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Human Metapneumovirus
Human metapneumovirus (HMPV or hMPV) is a negative-sense single-stranded RNA virus of the family ''Pneumoviridae'' and is closely related to the avian metapneumovirus (AMPV) subgroup C. It was isolated for the first time in 2001 in the Netherlands by using the RAP-PCR (RNA arbitrarily primed Polymerase chain reaction, PCR) technique for the identification of unknown viruses growing in cultured cells. As of 2016, it was the second most common cause—after respiratory syncytial virus (RSV)—of acute respiratory tract infection, respiratory tract illness in otherwise-healthy children under the age of 5 in a large US outpatient clinic. The peak age of hospitalization for infants with HMPV is between 6 and 12 months, slightly older than the peak of RSV, which is around 2 to 3 months. The clinical features and severity of HMPV are similar to those of RSV. HMPV is also an important cause of disease in older adults and infants. Taxonomy Discovery and naming Human metapneumovirus (HMP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative-sense Single-stranded RNA Virus
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, sense may have slightly different meanings. For example, the negative-sense strand of DNA is equivalent to the template strand, whereas the positive-sense strand is the non-template strand whose nucleotide sequence is equivalent to the sequence of the mRNA transcript. DNA sense Because of the complementary nature of base-pairing between nucleic acid polymers, a double-stranded DNA molecule will be composed of two strands with sequences that are reverse complements of each other. To help molecular biologists specifically identify each strand individually, the two strands are usually differentiated as the "sense" strand and the "antisense" strand. An individual strand of DNA is referred to as positive-sense (also positive (+) or simply sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Respiratory Syncytial Virus
Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. Its name is derived from the large cells known as ''syncytia'' that form when infected cells fuse. RSV is a common cause of respiratory hospitalization in infants, and reinfection remains common in later life, though often with less severity. It is a notable pathogen in all age groups. Infection rates are typically higher during the cold winter months, causing bronchiolitis in infants, common colds in adults, and more serious respiratory illnesses, such as pneumonia, in the elderly and immunocompromised. RSV can cause outbreaks both in the community and in hospital settings. Following initial infection via the eyes or nose, the virus infects the epithelial cells of the upper and lower airway, causing inflammation, cell damage, and airway obstruction. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heparan Sulfate
Heparan sulfate (HS) is a linear polysaccharide found in all animal tissues. It occurs in a proteoglycan (HSPG, i.e. Heparan Sulfate ProteoGlycan) in which two or three HS chains are attached in close proximity to cell surface or extracellular matrix proteins. In this form, HS binds to a variety of protein ligands, including Wnt signaling pathway, Wnt, and regulates a wide range of biological activities, including developmental processes, angiogenesis, blood coagulation, abolishing detachment activity by GrB (Granzyme B), and tumour metastasis. HS has also been shown to serve as cellular receptor for a number of viruses, including the respiratory syncytial virus. One study suggests that cellular heparan sulfate has a role in SARS-CoV-2 infection, particularly when the virus attaches with ACE2. Proteoglycans The major cell membrane HSPGs are the transmembrane syndecans and the glycosylphosphatidylinositol (GPI) anchored glypicans. Other minor forms of membrane HSPG include betaglyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golgi Apparatus
The Golgi apparatus (), also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic Cell (biology), cells. Part of the endomembrane system in the cytoplasm, it protein targeting, packages proteins into membrane-bound Vesicle (biology and chemistry), vesicles inside the cell before the vesicles are sent to their destination. It resides at the intersection of the secretory, lysosomal, and Endocytosis, endocytic pathways. It is of particular importance in processing proteins for secretion, containing a set of glycosylation enzymes that attach various sugar monomers to proteins as the proteins move through the apparatus. The Golgi apparatus was identified in 1898 by the Italian biologist and pathologist Camillo Golgi. The organelle was later named after him in the 1910s. Discovery Because of its large size and distinctive structure, the Golgi apparatus was one of the first organelles to be discovered and observed in detail. It was d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoproteins
Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (biology)
Transcription is the process of copying a segment of DNA into RNA for the purpose of gene expression. Some segments of DNA are transcribed into RNA molecules that can encode proteins, called messenger RNA (mRNA). Other segments of DNA are transcribed into RNA molecules called non-coding RNAs (ncRNAs). Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a Complementarity (molecular biology), complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, Antiparallel (biochemistry), antiparallel RNA strand called a primary transcript. In virology, the term transcription is used when referring to mRNA synthesis from a viral RNA molecule. The genome of many Orthornavirae, RNA viruses is composed of Sense (molecular biology), negative-sense RNA which acts as a template for positive sense viral messenger RNA - a necessary step in the synthesis of viral proteins needed for viral replication. This process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribonucleoprotein
Nucleoproteins are proteins conjugated with nucleic acids (either DNA or RNA). Typical nucleoproteins include ribosomes, nucleosomes and viral nucleocapsid proteins. Structures Nucleoproteins tend to be positively charged, facilitating interaction with the negatively charged nucleic acid chains. The Protein tertiary structure, tertiary structures and biological functions of many nucleoproteins are understood.Graeme K. Hunter G. K. (2000): Vital Forces. The discovery of the molecular basis of life. Academic Press, London 2000, . Important techniques for determining the structures of nucleoproteins include X-ray diffraction, nuclear magnetic resonance and cryo-electron microscopy. Viruses Virus genomes (either DNA virus, DNA or RNA virus, RNA) are extremely tightly packed into the Capsid, viral capsid. Many viruses are therefore little more than an organised collection of nucleoproteins with their binding sites pointing inwards. Structurally characterised viral nucleoproteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arginylglycylaspartic Acid
Arginylglycylaspartic acid (RGD) is the most common peptide Short linear motif, motif responsible for cell adhesion to the extracellular matrix (ECM), found in species ranging from ''Drosophila melanogaster, Drosophila'' to humans. Cell adhesion proteins called integrins recognize and bind to this sequence, which is found within many matrix proteins, including fibronectin, fibrinogen, vitronectin, osteopontin, and several other adhesive extracellular matrix proteins. The discovery of RGD and elucidation of how RGD binds to integrins has led to the development of a number of drugs and diagnostics, while the peptide itself is used ubiquitously in bioengineering. Depending on the application and the integrin targeted, RGD can be chemically modified or replaced by a similar peptide which promotes cell adhesion. Discovery RGD was identified as the minimal recognition sequence within fibronectin required for cell attachment by Ruoslahti and Pierschbacher in the early 1980s. To do this, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and plants, as opposed to a tissue extract or dead organism. Examples of investigations ''in vivo'' include: the pathogenesis of disease by comparing the effects of bacterial infection with the effects of purified bacterial toxins; the development of non-antibiotics, antiviral drugs, and new drugs generally; and new surgical procedures. Consequently, animal testing and clinical trials are major elements of ''in vivo'' research. ''In vivo'' testing is often employed over ''in vitro'' because it is better suited for observing the overall effects of an experiment on a living subject. In drug discovery, for example, verification of efficacy ''in vivo'' is crucial, because ''in vitro'' assays can sometimes yield misleading results with drug c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro
''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from ''in vitro'' experiments may not fully or accurately predict the effects on a whole organism. In contrast to ''in vitro'' experiments, ''in vivo'' studies are those conducted in living organisms, including humans, known as clinical trials, and whole plants. Definition ''In vitro'' (Latin language, Latin for "in glass"; often not italicized in English usage) studies are conducted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recombinant Virus
A recombinant virus may occur naturally or be produced by recombining pieces of DNA or RNA in a laboratory. Synthetic recombination This may be used to produce viral vaccines or gene therapy vectors. Natural recombination The term is also used to refer to naturally occurring recombination between virus genomes in a cell infected by more than one virus strain. This occurs either by Homologous recombination of the nucleic acid strands or by reassortment of genomic segments. Both these and mutation within the virus have been suggested as ways in which influenza and other viruses evolve. An example of a recombinant virus is Western equine encephalitis virus (WEE), which is a recombinant virus between two other closely related yet distinct encephalitis viruses. In addition, reassortment is most important for pandemic influenza viruses. See also * Reassortment * Mutation * Chromosomal crossover Chromosomal crossover, or crossing over, is the exchange of genetic material dur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithelial Cells
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. These tissues also lack blood or lymph supply. The tissue is supplied by nerves. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
