Everything below concerns Immune modulation. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids whose sequence matches the amino-terminal region of prothymosin alpha. The chain is acetylated at its first residue and contains one disulfide bridge between two cysteine residues, which folds the molecule into a compact loop. Its molecular formula, C129H215N33O55, corresponds to a monoisotopic mass of roughly 3,106 daltons. Material used in laboratories is made by solid-phase synthesis rather than isolated from animal tissue.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
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.
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.
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 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.
=== 2020s === In 2020, Sonic unveiled a new drive-in design with an updated, wider layout for car docks and the drive-thru lane, a new kitchen layout built for efficiency, and an aesthetic makeover. By March 2020, all locations indefinitely suspended patio dining due to COVID-19, but continued to serve take-away and pickup customers.
=== Mechanism of action === Opicapone blocks the enzyme catechol-O-methyltransferase (COMT) effectively (>90% at therapeutic doses), selectively and reversibly, and only outside the central nervous system. It dissociates slowly from COMT, resulting in a duration of action longer than 24 hours despite its short blood plasma half-life. As COMT and DOPA decarboxylase are the main enzymes for degrading levodopa, blocking the two effectively increases its concentrations in the bloodstream. More levodopa reaches the brain, where it is activated to dopamine.
Radium has 33 known isotopes with mass numbers from 202 to 234, all of which are radioactive. Four of these – 223Ra (half-life 11.4 days), 224Ra (3.64 days), 226Ra (1600 years), and 228Ra (5.75 years) – occur naturally in the decay chains of primordial thorium-232, uranium-235, and uranium-238 (223Ra from uranium-235, 226Ra from uranium-238, and the other two from thorium-232). These isotopes nevertheless still have half-lives too short to be primordial radionuclides, and only exist in nature from these decay chains. Together with the mostly artificial 225Ra (15 d), which occurs in nature only as a decay product of minute traces of neptunium-237, these are the five most stable isotopes of radium. All other 27 known radium isotopes have half-lives under two hours, and the majority have half-lives under a minute. Of these, 221Ra (half-life 28 s) also occurs as a 237Np daughter, and 220Ra and 222Ra would be produced by the still-unobserved double beta decay of natural radon isotopes. At least 12 nuclear isomers have been reported, the most stable of which is radium-205m with a half-life between 130~230 milliseconds; this is still shorter than twenty-four ground-state radium isotopes. 226Ra is the most stable isotope of radium and is the last isotope in the (4n + 2) decay chain of uranium-238 with a half-life of over a millennium; it makes up almost all of natural radium. Its immediate decay product is the dense radioactive noble gas radon (specifically the isotope 222Rn), which is responsible for much of the danger of environmental radium.
Stimulants such as epinephrine, theophylline, and salbutamol orally have been used to treat asthma, but inhaled adrenergic drugs are now preferred due to less systemic side effects. Pseudoephedrine is used to relieve nasal or sinus congestion caused by the common cold, sinusitis, allergic rhinitis, and other respiratory allergies; it is also used to relieve ear congestion caused by ear inflammation or infection.
Sources: en.wikipedia.org
=== Affinity therapy === Affinity therapy, or immunotoxins is a biorecognition-based approach to selectively deliver a cytotoxic drug or toxin to a specific target cell. The field of affinity therapy was pioneered by Wilchek, together with Michael Sela, Ester Hurwitz, and Ruth Arnon. In 1975, they applied drug-conjugated antibodies for the targeted delivery of cytotoxic compounds to cancer cells. They also demonstrated the advantage of having a polymeric spacer between the antibody and the drug and showed the effectiveness of conjugating simple polymers such as dextran for drug delivery and targeting. This approach was later adopted by others and eventually led to efficient treatment of human breast cancer by recombinant humanized anti-HER2 antibody (Herceptin) in a mixture with paclitaxel and doxorubicin. In 2003, Wilchek collaborated in a team who introduced a system based on antibody-directed enzyme prodrug therapy (ADEPT), using antibody-conjugated alliinase to produce a cytotoxic agent, allicin, in situ (at the site) of the cancer
TRH is synthesized within parvocellular neurons of the paraventricular nucleus of the hypothalamus. It is translated as a 242-amino acid precursor polypeptide that contains 6 copies of the sequence -Gln-His-Pro-Gly-, with both ends of the sequence flanked by Lys-Arg or Arg-Arg sequences. To produce the mature form, a series of enzymes are required. First, a protease cleaves to the C-terminal side of the flanking Lys-Arg or Arg-Arg. Second, a carboxypeptidase removes the Lys/Arg residues leaving Gly as the C-terminal residue. Then, this Gly is converted into an amide residue by a series of enzymes collectively known as peptidylglycine-alpha-amidating monooxygenase. Concurrently with these processing steps, the N-terminal Gln (glutamine) is converted into pyroglutamate (a cyclic residue). These multiple steps produce 6 copies of the mature TRH molecule per precursor molecule for human TRH (5 for mouse TRH). TRH synthesizing neurons of the paraventricular nucleus project to the medial portion of the external layer of the median eminence. Following secretion at the median eminence, TRH travels to the anterior pituitary via the hypophyseal portal system where it binds to the TRH receptor stimulating the release of thyroid-stimulating hormone from thyrotropes and prolactin from lactotropes. The half-life of TRH in the blood is approximately 6 minutes.
=== Travels === Jung emerged from his period of isolation in the late 1910s with the publication of several journal articles, followed in 1921 with Psychological Types, one of his most influential books. There followed a decade of active publication, interspersed with overseas travels. In addition to his international travels, in 1922, he bought some land at Bollingen in Zürich, where he built a tower. He would continue to build other additions to the building, constructing an "architectural mandala".
==== Spring ==== After a long period of consuming gimjang kimchi (김장김치) during the winter, fresh potherbs and vegetables were used to make kimchi. These kinds of kimchi were not fermented or even stored for long periods of time but were consumed fresh.
Following the Warsaw Pact summit in Moscow, the Soviet Union proceeded with a massive military build-up along Poland's border in December 1980, but during the summit Kania forcefully argued with Leonid Brezhnev and other allied communists leaders against the feasibility of an external military intervention, and no action was taken. The United States, under presidents Jimmy Carter and Ronald Reagan, repeatedly warned the Soviets about the consequences of a direct intervention, while discouraging an open insurrection in Poland and signaling to the Polish opposition that there would be no rescue by the NATO forces. In February 1981, Defense Minister General Wojciech Jaruzelski assumed the position of prime minister. The Solidarity social revolt had thus far been free of any major use of force, but in March 1981 in Bydgoszcz three activists were beaten up by the secret police. In a nationwide "warning strike" the 9.5-million-strong Solidarity union was supported by the population at large, but a general strike was called off by Wałęsa after the 30 March settlement with the government. Both Solidarity and the communist party were badly split and the Soviets were losing patience. Kania was re-elected at the Party Congress in July, but the collapse of the economy continued and so did the general disorder. At the first Solidarity National Congress in September–October 1981 in Gdańsk, Lech Wałęsa was elected national chairman of the union with 55% of the vote.
Sources: en.wikipedia.org
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
Trials differ in patient population, dose schedule, background treatment, and the endpoints used to judge success. Many are small and single-center, so random variation can dominate the reported effects.