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  1. Book ; Online ; E-Book: Viruses

    Payne, Susan

    from understanding to investigation

    2023  

    Author's details Susan Payne
    Keywords Viruses
    Subject code 579.2
    Language English
    Size 1 Online-Ressource (xiii, 423 Seiten), Illustrationen
    Edition Second edition
    Publisher Elsevier Academic Press
    Publishing place London
    Publishing country Great Britain
    Document type Book ; Online ; E-Book
    Remark Zugriff für angemeldete ZB MED-Nutzerinnen und -Nutzer
    HBZ-ID HT021491997
    ISBN 978-0-323-98476-8 ; 9780323903851 ; 0-323-98476-2 ; 0323903851
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

    Full text online

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  2. Article ; Online: Chapter 14 Family Astroviridae

    Payne, Susan

    Viruses

    Abstract: Abstract Astroviruses are unsegmented, positive-sense RNA viruses with ~7–9kb genomes. The family name derives from astron, meaning star, in Greek. These small unenveloped viruses have spikes that project about 41nm from the surface of the capsid, giving ...

    Abstract Abstract Astroviruses are unsegmented, positive-sense RNA viruses with ~7–9kb genomes. The family name derives from astron, meaning star, in Greek. These small unenveloped viruses have spikes that project about 41nm from the surface of the capsid, giving them a star-like appearance. Human astroviruses cause gastroenteritis in children and adults. Symptoms include diarrhea, nausea, vomiting, fever, malaise, and abdominal pain; for the most part disease is self-limiting.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00014-3
    Database COVID19

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  3. Article ; Online: Chapter 10 Introduction to RNA Viruses

    Payne, Susan

    Viruses

    Abstract: Abstract RNA viruses replicate their genomes using virally encoded RNA-dependent RNA polymerase (RdRp). The RNA genome is the template for synthesis of additional RNA strands. During replication of RNA viruses, there are at least three types of RNA that ... ...

    Abstract Abstract RNA viruses replicate their genomes using virally encoded RNA-dependent RNA polymerase (RdRp). The RNA genome is the template for synthesis of additional RNA strands. During replication of RNA viruses, there are at least three types of RNA that must be synthesized: the genome, a copy of the genome (copy genome), and mRNAs. Some RNA viruses also synthesize copies of subgenomic mRNAs. RdRp is the key player for all of these processes. RdRps of all RNA viruses probably arose from a common ancestor. The RdRp and other proteins required for viral genome synthesis are often called the replicase complex. The replicase complex consists of the set of proteins required to produce infectious genomes. In addition to the RdRp, the replicase complex may contain RNA-helicases (to unwind highly base-paired regions of the RNA genome) and NTPases (to supply energy for the polymerization process). The number of proteins in the replicase complex differs among virus families. There may also be a requirement for host cell proteins. The RNA virus group can be subdivided based on the type of RNA that serves as the genome. Positive or plus (+)-strand RNA viruses have genomes that are functional mRNAs. Their genomes are translated shortly after penetration into the host cell to produce the RdRp (and other viral proteins) required for synthesis of additional viral RNAs. Positive-strand RNA viruses often use large complexes of cellular membranes for genome replication. They actively modify host cell membranes to construct viral replication scaffolds. There are three groups of RNA viruses whose genomes are not mRNAs. They are the negative- or minus-strand RNA viruses, the closely related ambisense RNA viruses, and double-stranded RNA viruses. For each of these groups of viruses, the first synthetic event after genome penetration is transcription. This is accomplished by viral proteins (including the RdRp) that enter cell with the genome.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00010-6
    Database COVID19

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  4. Article ; Online: Introduction to RNA Viruses

    Payne, Susan

    Viruses

    Abstract: RNA viruses replicate their genomes using virally encoded RNA-dependent RNA polymerase (RdRp). The RNA genome is the template for synthesis of additional RNA strands. During replication of RNA viruses, there are at least three types of RNA that must be ... ...

    Abstract RNA viruses replicate their genomes using virally encoded RNA-dependent RNA polymerase (RdRp). The RNA genome is the template for synthesis of additional RNA strands. During replication of RNA viruses, there are at least three types of RNA that must be synthesized: the genome, a copy of the genome (copy genome), and mRNAs. Some RNA viruses also synthesize copies of subgenomic mRNAs. RdRp is the key player for all of these processes. RdRps of all RNA viruses probably arose from a common ancestor. The RdRp and other proteins required for viral genome synthesis are often called the replicase complex. The replicase complex consists of the set of proteins required to produce infectious genomes. In addition to the RdRp, the replicase complex may contain RNA-helicases (to unwind highly base-paired regions of the RNA genome) and NTPases (to supply energy for the polymerization process). The number of proteins in the replicase complex differs among virus families. There may also be a requirement for host cell proteins. The RNA virus group can be subdivided based on the type of RNA that serves as the genome. Positive or plus (+)-strand RNA viruses have genomes that are functional mRNAs. Their genomes are translated shortly after penetration into the host cell to produce the RdRp (and other viral proteins) required for synthesis of additional viral RNAs. Positive-strand RNA viruses often use large complexes of cellular membranes for genome replication. They actively modify host cell membranes to construct viral replication scaffolds. There are three groups of RNA viruses whose genomes are not mRNAs. They are the negative- or minus-strand RNA viruses, the closely related ambisense RNA viruses, and double-stranded RNA viruses. For each of these groups of viruses, the first synthetic event after genome penetration is transcription. This is accomplished by viral proteins (including the RdRp) that enter cell with the genome.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00010-6
    Database COVID19

    Kategorien

    Inter-library loan at ZB MED

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  5. Article ; Online: Chapter 17 Family Coronaviridae

    Payne, Susan

    Viruses

    Abstract: Abstract Members of the family Coronaviridae are large, enveloped, single-stranded RNA viruses. They are the largest known RNA viruses, with genomes ranging from 25 to 32kb and virions of 118–140nm in diameter. The family is divided into two subfamilies, ...

    Abstract Abstract Members of the family Coronaviridae are large, enveloped, single-stranded RNA viruses. They are the largest known RNA viruses, with genomes ranging from 25 to 32kb and virions of 118–140nm in diameter. The family is divided into two subfamilies, the Coronavirinae and the Torovirinae. They can be distinguished on the basis of their nucleocapsids as the toroviruses have unique doughnut-shaped nucleocapsids. Virions are roughly spherical and are notable for the large spike (S) glycoprotein that extends from the virus envelope. Current taxonomy places the family in the order Nidovirales. Within the subfamily Coronavirinae are four genera, the alpha-, beta-, gamma-, and deltacoronaviruses. All family members share the same unique strategy for mRNA synthesis whereby the polymerase complex jumps or moves from one region of the template to a more distant region. The need for the polymerase complex to dissociate from the template may explain the high rate of RNA recombination that occurs during genome replication. Both the coronaviruses and toroviruses are enteric and respiratory tract pathogens, usually associated with only mild disease (or inapparent infection). However the human severe acute respiratory syndrome (SARS) coronavirus and the Middle East respiratory syndrome (MERS) coronavirus cause severe respiratory diseases.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00017-9
    Database COVID19

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    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article ; Online: Family Astroviridae

    Payne, Susan

    Viruses

    Abstract: Astroviruses are unsegmented, positive-sense RNA viruses with ~7–9 kb genomes. The family name derives from astron, meaning star, in Greek. These small unenveloped viruses have spikes that project about 41 nm from the surface of the capsid, giving them a ...

    Abstract Astroviruses are unsegmented, positive-sense RNA viruses with ~7–9 kb genomes. The family name derives from astron, meaning star, in Greek. These small unenveloped viruses have spikes that project about 41 nm from the surface of the capsid, giving them a star-like appearance. Human astroviruses cause gastroenteritis in children and adults. Symptoms include diarrhea, nausea, vomiting, fever, malaise, and abdominal pain; for the most part disease is self-limiting.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00014-3
    Database COVID19

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article ; Online: Chapter 4 Methods to Study Viruses

    Payne, Susan

    Viruses

    Abstract: Abstract This chapter describes methods for growing, purifying, counting, and characterizing viruses. It also provides general principles of diagnostic virology. As obligate intracellular parasites, viruses require cell in which to replicate. The cells ... ...

    Abstract Abstract This chapter describes methods for growing, purifying, counting, and characterizing viruses. It also provides general principles of diagnostic virology. As obligate intracellular parasites, viruses require cell in which to replicate. The cells must express appropriate receptors and other proteins required by the virus. Cultured cells are often used to study basic steps in virus replication. Viruses can be purified away from cellular proteins and organelles using centrifugation techniques. Most viruses cannot be seen using standard light microscopes, but are often imaged using electron microscopy. Methods that combine image collection and computationally demanding image processing can provide incredible details about virus architecture. Another common way to visualize viruses is to use fluorescent tags or dyes. Although these techniques do not show detailed virus structures, they can be used to follow the progress of a virus through a cell and can provide a direct window into protein–protein interactions required for virus replication. A more indirect method to detect viruses is to look for virally induced changes to cell morphology. A variety of basic biochemical techniques are useful for analyzing viral proteins and nucleic acids. As the viral genomes are relatively simple, they can be manipulated/mutated to study the function of virtually any viral protein. Powerful genetic techniques can also be used to generate “designer” cells or organisms. There are a variety of methods for quantitating viruses. Infectivity assays measure the ability of a virus to productively infect a cell. Techniques that identify specific viral proteins or genomes provide ways to rapidly identify viruses. Some of these assays can be used at the bedside, or in the field. Powerful and inexpensive DNA sequencing technologies are being used to identify new viruses, many of which could not be found by other methods. The challenge is to understand how or if these viruses impact their hosts.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00004-0
    Database COVID19

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  8. Article ; Online: Chapter 18 Family Arteriviridae

    Payne, Susan

    Viruses

    Abstract: Abstract The family Arteriviridae is one of four families in the order Nidovirales. Arteriviruses are enveloped, plus-strand RNA viruses with genomes of 12.7–15.7kb. The overall genome organization and gene expression strategy of the arteriviruses is ... ...

    Abstract Abstract The family Arteriviridae is one of four families in the order Nidovirales. Arteriviruses are enveloped, plus-strand RNA viruses with genomes of 12.7–15.7kb. The overall genome organization and gene expression strategy of the arteriviruses is highly similar to the coronaviruses. Notably they use a discontinuous transcription strategy for synthesis of subgenomic mRNAs. There are no recognized human pathogens among the arteriviruses. Members of the family include equine arteritis virus and porcine reproductive and respiratory syndrome virus, the latter an economically important pathogen of pigs.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00018-0
    Database COVID19

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  9. Article ; Online: Chapter 3 Virus Interactions With the Cell

    Payne, Susan

    Viruses

    Abstract: Abstract Virus replication requires specific interactions with host cells. The replication cycle begins with attachment of viral proteins to host cell receptors. The presence or absence of receptors is an important factor in determining if the cell is ... ...

    Abstract Abstract Virus replication requires specific interactions with host cells. The replication cycle begins with attachment of viral proteins to host cell receptors. The presence or absence of receptors is an important factor in determining if the cell is permissive for infection. The next step in the virus replication cycle is transfer of the genome into cytosol or nucleoplasm. Some viruses transport just their nucleic acid genomes into the cell while others deliver the entire virion. Once in the cell, virion proteins and genome interact with a variety of cell proteins, nucleic acids, and membranes. Productive replication requires synthesis of viral mRNAs, protein, and genomes. The details of these processes vary widely. However, to be successful a virus must be able to compete with host cell for building materials. For example, as the cell is constantly synthesizing proteins, viral mRNAs must be able to redirect ribosomes to their own mRNAs. Some viruses can shut down cellular transcription and translation to redirect those processes to the production of viral proteins. In contrast DNA viruses have developed methods to induce cell DNA replication and/or cell division to obtain materials necessary for genome synthesis. Viruses pack a lot of information into their relatively small genomes. Most do not have the complex promoters that drive cell transcription nor do they have long noncoding introns in their genes. Viruses that replicate in the nucleus often use alternative splicing to generate families of related mRNAs from a single precursor transcript. In other cases a single transcript may be used to produce multiple proteins by ribosome-mediated processes such as leaky scanning, stop codon suppression, and frame shifting. Once viral building blocks have been synthesized, new virions are assembled and must leave the cell. Again, the details of these processes can vary widely. Some of the simplest viruses can assemble in a test tube, from purified capsid proteins and genomes. More complex viruses use a variety of cell proteins and structures for assembly and release.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00003-9
    Database COVID19

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  10. Article ; Online: Chapter 8 Virus Evolution and Genetics

    Payne, Susan

    Viruses

    Abstract: Abstract Viruses are very diverse and they infect organisms from all domains of life and across all ecosystems, but related viruses often infect very different types of organisms, pointing to their very ancient origins. Three commonly proposed mechanisms ...

    Abstract Abstract Viruses are very diverse and they infect organisms from all domains of life and across all ecosystems, but related viruses often infect very different types of organisms, pointing to their very ancient origins. Three commonly proposed mechanisms for the origins of viruses are: Viruses descended from primitive precellular life forms; viruses are escaped cellular genetic elements; viruses devolved from more complex intracellular parasites. None of these theories easily explains the origins of all viruses and it is widely accepted that all viruses did not share a single common ancestor. Instead, distinct lineages of viruses probably evolved by different mechanism. There is also good evidence that viruses have shaped the evolution of their hosts, for at least hundreds of millions of years. While some virologists consider the ancient origins of viruses, others examine the forces that drive virus evolution today. Examples of ongoing virus evolution include: Cross-species jumps; decreased or increased virulence; emergence of drug resistance; escape from immune responses at the level of individuals and populations. Virus evolution is the outcome of two independent events. The first is genome mutation and the second is selection. Viruses with RNA genomes tend to have high mutation rates, but some appear to be evolutionarily stable nonetheless. Viruses have distinct phenotypes. For examples, some influenza viruses are highly virulent but others are much less so; influenza viruses also differ tremendously in their ability to be transmitted. Modern studies of virus genetics seek to correlate diverse phenotypes with specific genes and sequences. The ability to do reverse genetics is key to understanding viral genes. Reverse genetics involves cloning viral genomes, designing specific mutation, and introducing the mutated genomes back into cells to produce infectious particles whose phenotypes can then be measured.
    Keywords covid19
    Publisher Elsevier; PMC
    Document type Article ; Online
    DOI 10.1016/b978-0-12-803109-4.00008-8
    Database COVID19

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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