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Janus-faced Molecule
A Janus molecule (or Janus-faced molecule) is a molecule which can represent both beneficial and toxic effects. The term Janus-faced molecule is derived from the ancient Roman god, Janus. Janus is depicted as having two faces; one facing the past and one facing the future. This is synonymous to a Janus molecule having two distinct purposes: a beneficial and a toxic purpose depending on its quantity. Examples Examples of a Janus-faced molecule are nitric oxide and cholesterol. In the case of cholesterol, the property that makes cholesterol useful in cell membranes, namely its absolute insolubility in water, also makes it lethal. When cholesterol accumulates in the wrong place, for example within the walls of an artery, it cannot be readily mobilized, and its presence eventually leads to the development of an atherosclerotic plaque. One such example of a Janus-faced molecule is S100A8/ A9 protein complex; this complex is associated with autoimmune and abnormal growth of cells dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Oxide
Nitric oxide (nitrogen oxide, nitrogen monooxide, or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its chemical formula (•N=O or •NO). Nitric oxide is also a heteronuclear diatomic molecule, a class of molecules whose study spawned early modern theories of chemical bonding. An important intermediate in industrial chemistry, nitric oxide forms in combustion systems and can be generated by lightning in thunderstorms. In mammals, including humans, nitric oxide is a signaling molecule in many physiological and pathological processes. It was proclaimed the " Molecule of the Year" in 1992. The 1998 Nobel Prize in Physiology or Medicine was awarded for discovering nitric oxide's role as a cardiovascular signalling molecule. Its impact extends beyond biology, with applications in medicine, such as the development of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholesterol
Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils. Cholesterol is biosynthesis, biosynthesized by all animal Cell (biology)#Eukaryotic cells, cells and is an essential structural and cholesterol signaling, signaling component of animal cell membranes. In vertebrates, hepatocyte, hepatic cells typically produce the greatest amounts. In the brain, astrocytes produce cholesterol and transport it to neurons. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as ''Mycoplasma'', which require cholesterol for growth. Cholesterol also serves as a Precursor (chemistry), precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Elevated levels of cholesterol in the blood, especially when bound to low-density lipoprotein (LDL, often referred to as "bad cholesterol"), may increase the risk of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S100A8
S100 calcium-binding protein A8 (S100A8) is a protein that in humans is encoded by the ''S100A8'' gene. It is also known as calgranulin A. The proteins S100A8 and S100A9 form a heterodimer called calprotectin. The protein encoded by this gene is a member of the S100 family of proteins containing 2 EF-hand The EF hand is a helix–loop–helix structural domain or ''motif'' found in a large family of calcium-binding proteins. The EF-hand motif contains a helix–loop–helix topology, much like the spread thumb and forefinger of the human hand, in ... calcium-binding motifs. S100 proteins are localized in the cytoplasm and/or nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. S100 genes include at least 13 members which are located as a cluster on chromosome 1q21. This protein may function in the inhibition of casein kinase and as a cytokine. Altered expression of this prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S100A9
S100 calcium-binding protein A9 (S100A9) also known as migration inhibitory factor-related protein 14 (MRP14) or calgranulin B is a protein that in humans is encoded by the ''S100A9'' gene. The proteins S100A8 and S100A9 form a heterodimer called calprotectin. Function S100A9 is a member of the S100 family of proteins containing 2 EF hand calcium-binding motifs. S100 proteins are localized in the cytoplasm and/or nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. S100 genes include at least 13 members which are located as a cluster on chromosome 1q21. This protein may function in the inhibition of casein kinase. MRP14 complexes with MRP-8 (S100A8), another member of the S100 family of calcium-modulated proteins; together, MRP8 and MRP14 regulate myeloid cell function by binding to Toll-like receptor 4 ( TLR4) and the receptor for advanced glycation end products. Intracel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Halayko
Andrew John Halayko is Professor of Physiology and Pathophysiology, and a Tier 1 Canada Research Chair in Lung Pathobiology and Treatment at the University of Manitoba. He is the current Editor-in-Chief of the ''American Journal of Respiratory Cell and Molecular Biology''. He was President of the Canadian Thoracic Society from 2016 to 2017. He has an h-index of 66 according to Semantic Scholar Semantic Scholar is a research tool for scientific literature. It is developed at the Allen Institute for AI and was publicly released in November 2015. Semantic Scholar uses modern techniques in natural language processing to support the resear .... References External link * {{DEFAULTSORT:Halayko, Andrew John Year of birth missing (living people) Living people Academic staff of the University of Manitoba Canada Research Chairs Canadian physiologists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteoglycan
Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to which the glycosaminoglycan is joined through a tetrasaccharide bridge (e.g. chondroitin sulfate- GlcA- Gal-Gal- Xyl-PROTEIN). The Ser residue is generally in the sequence -Ser- Gly-X-Gly- (where X can be any amino acid residue but proline), although not every protein with this sequence has an attached glycosaminoglycan. The chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions due to the occurrence of sulfate and uronic acid groups. Proteoglycans occur in connective tissue. Types Proteoglycans are categorized by their relative size (large and small) and the nature of their glycosaminoglycan chains. Types include: Certain members are considered members of the "small leucine-rich pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Janus
In ancient Roman religion and myth, Janus ( ; ) is the god of beginnings, gates, transitions, time, duality, doorways, passages, frames, and endings. He is usually depicted as having two faces. The month of January is named for Janus (''Ianuarius''). According to ancient Roman farmers' almanacs, Juno was mistaken as the tutelary deity of the month of January, but Juno is the tutelary deity of the month of June. Janus presided over the beginning and ending of conflict, and hence war and peace. The gates of the Temple of Janus in Rome were opened in time of war and closed to mark the arrival of peace. As a god of transitions, he had functions pertaining to birth and to journeys and exchange, and in his association with Portunus, a similar harbor and gateway god, he was concerned with travelling, trading, and shipping. Janus had no flamen or specialised priest ''( sacerdos)'' assigned to him, but the King of the Sacred Rites ''( rex sacrorum)'' himself carried out his cerem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicity
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacteria, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell (biology), cell (cytotoxicity) or an organ such as the liver (hepatotoxicity). Sometimes the word is more or less synonymous with poison#Poisoning, poisoning in everyday usage. A central concept of toxicology is that the effects of a toxicant are Dose (biochemistry), dose-dependent; even water can lead to water intoxication when taken in too high a dose, whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect. Toxicity is species-specific, making cross-species analysis problematic. Newer paradigms and metrics are evolving to bypass animal testing, while maintaining the concept of toxicity endpoints. Etymology In Ancient G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
