viral

Virus evolution

...on is an important aspect of the epidemiology of viral diseases such as influenza , HIV , hepatitis , and many others. It also causes problems in the development of successful antiviral drugs , as resistant mutations often appear within weeks to months after the beginning of the treatment. RNA vi...

Virus

...teins , lipids , and glycoproteins . Importantly viral genomes code not only for the proteins needed ...5 Viral replication 5.1 Steps associated with viral reproduction 6 Origins 7 Human viral diseases 7.1 Laboratory diagnosis of pathogenic v...

Virology

... phage , the virus of bacteria / prokaryotes viral plaque Important publications in virology Virus classification...

Yellow fever

... or sometimes The American Plague ) is an acute viral disease. It is still an important cause of hemorrhage illness in several African and South American countries despite existence of an effective vaccine . In the past it was a source of several devastating epidemics. The disease is caused b...

Vaccine

... The term derives from vaccinia , the infectious viral agent of cowpox , which, when administered to hum...system recognition) into human or animal cells, of viral or bacterial DNA . These cells then develop immunity against an infectious agent, without the effe...

Tobacco mosaic virus

... a single protein that assembles itself around the viral RNA in a helical structure (16.3 proteins per helix turn). The virions have a diameter ~18nm and an inner hole ~2nm. The protein coat consists of 158 aminoacids which are assembled into four main alpha-helices, which are joined by a prominent loop pr...

Tobacco mosaic virus

... a single protein that assembles itself around the viral RNA in a helical structure (16.3 proteins per helix turn). The virions have a diameter ~18nm and an inner hole ~2nm. The protein coat consists of 158 aminoacids which are assembled into four main alpha-helices, which are joined by a prominent loop pr...

RNA virus

...sized to provide a chemical function necessary for viral propagation. (See ribozyme .) If so, most mutations would render it unfit for that purpose and would not propagate. Some RNA viruses: Arenaviridae Bunyaviridae Flaviviridae : Yellow fever - Hepatitis C&G Orthomyxoviridae : Influ...

Restriction enzyme

...ed to be a mechanism evolved by bacteria to resist viral attack and to help in the removal of viral sequences. Contents showTocToggle("show","hide") 1 Sites of cleavage 2 Fragment comp...

Proteolysis

...ir transport through a membrane Separation of viral proteins that were translated from a monocistronic mRNA Digestion of proteins from foods as a source of amino acids Conversion of predecessor-proteins (proenzymes , zymogens , prehormones ) into their final structures. Examples of proteas...

Proteome

...le, all of the proteins in a virus can be called a viral proteome. The proteome is larger than the genome , expecially in eukaryotes , in the sense there are more proteins than genes . This is due to alternative splicing of genes and post-translational modifications like glycosylation or phosp...

Proprioception

...a young woman who lost her proprioception due to a viral infection of her spinal cord . At first she was not able to move properly at all. Later she relearned by using her sight (watching her feet) and vestibulum (or inner ear ) only. She eventually acquired a stiff and slow movement, which is believe...

Polymerase chain reaction

...be detected using PCR through amplification of the viral DNA. This analysis is possible right after infection, which can be from several days to several months before actual symptoms occur. Such early diagnoses give physicians a significant lead in treatment. Cloning genes Cloning a gene--not to be c...

Outbreak

...s occurred in the past. The study of pathogenic viral outbreaks is a branch of epidemiology and usuall...als, or plants sick. As with bacterial outbreaks, viral outbreaks are classified as sporadic (occasional occurrence), endemic (regular cases often occurri...

Molecular biology

... a carrier. In such cases, the technique is called viral transduction, and the cells are said to be transduced. In either case, DNA coding for a protein of interest is now inside a cell, and the protein can now be expressed. A variety of systems, such as inducible promoters and specific cell-signaling fac...

Lytic cycle

The lytic cycle is one of the two cycles of viral reproduction , the other being the lysogenic cy...ycle is typically thought of as the main method of viral replication, since it results in the destruction of the infected cell , which is how viruses cause ...

Lysis

... cytolysis osmotic lysis chemical lysis viral lysis a dialogue of Plato about friendship ( philia ), see Lysis (Plato)...

Immune system

...cteriophage attempts to infect this bacterium, the viral DNA has not been protected, and gets degraded by the first enzyme. While study of the bacterial immune system provides useful insights into immunology, the remainder of this article will focus on higher organisms' immune systems, particularly the hum...

Hepatitis B

...vantages. In general, each works by reducing the viral load by several orders of magnitude thus helping ...ations of persistent infection, and development of viral resistance with treatment. Chronic carriers should be strongly encouraged to avoid consuming alcoho...

Gene therapy

...ntists have removed certain crucial genes from the viral genome , so that they cannot damage the host. RPR Gencell (a French pharmaceutical company) conducted experiments injecting retroviruses into lung cancer patients. After the injections of vectors containing p53 — a gene that suppresses t...

Foot and mouth disease

... disease , is a highly contagious but non-fatal viral disease of cattle and pigs . It can also in...ry rarely. The cause of FMD was first shown to be viral in 1897 by Friedrich Loeffler . He passed the blood of an infected animal through a fine porcel...

Flaviviridae

...virus ) Genus Pestivirus (type species Bovine viral diarrhea virus , others include classical swine fever or hog cholera) The genome of the Flaviviridae viruses is a monopartite, linear, single-stranded RNA of positive sense that is 10,000-11,000 nucleotides long. The 5'-terminus carries ...

Evolutionary biology

...estions. Similar features have led to progress in viral evolution, particularly for bacteriophage . Notable evolutionary biologists Notable contributors to evolutionary biology include: Charles Darwin Erasmus Darwin Richard Dawkins Theodosius Dobzhansky Paul W. Ewald - Applying...

Bacterium

...ransfer of viral, bacterial, or both bacterial and viral DNA from one cell to another via bacteriophage) and; bacterial conjugation (the transfer of DNA from one bacterial cell to another via a special protein structure called a conjugation pilus ). Bacteria, having acquired DNA from any of these e...

Ebola

...ristic filamentous structure of a filovirus . The viral filaments can appear in images in various shapes i...length of a filament associated with an individual viral particle is extremely variable, with Ebola particles of up to 14,000 nm in length being reported. An...

Full blood count

...ial infection. Lymphocytes - Higher with some viral infections such as glandular fever . Also raised in lymphocytic leukaemia CLL . Monocytes - May be raised in bacterial infection Eosinophil granulocytes - Increased in parasitic infections. Basophil granulocytes A manual count will al...

Bacterium

...ransfer of viral, bacterial, or both bacterial and viral DNA from one cell to another via bacteriophage) and; bacterial conjugation (the transfer of DNA from one bacterial cell to another via a special protein structure called a conjugation pilus ). Bacteria, having acquired DNA from any of these e...

Apoptosis

...ith foreign antigen produced as a consequence of a viral infection. After becoming activated, they migrate ...so important in eliciting an apoptotic response to viral infection and consequent damage to the cell's reproductive cycle. Cancer and defective apoptotic...

Antigenic shift

... is specific to the influenza literature. In other viral systems, the same process is called reassortment or viral shift ....

Antigen

... result of normal cell metabolism , or because of viral or intracellular bacterial infection . The fragments are then presented on the cell surface in the complex with class I histocompatibility molecules . If cytotoxic CD8 + T cells recognize them, they begin to secrete different toxins that cause...

Antibody

...gocytosis by macrophages and other cells, block viral receptors and stimulate other immune responses such as the complement pathway . Antibodies that recognize viruses can block these directly by their sheer size. The virus will be unable to dock to a cell and infect it, hindered by the antibody. Th...

Antibiotic

...arming the host. Antibiotics are not effective in viral , fungal and other nonbacterial infections, and ...iotic, in particular the use of antibacterials for viral infections like the common cold, and failure to take the entire prescribed course of the antibiotic,...