United States, over 6 million people are under correctional supervision and over 2 million are in custody and receiving\\u000a health care. Prisoners are overrepresented by individuals with high risk for hepatitis C virus (HCV) infection, including\\u000a injection drug users, the sexual partners of injection drug users, and people living with HIV or AIDS and mental illness.\\u000a As such,

Frederick L. Altice; R. Douglas Bruce

2004-01-01

362

Immunopathogenesis of Simian Immunodeficiency Virus (SIV) Infection in Nonhuman Primates  

Microsoft Academic Search

Purpose of review—Soon after the discovery of HIV-infected humans, rhesus macaques in a colony at the New England Primate Research Center showed similar signs of a progressive immune suppression. The discovery of the Simian Immunodeficiency Virus (SIV)-associated disease opened the door to study an AIDS-like illness in nonhuman primates (NHP). Even after three decades, this animal model remains an invaluable

Joern E. Schmitz; Birgit Korioth-Schmitz

2013-01-01

363

The roles of microRNAs in mammalian virus infection  

Microsoft Academic Search

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression that are important for the control of a multitude of critical processes in mammalian cells. Increasing evidence supports that miRNAs also have important functions in viral replication and may be used by host cells to control viral infection. Expression of miRNAs has been reported for various groups of viruses including herpesviruses, small

Ralph Grassmann; Kuan-Teh Jeang

2008-01-01

364

Neonatal Herpes Simplex Virus Infections: Where Are We Now?  

Microsoft Academic Search

\\u000a Neonatal herpes simplex virus (HSV) infection continues to cause significant morbidity and mortality despite advances in diagnosis\\u000a and treatment. Prior to antiviral therapy, 85% of patients with disseminated HSV disease and 50% of patients with central\\u000a nervous system disease died within 1 year. The advent of antiviral therapy has dramatically improved the prognosis of neonatal\\u000a HSV with initially vidarabine and

Clara Thompson; Richard Whitley

365

Avascular necrosis of bone in human immunodeficiency virus infected patients  

Microsoft Academic Search

The objective of this article was to delineate the causes of avascular necrosis (AVN) in patients with human immunodeficiency virus (HIV). HIV-infected patients with pain in large joints were prospectively screened. Patients had radiographs and magnetic resonance imaging of their affected joints. Serum lipids, anticardiolipin antibody levels (IgG, IgM), and hemoglobin electrophoresis were performed on all patients who had radiographic

Marcia F Blacksin; Patricia C Kloser; Jocelyn Simon

1999-01-01

366

Molecular Umbrellas: a Novel Class of Candidate Topical Microbicides To Prevent Human Immunodeficiency Virus and Herpes Simplex Virus Infections  

Microsoft Academic Search

Molecular umbrella compounds may function as novel topical microbicides to prevent human immunode- ficiency virus (HIV) and herpes simplex virus (HSV) infections. In a preliminary structure-activity investiga- tion, one umbrella compound, designated Spm8CHAS, was identified which inhibited both HIV and HSV infections with no cellular toxicity. The objectives of the current studies were to define its spectrum of antiviral activity,

Rebecca Pellett Madan; Pedro M. M. Mesquita; Natalia Cheshenko; Bingwen Jing; Vikas Shende; Esmeralda Guzman; Taylor Heald; Marla J. Keller; Steven L. Regen; Robin J. Shattock; Betsy C. Herold

2007-01-01

367

Performance of virus isolation and Directigen® Flu A to detect influenza A virus in experimental human infection  

Microsoft Academic Search

Background: few data exist to assess the sensitivity of different specimen types for viral detection during the course of influenza virus infection. Objectives: this study assessed the relationships between quantitative influenza A virus replication and antigen detectability by the enzyme immunosorbent assay (EIA) Directigen® Flu A in different type of samples during experimental human infection. Study design: fourteen volunteers were

Laurent Kaiser; Marcus S Briones; Frederick G Hayden

1999-01-01

368

Ebola virus-like particles protect from lethal Ebola virus infection.  

PubMed

The filovirus Ebola causes hemorrhagic fever with 70-80% human mortality. High case-fatality rates, as well as known aerosol infectivity, make Ebola virus a potential global health threat and possible biological warfare agent. Development of an effective vaccine for use in natural outbreaks, response to biological attack, and protection of laboratory workers is a higher national priority than ever before. Coexpression of the Ebola virus glycoprotein (GP) and matrix protein (VP40) in mammalian cells results in spontaneous production and release of virus-like particles (VLPs) that resemble the distinctively filamentous infectious virions. VLPs have been tested and found efficacious as vaccines for several viruses, including papillomavirus, HIV, parvovirus, and rotavirus. Herein, we report that Ebola VLPs (eVLPs) were immunogenic in vitro as eVLPs matured and activated mouse bone marrow-derived dendritic cells, assessed by increases in cell-surface markers CD40, CD80, CD86, and MHC class I and II and secretion of IL-6, IL-10, macrophage inflammatory protein (MIP)-1alpha, and tumor necrosis factor alpha by the dendritic cells. Further, vaccinating mice with eVLPs activated CD4+ and CD8+ T cells, as well as CD19+ B cells. After vaccination with eVLPs, mice developed high titers of Ebola virus-specific antibodies, including neutralizing antibodies. Importantly, mice vaccinated with eVLPs were 100% protected from an otherwise lethal Ebola virus inoculation. Together, our data suggest that eVLPs represent a promising vaccine candidate for protection against Ebola virus infections and a much needed tool to examine the genesis and nature of immune responses to Ebola virus. PMID:14673108

Warfield, Kelly L; Bosio, Catharine M; Welcher, Brent C; Deal, Emily M; Mohamadzadeh, Mansour; Schmaljohn, Alan; Aman, M Javad; Bavari, Sina

2003-12-23

369

[Individualized treatment of hepatitis C virus infection].  

PubMed

The current treatment of chronic hepatitis C since several years, the association of pegylated interferon and ribavirine, allows to obtain a virological eradication in around 55% of patients, including 45% of those infected with the genotype 1. The cure, defined by an undetectable viremia 24 weeks after the discontinuation of treatment, is associated to an improvement of the prognosis of the patients with a decrease of mortality and morbidity. If the virologic recovery allows fibrosis regression, including cirrhosis reversal, why not to treat every HCV-infected patient? Because first therapy is not mandatory in all the patients (minim liver disease, co-morbidities which may be contraindications to therapy), second adverse events are frequent and may be severe, third costs are high (the antiviral treatment but also hematological growth factors…) and finally the treated patients do not recover constantly. This has resulted in personalized therapies based on the severity of the disease, the early viral kinetics, pharmacologic monitoring, genetic and immunological factors. In addition to these factors of personalization, the development of new anti-viral C molecules, the protease inhibitors (boceprevir or telaprevir which are about to be approved in combination with pegylated interferon and ribavirine) will allow to achieve a sustained virologic response in around 75% of cases. PMID:22154925

Pol, Stanislas; Fontaine, Hélène

2012-02-01

370

Occult Hepatitis B Virus Infection in Chacma Baboons, South Africa  

PubMed Central

During previous studies of susceptibility to hepatitis B virus (HBV) infection, HBV DNA was detected in 2/6 wild-caught baboons. In the present study, HBV DNA was amplified from 15/69 wild-caught baboons. All animals were negative for HBV surface antigen and antibody against HBV core antigen. Liver tissue from 1 baboon was immunohistochemically negative for HBV surface antigen but positive for HBV core antigen. The complete HBV genome of an isolate from this liver clustered with subgenotype A2. Reverse transcription PCR of liver RNA amplified virus precore and surface protein genes, indicating replication of virus in baboon liver tissue. Four experimentally naive baboons were injected with serum from HBV DNA–positive baboons. These 4 baboons showed transient seroconversion, and HBV DNA was amplified from serum at various times after infection. The presence of HBV DNA at relatively low levels and in the absence of serologic markers in the baboon, a nonhuman primate, indicates an occult infection. PMID:23631817

Dickens, Caroline; Kew, Michael C.; Purcell, Robert H.

2013-01-01

371

Effective etanercept treatment for psoriatic arthritis complicating concomitant human immunodeficiency virus and hepatitis C virus infection.  

PubMed

High levels of tumor necrosis factor-alpha (TNF-alpha) are associated with hepatitis C virus (HCV) infection and all stages of human immunodeficiency virus (HIV) infection. TNF-alpha may have a role in both the pathogenesis and the response to treatment of these chronic viral diseases. We describe a 42-year-old HIV/HCV coinfected hemophiliac man who developed psoriasis and severe psoriatic arthritis not responding to combination treatment with methotrexate and cyclosporin A. Treatment with etanercept 25 mg twice weekly was followed by remission of the joint inflammation and improvement of the exanthem. This is the first report of anti-TNF-alpha treatment for rheumatic complications in a patient with both HIV and HCV infection. PMID:17552060

Linardaki, Garifallia; Katsarou, Olga; Ioannidou, Panagiota; Karafoulidou, Anastasia; Boki, Kyriaki

2007-06-01

372

Viral myocarditis: potential defense mechanisms within the cardiomyocyte against virus infection  

PubMed Central

Virus infection can inflict significant damage on cardiomyocytes through direct injury and secondary immune reactions, leading to myocarditis and dilated cardiomyopathy. While viral myocarditis or cardiomyopathy is a complication of systemic infection of cardiotropic viruses, most individuals infected with the viruses do not develop significant cardiac disease. However, some individuals proceed to develop severe virus-mediated heart disease. Recent studies have shown that viral infection of cardiomyocytes is required for the development of myocarditis and subsequent cardiomyopathy. This suggests that viral infection of cardiomyocytes can be an important step that determines the pathogenesis of viral myocarditis during systemic infection. Accordingly, this article focuses on potential defense mechanisms within the cardiomyocyte against virus infection. Understanding of the cardiomyocyte defense against invading viruses may give us novel insights into the pathophysiology of viral myocarditis, and enable us to develop innovative strategies of diagnosis and treatment for this challenging clinical entity. PMID:21585262

Yajima, Toshitaka

2011-01-01

373

Kunjin Virus Replicon-Based Vaccines Expressing Ebola Virus Glycoprotein GP Protect the Guinea Pig Against Lethal Ebola Virus Infection  

PubMed Central

Pre- or postexposure treatments against the filoviral hemorrhagic fevers are currently not available for human use. We evaluated, in a guinea pig model, the immunogenic potential of Kunjin virus (KUN)–derived replicons as a vaccine candidate against Ebola virus (EBOV). Virus like particles (VLPs) containing KUN replicons expressing EBOV wild-type glycoprotein GP, membrane anchor-truncated GP (GP/Ctr), and mutated GP (D637L) with enhanced shedding capacity were generated and assayed for their protective efficacy. Immunization with KUN VLPs expressing full-length wild-type and D637L-mutated GPs but not membrane anchor–truncated GP induced dose-dependent protection against a challenge of a lethal dose of recombinant guinea pig-adapted EBOV. The surviving animals showed complete clearance of the virus. Our results demonstrate the potential for KUN replicon vectors as vaccine candidates against EBOV infection. PMID:21987742

Reynard, O.; Mokhonov, V.; Mokhonova, E.; Leung, J.; Page, A.; Mateo, M.; Pyankova, O.; Georges-Courbot, M. C.; Raoul, H.; Khromykh, A. A.

2011-01-01

374

Kunjin virus replicon-based vaccines expressing Ebola virus glycoprotein GP protect the guinea pig against lethal Ebola virus infection.  

PubMed

Pre- or postexposure treatments against the filoviral hemorrhagic fevers are currently not available for human use. We evaluated, in a guinea pig model, the immunogenic potential of Kunjin virus (KUN)-derived replicons as a vaccine candidate against Ebola virus (EBOV). Virus like particles (VLPs) containing KUN replicons expressing EBOV wild-type glycoprotein GP, membrane anchor-truncated GP (GP/Ctr), and mutated GP (D637L) with enhanced shedding capacity were generated and assayed for their protective efficacy. Immunization with KUN VLPs expressing full-length wild-type and D637L-mutated GPs but not membrane anchor-truncated GP induced dose-dependent protection against a challenge of a lethal dose of recombinant guinea pig-adapted EBOV. The surviving animals showed complete clearance of the virus. Our results demonstrate the potential for KUN replicon vectors as vaccine candidates against EBOV infection. PMID:21987742

Reynard, O; Mokhonov, V; Mokhonova, E; Leung, J; Page, A; Mateo, M; Pyankova, O; Georges-Courbot, M C; Raoul, H; Khromykh, A A; Volchkov, V E

2011-11-01

375

Hepatitis B Virus Infection and Immunizations among Asian American College Students: Infection, Exposure, and Immunity Rates  

ERIC Educational Resources Information Center

Objectives: To evaluate the prevalence of hepatitis B virus (HBV) infection, exposure, and immunity among Asian American college students as a basis for evaluating HBV screening and vaccination policy. Participants and Methods: Self-identified Asian American college students aged 18 years or older were examined. Serological tests of HBV surface…

Lee, Haeok; Kiang, Peter; Watanabe, Paul; Halon, Patricia; Shi, Ling; Church, Daniel R.

2013-01-01

376

Human Febrile Illness Caused by Encephalomyocarditis Virus Infection, Peru  

PubMed Central

Etiologic studies of acute febrile disease were conducted in sites across South America, including Cusco and Iquitos, Peru. Patients’ clinical signs and symptoms were recorded, and acute- and convalescent-phase serum samples were obtained for serologic examination and virus isolation in Vero E6 and C6/36 cells. Virus isolated in Vero E6 cells was identified as encephalomyocarditis virus (EMCV) by electron microscopy and by subsequent molecular diagnostic testing of samples from 2 febrile patients with nausea, headache, and dyspnea. The virus was recovered from acute-phase serum samples from both case-patients and identified with cardiovirus-specific reverse transcription–PCR and sequencing. Serum samples from case-patient 1 showed cardiovirus antibody by immunoglobulin M ELISA (acute phase <8, convalescent phase >1,024) and by neutralization assay (acute phase <10, convalescent phase >1,280). Serum samples from case-patient 2 did not contain antibodies detectable by either assay. Detection of virus in serum strongly supports a role for EMCV in human infection and febrile illness. PMID:19331761

Gotuzzo, Eduardo; Blair, Patrick; Nix, W. Allan; Ksiazek, Thomas G.; Comer, James A.; Rollin, Pierre; Goldsmith, Cynthia S.; Olson, James; Kochel, Tadeusz J.

2009-01-01

377

Paramyxovirus type 1 infections of racing pigeons: 1 characterisation of isolated viruses  

Microsoft Academic Search

Viruses isolated from field outbreaks of disease in racing pigeons in continental Europe and Great Britain were shown to be identical by serological tests using conventional chicken antisera and mouse monoclonal antibodies. The pigeon viruses showed high levels of cross-reaction to Newcastle disease virus (NDV) in haemagglutination inhibition tests and Madin-Darby bovine kidney cells infected with pigeon virus isolates bound

DJ Alexander; PH Russell

1984-01-01

378

Determination of Baylisascaris schroederi infection in wild giant pandas by an accurate and sensitive PCR/CE-SSCP method.  

PubMed

It has been recognized that other than habitat loss, degradation and fragmentation, the infection of the roundworm Baylisascaris schroederi (B. schroederi) is one of the major causes of death in wild giant pandas. However, the prevalence and intensity of the parasite infection has been inconsistently reported through a method that uses sedimentation-floatation followed by a microscope examination. This method fails to accurately determine infection because there are many bamboo residues and/or few B. schroederi eggs in the examined fecal samples. In the present study, we adopted a method that uses PCR and capillary electrophoresis combined with a single-strand conformation polymorphism analysis (PCR/CE-SSCP) to detect B. schroederi infection in wild giant pandas at a nature reserve, and compared it to the traditional microscope approach. The PCR specifically amplified a single band of 279-bp from both fecal samples and positive controls, which was confirmed by sequence analysis to correspond to the mitochondrial COII gene of B. schroederi. Moreover, it was demonstrated that the amount of genomic DNA was linearly correlated with the peak area of the CE-SSCP analysis. Thus, our adopted method can reliably detect the infectious prevalence and intensity of B. schroederi in wild giant pandas. The prevalence of B. schroederi was found to be 54% in the 91 fecal samples examined, and 48% in the fecal samples of 31 identified individual giant pandas. Infectious intensities of the 91 fecal samples were detected to range from 2.8 to 959.2 units/gram, and from 4.8 to 959.2 units/gram in the fecal samples of the 31 identified giant pandas. For comparison, by using the traditional microscope method, the prevalence of B. schroederi was found to be only 33% in the 91 fecal samples, 32% in the fecal samples of the 31 identified giant pandas, and no reliable infectious intensity was observed. PMID:22911871

Zhang, Wenping; Yie, Shangmian; Yue, Bisong; Zhou, Jielong; An, Renxiong; Yang, Jiangdong; Chen, Wangli; Wang, Chengdong; Zhang, Liang; Shen, Fujun; Yang, Guangyou; Hou, Rong; Zhang, Zhihe

2012-01-01

379

Epidemiology of bovine ephemeral fever virus infection in Taiwan.  

PubMed

Sick animals with excessive nasal discharges and protruding tongue as a result of dyspnea were observed in the August of 1996. Eight strains of BEF virus were isolated from heparinized blood samples of the affected cattle. Most of the affected cattle were difficult to be treated and had a poor prognosis. A total of 516 farms in the 9 districts of Taiwan were affected in 1996. Among a population of 110,247 dairy cattle, 14,993 (13.6%) cattle were found to be clinically ill. During the epidemic, 1,685 (11.3%) affected cattle were culled or dead after the onset of the disease. Furthermore, a strain of Ibaraki virus was isolated from the blood sample of a sick cattle that showed pyrexia, labored respiration and solitary behavior in the affected farm. The cattle with Ibaraki virus infection had typical symptoms of BEF at the early stage of the disease, but neither stomatitis nor pharyngoesophageal paralysis was observed at the onset of the disease. The outbreak was presumably brought about by the low level or non-immune status of a large cattle population due to the negligence of BEF vaccination. Therefore, the disease easily recurred in Taiwan after a typhoon episode in the August of 1996, which resulted in the proliferation of biting midges in the field. No difference in the antigenicty was found between the new and the previous isolates of BEF virus. As analyzed by cross neutralization test, the isolated BEF viruses showed no relationship to the Kimberley and Berrimah viruses that were isolated from the blood of cattle and related to BEF virus in Australia. We have tried to advise farmers that they must vaccinate their cattle annually to prevent BEF outbreak in the future. PMID:9880933

Liao, Y K; Inaba, Y; Li, N J; Chain, C Y; Lee, S L; Liou, P P

1998-11-01

380

A Human Lung Xenograft Mouse Model of Nipah Virus Infection  

PubMed Central

Nipah virus (NiV) is a member of the genus Henipavirus (family Paramyxoviridae) that causes severe and often lethal respiratory illness and encephalitis in humans with high mortality rates (up to 92%). NiV can cause Acute Lung Injury (ALI) in humans, and human-to-human transmission has been observed in recent outbreaks of NiV. While the exact route of transmission to humans is not known, we have previously shown that NiV can efficiently infect human respiratory epithelial cells. The molecular mechanisms of NiV-associated ALI in the human respiratory tract are unknown. Thus, there is an urgent need for models of henipavirus infection of the human respiratory tract to study the pathogenesis and understand the host responses. Here, we describe a novel human lung xenograft model in mice to study the pathogenesis of NiV. Following transplantation, human fetal lung xenografts rapidly graft and develop mature structures of adult lungs including cartilage, vascular vessels, ciliated pseudostratified columnar epithelium, and primitive “air” spaces filled with mucus and lined by cuboidal to flat epithelium. Following infection, NiV grows to high titers (107 TCID50/gram lung tissue) as early as 3 days post infection (pi). NiV targets both the endothelium as well as respiratory epithelium in the human lung tissues, and results in syncytia formation. NiV infection in the human lung results in the production of several cytokines and chemokines including IL-6, IP-10, eotaxin, G-CSF and GM-CSF on days 5 and 7 pi. In conclusion, this study demonstrates that NiV can replicate to high titers in a novel in vivo model of the human respiratory tract, resulting in a robust inflammatory response, which is known to be associated with ALI. This model will facilitate progress in the fundamental understanding of henipavirus pathogenesis and virus-host interactions; it will also provide biologically relevant models for other respiratory viruses. PMID:24699832

Borisevich, Viktoriya; Goez, Yenny; Rockx, Barry

2014-01-01

381

Index cluster study of dengue virus infection in Nicaragua.  

PubMed

Traditional study designs do not identify acute asymptomatic or pre-symptomatic dengue virus (DENV) infections, thus limiting our understanding of immunologic and viral factors that modulate infection outcome. In the 2006 and 2007 dengue seasons, we conducted a pilot index cluster study in Managua, Nicaragua, in which 442 persons living within 50 meters of 22 index cases identified through an ongoing pediatric cohort study were evaluated for DENV infection. Post-enrollment and pre-enrollment DENV infections were confirmed in 12 (2.7%) and 19 (4.3%) contacts, respectively. Five (42%) post-enrollment infections were asymptomatic, and DENV-2 was identified in 9 (75%) infections. Phylogenetic analysis with full-length DENV genomic sequence from contacts, index cases, and cohort dengue cases indicated focal transmission and infection outside the local area. We demonstrate the feasibility of identification of acute asymptomatic and pre-symptomatic cases in urban Latin America, the first report of such a study in the Americas, and identify age and concomitant immunity to DENV of contacts as a key factor in index cluster study design. PMID:20810839

Reyes, Miguel; Mercado, Juan Carlos; Standish, Katherine; Matute, Juan Carlos; Ortega, Oscar; Moraga, Berman; Avilés, William; Henn, Matthew R; Balmaseda, Angel; Kuan, Guillermina; Harris, Eva

2010-09-01

382

Genomewide Association Analysis of Respiratory Syncytial Virus Infection in Mice? †  

PubMed Central

Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in infants, with about half being infected in their first year of life. Yet only 2 to 3% of infants are hospitalized for RSV infection, suggesting that individual susceptibility contributes to disease severity. Previously, we determined that AKR/J (susceptible) mice developed high lung RSV titers and showed delayed weight recovery, whereas C57BL/6J (resistant) mice demonstrated low lung RSV titers and rapid weight recovery. In addition, we have reported that gene-targeted mice lacking the cystic fibrosis transmembrane conductance regulator (Cftr; ATP-binding cassette subfamily C, member 7) are susceptible to RSV infection. For this report, recombinant backcross and F2 progeny derived from C57BL/6J and AKR/J mice were infected with RSV, their lung titers were measured, and quantitative trait locus (QTL) analysis was performed. A major QTL, designated Rsvs1, was identified on proximal mouse chromosome 6 in both recombinant populations. Microarray analysis comparing lung transcripts of the parental strains during infection identified several candidate genes that mapped to the Rsvs1 interval, including Cftr. These findings add to our understanding of individual RSV susceptibility and strongly support a modifier role for CFTR in RSV infection, a significant cause of respiratory morbidity in infants with cystic fibrosis. PMID:20015999

Stark, James M.; Barmada, M. Michael; Winterberg, Abby V.; Majumber, Nilanjana; Gibbons, William J.; Stark, Marilyn A.; Sartor, Maureen A.; Medvedovic, Mario; Kolls, Jay; Bein, Kiflai; Mailaparambil, Beena; Krueger, Marcus; Heinzmann, Andrea; Leikauf, George D.; Prows, Daniel R.

2010-01-01

383

IL-10 Signaling Blockade Controls Murine West Nile Virus Infection  

PubMed Central

West Nile virus (WNV), a mosquito-borne single-stranded RNA flavivirus, can cause significant human morbidity and mortality. Our data show that interleukin-10 (IL-10) is dramatically elevated both in vitro and in vivo following WNV infection. Consistent with an etiologic role of IL-10 in WNV pathogenesis, we find that WNV infection is markedly diminished in IL-10 deficient (IL-10?/?) mice, and pharmacologic blockade of IL-10 signaling by IL-10 neutralizing antibody increases survival of WNV-infected mice. Increased production of antiviral cytokines in IL-10?/? mice is associated with more efficient control of WNV infection. Moreover, CD4+ T cells produce copious amounts of IL-10, and may be an important cellular source of IL-10 during WNV infection in vivo. In conclusion, IL-10 signaling plays a negative role in immunity against WNV infection, and blockade of IL-10 signaling by genetic or pharmacologic means helps to control viral infection, suggesting a novel anti-WNV therapeutic strategy. PMID:19816558

Bai, Fengwei; Wang, Penghua; Kamanaka, Masahito; Connolly, Tarah M.; Gate, David; Montgomery, Ruth R.; Flavell, Richard A.; Fikrig, Erol

2009-01-01

384

RESTRAINT STRESS MODULATES VIRUS SPECIFIC ADAPTIVE IMMUNITY DURING ACUTE THEILER'S VIRUS INFECTION  

PubMed Central

Multiple sclerosis (MS) is a devastating CNS disease of unknown origin. Multiple factors including genetic background, infection, and psychological stress affect the onset or progression of MS. Theiler’s murine encephalomyelitis virus (TMEV) infection is an animal model of MS in which aberrant immunity leads to viral persistence and subsequently results in demyelination that resembles MS. Here, we examined how stress during acute TMEV infection altered virus-specific cell mediated responses. Using immunodominant viral peptides specific for either CD4+ or CD8+ T cells, we found that stress reduced IFN-? producing virus-specific CD4+ and CD8+ T cells in the spleen and CD8+ T cells CNS. Cytokine production by cells isolated from the CNS or spleens following stimulation with virus or viral peptides, indicated that stress decreased both type 1 and type 2 responses. Glucocorticoids were implicated in the decreased T cell function as the effects of stress were partially reversed by concurrent RU486 administration but mimicked by dexamethasone. As T cells mediate viral clearance in this model, our data support the hypothesis that stress-induced immunosuppression may provide a mechanism for enhanced viral persistence within the CNS. PMID:19348911

Steelman, Andrew J.; Dean, Dana D.; Young, Colin R.; Smith, Roger; Prentice, Thomas W.; Meagher, Mary W.; Welsh, C. Jane R.

2009-01-01

385

Avian influenza virus infection dynamics in shorebird hosts.  

PubMed

To gain insight into avian influenza virus (AIV) transmission, exposure, and maintenance patterns in shorebirds at Delaware Bay during spring migration, we examined temporal AIV prevalence trends in four Charadriiformes species with the use of serial cross-sectional data from 2000 through 2008 and generalized linear and additive models. Prevalence of AIV in Ruddy Turnstones (Arenaria interpres morinella) increased after arrival, peaked in mid-late May, and decreased prior to departure. Antibody prevalence also increased over this period; together, these results suggested local infection and recovery prior to departure. Red Knots (Calidris canutus rufa), Sanderlings (Calidris alba), and Laughing Gulls (Leucophaeus atricilla) were rarely infected, but dynamic changes in antibody prevalence differed among species. In Red Knots, declining antibody prevalence over the stopover period suggested AIV exposure prior to arrival at Delaware Bay with limited infection at this site. Antibody prevalence was consistently high in Laughing Gulls and low in Sanderlings. Both viral prevalence and antibody prevalence in Sanderlings varied directly with those in turnstones, suggesting virus spillover to Sanderlings. Results indicate that, although hundreds of thousands of birds concentrate at Delaware Bay during spring, dynamics of AIV infection differ among species, perhaps due to differences in susceptibility, potential for contact with AIV at this site, or prior exposure. Additionally, Ruddy Turnstones possibly act as a local AIV amplifying host rather than a reservoir. PMID:22493108

Maxted, Angela M; Luttrell, M Page; Goekjian, Virginia H; Brown, Justin D; Niles, Lawrence J; Dey, Amanda D; Kalasz, Kevin S; Swayne, David E; Stallknecht, David E

2012-04-01

386

Host immune status and response to hepatitis E virus infection.  

PubMed

Hepatitis E virus (HEV), identified over 30 years ago, remains a serious threat to life, health, and productivity in developing countries where access to clean water is limited. Recognition that HEV also circulates as a zoonotic and food-borne pathogen in developed countries is more recent. Even without treatment, most cases of HEV-related acute viral hepatitis (with or without jaundice) resolve within 1 to 2 months. However, HEV sometimes leads to acute liver failure, chronic infection, or extrahepatic symptoms. The mechanisms of pathogenesis appear to be substantially immune mediated. This review covers the epidemiology of HEV infection worldwide, the humoral and cellular immune responses to HEV, and the persistence and protection of antibodies produced in response to both natural infection and vaccines. We focus on the contributions of altered immune states (associated with pregnancy, human immunodeficiency virus [HIV], and immunosuppressive agents used in cancer and transplant medicine) to the elevated risks of chronic infection (in immunosuppressed/immunocompromised patients) and acute liver failure and mortality (among pregnant women). We conclude by discussing outstanding questions about the immune response to HEV and interactions with hormones and comorbid conditions. These questions take on heightened importance now that a vaccine is available. PMID:24396140

Krain, Lisa J; Nelson, Kenrad E; Labrique, Alain B

2014-01-01

387

Giant kidney worm (Dioctophyma renale) infections in dogs from Northern Paraná, Brazil.  

PubMed

This article describes the pathological observations of Dioctophyma renale in dogs from the northern region of the State of Paraná, Brazil. A female, 6-year-old dog, Fila Brasileiro breed and a 16-year-old, male Poodle were diagnosed positive for D. renale during routine necropsy. Clinically, both dogs demonstrated hematuria, and the Poodle had a radiographic diagnosis of prostatic tumor, but neither had a clinical diagnosis of this infection prior to necropsy. Three giant worms were observed in the urinary bladder of the first case and one within the renal pelvis of the other dog. Histological findings were similar in both cases and represented compressive atrophy due to the presence of the nematode. Additionally, aspects of the life cycle, pathogenesis and epidemiology associated with this parasitism in Brazil are also discussed. PMID:17156927

Nakagawa, Tizianne Larissa Duim Ribeiro; Bracarense, Ana Paula Frederico Rodrigues Loureiro; dos Reis, Antônio Carlos Faria; Yamamura, Milton Hissashi; Headley, Selwyn Arlington

2007-04-30

388

The Transcriptional Response of Drosophila melanogaster to Infection with the Sigma Virus  

E-print Network

The Transcriptional Response of Drosophila melanogaster to Infection with the Sigma Virus immune response in Drosophila melanogaster, but it is unclear whether viral infections induce of Drosophila melanogaster to Infection with the Sigma Virus (Rhabdoviridae). PLoS ONE 4(8): e6838. doi:10

Jiggins, Francis

389

Social stress alters the severity and onset of the chronic phase of Theiler's virus infection  

E-print Network

Social stress alters the severity and onset of the chronic phase of Theiler's virus infection Robin form 3 February 2006; accepted 27 February 2006 Abstract Social stress alters the acute phase of Theiler's virus infection (TMEV), a model of multiple sclerosis. Stress applied prior to infection had

Meagher, Mary

390

Platforms for exploring host-pathogen interactions in hepatitis C virus infection  

E-print Network

Afflicting almost 200 million worldwide, hepatitis C virus (HCV) mounts a chronic infection of liver hepatocytes that causes substantial morbidity and mortality. An understanding of host-virus interactions will drive the ...

Trehan, Kartik

2012-01-01

391

RNA Interference-Based Approach to Combat Viral Infections: Vesicular Stomatitis Virus Group Prototype  

E-print Network

Vesicular stomatitis virus (VSV) is considered a prototype for studying non-segmented negative-stranded ribonucleic acid (RNA) viruses. Livestock are naturally infected by VSV, causing severe economic impact due to lack of any effective treatment...

Ramirez Carvajal, Lisbeth

2012-10-19

392

Vaccine to Confer to Nonhuman Primates Complete Protection Against Multistrain Ebola and Marburg Virus Infections.  

National Technical Information Service (NTIS)

Filoviruses (Ebola and Marburg viruses) are among the deadliest viruses known to mankind with mortality rates nearing 90%. These pathogens are highly infectious through contact with infected body fluids and can be easily aerosolized. Additionally, there a...

D. Wang, D. L. Swenson, J. Woraratanadharm, K. L. Warfield, M. Luo

2008-01-01

393

ULTRASTRUCTURAL FEATURES OF BETA LEAVES INFECTED WITH BEET YELLOWS VIRUS  

PubMed Central

A cytochemical and electron microscope study has been made of leaves of sugar beet infected with beet yellows virus. Inclusions of particles, which agree in size with beet yellows virus particles isolated by other investigators, have been localized in the ground cytoplasm, in the chloroplasts, and in the nuclei. These particles are circa 100 A in diameter and have an electron-transparent core of 30 to 40 A. Use of acridine orange, azure B, and pyronine Y has revealed that the cytoplasmic inclusion bodies, which consist wholly of the elongate particles, have a strong RNA reaction removable by RNase pretreatment. Particles observed in the chloroplasts may or may not be associated with lipid spheres. If they are, the particles are confined to the periphery of the spheres. In this position the particles are arranged tangentially and are further arranged parallel into groups which lie at various angles to one another. Within the groups the particles are regularly spaced in a three dimensional lattice. Particles located free in the stromal regions are often arranged regularly in curved rows which lie parallel to one another so that a three dimensional lattice is formed. The dispersed and compact forms of virus inclusions are described and related to the condition of the associated cytoplasm. The ground cytoplasm of cells associated with the sieve elements contains numerous ribosomes. A decrease in the number of ribosomes is concomitant with the increase in size of virus aggregations in a cell. Vesiculation of some component of the cytoplasm occurs during the period of virus replication. The vesicles are approximately 100 mµ in diameter and could be derived from the dictyosomes. At later stages of infection these vesicles collapse and convoluted membranous material appears. PMID:5971643

Cronshaw, J.; Hoefert, L.; Esau, K.

1966-01-01

394

Differing Effects of Herpes Simplex Virus 1 and Pseudorabies Virus Infections on Centrosomal Function  

PubMed Central

Efficient intracellular transport of the capsid of alphaherpesviruses, such as herpes simplex virus 1 (HSV-1), is known to be dependent upon the microtubule (MT) network. Typically, the MT network radiates from an MT-organizing center (MTOC), which is, in most cases, the centrosome. During herpesvirus egress, it has been assumed that capsids travel first from the nucleus to the centrosome and then from the centrosome to the site of envelopment. Here we report that the centrosome is no longer a primary MTOC in HSV-1-infected cells, but it retains this function in cells infected by another alphaherpesvirus, pseudorabies virus (PrV). As a result, MTs formed at late times after infection with PrV grow from a major, centralized MTOC, while those formed after HSV-1 infection arise from dispersed locations in the cytoplasm, indicating the presence of alternative and minor MTOCs. Thus, loss of the principal MT nucleating center in cells following HSV-1 infection raises questions about the mechanism of HSV-1 capsid egress. It is possible that, rather than passing via the centrosome, capsids may travel directly to the site of envelopment after exiting the nucleus. We suggest that, in HSV-1-infected cells, the disruption of centrosomal functions triggers reorganization of the MT network to favor noncentrosomal MTs and promote efficient viral spread. PMID:23596303

Labetoulle, Marc; Rixon, Frazer J.

2013-01-01

395

Necrosis of adipose tissue induced by sequential infections with unrelated viruses.  

PubMed Central

Vaccinia virus infection in mice previously infected with and immune to lymphocytic choriomeningitis virus resulted in a clinical illness which neither virus alone induced. The main pathologic finding was extensive fat necrosis with a cellular infiltrate suggestive of delayed type hypersensitivity. Vaccinia virus titers in adipose tissue of clinically ill mice were not higher than those in relevant control groups. This indicates that an unusual virus-induced disease can arise in an animal with a history of unrelated virus infection, and that this disease may be due to an altered host response to infection. The experimental model presented here suggests that chronic inflammation and necrosis of a given tissue may depend on sequential infection with two viruses, neither of which would be capable of inducing such a lesion. Images Figure 1 Figures 2-6 PMID:4025507

Yang, H. Y.; Joris, I.; Majno, G.; Welsh, R. M.

1985-01-01

396

Experimental Infections of Wild Birds with West Nile Virus  

PubMed Central

Avian models of West Nile virus (WNV) disease have become pivotal in the study of infection pathogenesis and transmission, despite the intrinsic constraints that represents this type of experimental research that needs to be conducted in biosecurity level 3 (BSL3) facilities. This review summarizes the main achievements of WNV experimental research carried out in wild birds, highlighting advantages and limitations of this model. Viral and host factors that determine the infection outcome are analyzed in detail, as well as recent discoveries about avian immunity, viral transmission, and persistence achieved through experimental research. Studies of laboratory infections in the natural host will help to understand variations in susceptibility and reservoir competence among bird species, as well as in the epidemiological patterns found in different affected areas. PMID:24531334

Perez-Ramirez, Elisa; Llorente, Francisco; Jimenez-Clavero, Miguel Angel

2014-01-01

397

Molecular evidence of simian virus 40 infections in children  

NASA Technical Reports Server (NTRS)

Recent studies have detected simian virus 40 (SV40) DNA in certain human tumors and normal tissues. The significance of human infections by SV40, which was first discovered as a contaminant of poliovirus vaccines used between 1955 and 1963, remains unknown. The occurrence of SV40 infections in unselected hospitalized children was evaluated. Polymerase chain reaction and DNA sequence analyses were done on archival tissue specimens from patients positive for SV40 neutralizing antibody. SV40 DNA was identified in samples from 4 of 20 children (1 Wilms' tumor, 3 transplanted kidney samples). Sequence variation among SV40 regulatory regions ruled out laboratory contamination of specimens. This study shows the presence of SV40 infections in pediatric patients born after 1982.

Butel, J. S.; Arrington, A. S.; Wong, C.; Lednicky, J. A.; Finegold, M. J.

1999-01-01

398

Alcoholic hepatitis and concomitant hepatitis C virus infection.  

PubMed

Hepatitis C virus (HCV) infection and alcohol abuse are two most important causes of chronic liver disease in the United States. Alcoholic hepatitis is a unique clinical syndrome among patients with chronic and active alcohol abuse with a potential for high short-term mortality. About 20% of patients presenting with alcoholic hepatitis have concomitant HCV infection. Mortality from alcoholic hepatitis is increased in the presence of concomitant hepatitis C due to synergistic interaction between HCV and alcohol in causing hepatocellular damage. Large prospective randomized studies are needed to develop guidelines on the use of corticosteroids among patients with alcoholic hepatitis and concomitant HCV infection. The impact of antiviral therapy on mortality and outcome in the setting of alcoholic hepatitis remains a novel area for future research. PMID:25232227

Shoreibah, Mohamed; Anand, Bhupinderjit S; Singal, Ashwani K

2014-09-14

399

Gamma Interferon Primes Productive Human Immunodeficiency Virus Infection in Astrocytes  

PubMed Central

Considerable controversy exists over whether astrocytes can support human immunodeficiency virus (HIV) infection. We evaluated the impact of three cytokines critical to the development of HIV neuropathogenesis, gamma interferon (IFN-?), granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor alpha, on priming astrocytes for HIV infection. We demonstrate that IFN-? was the most potent in its ability to facilitate substantial productive HIV infection of an astroglioma cell line (U87MG) and human fetal astrocytes (HFA). The mechanism of IFN-?-mediated priming of HIV in HFA is unlikely to be at the level of up-regulation of receptors and coreceptors relevant to HIV entry. These data demonstrate that cytokine priming can alter HIV replication in astrocytes. PMID:16352578

Carroll-Anzinger, Deborah; Al-Harthi, Lena

2006-01-01

400

Epstein-Barr virus infection and replication in a human epithelial cell system  

Microsoft Academic Search

EPSTEIN-BARR virus, a human herpesvirus with oncogenic potential, infects two target tissues in vivo: B lymphocytes, where the infection is largely non-productive1, and stratified squamous epithelium in which virus replication occurs2,3. The interaction with B cells, initiated through virus binding to the B-cell surface molecule CR2 (ref. 4), has been studied in vitro and the virus 'latent' genes associated with

Q. X. Li; L. S. Young; G. Niedobitek; C. W. Dawson; M. Birkenbach; F. Wang; A. B. Rickinson

1992-01-01

401

Highly pathogenic avian influenza virus (H5N1) in experimentally infected adult mute swans.  

PubMed

Adult, healthy mute swans were experimentally infected with highly pathogenic avian influenza virus A/Cygnus cygnus/Germany/R65/2006 subtype H5N1. Immunologically naive birds died, whereas animals with preexisting, naturally acquired avian influenza virus-specific antibodies became infected asymptomatically and shed virus. Adult mute swans are highly susceptible, excrete virus, and can be clinically protected by preexposure immunity. PMID:18680652

Kalthoff, Donata; Breithaupt, Angele; Teifke, Jens P; Globig, Anja; Harder, Timm; Mettenleiter, Thomas C; Beer, Martin

2008-08-01

402

The woodchuck model of hepatitis B virus infection.  

PubMed

The woodchuck hepatitis virus (WHV) was the first of the mammalian and avian hepadnaviruses described after discovery of the virus of hepatitis B (HBV). Woodchucks chronically infected with WHV develop progressively severe hepatitis and hepatocellular carcinoma, which present as lesions that are remarkably similar to those associated with HBV infection in humans. The initial virological studies and studies of pathogenesis utilized woodchucks that had been trapped in the wild and had acquired WHV infection naturally. Research with wild woodchucks was complicated by lack of knowledge of their backgrounds (e.g., dietary history, exposure to parasites or environmental toxins, and source and duration of WHV infection). Breeding colonies of woodchucks have been established and maintained in laboratory animal facilities, and laboratory-reared woodchucks are superior for experimental studies of pathogenesis or hepatocarcinogenesis. It is possible to infect neonatal woodchucks born in the laboratory with standardized inocula and produce a high rate of chronic WHV carriers that are useful for controlled investigations. WHV has been shown experimentally to cause hepatocellular carcinoma, supporting conclusions based on epidemiological and molecular virological studies that HBV is an important etiological factor in human hepatocarcinogenesis. Chronic WHV carrier woodchucks have become a valuable animal model for the preclinical evaluation of antiviral therapy for HBV infection, providing useful pharmacokinetic and pharmacodynamic results in a relevant animal disease model. It also has been shown that the pattern of toxicity and hepatic injury observed in woodchucks treated with certain fluorinated pyrimidines is remarkably similar to that observed in humans that were treated with the same drugs, suggesting the woodchuck has significant potential for the preclincial assessment of antiviral drug toxicity. PMID:11406711

Tennant, B C; Gerin, J L

2001-01-01

403

Herpes simplex and varicella-zoster virus infections during pregnancy: current concepts of prevention, diagnosis and therapy. Part 1: Herpes simplex virus infections  

Microsoft Academic Search

Primary herpes simplex virus (HSV) infection may lead to severe illness in pregnancy and may be associated with transplacental\\u000a virus transmission and fetal infection. The consequences may be abortion, stillbirth and congenital malformations. In neonates,\\u000a the clinical findings after intrauterine HSV infection are characterized by skin lesions, diseases of the eye and neurologic\\u000a damage. Herpes genitalis of pregnant women at

A. Sauerbrei; P. Wutzler

2007-01-01

404

Immunologic, metabolic and genetic factors in hepatitis C virus infection  

PubMed Central

The mechanisms that regulate disease progression during hepatitis C virus (HCV) infection and the response to treatment are not clearly identified. Numerous studies have demonstrated that a strong host immune response against HCV favors HCV clearance. In addition, genetic factors and metabolic machinery, particularly cholesterol modulation, are involved in HCV infection. It is likely that the interplay between all of these factors contributes to the outcome of HCV infection. In recent years, the world has experienced its largest epidemic of obesity. Mexico and the United States are the leading sufferers from this epidemic at the global level. Obesity is associated with the development of numerous pathologies including hypercholesterolemia which is one of the eight most important risk factors for mortality in Mexico. This may be related to the course of HCV infection in this population. Here, we focus on the urgent need to study the progression of HCV infection in relation to ethnic characteristics. Discoveries are discussed that hold promise in identifying immune, metabolic and genetic factors that, in conjunction, could be therapeutic targets or predictors of the progression of HCV infection. PMID:24707127

Fierro, Nora A; Gonzalez-Aldaco, Karina; Torres-Valadez, Rafael; Martinez-Lopez, Erika; Roman, Sonia; Panduro, Arturo

2014-01-01

405

Management of hepatitis C virus infection in hemodialysis patients.  

PubMed

The prevalence of hepatitis C virus (HCV) infection in patients on maintenance hemodialysis (MHD) is relatively higher than those without MHD. Chronic HCV infection detrimentally affects the life quality and expectancy, leads to renal transplant rejection, and increases the mortality of MHD patients. With the application of erythropoietin to improve uremic anemia and avoid blood transfusion, the new HCV infections during MHD in recent years are mainly caused by the lack of stringent universal precautions. Strict implementation of universal precautions for HCV transmission has led to markedly decreased HCV infections in many hemodialysis units, but physicians still should be alert for the anti-HCV negative HCV infection and occult HCV infection in MHD patients. Standard interferon alpha and pegylated interferon alpha monotherapies at a reduced dose are currently the main treatment strategies for MHD patients with active HCV replication, but how to increase the sustained virological response and decrease the side effects is the key problem. IFN?-free treatments with two or three direct-acting antivirals without ribavirin in MHD patients are waiting for future investigations. PMID:25018852

Yu, Yue-Cheng; Wang, Yue; He, Chang-Lun; Wang, Mao-Rong; Wang, Yu-Ming

2014-06-27

406

Inhibition of lytic infection of pseudorabies virus by arginine depletion  

SciTech Connect

Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzing the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression.

Wang, H.-C. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China); Kao, Y.-C. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China); Chang, T-J. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China); Wong, M.-L. [Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan (China)]. E-mail: mlwong@dragon.nchu.edu.tw

2005-08-26

407

Inapparent Virus Infections and their Interactions in Pupae of the Honey Bee (Apis mellifera Linnaeus) in Australia  

Microsoft Academic Search

SUMMARY When honey bee pupae from seemingly healthy Australian colonies were injected with various salt solutions, inapparent infections of black queen-cell virus (BQCV), Kashmir bee virus (KBV), sacbrood virus (SBV) and, occasionally, cricket paralysis virus were activated. The activated viruses replicated to detectable concentrations after pupae were incubated at 35 °C for 3 days. Inapparent infections of SBV, but not

D. L. Anderson; A. J. Gibbs

1988-01-01

408

Experimental Infection of Raccoons (Procyon lotor) with West Nile Virus  

PubMed Central

To characterize the responses of raccoons to West Nile virus (WNV) infection, we subcutaneously exposed them to WNV. Moderately high viremia titers (? 104.6 plaque forming units [PFU]/mL of serum) were noted in select individuals; however, peak viremia titers were variable and viremia was detectable in some individuals as late as 10 days post-inoculation (DPI). In addition, fecal shedding was prolonged in some animals (e.g., between 6 and 13 DPI in one individual), with up to105.0 PFU/fecal swab detected. West Nile virus was not detected in tissues collected on 10 or 16 DPI, and no histologic lesions attributable to WNV infection were observed. Overall, viremia profiles suggest that raccoons are unlikely to be important WNV amplifying hosts. However, this species may occasionally shed significant quantities of virus in feces. Considering their behavioral ecology, including repeated use of same-site latrines, high levels of fecal shedding could potentially lead to interspecies fecal-oral WNV transmission. PMID:20889868

Root, J. Jeffrey; Bentler, Kevin T.; Nemeth, Nicole M.; Gidlewski, Thomas; Spraker, Terry R.; Franklin, Alan B.

2010-01-01

409

Influenza C virus infection in military recruits--symptoms and clinical manifestation.  

PubMed

Due to the lack of rapid diagnostic tests, clinical features of Influenza C virus infections are poorly characterized. Respiratory infections in military recruits in eastern Finland were monitored between July 2004 and December 2005 in order to study the epidemiology and clinical picture of infections caused by this virus. Blood samples were obtained at entry and at the end of the military service, and during each episode of respiratory infection to measure antibody responses against 10 viral and 2 bacterial pathogens. If possible, sputum samples were collected during the acute phase of respiratory infection episodes. Symptoms of the episodes were recorded for comparison of the clinical picture caused by various infectious agents. Infection with influenza C virus was detected in 38 of 892 young men during their service. The virus usually caused a mild upper respiratory tract infection. Most typical clinical features of influenza C virus infection were cough, rhinitis, and hoarseness. A striking difference to infections caused by influenza A virus was the lack of fever. Influenza C virus is an important cause of a respiratory tract infection in army conscripts. Infections with this virus are usually mild but can be complicated in some cases. PMID:24122799

Kauppila, Jaana; Rönkkö, Esa; Juvonen, Raija; Saukkoriipi, Annika; Saikku, Pekka; Bloigu, Aini; Vainio, Olli; Ziegler, Thedi

2014-05-01

410

Autoimmunity and extrahepatic manifestations in hepatitis C virus infection.  

PubMed

Hepatitis C virus (HCV) infection is associated with various extrahepatic manifestations: mixed cryoglobulinaemia, membranoproliferative glomerulonephritis and, in southern Europe, to some extent with porphyria cutanea tarda. The association of haplotype HLA B-8 and DR-3 mixed cryoglobulinaemia and HCV infection has recently been demonstrated. Interferon alpha therapy decreases hepatitis C viraemia and improves the clinical signs and biochemical abnormalities of cryoglobulinaemia. There seems to be a south-north gradient in the prevalence of HCV-associated cryoglobulinaemia. The rare combination of hepatitis C and panarteritis nodosa has still not been confirmed. The sicca syndrome also seems to be associated with hepatitis C virus, but this is not the typical Sjögren syndrome. Existing studies have not answered the question of whether HCV plays a pathogenic role in the development of thyroid dysfunction and autoimmune thyroiditis. There seems to be a genetic predisposition for the manifestations of thyroid disease in the case of hepatitis C infection and interferon therapy. This predominantly affects women with haplotype HLA DR-3. Before beginning interferon therapy, these patients often show thyroid autoantibodies against the thyroid peroxidase and/or thyroglobulin. It is still unclear whether the rare combination of hepatitis C with aplastic anaemia and lymphoma has pathogenic aspects. These haematological manifestations are thought to be induced by the infection of haematopoietic cells with the hepatitis C virus. In rare cases, a stimulated HCV-induced interferon gamma synthesis by haematopoietic stem cells has been shown. Although an epidemiological association of hepatitis C with lichen planus, neuropathies and other diseases has been observed, the aetiological role and the pathogenic involvement of the hepatitis C infection remains unclear. Furthermore, the question of whether these extrahepatic diseases are autoimmune has not been clarified. On the other hand, a number of autoantibodies may be observed during the course of hepatitis C. Of particular interest are liver/kidney microsomal antibodies (LKM). Their occurrence in viral hepatitis may indicate an increased risk for treatment with interferons. In the clinical setting, the presence of these diseases should suggest hepatitis C infection and hepatitis C antibodies should be tested and, if positive, hepatitis C-RNA is indicated. If there is any evidence of an aetiological association of replicative hepatitis C infection and the above-mentioned extrahepatic diseases, antiviral treatment should be considered. PMID:10622558

Manns, M P; Rambusch, E G

1999-01-01

411

The effect of fungicides on sugar beet infected with beet mild yellowing virus  

Microsoft Academic Search

Studies were made in 1989, 1990 and 1991 to establish whether carbendazim (MBC) had a direct therapeutic effect on sugar beet plants infected with beet mild yellowing virus (BMW), resulting in detectable yield benefits. In a field trial in 1989 virus-infected plots treated with carbendazim gave a significantly higher yield, of 0.66 t sugar\\/ha, than virus-infected plots sprayed with sulphur

H. G. Smith; M. J. C. Asher; G. E. Williams; P. B. Hallsworth

1995-01-01

412

Early Events Associated with Infection of Epstein-Barr Virus Infection of Primary B-Cells  

PubMed Central

Epstein Barr virus (EBV) is closely associated with the development of a vast number of human cancers. To develop a system for monitoring early cellular and viral events associated with EBV infection a self-recombining BAC containing 172-kb of the Epstein Barr virus genome BAC-EBV designated as MD1 BAC (Chen et al., 2005, J.Virology) was used to introduce an expression cassette of green fluorescent protein (GFP) by homologous recombination, and the resultant BAC clone, BAC-GFP-EBV was transfected into the HEK 293T epithelial cell line. The resulting recombinant GFP EBV was induced to produce progeny virus by chemical inducer from the stable HEK 293T BAC GFP EBV cell line and the virus was used to immortalize human primary B-cell as monitored by green fluorescence and outgrowth of the primary B cells. The infection, B-cell activation and cell proliferation due to GFP EBV was monitored by the expression of the B-cell surface antigens CD5, CD10, CD19, CD23, CD39, CD40 , CD44 and the intercellular proliferation marker Ki-67 using Flow cytometry. The results show a dramatic increase in Ki-67 which continues to increase by 6–7 days post-infection. Likewise, CD40 signals showed a gradual increase, whereas CD23 signals were increased by 6–12 hours, maximally by 3 days and then decreased. Monitoring the viral gene expression pattern showed an early burst of lytic gene expression. This up-regulation of lytic gene expression prior to latent genes during early infection strongly suggests that EBV infects primary B-cell with an initial burst of lytic gene expression and the resulting progeny virus is competent for infecting new primary B-cells. This process may be critical for establishment of latency prior to cellular transformation. The newly infected primary B-cells can be further analyzed for investigating B cell activation due to EBV infection. PMID:19784370

Halder, Sabyasachi; Murakami, Masanao; Verma, Subhash C.; Kumar, Pankaj; Yi, Fuming; Robertson, Erle S.

2009-01-01

413

Epizootic canine distemper virus infection among wild mammals.  

PubMed

In the spring of 2007, seven raccoon dogs and a weasel were captured near the city of Tanabe in Wakayama prefecture, Japan. The causative agent of the animals' death 1-2 days after capture was identified as canine distemper virus (CDV) by virus isolation, immunostaining with an anti-CDV polyclonal antibody, and a commercially available CDV antigen-detection kit. Sequence analysis of hemagglutinin genes indicated the isolated viruses belong to genotype Asia-1 and possess the substitution from tyrosine (Y) to histidine (H) at position 549 that is associated with the spread of CDV to non-canine hosts. A serosurvey for CDV was then conducted among wild animals in the region. The animals assayed consisted of 104 raccoons, 41 wild boars, 19 raccoon dogs, five Sika deer, two badgers, one weasel, one marten, one Siberian weasel and one fox. Virus-neutralization (VN) tests showed that, except for fox and weasel, all of the species assayed had VN antibodies to CDV. Interestingly, 11 of the 41 wild boars (27%) and two of the five Sika deer assayed possessed VN antibodies to CDV. These findings indicate that CDV infection was widespread among wild mammals during this epizootic. PMID:21840141

Kameo, Yuki; Nagao, Yumiko; Nishio, Yohei; Shimoda, Hiroshi; Nakano, Hitoshi; Suzuki, Kazuo; Une, Yumi; Sato, Hiroshi; Shimojima, Masayuki; Maeda, Ken

2012-01-27

414

West Nile virus infection and diplopia: a case report and review of literature  

PubMed Central

West Nile virus is a neurotropic virus transmitted to humans via an infected mosquito bite. The increase in the incidences and fatalities of West Nile virus disease has made West Nile virus an important pathogen. Here we describe a case of a 65-year-old man with fever and diplopia presenting to the emergency department during a fall season and who was later diagnosed with West Nile virus infection. Diplopia is an uncommon manifestation of West Nile virus and recognition of the different modes of presentation, especially the uncommon ones like diplopia, will aid in the diagnosis of this emerging infectious disease. PMID:23723715

Dahal, Udip; Mobarakai, Neville; Sharma, Dikshya; Pathak, Bandana

2013-01-01

415

Remarkable sequence similarity between the dinoflagellate-infecting marine girus and the terrestrial pathogen African swine fever virus  

PubMed Central

Heterocapsa circularisquama DNA virus (HcDNAV; previously designated as HcV) is a giant virus (girus) with a ~356-kbp double-stranded DNA (dsDNA) genome. HcDNAV lytically infects the bivalve-killing marine dinoflagellate H. circularisquama, and currently represents the sole DNA virus isolated from dinoflagellates, one of the most abundant protists in marine ecosystems. Its morphological features, genome type, and host range previously suggested that HcDNAV might be a member of the family Phycodnaviridae of Nucleo-Cytoplasmic Large DNA Viruses (NCLDVs), though no supporting sequence data was available. NCLDVs currently include two families found in aquatic environments (Phycodnaviridae, Mimiviridae), one mostly infecting terrestrial animals (Poxviridae), another isolated from fish, amphibians and insects (Iridoviridae), and the last one (Asfarviridae) exclusively represented by the animal pathogen African swine fever virus (ASFV), the agent of a fatal hemorrhagic disease in domestic swine. In this study, we determined the complete sequence of the type B DNA polymerase (PolB) gene of HcDNAV. The viral PolB was transcribed at least from 6 h post inoculation (hpi), suggesting its crucial function for viral replication. Most unexpectedly, the HcDNAV PolB sequence was found to be closely related to the PolB sequence of ASFV. In addition, the amino acid sequence of HcDNAV PolB showed a rare amino acid substitution within a motif containing highly conserved motif: YSDTDS was found in HcDNAV PolB instead of YGDTDS in most dsDNA viruses. Together with the previous observation of ASFV-like sequences in the Sorcerer II Global Ocean Sampling metagenomic datasets, our results further reinforce the ideas that the terrestrial ASFV has its evolutio