Suchergebnisse

1 Introduction -- 1.1 Historical development of molecular virology -- 1.2 What is a virus? -- 1.3 Titration of viruses -- 1.4 Virus-host interactions -- 2 The virion -- 2.1 Principles of virion construction -- 2.2 Special features of virion anatomy -- 2.3 Viral nucleic acids -- 2.4 The virion: function -- 3 The virus-infected cell -- 3.1 Transcription and translation in the virus-infected cell -- 3.2 Post-translational modification of proteins -- 3.3 Genome replication -- 3.4 Virus assembly -- 3.5 Virus release -- 3.6 Temperate phage and lysogeny -- 4 Virus genetics -- 4.1 Mutations -- 4.2 Functional or complementation analysis -- 4.3 Fundamental studies in recombination -- 4.4 Chromosome mapping -- 4.5 Genetic recombination -- 5 Tumour virology -- 5.1 What is a tumour? -- 5.2 Causation of tumours -- 5.3 Papovaviruses -- 5.4 RNA tumour viruses -- 5.5 Comparison of transformation by DNA and RNA tumour viruses; oncogene theory -- Suggestions for further reading.

This work is performed as part of the cognitive-discursive paradigm of modern linguistics. The object of the investigation is the concept "computer virus" and its linguistic representation in a computer virology discourse. The research is based on the texts from the Corpus of Contemporary American English. The first stage of the linguistic and conceptual investigation of "computer virus" is based on Metaphor Investigation Process (MIPVU) developed by the Metaphor Lab at VU University Amsterdam. The identification procedure includes the following main steps: reading the text/discourse, acquiring a general understanding of its meaning, selecting lexical units from the text/discourse, and establishing their contextual and contemporary meanings. If the contextual meaning contrasts with the basic meaning but can be understood in comparison with it, the lexical unit is marked as metaphorical (Pragglejaz Group 2007). The second stage of the investigation is based on the method of metaphorical modeling, which implies taxonomic categorization, developed by S. Mishlanova (Mishlanova 2002). On the basis of corpus analysis a metaphorical model "computer virus" was constructed. The model represents a taxonomic structure, which includes the basic taxons "man as a social subject," "man as a biological creature," and "animal." The most representative areas of source domains included, "military operation" (represented by such linguistic metaphors as attack, strike, defeat ), "diseases" ( crippling, succumb, infected ), and "interpersonal relations" ( be angry at, enter into, want ). At the current stage of computer virology development, metaphor plays a very important role as a universal tool for conceptualization and categorization of new knowledge that relies on the preceding experience of the person participating in the cognitive process. The structure of the concept "computer virus" is a hierarchical system, fixing the unscientific notion of a computer virus, the peculiarities of its functioning, and the ways to combat this malicious program.

BACKGROUND: Viral pandemics have had catastrophic consequences on population health and economies. The Philippine government intends to establish the Virology Institute of the Philippines, one of the key areas of which will be virology research. This project aimed to develop the institute's research agenda across the fields of human, plant, and animal virology. METHODOLOGY: Key considerations for the prioritization methodology were (1) the imminent establishment of the Virology Institute of the Philippines, (2) mobility restrictions caused by the coronavirus disease 2019 (COVID-19) pandemic, (3) the timeline to develop the research agenda, and (4) the need to separate the research agenda for the three fields of human, plant, and animal virology. The process was fully conducted online in four steps: stakeholder identification, soliciting research priorities, generating initial research priorities, and final prioritization consultations conducted on Zoom Pro. RESULTS: Twenty-eight participants attended three online consultations between 21 and 27 July 2020 through Zoom Pro. Participants selected the research prioritization criteria and its weights, and used these to evaluate the research priorities. The final research agenda covers topics in epidemiology, diagnostics, surveillance, biosafety, and genomics. CONCLUSION: This initiative resulted in the first research agenda for the Virology Institute of the Philippines across the three fields of human, plant, and animal virology. An expert-driven process which places a premium on consensus-building facilitated through online platforms was the most feasible approach to develop the research agenda. This process resulted in an agenda aligned with the mandates of national research councils but leaves gaps on areas such as emerging infectious diseases. Pre-COVID-19 literature expressed apprehensions on the online medium that weakens social ties necessary for consensus. Our experience with changing the mode of consensus-building shows that users will continually adapt to ...

This thesis deals with the molecular diagnosis of infectious diseases concerning animal and human health: in particular, with diseases notifiable to the World Organization for Animal Health, OIE (the vesicular complex and avian influenza), as well as with Hepatitis E, representing emerging zoonotic aspects. With the worldwide introduction and use of the polymerase chain reaction (PCR) methodologies, the detection of different pathogens improved significantly - however, these systems have weak points as well. The parallel screening of more than a few pathogens is not resolved and, in general, the multiplexing capacity of most of the methods used in this area is insufficient. In the case of the detection of pathogens causing similar symptoms (like the vesicular complex, involving Foot-and-Mouth Disease (FMD), Swine Vesicular Disease (SVD) and Vesicular Stomatitis (VS), the immediate differential diagnosis is essential, not only regarding the multiplexing, but also because of the high economic risks and the strict legislations. Subtyping of the avian influenza viruses is a broad and extensive task because it needs to differentiate 16 hemagglutinin and 9 neuraminidase types and their variants. The padlock probes, as used in these studies, seem to be optimal to fulfill the multiplexing requirements and to provide novel, high-throughput tools for the improved diagnosis of the vesicular complex and of avian influenza. The general detection and subtyping of Hepatitis E Virus (HEV) is an important and complicated task today, as the virus shows zoonotic potential by causing endemics in humans and persisting infections in different animal species. Thus, there is a high need for sensitive and specific methods and identification of HEV variants. In the frame of this work, a highly specific and sensitive diagnostic assay was developed, based on two types of real-time PCR methods. In addition, a genotyping system was constructed using a simple and quick ligation-based technique.

The title of the book pays tribute to two Dutch scientists without whom
virology would arguably not exist today, at least not in its present guise. The
first is Antony van Leeuwenhoek, whose reports of microscopic discoveries
in the early eighteenth century aroused interest in the world of invisible
creatures. His findings laid the basis for a theory of a particulate cause
of infectious diseases, but, as George Rosen wrote, without any tangible
results in support of the theory (1993/1958, pp. 84-85). Some 250 years later
Martinus Willem Beijerinck launched the discipline of virology with his
idea that tobacco mosaic disease (TMD) was caused by a living contagious
fluid or filterable living pathogen.

Every year we see many changes in the world around us. One of these changes is the climate and weather, and it could be one of the reasons for changing behaviors between humans and animals, which could cause zoonotic diseases. We usually face new diseases that infect a growing population leading to a pandemic. Different reasons are leading to an increase in the emergence of new infections. Some of these diseases can be associated with zoonotic diseases and the diverse world of viral genetics and its failures. Furthermore, properties like mutations and also unknown effects of these mutations on the virulence of the agents make it challenging to trace new diseases. As we know, preventing emerging diseases is inevitable and viral diseases are dangerous, and some viruses can spread quickly and cause an endemic or pandemic. As was noticed during the recent pandemic, the need to study emerging diseases in the field of virology has become more and more apparent to us. In this review, we want to look at how we could monitor and control these diseases with new approaches and what should be done when a disease emerges. Moreover, we will investigate risk factors, ways to deal with emerging viral infections, new treatments that make the condition better when a person gets infected, and the future of these diseases. We will also study the ways to deal with pandemics with the new generations of vaccines

HIV therapeutic targets: Basic virology to the discovery of antiretroviral drugs
Do we need new antiretroviral drugs to treat HIV infection, and if so, what are the promising targets? Dr Eric O. Freed, Director of the HIV Dynamics and Replication Program at the National Cancer Institute in Frederick, Maryland, discusses these questions. The HIV replication cycle (1) (see figure) presents numerous potential therapeutic targets, but only a few have been successfully exploited. HIV-1 infection begins when the viral envelope glycoprotein (known as Env) binds to its primary receptor (CD4) and coreceptors on the surface of a target cell, leading to a fusion between the lipid bilayer of the virus particle and the plasma membrane of the cell, allowing the viral core – which contains the viral RNA genome and key viral enzymes – to gain access to the target cell cytoplasm.

AbstractGlobal warming and air pollution affect the transmission pathway and the survival of viruses, altering the human immune system as well. The first wave of the COVID-19 pandemic dramatically highlights the key roles of climate and air chemistry in viral epidemics. The elongated form of the Italian peninsula and the two major islands (the largest in Europe) is a perfect case study to assess some of these key roles, as the fate of the virus is mirroring the industrialization in the continental part of our country. Fine particulate matter (PM2.5), geography, and climate explain what is happening in Italy and support cleaner air actions to address efficiently other outbreaks. Besides the environmental factors, future works should also address the genetic difference among individuals to explain the spatial variability of the human response to viral infections.

This article aims to open up the biographical black box of three experts working in the boundary zone between science, policy and public debate. A biographical-narrative approach is used to analyse the roles played by the virologists Albert Osterhaus, Roel Coutinho and Jaap Goudsmit in policy and public debate. These figures were among the few leading virologists visibly active in the Netherlands during the revival of infectious diseases in the 1980s. Osterhaus and Coutinho in particular are still the key figures today, as demonstrated during the outbreak of novel influenza A (H1N1). This article studies the various political and communicative challenges and dilemmas encountered by these three virologists, and discusses the way in which, strategically or not, they handled those challenges and dilemmas during the various stages of the field's recent history. Important in this respect is their pursuit of a public role that is both effective and credible. We will conclude with a reflection on the H1N1 pandemic, and the historical and biographical ties between emerging governance arrangements and the experts involved in the development of such arrangements.

To assess the performance of laboratories in detecting and quantifying hepatitis C virus (HCV) RNA levels in HCV-infected patients, we distributed two proficiency panels for qualitative and quantitative HCV RNA testing. The panels were designed by the European Union Quality Control Concerted Action, prepared by Boston Biomedica Inc., and distributed in May 1999 (panel 1) and February 2000 (panel 2). Each panel consisted of two negative samples and six positive samples, with HCV RNA target levels from 200 to 500,000 copies/ml. Panel 1 had four samples with at least 50,000 copies/ml, and panel 2 had two samples with at least 50,000 copies/ml. Fifty-seven laboratories submitted 45 qualitative and 35 quantitative data sets on panel 1, and 81 laboratories submitted 75 qualitative and 48 quantitative data sets on panel 2. In both panels, about two-thirds of the qualitative data sets and >90% of the quantitative data sets were obtained with commercial assays. With each panel, two data sets gave one false-positive result, corresponding to false-positivity rates of 1.3% and 0.8% for panel 1 and panel 2, respectively. Samples containing at least 50,000 copies/ml were found positive in 97% and 99% of the cases with panel 1 and panel 2, respectively. In contrast, the positive samples containing ≤5,000 copies/ml were reported positive in only 71% and 77% of the cases with panel 1 and panel 2, respectively. Adequate or better scores on qualitative results (all results correct or only the low-positive samples missed) were obtained in 84% (panel 1) and 80% (panel 2) of the data sets. In the analysis of quantitative results, 60% (panel 1) and 73% (panel 2) of the data sets obtained an adequate or better score (≥80% of the positive results within the range of the geometric mean ± 0.5 log10). Our results indicate that considerable improvements in molecular detection and quantitation of HCV have been achieved, particularly through the use of commercial assays. However, the lowest detection levels of many assays are still too ...

Approximately 5% of individuals infected with hepatitis B virus (HBV) are coinfected with hepatitis D virus (HDV). Chronic HBV/HDV coinfection is associated with an unfavourable outcome, with many patients developing liver cirrhosis, liver failure and eventually hepatocellular carcinoma within 5–10 years. The identification of the HBV/HDV receptor and the development of novel in vitro and animal infection models allowed a more detailed study of the HDV life cycle in recent years, facilitating the development of specific antiviral drugs. The characterisation of HDV-specific CD4+ and CD8+T cell epitopes in untreated and treated patients also permitted a more precise understanding of HDV immunobiology and possibly paves the way for immunotherapeutic strategies to support upcoming specific therapies targeting viral or host factors. Pegylated interferon-α has been used for treating HDV patients for the last 30 years with only limited sustained responses. Here we describe novel treatment options with regard to their mode of action and their clinical effectiveness. Of those, the entry-inhibitor bulevirtide (formerly known as myrcludex B) received conditional marketing authorisation in the European Union (EU) in 2020 (Hepcludex). One additional drug, the prenylation inhibitor lonafarnib, is currently under investigation in phase III clinical trials. Other treatment strategies aim at targeting hepatitis B surface antigen, including the nucleic acid polymer REP2139Ca. These recent advances in HDV virology, immunology and treatment are important steps to make HDV a less difficult-to-treat virus and will be discussed.