Tag: AGING
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🧬 How Sodium Shapes Calcium Signaling
🔹 Sodium-Calcium Coupling 🔹 Vault Consequence Vault logic: sodium maintains calcium coherence — without it, bone terrain fractures from the inside. 🦴 Sodium-Calcium Balance & Bone Health Factor Effect of Low Sodium Bone Impact Na⁺/Ca²⁺ exchanger Reduced efficiency Intracellular Ca²⁺ buildup Osteoblasts Mitochondrial stress ↓ bone formation Osteoclasts Overactivation ↑ bone resorption Calcium excretion ↑…
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Chalone Rangers: The Tissue-Specific Mitotic Inhibitors You Never Knew You Needed
Chalones are the unsung heroes of cellular crowd control. These tissue-specific, water-soluble substances are like the bouncers of your body, standing at the gates of mitosis with their arms crossed, saying, “Not tonight, buddy.” They’re the biochemical equivalent of that one friend who knows when to call it a night before things get out of…
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Structure of DNA repair protein XRCC4 aka X-ray repair cross-complementing protein 4
XRCC4 protein is a TETRAMER that resembles the shape of a DUMBBELL containing two globular ends separated by a long, thin stalk. The tetramer is composed of two dimers, and each dimer is made up of two similar subunits. The first subunit (L) contains amino acid residues 1 – 203 and has a longer stalk than the second…
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Freeze branding aka CryoBranding and the resulting brands, trichoglyphs, is a technique involving a cryogenic coolant instead of heat to produce permanent marks on a variety of animals
The coolant is used to lower the temperature of a branding iron such that its application to shaved skin will permanently alter hair follicles. The intense cold destroys the pigmentation apparatus in the animal’s hair follicles, leaving all subsequent hair growth without color. This creates a high-contrast, permanent mark in the shape of the branding iron’s head. A longer application of the cold iron can also…
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Adrenarche and Adrenopause
Adrenarche is an early stage in sexual maturation that happens in some higher primates and in humans, typically peaks at around 20 years of age, and is involved in the development of pubic hair, body odor, skin oiliness, axillary hair, sexual attraction/sexual desire/increased libido and mild acne. During adrenarche the adrenal glands secrete increased levels of weak adrenal androgens, including dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione (A4), but without increased cortisol levels. Adrenarche is the result of the development of a…
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Heterochromatin
Heterochromatin is a tightly packed form of DNA or condensed DNA, which comes in multiple varieties. These varieties lie on a continuum between the two extremes of constitutive heterochromatin and facultative heterochromatin. Both play a role in the expression of genes. Because it is tightly packed, it was thought to be inaccessible to polymerases and therefore not transcribed; however, according to Volpe et…
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Leydig cells aka interstitial cells of the testes and interstitial cells of Leydig
Leydig cells, also known as interstitial cells of the testes and interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle and produce testosterone in the presence of luteinizing hormone (LH).[1][2] They are polyhedral in shape and have a large, prominent nucleus, an eosinophiliccytoplasm, and numerous lipid-filled vesicles.[3] Structure The mammalian Leydig cell is a polyhedral epithelioid cell with a single eccentrically located ovoid nucleus.…
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What Is Nitrophenol? (besides something mentioned in ‘Scientific Opinion on the re‐evaluation of aspartame as a food additive’)
Nitrophenols are compounds of the formula HOC6H5−x(NO2)x. The conjugate bases are called nitrophenolates. Nitrophenols are more acidic than phenol itself. Wikipedia Mono-nitrophenols with the formula HOC6H4NO2. Three isomeric nitrophenols exist: o-Nitrophenol (2-nitrophenol; OH and NO2 groups are neighboring; CAS number: 88-75-5), a yellow crystalline solid (m.p. 46 °C). m-Nitrophenol (3-nitrophenol, CAS number: 554-84-7), a yellow solid (m.p. 97 °C) and precursor to the…
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Human chorionic gonadotropin (hCG)
Human chorionic gonadotropin (hCG) is a hormone for the maternal recognition of pregnancy produced by trophoblast cells that are surrounding a growing embryo (syncytiotrophoblast initially), which eventually forms the placenta after implantation. Cole LA (2009). “New discoveries on the biology and detection of human chorionic gonadotropin”. Reprod. Biol. Endocrinol. 7: 8. doi:10.1186/1477-7827-7-8. PMC 2649930. PMID 19171054. Gregory JJ, Finlay JL (April 1999). “Alpha-fetoprotein and beta-human chorionic gonadotropin: their clinical significance as…
