This is a working overview of thymus extract, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-08-12 and is reviewed periodically as new material appears.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
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.
Lyophilized material is typically treated as a hygroscopic solid that should be brought to room temperature before the container is opened, which limits condensation on the powder. Reconstitution is commonly done with sterile water or a buffered diluent, and gentle mixing is preferred over vigorous agitation to reduce foaming and surface adsorption. Because peptides can bind to plastic and glass, diluents containing a small amount of carrier protein are sometimes used in laboratory work. Working solutions are generally aliquoted and prepared fresh rather than subjected to repeated freezing and thawing.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | Approximately 3,108 Da | Consistent with a 28-residue acetylated peptide |
| Residue count | 28 | Corresponds to the amino terminal region of prothymosin alpha |
| Appearance of dry powder | White to off-white solid | Slight variation between lots is normal |
| Solubility class | Freely soluble in water | Low solubility in most organic solvents |
| Common synonyms | Thymosin alpha 1, T alpha 1 | The numeral reflects an early fraction numbering scheme |
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.
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。
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
Living organisms must obey the laws of thermodynamics, which describe the transfer of heat and work. The second law of thermodynamics states that in any isolated system, the amount of entropy (disorder) cannot decrease. Although living organisms' amazing complexity appears to contradict this law, life is possible as all organisms are open systems that exchange matter and energy with their surroundings. Living systems are not in equilibrium, but instead are dissipative systems that maintain their state of high complexity by causing a larger increase in the entropy of their environments. The metabolism of a cell achieves this by coupling the spontaneous processes of catabolism to the non-spontaneous processes of anabolism. In thermodynamic terms, metabolism maintains order by creating disorder.
== Genetics == Multiple epiphyseal dysplasia (MED) encompasses a spectrum of skeletal disorders, in which are inherited in an autosomal dominant form. However, there is an autosomal recessive form. Associated genes include COL9A1, COL9A2, COL9A3, COMP, and MATN3. Types include:
=== External phylogeny === Animals are monophyletic, meaning they are derived from a common ancestor. Animals are the sister group to the choanoflagellates, with which they form the Choanozoa. Ros-Rocher and colleagues (2021) trace the origins of animals to unicellular ancestors, providing the external phylogeny shown in the cladogram. Uncertainty of relationships is indicated with dashed lines. The animal clade had certainly originated by 650 mya, and may have come into being as much as 800 mya, based on molecular clock evidence for different phyla.
Thoracic outlet syndrome Arterial rupture Valvular heart disease, such as mitral valve prolapse, creates an increased risk for infective endocarditis during surgery. This may progress to a life-threatening degree. Heart conduction abnormalities have been found in those with hypermobility form of EDS. Dilation (aneurysm) or rupture (dissection) of ascending aorta Cardiovascular autonomic dysfunction such as postural orthostatic tachycardia syndrome Raynaud's phenomenon Varicose veins Heart murmur Heart conduction abnormalities
Sources: en.wikipedia.org
The next doubly magic nucleus is now expected to be around 306Ubb, but this nuclide's expected short half-life and low production cross section make its synthesis challenging. Still, the island of stability is expected to exist in this region, and nearer its centre (which has not been approached closely enough yet) some nuclides, such as 291Mc and its alpha- and beta-decay daughters, may be found to decay by positron emission or electron capture and thus move into the centre of the island. Due to the expected high fission barriers, any nucleus in this island of stability would decay exclusively by alpha decay and perhaps some electron capture and beta decay, both of which would bring the nuclei closer to the beta-stability line where the island is expected to be. Electron capture is needed to reach the island, which is problematic because it is not certain that electron capture is a major decay mode in this region of the chart of nuclides. Experiments were done in 2000–2004 at Flerov Laboratory of Nuclear Reactions in Dubna studying the fission properties of the compound nucleus 292Fl by bombarding 244Pu with accelerated 48Ca ions. A compound nucleus is a loose combination of nucleons that have not yet arranged themselves into nuclear shells. It has no internal structure and is held together only by the collision forces between the two nuclei. Results showed how such nuclei fission mainly by expelling doubly magic or nearly doubly magic fragments such as 40Ca, 132Sn, 208Pb, or 209Bi.
Phenformin is an antidiabetic drug from the biguanide class. It was marketed as DBI by Ciba-Geigy, but was withdrawn from most markets in the late 1970s due to a high risk of lactic acidosis, which was fatal in 50% of cases. Phenformin was developed in 1957 by Ungar, Freedman and Seymour Shapiro, working for the U.S. Vitamin Corporation. Clinical trials begun in 1958 showed it to be effective, but with gastrointestinal side effects.
Soaking and cooking: The soybeans are soaked in water and boiled until cooked. Wheat is roasted and crushed. Koji culturing: Equal amounts of boiled soybeans and roasted wheat are mixed to form a grain mixture. A culture of Aspergillus spore is added to the grain mixture and mixed, or the mixture is allowed to gather spores from the environment itself. The cultures include: Aspergillus: a genus of fungus that is used for fermenting various ingredients (the cultures are called koji in Japanese). Three species are used for brewing soy sauce: A. oryzae: Strains with high proteolytic capacity are used for brewing soy sauce. A. sojae: This fungus also has a high proteolytic capacity. A. tamarii: This fungus is used for brewing tamari, a variety of soy sauce. Saccharomyces cerevisiae: the yeasts in the culture convert some of the sugars to ethanol which can undergo secondary reactions to make other flavor compounds Other microbes contained in the culture: Bacillus spp. (genus): This organism is likely to grow in soy sauce ingredients, and to generate odors and ammonia. Lactobacillus species: This organism makes a lactic acid that increases the acidity in the feed. Brewing: The cultured grain mixture is mixed into a specific amount of salt brine for wet fermentation or with coarse salt for dry fermentation and left to brew. Over time, the Aspergillus mold on the soy and wheat break down the grain proteins into free amino acid and protein fragments and starches into simple sugars. This amino-glycosidic reaction gives soy sauce its dark brown color.
== Preventive methods == Because virtually all raw materials involved in a production process, including factory employees, can be potential sources of pyrogen contamination, raw material screening and depyrogenation can often go a long way to ensuring the final product is free of pyrogens and does not require costly removal or inactivation methods. Ultrafiltration of chemicals and buffer solutions, applying appropriate hygienic practices, and performing regular tests can all be helpful.
There was concern about the possibility of arsenic from embalmed bodies contaminating ground water supplies, as well as legal concerns that people suspected of murder by arsenic poisoning might claim that levels of poison in the deceased's body were the result of post-mortem embalming, not homicide. In 1855, the Russian chemist Alexander Michailowitsch Butlerow discovered formaldehyde, the preservative properties of which were soon noted, and it became the foundation for modern methods of embalming. Dr Frederic Ruysch was the first to have used the arterial injection method for embalming. His work of embalming was so nearly perfect that people thought the dead body was actually alive; however, he only used it to prepare specimens for his anatomical work.
Sources: en.wikipedia.org
Tracy Lauren Marrow (born February 16, 1958), known professionally as Ice-T (or Ice T), is an American rapper and actor. He is active in both hip-hop and heavy metal. Ice-T began his career as an underground rapper in the 1980s and was signed to Sire Records in 1987, when he released his debut album Rhyme Pays. The following year, he founded the record label Rhyme $yndicate Records (named after his collective of fellow hip-hop artists called the "Rhyme $yndicate") and released another album, Power (1988), which is Ice-T's only album to be certified platinum by the RIAA. His next three albums, The Iceberg/Freedom of Speech... Just Watch What You Say! (1989), O.G. Original Gangster (1991) and Home Invasion (1993), were also critically acclaimed and commercially successful, and were all certified gold in the US. Ice-T co-founded the heavy metal band Body Count in 1990, which he introduced on O.G. Original Gangster, on the track titled "Body Count". The band released its self-titled debut album in 1992. Ice-T encountered controversy over his track "Cop Killer", the lyrics of which discussed killing police officers. He asked to be released from his contract with Warner Bros. Records, and his follow-up solo album, Home Invasion, was released through Priority Records. Ice-T released two more albums in the late 1990s and one in the 2000s before focusing on both his acting career and Body Count, who have released eight studio albums to date, the latest being 2024's Merciless.
== History == The individual subunits of the G protein complex were first identified in 1980 when the regulatory component of adenylate cyclase was successfully purified, yielding three polypeptides of different molecular weights. Initially, it was thought that Gα, the largest subunit, was the major effector regulatory subunit, and that Gβγ was largely responsible for inactivating the Gα subunit and enhancing membrane binding. However, downstream signalling effects of Gβγ were later discovered when the purified Gβγ complex was found to activate a cardiac muscarinic K+ channel. Shortly after, the Gβγ complex associated with a mating factor receptor-coupled G protein in yeast was found to initiate a pheromone response. Although these hypotheses were initially controversial, Gβγ has since been shown to directly regulate as many different protein targets as the Gα subunit. Recently, possible roles of the Gβγ complex in retinal rod photoreceptors have been investigated, with some evidence for the maintenance of Gα inactivation. However, these conclusions were drawn from in vitro experiments under unphysiological conditions, and the physiological role of the Gβγ complex in vision is still unclear. Nevertheless, recent in vivo findings demonstrate the necessity of the transducin Gβγ complex in the functioning of rod photoreceptors under low light conditions.
=== Sphingomyelin hydrolysis === Hydrolysis of sphingomyelin is catalyzed by the enzyme sphingomyelinase. Because sphingomyelin is one of the four common phospholipids found in the plasma membrane of cells, the implications of this method of generating ceramide is that the cellular membrane is the target of extracellular signals leading to programmed cell death. There has been research suggesting that when ionizing radiation causes apoptosis in some cells, the radiation leads to the activation of sphingomyelinase in the cell membrane and ultimately, to ceramide generation.
== Metabolism == In the main pathway to quinolinic acid, the next step is an oxidation reaction catalysed by kynurenine 3-hydroxylase, which uses oxygen and nicotinamide adenine dinucleotide phosphate (NADPH) to place a phenolic group next to the aromatic amine.
== See also == Digital mammography: use of a computer to produce images of the breast Global radiology: improving access to radiology resources in poor and developing countries Medical radiography: the use of ionizing electromagnetic radiation, such as X-rays, in medicine Radiation protection: the science of preventing people and the environment from suffering harmful effects from ionizing radiation Radiologists Without Borders Radiosensitivity: measure of the susceptibility of organic tissues to the harmful effects of radiation X-ray image intensifier: equipment that uses X-rays to produce an image feed displayed on a TV screen International Day of Radiology: an awareness day for medical imaging Electrogram
Sources: en.wikipedia.org
The name reflects an early convention for naming thymus-derived fractions. The peptide is characterized and measured as a defined molecule, and it does not operate through a single classical endocrine axis.
Cold storage slows the chemical degradation reactions that occur in solution. Lyophilized powder is more stable than reconstituted liquid and tolerates longer storage periods. Repeated temperature cycling should still be avoided because it can drive aggregation and loss of material.
Mass spectrometry is the standard confirmation of molecular mass and acetylation state. Chromatography establishes purity but does not identify the molecule on its own. The two techniques are normally applied together during verification.
No, because the reported value reflects the detection method and wavelength used, which vary between laboratories. A number stated without method details cannot be compared directly with another supplier's figure. Requesting the chromatogram and the method conditions is a common way to interpret it.