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Evaluation of non-reciprocal heterologous immunity between unrelated viruses.

Heterologous immunity refers to the phenomenon whereby a history of an immune response against one pathogen can provide a level of immunity … gainst LCMV simply by experimentally amplifying the quantity of T cells cross-reactive with the two viruses. Thus, one cause for lack of reciprocity is differences in the frequencies of cross-reactive T cells in immune hosts.

How do viruses trick B cells into becoming lymphomas?

PURPOSE OF REVIEW: Since the discovery of Epstein-Barr virus in Burkitt's lymphoma 50  years ago, only one other virus, namely Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8, has been confirmed to be a direct cause of B-cell lymphoma. Here we will review the evidence for Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus as causal lymphoma agents. RECENT FINDINGS: A deeper understanding of specific mechanisms by which Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus cause B-cell lymphomas has been acquired over the past years, in particular with respect

'Liver let die': oxidative DNA damage and hepatotropic viruses.

Chronic infections by the hepatotropic viruses hepatitis B virus (HBV) and hepatitis C virus (HCV) are major risk factors for the development of hepatocellular carcinoma (HCC). It is estimated that more than 700,000 individuals per year die from HCC, and around 80 % of HCC is attributable to HBV or HCV infection. Despite the clear clinical importance of virus-associated HCC, the underlying molecular mechanisms remain largely elusive. Oxidative stress, in particular DNA lesions associated with oxidative damage, play a major contributory role in carcinogenesis, and are strongly linked to the dev…

Antiviral strategies for emerging influenza viruses in remote communities.

BACKGROUND: Due to the lack of timely access to resources for critical care, strategic use of antiviral drugs is crucial for mitigating the impact of novel influenza viruses with pandemic potential in remote and isolated communities. We sought to evaluate the effect of antiviral treatment and prophylaxis of close contacts in a Canadian remote northern community. METHODS: We used an agent-based, discrete-time simulation model for disease spread in a remote community, which was developed as an in-silico population using population census data. Relative and cumulative age-specific attack rates, …

Wild-type measles viruses with non-standard genome lengths.

The length of the single stranded, negative sense RNA genome of measles virus (MeV) is highly conserved at 15,894 nucleotides (nt). MeVs can … of 6 nt complies with the rule-of-six required for replication competency of the genomes of morbilliviruses. The insertions and deletion (indels) were confirmed in a patient sample that was the source of one of the viral isolates. The positions of the indels were identical in both viral isolates, even though epidemiological data and the 3 nt differences i …

Adenovirus-based vaccines against avian-origin H5N1 influenza viruses.

Since 1997, human infection with avian H5N1, having about 60% mortality, has posed a threat to public health. In this review, we describe the epidemiology of H5N1 transmission, advantages and disadvantages of different influenza vaccine types, and characteristics of adenovirus, finally summarizing advances in adenovirus-based H5N1 systemic and mucosal vaccines.

Many respiratory viruses have temporal association with meningococcal disease.

BACKGROUND: Previous ecological studies have shown a temporal and spatial association between influenza epidemics and meningococcal disease (MNG); however, none have examined more than two respiratory viruses. METHODS: Data were obtained in Chile between 2000 and 2005 on confirmed cases of MNG and all confirmed cases of respiratory viruses (influenza A and B; parainfluenza; adenovirus; and respiratory syncytial virus [RSV]). Both variables were divided by epidemiological weeks, age range, and regions. Models of transference functions were run for rates of MNG. RESULTS: In this period, 1022 r…

Molecular epidemiology of human rabies viruses in Sri Lanka.

Rabies is a lethal zoonotic disease caused by the rabies virus, which is transmitted by rabid animals to humans. Rabies is prevalent in all continents, with over 60% of human deaths occurring in Asia. Sri Lanka is a rabies-endemic country. This study shows that rabies afflicted more older individuals than children in Sri Lanka between 2008 and 2010. This novel finding indicates that older people in Sri Lanka should be more aware of the risk of rabies. Phylogenetic analyses of the rabies N and G genes showed that the Sri Lankan rabies viruses are distinct and probably originated from a single c…

Environmental management of mosquito-borne viruses in Rhode Island.

West Nile Virus (WNV) and Eastern Equine Encephalitis Virus (EEEV) are both primarily bird viruses, which can be transmitted by several mosquito species. Differences in larval habitats, flight, and biting patterns of the primary vector species result in substantial differences in epidemiology, with WNV more common, primarily occurring in urban areas, and EEEV relatively rare, typically occurring near swamp habitats. The complex transmission ecology of these viruses complicates prediction of disease outbreaks. The Rhode Island Department of Environmental Management (DEM) and Department of Healt…

Antiviral drugs for viruses other than human immunodeficiency virus.

Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin…

Viruses and cytotoxic T lymphocytes in type 1 diabetes.

Histopathological studies on pancreas tissues from individuals with recent-onset type 1 diabetes (T1D) consistently find that CD8 T cells substantially contribute to the formation of islet lesions. CD8 T cells reactive against islet-associated antigens can also be found in blood samples from T1D patients. Mechanistic studies on the pathogenic role of this T cell subset have mostly focused on two animal models, i.e., the non-obese diabetic mouse and the virally induced rat insulin promoter-lymphocytic choriomeningitis virus model. Data were obtained in support of a role for viral infection in e

Phylogenetic analysis of rabies viruses from Burkina Faso, 2007.

Genetic characterization of 32 canine rabies viruses circulating in Burkina Faso in 2007 identified two clades both belonging to the Africa 2 lineage. Sequence homology data suggest that transboundary spread is the most likely means of introduction, highlighting an evolving epidemiological situation.

Oseltamivir-resistant influenza viruses A (H1N1), Norway, 2007-08.

In Norway in January 2008, unprecedented levels of oseltamivir resistance were found in 12 of 16 influenza viruses A (H1N1) tested. To investigate the epidemiologic and clinical characteristics of these viruses, we used sequence analysis to test all available subtype H1N1 viruses from the 2007-08 season for resistance. Questionnaires from physicians provided information on predisposing diseases, oseltamivir use, symptoms, and complications. Clinical data were obtained for 265 patients. In total, 183 (67.3%) of 272 viruses were oseltamivir resistant. Resistance was not associated with prior use…

Emerging and re-emerging viruses in Malaysia, 1997-2007.

Over the past decade, a number of unique zoonotic and non-zoonotic viruses have emerged in Malaysia. Several of these viruses have resulted in significant morbidity and mortality to those affected and they have imposed a tremendous public health and economic burden on the state. Amongst the most devastating was the outbreak of Nipah virus encephalitis in 1998, which resulted in 109 deaths. The culling of more than a million pigs, identified as the amplifying host, ultimately brought the outbreak under control. A year prior to this, and subsequently again in 2000 and 2003, large outbreaks of ha…

Influenza (H5N1) viruses in poultry, Russian Federation, 2005-2006.

We studied 7 influenza (H5N1) viruses isolated from poultry in western Siberia and the European part of the Russian Federation during July 2005-February 2006. Full genome sequences showed high homology to Qinghai-like influenza (H5N1) viruses. Phylogenetic analysis not only showed a close genetic relationship between the H5N1 strains isolated from poultry and wild migratory waterfowls but also suggested genetic reassortment among the analyzed isolates. Analysis of deduced amino acid sequences of the M2 and neuraminidase proteins showed that all isolates are potentially sensitive to currently a…

Frequent transmission of immunodeficiency viruses among bobcats and pumas.

With the exception of human immunodeficiency virus (HIV), which emerged in humans after cross-species transmissions of simian immunodeficiency viruses from nonhuman primates, immunodeficiency viruses of the family Lentiviridae represent species-specific viruses that rarely cross species barriers to infect new hosts. Among the Felidae, numerous immunodeficiency-like lentiviruses have been documented, but only a few cross-species transmissions have been recorded, and these have not been perpetuated in the recipient species. Lentivirus seroprevalence was determined for 79 bobcats (Lynx rufus) and…

Вирусы нейротропического герпеса: герпес простейший и варицелла-зостер.

Герпес простые вирусы типов 1 и 2 (HSV1 и HSV2) и вирус варицелла-зостера (VZV) обнаруживают скрытые инфекции в дорсальной корневой ганглии на протяжении всей жизни хозяина. Из этого резервуара они могут возродиться, чтобы вызвать человеческую заболеваемость и смертность. Хотя вирусы различаются в клинических расстройствах, которые они вызывают, и в их молекулярной структуре, они имеют несколько особенностей, которые влияют на процесс заражения нервной системы человека. HSV1 является источником энцефалита, кукурузной слепоты и нескольких расстройств периферической нервной системы; HSV2 являетс

Совпадение в аннотации оригинала
Herpes simplex viruses types 1 and 2 (HSV1 and HSV2) and varicella-zoster virus (VZV) establish latent infection in dorsal root ganglia for the entire life of the host. From this reservoir they can reactivate to cause human morbidity and mortality. Although the viruses vary in the clinical disorders they cause and in their molecular structure, they share sev…

Beyond viruses: clinical profiles and etiologies associated with encephalitis.

BACKGROUND: Encephalitis is a complex syndrome, and its etiology is often not identified. The California Encephalitis Project was initiated in 1998 to identify the causes and further describe the clinical and epidemiologic characteristics of encephalitis. METHODS: A standardized report form was used to collect demographic and clinical data. Serum, cerebrospinal fluid, and respiratory specimens were obtained prospectively and were tested for the presence of herpesviruses, arboviruses, enteroviruses, measles, respiratory viruses, Chlamydia species, and Mycoplasma pneumoniae. The association bet…

Respiratory viruses do not trigger meningococcal disease in children.

OBJECTIVES: To determine whether the nasopharyngitis prodrome of meningococcal disease is caused by the disease itself or respiratory viral coinfection. METHODS: Case control study of children with suspected meningococcal disease. Nasal swabs and a respiratory history were obtained from suspected cases and matched controls. Molecular testing for 12 respiratory viruses was used. RESULTS: 104 suspected cases and controls were recruited. Detection rates for respiratory viruses were 27% (28/104) for suspected cases and 29% (30/104) for controls. Rhinoviruses (43/58, 74%) and adenoviruses (14/58,…

Genetic analysis of dog rabies viruses circulating in Bangkok.

The genetic diversity of the rabies virus glycoprotein (G) gene isolated from individual rabid dogs (inter-hosts) and within a single infected dog (intra-host) has been analyzed in an effort to better understand selective pressures and population shifts among rabies viruses circulating in Bangkok. Comparison of individual master sequences among inter-hosts revealed that the dog virus isolates circulating in Bangkok were phylogenetically closely related. The ectodomain of the glycoprotein was highly conserved among the virus isolates. Furthermore, the genetic diversity of the G gene within an i…