胸腺素α1 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-24. Where a claim depends on a specific study, the study is described rather than over-claimed.
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
Identity and purity are normally confirmed by reversed-phase high-performance liquid chromatography and mass spectrometry. The expected mass for the acetylated 28-residue peptide is close to 3108 daltons, and a mass shift indicates a modification or truncation. Peptide mapping after enzymatic digestion can resolve sequence-level questions. Counter-ion content, water content, and residual solvents are separate quality attributes that a certificate of analysis may or may not report. Aggregation is monitored by size-exclusion chromatography when relevant.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
Thymosin alpha-1 is a 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
Proper nutrition is important after delivery to help the mother recover, and to provide enough food energy and nutrients for a woman to breastfeed her child. Women having serum ferritin less than 70 μg/L may need iron supplements to prevent iron deficiency anaemia during pregnancy and postpartum. During lactation, water intake may need to be increased. Human milk is made of 88% water, and the IOM recommends that breastfeeding women increase their water intake by about 300 mL/day to a total volume of 3000 mL/day (from food and drink), approximately 2,400 mL/day from fluids. Fetal alcohol spectrum disorder Prenatal nutrition Smoking and pregnancy "Nutrition During Pregnancy Resource List for Consumers" (PDF). USDA NAL Food and Nutrition Information Center. Archived from the original (PDF) on 2007-07-14. Retrieved 2007-10-17. Health Education Authority (1996) Folic acid - what all women should know (leaflet) London:HEA
Laser-based bioprinting can be split into two major classes: those based on cell transfer technologies or photo-polymerization. In cell transfer laser printing, a laser stimulates the connection between energy-absorbing material (e.g. gold, titanium, etc.) and the bioink. This 'donor layer' vaporizes under the laser's irradiation, forming a bubble from the bioink layer which gets deposited from a jet. Photo-polymerization techniques rather use photoinitiated reactions to solidify the ink, moving the beam path of a laser to induce the formation of a desired construct. Certain laser frequencies paired with photopolymerization reactions can be carried out without damaging cells in the material. In this form of printing, plastic residues are melted down and individual layered in sections to create a desired shape. Nylon and PVA are examples of biomaterials used in this method. This technique is most often used to design prototypes for prosthetics and cartilage construction.
Sendai virus (family Paramyxoviridae) has a linear, single-stranded, negative-sense, nonsegmented RNA genome. The viral RdRp consists of two virus-encoded subunits, a smaller one P and a larger one L. Testing different inactive RdRp mutants with defects throughout the length of the L subunit in pairwise combinations, restoration of viral RNA synthesis was observed in some combinations. This positive L–L interaction is referred to as intragenic complementation and indicates that the L protein is an oligomer in the viral RNA polymerase complex.
25. Indian J Exp Biol. 2010 Apr;48(4):378-82. Neuroprotective effect of hydroalcoholic extract of dried fruits of Trapa bispinosa Roxb on lipofuscinogenesis and fluorescence product in brain of D-galactose induced ageing accelerated mice. Ambikar DB(1), Harle UN, Khandare RA, Bore VV, Vyawahare NS. Author information: (1)Department of Pharmacology, AISSMS College of Pharmacy, Kennedy Road, Pune 411 001, India. Effect of hydroalcoholic extract T. bispinosa (TB) was studied on fluorescence product and biochemical parameter like lipid peroxidation, catalase activity and glutathione peroxidase activity in the brain of female albino mice. Ageing was accelerated by the treatment of 0.5 ml 5% D-galactose for 15 days. This resulted in increased fluorescence product, increase lipid peroxidation and decrease antioxidant enzyme like glutathione peroxides and catalase in cerebral cortex. After cotreatment with hydroalcoholic extract of TB (500 mg/kg, po) there was decrease in fluorescence product in cerebral cortex. Moreover, TB inhibited increase lipid peroxidation and restores glutathione peroxidase and catalase activity in cerebral cortex as compare to ageing accelerated control group. To conclude TB found to be effective antioxidative agent which could to some extent reverse D-galactose induced ageing changes resulted due to oxidative damage.
Sources: en.wikipedia.org
Three of the hydroxylated and glycosylated propeptides twist into a triple helix (except for its ends), forming procollagen. It is packaged into a transfer vesicle destined for the Golgi apparatus. Modification and secretion: In the Golgi apparatus, the procollagen goes through one last post-translational modification, adding oligosaccharides (not monosaccharides as in step 3). Then it is packaged into a secretory vesicle to be secreted from the cell. Tropocollagen formation: Outside the cell, propeptides at both ends of procollagen are removed by specific enzymes – procollagen N-proteinases and C-proteinases – producing tropocollagen. Defects in this step produce collagenopathies such as dermatosparaxis-type Ehlers–Danlos syndrome. For type III collagen this processing is delayed rather than absent: the C-propeptide is cleaved first, leaving a soluble pN-collagen III intermediate, and the N-propeptide is then removed more slowly by the procollagen N-proteinase ADAMTS-2. Collagen fibril formation: Lysyl oxidase, a copper-dependent enzyme, acts on lysines and hydroxylysines, producing aldehyde groups, which eventually form covalent bonds between tropocollagen molecules. This polymer of tropocollagen is called a collagen fibril.
When cooled, water is trapped within its network structure, resulting in what is known as a hydrogel. As a hydrogel, gelatin's uniqueness lies in its ability to maintain a stable structure and function even when it contains up to 90% water. This makes gelatin widely used in medical, food and cosmetic industries, especially in drug delivery systems and wound dressings, as it provides stable hydration and promotes the healing process. Moreover, its biodegradability and biocompatibility make it an ideal hydrogel material. Research on hydrolyzed collagen shows no established benefit for joint health, though it is being explored for wound care. While safety concerns exist due to its animal origins, regulatory bodies have determined the risk of disease transmission to be very low when standard processing methods are followed.
About 75% of the fluorine-18 activity remains in tissues and is eliminated with a half-life of 110 minutes, presumably by decaying in place to O-18 to form [18O]O-glucose-6-phosphate, which is non-radioactive (this molecule can soon be metabolized to carbon dioxide and water, after nuclear transmutation of the fluorine to oxygen ceases to prevent metabolism). Another fraction of [18F]FDG, representing about 20% of the total fluorine-18 activity of an injection, is excreted renally by two hours after a dose of [18F]FDG, with a rapid half-life of about 16 minutes (this portion makes the renal-collecting system and bladder prominent in a normal PET scan). This short biological half-life indicates that this 20% portion of the total fluorine-18 tracer activity is eliminated renally much more quickly than the isotope itself can decay. Unlike normal glucose, FDG is not fully reabsorbed by the kidney. Because of this rapidly excreted urine 18F, the urine of a patient undergoing a PET scan may therefore be especially radioactive for several hours after administration of the isotope. All radioactivity of [18F]FDG, both the 20% which is rapidly excreted in the first several hours of urine which is made after the exam, and the 80% which remains in the patient, decays with a half-life of 110 minutes (just under two hours).
== Mechanism of action == Like all sulfonylureas, glimepiride acts as an insulin secretagogue. It lowers blood sugar by stimulating the release of insulin by pancreatic beta cells and by inducing increased activity of intracellular insulin receptors. Not all secondary sulfonylureas have the same risk of hypoglycemia. Glibenclamide (glyburide) is associated with an incidence of hypoglycemia of up to 20–30%, compared to as low as 2% to 4% with glimepiride. Glibenclamide also interferes with the normal homeostatic suppression of insulin secretion in reaction to hypoglycemia, whereas glimepiride does not. Also, glibenclamide diminishes glucagon secretion in reaction to hypoglycemia, whereas glimepiride does not.
The pools of A, B, and C have delta values defined as δA, δB, and δC respectively. These values are related to the ratio of heavy to light isotopes in each pool, and are the conventional means by which scientists express the isotopic composition of materials. Importantly, δB is distinct from δb listed on the diagram, as δb is the isotopic composition of B produced from A before it mixes with the pool of B. The isotopic compositions of the pools and products are related through fractionation factors that reflect the kinetic isotope effects (KIEs) associated with each reaction. For A → B,
Sources: en.wikipedia.org
Bowery by Forgotten NY – images, descriptions, and history East Village History Project Bowery research – in-depth, lot by lot research The Street of Forgotten Men: From Story to Screen and Beyond, 2023, ISBN 979-8-218-209858 (a look at the 1925 film and its relationship to the Bowery and impact on American language and culture)
Expression. The 5-HT3C, 5-HT3D and 5-HT3E genes tend to show peripherally restricted pattern of expression, with high levels in the gut. In human duodenum and stomach, for example, 5-HT3C and 5-HT3E mRNA might be greater than for 5-HT3A and 5-HT3B. Polymorphism. In patients treated with chemotherapeutic drugs, certain polymorphism of the HTR3B gene could predict successful antiemetic treatment. This could indicate that the 5-HTR3B receptor subunit could be used as biomarker of antiemetic drug efficacy.
Fosdagrocorat (developmental code names PF-04171327 and PF-4171327; also known as dagrocorat 2-(dihydrogen phosphate)) is a nonsteroidal but steroid-like selective glucocorticoid receptor modulator (SGRM) which was under development for the treatment of rheumatoid arthritis but was never marketed. It is the C2 dihydrogen phosphate ester of dagrocorat, and acts as a prodrug of dagrocorat with improved pharmacokinetics. The drug reached phase II clinical trials prior to the discontinuation of its development.
For a first-order reaction, the half-life of a reactant is independent of its initial concentration. Therefore, if the concentration of A at some arbitrary stage of the reaction is [A], then it will have fallen to 1/2[A] after a further interval of
Stained brain slice images which include the "Hypothalamus" at the BrainMaps project The Hypothalamus and Pituitary at endotexts.org NIF Search - Hypothalamus via the Neuroscience Information Framework Space-filling and cross-sectional diagrams of hypothalamic nuclei: right hypothalamus, anterior, tubular, posterior.
Sources: en.wikipedia.org
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
Lyophilized powder is normally kept at minus twenty degrees Celsius or below, in a sealed container, desiccated and away from light. Reconstituted solutions are less stable and are usually refrigerated and used quickly. Repeated temperature cycling should be avoided.