If you have been reading about prothymosin alpha and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | About 3.1 kDa | 28 residues, N-terminally acetylated |
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in aqueous buffers |
| Storage temperature | 2 to 8 °C | Protect from light and moisture |
| Common synonyms | Thymalfasin; Tα1 | Same peptide sequence |
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
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.
Subjects may experience extreme confusion and/or a depressed mood. The visionary stage typically lasts 4–8 hours, but may last longer with especially high doses. The introspective phase is poorly defined, often simply as 24 or 36 hours post-treatment. Sensation and perception return to normal, but nausea, headaches, and other side effects linger. Insomnia, irritability, and mood changes are often seen, including depression and sometimes mania. Depression can persist well after 36 hours, known as a "grey day"; the effect is well-recognized. A persistently low mood can progress into major depressive disorder, a chronic condition. For the treatment of opioid or alcohol addiction, the subjective experiences do not appear to be important, although they are correlated with some secondary measures (e.g., satisfaction in self-assessments). Ibogaine has been referred to as an oneirogen (oneirophrenic or oneiric), or a hallucinogen that produces a dream-like state of consciousness. This unique altered state of consciousness is shared with harmala alkaloids like harmaline but is distinct from that of other hallucinogens like serotonergic psychedelics such as LSD or psilocybin.
=== Upper motor neuron syndrome === Botulinum toxin type-A is now a common treatment for muscles affected by the upper motor neuron syndrome (UMNS), such as cerebral palsy, for muscles with an impaired ability to effectively lengthen. Muscles affected by UMNS frequently are limited by weakness, loss of reciprocal inhibition, decreased movement control, and hypertonicity (including spasticity). In January 2014, botulinum toxin was approved by UK's Medicines and Healthcare products Regulatory Agency (MHRA) for the treatment of ankle disability due to lower limb spasticity associated with stroke in adults. Joint motion may be restricted by severe muscle imbalance related to the syndrome, when some muscles are markedly hypertonic, and lack effective active lengthening. Injecting an overactive muscle to decrease its level of contraction can allow improved reciprocal motion, so improved ability to move and exercise.
The Singapore government states that the death penalty is only used in the most serious of crimes, sending a strong message to potential offenders. They point out that in 1994 and 1999 the United Nations General Assembly failed to adopt United Nations resolutions calling for a moratorium on the death penalty worldwide, as a majority of countries opposed such a move. Singapore's permanent representative to the United Nations wrote a letter to the Special Rapporteur on extrajudicial, summary or arbitrary executions in 2001 which stated:
The brown recluse (Loxosceles reclusa, Sicariidae, formerly placed in a family "Loxoscelidae") is a recluse spider with necrotic venom. Similar to those of other recluse spiders, their bites sometimes require medical attention. The brown recluse is one of two spiders in North America with dangerous venom, the other being the black widow. Brown recluse spiders are usually between 6 and 20 millimetres (0.24 and 0.79 in), but may grow larger. While typically light to medium brown, they range in color from whitish to dark brown or blackish gray. The cephalothorax and abdomen are not necessarily the same color. These spiders usually have markings on the dorsal side of their cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddleback spider, brown fiddler, or violin spider.
Sources: en.wikipedia.org
=== Americas === Trump's second presidency has been characterized by a renewed American interference in the internal affairs of Latin American nations. These efforts have included both threats and promises made to influence the outcomes of elections in Honduras, Chile and Argentina, as well as tariff threats against Brazil and Mexico and military action against Venezuela.
The common name birch comes from Old English birce, bierce, from Proto-Germanic *berk-jōn (cf. German Birke, West Frisian bjirk), an adjectival formation from *berkōn (cf. Dutch berk, Low German Bark, Danish birk, Norwegian bjørk), itself from the Proto-Indo-European root *bʰerHǵ- ~ bʰrHǵ-, which also gave Lithuanian béržas, Latvian Bērzs, Russian берёза (berëza), Ukrainian береза (beréza), Albanian bredh 'fir', Ossetian bærz(æ), Sanskrit bhurja, Polish brzoza, Czech bříza, Slovak breza. This root is presumably derived from *bʰreh₁ǵ- 'to shine, whiten', in reference to the birch's white bark. The Proto-Germanic rune berkanan is named after the birch. The generic name Betula is from Latin, which is a diminutive borrowed from Gaulish betua (cf. Old Irish bethe, Welsh bedw).
The three substrates of this enzyme are L-tryptophan, oxidised nicotinamide adenine dinucleotide (NAD+), and water. Its products are indole-3-pyruvic acid, ammonia, reduced NADH, and a proton. Nicotinamide adenine dinucleotide phosphate can be used as an alternative cofactor. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-tryptophan:NAD(P)+ oxidoreductase (deaminating). Other names in common use include NAD(P)+-L-tryptophan dehydrogenase, L-tryptophan dehydrogenase, L-Trp-dehydrogenase, and TDH. This enzyme has at least one effector, calcium.
The German Islands of Sylt, Föhr, Pellworm, Amrum, Heligoland and Fehmarn are part of Schleswig-Holstein, with the latter being the largest and the only Island of Schleswig-Holstein located on the east coast. Heligoland is Germany's only high-sea island.
The oldest known fabric dyed indigo, dated to 6,000 years ago, was discovered in Huaca Prieta, Peru. Many Asian countries, such as India, China, Japan, and Southeast Asian nations have used indigo as a dye (particularly for silk) for centuries. The dye was also known to ancient civilizations in Mesopotamia, Egypt, Britain, Mesoamerica, Peru, Iran, and West Africa. Indigo was also cultivated in India, which was also the earliest major center for its production and processing. The Indigofera tinctoria species was domesticated in India. Indigo, used as a dye, made its way to the Greeks and the Romans, where it was valued as a luxury product. In Mesopotamia, a neo-Babylonian cuneiform tablet of the seventh century BC gives a recipe for the dyeing of wool, where lapis-colored wool (uqnatu) is produced by repeated immersion and airing of the cloth. Indigo was most probably imported from India. The Romans used indigo as a pigment for painting and for medicinal and cosmetic purposes. It was a luxury item imported to the Mediterranean from India by Arab merchants.
Sources: en.wikipedia.org
In the U.S., tetrodotoxin appears on the select agents list of the Department of Health and Human Services, and scientists must register with HHS to use tetrodotoxin in their research. However, investigators possessing less than 500 mg are exempt from regulation.
== Strong bases == A strong base is a base that is quantitatively protonated upon exposure to water. This complete protonation is a result of the leveling effect. The term "strong base" can lead to confusion, since in this case "strong" is a category of base rather than a qualitative description. For example, guanidine is a very basic molecule, but it does not meet the definition of a strong base because it is not fully protonated by water. Common examples of strong bases include hydroxides of alkali metals and alkaline earth metals, like sodium hydroxide and calcium hydroxide, respectively. Due to their low solubility, some bases, such as alkaline earth hydroxides, can be used when the solubility factor is not taken into account. One advantage of this low solubility is that "many antacids were suspensions of metal hydroxides such as aluminium hydroxide and magnesium hydroxide"; compounds with low solubility and the ability to stop an increase in the concentration of the hydroxide ion, preventing the harm of the tissues in the mouth, oesophagus, and stomach. As the reaction continues and the salts dissolve, the stomach acid reacts with the hydroxide produced by the suspensions. Strong bases hydrolyze in water completely due to the leveling effect. In this process, the water molecule acts as an acid to protonate the base, resulting in the formation of a hydroxide anion. Under anhydrous conditions, some strong bases can even deprotonate weakly acidic C–H bonds. Here is a list of several strong bases:
A highly divisive figure, Gaddafi dominated Libya's politics for four decades and was the subject of a pervasive cult of personality. He was decorated with various awards and praised for his anti-imperialist stance, support for Arab—and then African—unity, as well as for significant development to the country after the discovery of oil reserves. Conversely, many Libyans strongly opposed Gaddafi's social and economic reforms; he was accused of various human rights violations. He was condemned by many as a dictator whose authoritarian administration systematically violated human rights and financed terrorism in the region and abroad.
== Insulin pen == Reith's daughter was diagnosed with Type 1 diabetes when she was four. When her daughter was five, they travelled from Glasgow to London by train as the family relocated to Scotland, and Reith had to use the public toilets at Euston Station to inject her with insulin, a process involving drawing the insulin from a glass phial using a steel hypodermic syringe, which would later require being boiled to re-sterilise it. The inconvenience, discomfort and hygiene implications of this situation led her to conceive a reusable, cartridge-based system. She developed the idea at the Southern General Hospital from 1978 with her colleague and fellow physician John Ireland, and John Paton, a bioengineer recruited at the University of Glasgow's Department of Clinical Physics and Bio-Engineering, for the project. The invention was announced in a January 1981 paper in The Lancet by Reith alongside Ireland, Paton and Margaret Wilson, also of Southern General. It described the use of the prototype, based on a device known as the Becton-Dickinson 'Plastipak' self-contained insulin syringe, by seven patients aged from 8 to 49. Further clinical trials commenced the same year, using 100 pens and 5,000 insulin cartridges funded by Diabetes UK. Within two years the world's first insulin pen, branded "Penject", entered general use.
The process of population relaxation refers to nuclear spins that return to thermodynamic equilibrium in the magnet. This process is also called T1, "spin–lattice" or "longitudinal magnetic" relaxation, where T1 refers to the mean time for an individual nucleus to return to its thermal equilibrium state of the spins. After the nuclear spin population has relaxed, it can be probed again, since it is in the initial, equilibrium (mixed) state. The precessing nuclei can also fall out of alignment with each other and gradually stop producing a signal. This is called T2, "spin–spin" or transverse relaxation. Because of the difference in the actual relaxation mechanisms involved (for example, intermolecular versus intramolecular magnetic dipole-dipole interactions), T1 is usually (except in rare cases) longer than T2 (that is, slower spin–lattice relaxation, for example because of smaller dipole-dipole interaction effects). In practice, the value of T2*, which is the actually observed decay time of the observed NMR signal, or free induction decay (to 1/e of the initial amplitude immediately after the resonant RF pulse), also depends on the static magnetic field inhomogeneity, which may be quite significant. (There is also a smaller but significant contribution to the observed FID shortening from the RF inhomogeneity of the resonant pulse). In the corresponding FT–NMR spectrum – meaning the Fourier transform of the free induction decay – the width of the NMR signal in frequency units is inversely related to the T2* time.
Sources: en.wikipedia.org
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.
The name traces back to thymosin fraction 5, a crude thymus extract examined in the 1970s. Individual peptides in that mixture were labeled with Greek letters, and alpha-1 was one of them. The international nonproprietary name thymalfasin was assigned later.
No. Thymosin beta-4 contains 43 residues and binds actin, while thymosin alpha-1 contains 28 residues and acts on immune cells. The two sit in a historical naming group but share no sequence similarity, and they are not substitutes for one another.
It corresponds to the first 28 amino acids of thymosin beta-4, a larger protein found in many tissues. The fragment is acetylated at its N-terminus and is produced synthetically for research and pharmaceutical use. Synthetic and natural forms share the same sequence.