thymosin alpha-1 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-01-18. Numbers and descriptions here follow the published literature rather than marketing material.
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
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。
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
| 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 |
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
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.
Labour was determined to destroy the Liberals and become the sole party of the left. Ramsay MacDonald was forced into a snap election in 1924 and although his government was defeated, he achieved his objective of virtually wiping the Liberals out as many more radical voters now moved to Labour whilst moderate middle-class Liberal voters concerned about socialism moved to the Conservatives. The Liberals were reduced to a mere forty seats in Parliament, only seven of which had been won against candidates from both parties and none of these formed a coherent area of Liberal survival. The party seemed finished, and during this period some Liberals, such as Churchill, went over to the Conservatives while others went over to Labour. Several Labour ministers of later generations, such as Michael Foot and Tony Benn, were the sons of Liberal MPs. Asquith finally resigned as Liberal leader in 1926 (he died in 1928). Lloyd George, now party leader, began a drive to produce coherent policies on many key issues of the day. In the 1929 general election, he made a final bid to return the Liberals to the political mainstream, with an ambitious programme of state stimulation of the economy called We Can Conquer Unemployment!, largely written for him by the Liberal economist John Maynard Keynes. The Liberal Party stood in Northern Ireland for the first and only time in the 1929 general election, gaining 17% of the vote, but won no seats. Nationally the Liberals gained ground, but once again it was at the Conservatives' expense whilst also losing seats to Labour.
"Upflaming Liver fire" (肝火上炎; gānhuǒ shàng yán): Headache, red face, reddened eyes, dry mouth, nosebleeds, constipation, dry or hard stools, profuse menstruation, sudden tinnitus or deafness, vomiting of sour or bitter fluids, expectoration of blood, irascibility, impatience; red tongue with dry yellow fur; slippery and string-like pulse.
=== Type III === A civilization with energy on the scale of its own galaxy, with an energy consumption of ≈4×1044 erg/s. Lemarchand defined civilizations of this type as having access to energy comparable to the luminosity of the entire Milky Way galaxy, about ≈4×1044 erg/s" (≈4×1037 watts). In accordance with the data available at the time, Kardashev did not go beyond a Type III civilization. However, new types (0, IV, V, and VI) have been proposed.
=== Probiotics === Some probiotic supplements use the yeast S. boulardii to maintain and restore the natural flora in the gastrointestinal tract. S. boulardii has been shown to reduce the symptoms of acute diarrhea, reduce the chance of infection by Clostridium difficile (often identified simply as C. difficile or C. diff), reduce bowel movements in diarrhea-predominant IBS patients, and reduce the incidence of antibiotic-, traveler's-, and HIV/AIDS-associated diarrheas.
== History == Acrolein was first named and characterized as an aldehyde by the Swedish chemist Jöns Jacob Berzelius in 1839. He had been working with it as a thermal degradation product of glycerol, a material used in the manufacture of soap. The name is a contraction of 'acrid' (referring to its pungent smell) and 'oleum' (referring to its oil-like consistency). In the 20th century, acrolein became an important intermediate for the industrial production of acrylic acid and acrylic plastics.
Sources: en.wikipedia.org
The 1980s saw several new technologies that promised to change the way creatinine testing was done. Enzymatic and ion-exchange methods provided better accuracy but had other drawbacks. Enzymatic methods reduced some interferences but other new ones were discovered. High-performance liquid chromatography, HPLC, was more sensitive and specific, and had become the new reference method endorsed by the American Association for Clinical Chemistry. HPLC addressed the shortcomings of Jaffe-based methods, but was labor-intensive, expensive, and therefore impractical for routine analysis of the most frequently ordered renal analyte in medical labs. Simple, easily automated and cost-effective, Jaffe-based methods have persisted into the 21st century, despite their imperfections. By 2006, isotope dilution mass spectrometry (IDMS) became the reference method. To improve the accuracy in creatinine testing, new standards were developed by the National Institute of Standards and Technology (NIST). The College of American Pathologists (CAP) and the National Kidney Disease Education Program (NKDEP) collaborated with NIST to develop a new control reference called standard reference material 967 (SRM 967). SRM 967 aims to standardize calibration of creatinine testing, including Jaffe methods. Use of both IDMS and SRM 967 are currently recommended by the National Institutes of Health.
Among the most important governance standards are rights vote for who is on the board of directors for investors of labour and capital. A Draft Fifth Company Law Directive proposed in 1972, which would have required EU-wide rights for employees to vote for boards stalled mainly because it attempted to require two-tier board structures, although most EU member states have codetermination today with unified boards. The Shareholder Rights Directive 2007 requires shareholders be able to make proposals, ask questions at meetings, vote by proxy and vote through intermediaries. This has become increasingly important as most company shares are held by institutional investors (primarily asset managers or banks, depending on the member state) who are holding "other people's money". A large proportion of this money comes from employees and other people saving for retirement, but who do not have an effective voice. Unlike Switzerland after a 2013 people's initiative, or the U.S. Dodd-Frank Act 2010 in relation to brokers, the EU has not yet prevented intermediaries casting votes without express instructions of beneficiaries. This concentrates power into a small number of financial institutions, and creates the potential for conflicts of interest where financial institutions sell retirement, banking or products to companies in which they cast votes with other people's money. A series of rights for ultimate investors exist in the Institutions for Occupational Retirement Provision Directive 2003.
== External links == Histology image: 14805loa – Histology Learning System at Boston University Anatomy photo: Reproductive/mammal/ovary2/ovary5 - Comparative Organology at University of California, Davis - "Mammal, canine ovary (LM, High)" Anatomy photo: Reproductive/mammal/ovary5/ovary6 - Comparative Organology at University of California, Davis - "Mammal, bovine ovary (LM, Medium)" Anatomy Atlases – Microscopic Anatomy, plate 13.249 Slide at trinity.edu
Plasma is normally yellow due to bilirubin, carotenoids, hemoglobin, and transferrin. In abnormal cases, plasma can have varying shades of orange, green, or brown. The green color can be due to ceruloplasmin or sulfhemoglobin. The latter may form due to medicines that are able to form sulfonamides once ingested. A dark brown or reddish color can appear due to hemolysis, in which methemoglobin is released from broken blood cells. Plasma is normally relatively transparent, but sometimes it can be opaque. Opaqueness is typically due to elevated content of lipids like cholesterol and triglycerides.
Sources: en.wikipedia.org
In fluid dynamics, the Darcy–Weisbach equation is an empirical equation that relates the head loss, or pressure loss, due to viscous shear forces along a given length of pipe to the average velocity of the fluid flow for an incompressible fluid. The equation is named after Henry Darcy and Julius Weisbach. Currently, there is no formula more accurate or universally applicable than the Darcy–Weisbach supplemented by the Moody diagram or Colebrook equation. The Darcy–Weisbach equation contains a dimensionless friction factor, known as the Darcy friction factor. This is also variously called the Darcy–Weisbach friction factor, friction factor, resistance coefficient, or flow coefficient.
New Brunswick was in turn split from Nova Scotia as part of a reorganization of Loyalist settlements in the Maritimes, which led to the incorporation of Saint John, New Brunswick, as Canada's first city. To accommodate the influx of English-speaking Loyalists in Central Canada, the Constitutional Act of 1791 divided the Province of Quebec into French-speaking Lower Canada (later Quebec) and English-speaking Upper Canada (later Ontario), granting each its own elected legislative assembly.
Antihistamines (or "histamine antagonists") inhibit the release or action of histamine. "Antihistamine" can be used to describe any histamine antagonist, but the term is usually reserved for the classical antihistamines that act upon the H1 histamine receptor. Antihistamines are used as treatment for allergies. Allergies are caused by an excessive response of the body to allergens, such as the pollen released by grasses and trees. An allergic reaction causes release of histamine by the body. Other uses of antihistamines are to help with normal symptoms of insect stings even if there is no allergic reaction. Their recreational appeal exists mainly due to their anticholinergic properties, that induce anxiolysis and, in some cases such as diphenhydramine, chlorpheniramine, and orphenadrine, a characteristic euphoria at moderate doses. High dosages taken to induce recreational drug effects may lead to overdoses. Antihistamines are also consumed in combination with alcohol, particularly by youth who find it hard to obtain alcohol. The combination of the two drugs can cause intoxication with lower alcohol doses. Hallucinations and possibly delirium resembling the effects of Datura stramonium can result if the drug is taken in much higher than therapeutic doses. Antihistamines are widely available over the counter at drug stores (without a prescription), in the form of allergy medication and some cough medicines. They are sometimes used in combination with other substances such as alcohol.
== Effects on health == Ninhydrin may cause allergic, IgE-mediated rhinitis and asthma. A case has been described in which a 41 year old forensic laboratory worker working with Ninhydrin developed rhinitis and respiratory difficulty. Her specific IgE levels were found almost doubled.
=== Adverse effects === Whether naltrexone causes dysphoria, depression, anhedonia, or other aversive effects has been studied and reviewed. In early studies of opioid-abstinent individuals, acute and short-term administration of naltrexone was reported to produce a variety of aversive effects including fatigue, loss of energy, sleepiness, mild dysphoria, depression, lightheadedness, faintness, confusion, nausea, gastrointestinal disturbances, sweating, and occasional derealization. However, these studies were small, often uncontrolled, and used subjective means of assessing side effects. Most subsequent longer-term studies of naltrexone for indications like alcohol or opioid dependence have not reported dysphoria or depression with naltrexone in most individuals. According to one source:
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。
It is usually described as an immunomodulatory peptide rather than a classic circulating hormone. No endocrine gland is known to release it as a primary secretory product, and its measured presence in blood is not firmly established.