Tag: Cholesterol

  • Maculopapular rash is seen in graft-versus-host disease (GVHD) 

    Maculopapular rash is seen in graft-versus-host disease (GVHD) 

    A maculopapular rash is a type of rash characterized by a flat, red area on the skin that is covered with small confluent bumps. It may only appear red in lighter-skinned people. The term “maculopapular” is a compound: macules are small, flat discolored spots on the surface of the skin; and papules are small, raised bumps. It is also described as erythematous, or red.…

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  • Steroidogenic factor 1 (SF-1) protein and a few related things

    The steroidogenic factor 1 (SF-1) protein is a transcription factor involved in sex determination by controlling the activity of genes related to the reproductive glands or gonads and adrenal glands. This protein is encoded by the NR5A1 gene, a member of the nuclear receptor subfamily, located on the long arm of chromosome 9 at position 33.3. It was originally identified as a regulator of genes encoding cytochrome P450 steroid hydroxylases, however, further roles…

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  • p-Phenylenediamine (PPD) is a derivative of aniline used in kevlar, hair dye and henna substitutions among other things, the derivatives of which are used in antiozonants among other horrors

    p-Phenylenediamine (PPD) is a derivative of aniline used in kevlar, hair dye and henna substitutions among other things, the derivatives of which are used in antiozonants among other horrors

    p-Phenylenediamine (PPD) is an organic compound with the formula C6H4(NH2)2. This derivative of aniline is a white solid, but samples can darken due to air oxidation.It is mainly used as a component of engineering polymers and composites like kevlar. It is also an ingredient in hair dyes and is occasionally used as a substitute for henna. Production PPD is produced via three routes. Most commonly, 4-nitrochlorobenzene is treated…

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  • Nuclear factor erythroid 2-related factor 2 (NRF2)

    Glutathione Local Links Nuclear factor erythroid 2-related factor 1 Local Links Reference for subtitle: Finamor IA, Bressan CA, Torres-Cuevas I, Rius-Pérez S, da Veiga M, Rocha MI, Pavanato MA, Pérez S. Long-Term Aspartame Administration Leads to Fibrosis, Inflammasome Activation, and Gluconeogenesis Impairment in the Liver of Mice. Biology. 2021; 10(2):82. https://doi.org/10.3390/biology10020082 Nuclear factor erythroid 2-related…

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  • Sterol carrier proteins (aka nonspecific lipid transfer proteins)

    Sterol carrier proteins (aka nonspecific lipid transfer proteins)

    These proteins are different from plant nonspecific lipid transfer proteins but structurally similar to small proteins of unknown function from Thermus thermophilus. This domain is involved in binding sterols. The human sterol carrier protein 2 (SCP2) is a basic protein that is believed to participate in the intracellular transport of cholesterol and various other lipids. Human…

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  • Temporins and Musth or must

    Temporins and Musth or must

    Temporins are a family of peptides isolated originally from the skin secretion of the European red frog, Rana temporaria. Peptides belonging to the temporin family have been isolated also from closely related North American frogs, such as Rana sphenocephala. In elephants, temporin is secreted by temporal glands during the period of musth. It contains proteins, lipids (notably cholesterol), phenols, cresols and sesquiterpenes (notably farnesol and its derivatives). This is not related to temporins that are antimicrobial peptides. In old Sanskrit…

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  • Bile acid receptor (BAR) aka farnesoid X receptor (FXR) or NR1H4

    The bile acid receptor (BAR), also known as farnesoid X receptor (FXR) or NR1H4 (nuclear receptor subfamily 1, group H, member 4), is a nuclear receptor that is encoded by the NR1H4 gene in humans. Function FXR is expressed at high levels in the liver and intestine. Chenodeoxycholic acid and other bile acids are natural ligands for FXR. Similar to other nuclear receptors, when activated, FXR translocates to the cell nucleus, forms…

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  • The halloween genes

    The halloween genes are a set of genes identified in Drosophila melanogaster that influence embryonic development. All of the genes code for cytochrome P450 enzymes in the ecdysteroidogenic pathway (biosynthesis of ecdysone from cholesterol). Ecdysteroids such as 20-hydroxyecdysone and ecdysone influence many of the morphological, physiological, biochemical changes that occur during molting in insects. Steroid hormones control many aspects of reproduction, development, and homeostasis in higher organisms.  In arthropods, steroid hormones play equal or even more…

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  • Chrysolina beetles, including Chrysolina coerulans, have cardiac glycosides (including xylose) in their defensive glands

    Chrysolina beetles, including Chrysolina coerulans, have cardiac glycosides (including xylose) in their defensive glands

    The defensive secretions of some chrysomelid beetles belonging to the genera Chrysolina, Chrysochloa, and Dlochrysa contain complex mixtures of cardenolides. The spectral data for some of these compounds suggest that they are monohydroxylated digitoxigenin derivatives linked to a pentose (such as xylose or arabinose). Evidence indicates that the beetles do not sequester these steroid glycosides…

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  • 20α,22R-Dihydroxycholesterol

    20α,22R-Dihydroxycholesterol, or (3β)-cholest-5-ene-3,20,22-triol is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones. CHAUDHURI AC, HARADA Y, SHIMIZU K, GUT M, DORFMAN RI (March 1962). “Biosynthesis of pregnenolone from…

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  • 22R-Hydroxycholesterol

    22R-Hydroxycholesterol, or (3β)-cholest-5-ene-3,22-diol is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol.  Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones. [CHAUDHURI AC, HARADA Y, SHIMIZU K, GUT M, DORFMAN RI (March 1962). “Biosynthesis of pregnenolone…

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