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Cytopathic Effect
Cytopathic effect (abbreviated CPE) refers to structural changes in host cells that are caused by viral invasion. The infecting virus causes lysis of the host cell or when the cell dies without lysis due to an inability to replicate. If a virus causes these morphological changes in the host cell, it is said to be cytopathogenic. Common examples of CPE include rounding of the infected cell, fusion with adjacent cells to form syncytia, and the appearance of nuclear or cytoplasmic inclusion bodies. CPEs and other changes in cell morphology are only a few of the many effects by cytocidal viruses. When a cytocidal virus infects a permissive cell, the viruses kill the host cell through changes in cell morphology, in cell physiology, and the biosynthetic events that follow. These changes are necessary for efficient virus replication but at the expense of the host cell. Diagnostics CPEs are important aspects of a viral infection in diagnostics. Many CPEs can be seen in unfixed, unstaine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpes Simplex Virus Pap Test
Herpes simplex, often known simply as herpes, is a viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are oral herpes and genital herpes, though other forms also exist. Oral herpes involves the face or mouth. It may result in small blisters in groups, often called cold sores or fever blisters, or may just cause a sore throat. Genital herpes involves the genitalia. It may have minimal symptoms or form blisters that break open and result in small ulcers. These typically heal over two to four weeks. Tingling or shooting pains may occur before the blisters appear. Herpes cycles between periods of active disease followed by periods without symptoms. The first episode is often more severe and may be associated with fever, muscle pains, swollen lymph nodes and headaches. Over time, episodes of active disease decrease in frequency and severity. Herpetic whitlow typically invo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Culture
Viral culture is a laboratory technique in which samples of a virus are placed to different cell lines which the virus being tested for its ability to infect. If the cells show changes, known as cytopathic effects, then the culture is positive. Traditional viral culture has been generally superseded by shell vial culture, in which the sample is centrifuged onto a single layer of cells and viral growth is measured by antigen detection methods. This greatly reduces the time to detection for slow growing viruses such as cytomegalovirus, for which the method was developed. In addition, the centrifugation step in shell vial culture enhances the sensitivity of this method because after centrifugation, the viral particles of the sample are in close proximity to the cells. Human and monkey cells are used in both traditional viral culture and shell vial culture. Human virus types that can be identified by viral culture include adenovirus, cytomegalovirus, enteroviruses, herpes simplex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indirect Immunoperoxidase Assay
Indirect immunoperoxidase assay (IPA) is a laboratory technique used to detect and titrate viruses that do not cause measurable cytopathic effects and cannot be measured by classical plaque assays. These viruses include human coronavirus 229E and OC43. Methodology Susceptible cells are inoculated with serial logarithmic dilutions of samples in a 96-well plate. After viral growth, viral detection by IPA yields the infectious virus titer, expressed as tissue culture infectious dose (TCID50). This represents the dilution of a virus-containing sample at which half of a series of laboratory wells contain replicating viruses. This technique is a reliable method for the titration of human coronaviruses (HCoV) in biological samples (cells, tissues, or fluids). It is also reliable in the detection of antibodies to human cytomegalovirus.G Gerna, C J McCloud and R W Chambers: Immunoperoxidase technique for detection of antibodies to Human cytomegalovirus. J. Clin. Microbiol. 1976, 3(3):364 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basophilic
Basophilic is a technical term used by pathologists. It describes the appearance of cells, tissues and cellular structures as seen through the microscope after a histological section has been stained with a basic dye. The most common such dye is haematoxylin. The name basophilic refers to the characteristic of these structures to be stained very well by basic dyes. This can be explained by their charges. Basic dyes are cationic, i.e. contain positive charges, and thus they stain anionic structures (i.e. structures containing negative charges), such as the phosphate backbone of DNA in the cell nucleus and ribosomes. "Basophils" are cells that "love" (from greek "-phil") basic dyes, for example haematoxylin, azure and methylene blue. Specifically, this term refers to: * basophil granulocytes * anterior pituitary basophils An abnormal increase in basophil granulocytes is therefore also described as basophilia."Basophilia" ''Collins Online Dictionary'' 2024 https://www.colli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosinophilic
Eosinophilic (Greek suffix '' -phil'', meaning ''eosin-loving'') describes the staining of tissues, cells, or organelles after they have been washed with eosin, a dye commonly used in histological staining. Eosin is an acidic dye for staining cell cytoplasm, collagen, and muscle fibers. ''Eosinophilic'' describes the appearance of cells and structures seen in histological sections that take up the staining dye eosin. Such eosinophilic structures are, in general, composed of protein. Eosin is usually combined with a stain called hematoxylin to produce a hematoxylin- and eosin-stained section (also called an H&E stain, HE or H+E section). It is the most widely used histological stain for a medical diagnosis. When a pathologist examines a biopsy of a suspected cancer, they will stain the biopsy with H&E. Some structures seen inside cells are described as being eosinophilic; for example, Lewy and Mallory bodies. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of List of virus species, virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpesviridae
''Orthoherpesviridae'', previously named and more widely known as ''Herpesviridae'', is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are commonly known as herpesviruses. The family name is derived from the Greek word ἕρπειν ( 'to creep'), referring to spreading cutaneous lesions, usually involving blisters, seen in flares of herpes simplex 1, herpes simplex 2 and herpes zoster ( shingles). In 1971, the International Committee on the Taxonomy of Viruses (ICTV) established ''Herpesvirus'' as a genus with 23 viruses among four groups. Since then, the number of identified herpesviruses has grown to more than 100. Herpesviruses can cause both latent and lytic infections. Nine herpesvirus types are known to primarily infect humans, at least five of which are extremely widespread among most human populations, and which cause common diseases: herpes simplex 1 and 2 (HSV-1 and HSV-2, also know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavivirus
''Flavivirus'', renamed ''Orthoflavivirus'' in 2023, is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika virus and several other viruses which may cause encephalitis, as well as insect-specific flaviviruses (ISFs) such as cell fusing agent virus (CFAV), Palm Creek virus (PCV), and Parramatta River virus (PaRV). While dual-host flaviviruses can infect vertebrates as well as arthropods, insect-specific flaviviruses are restricted to their competent arthropods. The means by which flaviviruses establish persistent infection in their competent vectors and cause disease in humans depends upon several virus-host interactions, including the intricate interplay between flavivirus-encoded immune antagonists and the host antiviral innate immune effector molecules. Flaviviruses are named for the yellow fever virus; the word ''flavus'' means 'yellow' in Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrovirus
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus ''retro'' (backward). The new DNA is then retroviral integration, incorporated into the host cell genome by an integrase enzyme, at which point the retroviral DNA is referred to as a provirus. The host cell then treats the viral DNA as part of its own genome, transcribing and translating the viral genes along with the cell's own genes, producing the proteins required to assemble new copies of the virus. Many retroviruses cause serious diseases in humans, other mammals, and birds. Retroviruses have many subfamilies in three basic groups. * Oncovirus, Oncoretroviruses (cancer-causing retroviruses) include human T-lymphotropic virus (HTLV) causing a type of leuk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenoviridae
Adenoviruses (members of the family (biology), family ''Adenoviridae'') are medium-sized (90–100 nanometer, nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953. They have a broad range of vertebrate hosts; in humans, more than 50 distinct adenoviral serotypes have been found to cause a wide range of Adenovirus infection, illnesses, from mild respiratory infections in young children (the common cold) to life-threatening multi-organ disease in people with a Immunodeficiency, weakened immune system. Virology Classification This family contains the following genus, genera: * ''Aviadenovirus'' * ''Barthadenovirus'' * ''Ichtadenovirus'' * ''Mastadenovirus'' (including all human adenoviruses) * ''Siadenovirus'' * ''Testadenovirus'' Diversity In humans, currently there are 88 human adenoviruses (HAdVs) in seven species (H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poxviridae
''Poxviridae'' is a family of double-stranded DNA viruses. Vertebrates and arthropods serve as natural hosts. The family contains 22 genera that are assigned to two subfamilies: ''Chordopoxvirinae'' and ''Entomopoxvirinae''. ''Entomopoxvirinae'' infect insects and ''Chordopoxvirinae'' infect vertebrates. Diseases associated with this family include smallpox. Four genera of poxviruses can infect humans: ''Orthopoxvirus'', ''Parapoxvirus'', ''Yatapoxvirus'', ''Molluscipoxvirus''. ''Orthopoxvirus'': smallpox virus (variola), vaccinia virus, cowpox virus, Mpox virus; ''Parapoxvirus'': Orf (disease), orf virus, pseudocowpox, bovine papular stomatitis virus; ''Yatapoxvirus'': tanapox virus, yaba monkey tumor virus; ''Molluscipoxvirus'': molluscum contagiosum, molluscum contagiosum virus (MCV). The most common are vaccinia (seen on the Indian subcontinent) and molluscum contagiosum, but Mpox infections are rising (seen in west and central African rainforest countries). The similarly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
