Dna

protein synthesis by host cell ribosome inhibition of viral DNA polymerase acyclovir, vidarabine, foscarnet, ganciclovir

FIGURE 49-1 Replicative cycles of DNA (A) and RNA (B) viruses. The replicative cycles of herpesvirus (A) and influenza (B) are examples of DNA-encoded and RNA-encoded viruses, respectively. Sites of action of antiviral agents also are shown. Key: mRNA = messenger RNA; cDNA = complementary DNA; vRNA = viral RNA; DNAp = DNA polymerase; RNAp = RNA polymerase; cRNA = complementary RNA. An X on top of an arrow indicates a block or inhibition. A. Replicative cycles of herpes simplex virus, a DNA virus, and the probable sites of action of antiviral agents. Herpes virus replication is a regulated multistep process. After infection, a small number of immediate-early genes are transcribed; these genes encode proteins that regulate their own synthesis and are responsible for synthesis of early genes involved in genome replication, such as thymidine kinases, DNA polymerases, etc. After DNA replication, the bulk of the herpes virus genes (called late genes) are expressed and encode proteins that either are incorporated into or aid in the assembly of progeny virions. B. Replicative cycles of influenza, an RNA virus, and the loci for effects of antiviral agents. The mammalian cell shown is an airway epithelial cell. The M2 protein of influenza virus allows an influx of hydrogen ions into the virion interior, which in turn promotes dissociation of the RNAp segments and release into the cytoplasm (uncoating). Influenza virus mRNA synthesis requires a primer cleared from cellular mRNA and used by the viral RNAp complex. The neuraminidase inhibitors zanamivir and oseltamivir specifically inhibit release of progeny virus. Small capitals indicate virus proteins.

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amantadine rimantadine

FIGURE 49-1 Replicative cycles of DNA (A) and RNA (B) viruses. The replicative cycles of herpesvirus (A) and influenza (B) are examples of DNA-encoded and RNA-encoded viruses, respectively. Sites of action of antiviral agents also are shown. Key: mRNA = messenger RNA; cDNA = complementary DNA; vRNA = viral RNA; DNAp = DNA polymerase; RNAp = RNA polymerase; cRNA = complementary RNA. An X on top of an arrow indicates a block or inhibition. A. Replicative cycles of herpes simplex virus, a DNA virus, and the probable sites of action of antiviral agents. Herpes virus replication is a regulated multistep process. After infection, a small number of immediate-early genes are transcribed; these genes encode proteins that regulate their own synthesis and are responsible for synthesis of early genes involved in genome replication, such as thymidine kinases, DNA polymerases, etc. After DNA replication, the bulk of the herpes virus genes (called late genes) are expressed and encode proteins that either are incorporated into or aid in the assembly of progeny virions. B. Replicative cycles of influenza, an RNA virus, and the loci for effects of antiviral agents. The mammalian cell shown is an airway epithelial cell. The M2 protein of influenza virus allows an influx of hydrogen ions into the virion interior, which in turn promotes dissociation of the RNAp segments and release into the cytoplasm (uncoating). Influenza virus mRNA synthesis requires a primer cleared from cellular mRNA and used by the viral RNAp complex. The neuraminidase inhibitors zanamivir and oseltamivir specifically inhibit release of progeny virus. Small capitals indicate virus proteins.

Nomenclature of Antiviral Agents

Generic Name

Other Names

Trade Names (USA)

Dosage Forms Available

Antiherpesvirus agents Acyclovir Cidofovir Famciclovir Foscarnet

Fomivirsen Ganciclovir Idoxuridine

Penciclovir Trifluridine

Valacyclovir Valganciclovir

Anti-influenza agents Amantadine Oseltamivir Rimantadine Zanamivir

Antihepatitis agents Adefovir dipivoxil Interferon-alfa

Lamivudine

Pegylated interferon alfa Other antiviral agents Ribavirin

ACV, acycloguanosine HPMPC, CDV FCV PFA, phosphonoformate ISIS 2922 GCV, DHPG IDUR

PCV TFT, trifluorothymidine

Blood Pressure Health

Blood Pressure Health

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