thymic extract 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 2026-05-06. Numbers and descriptions here follow the published literature rather than marketing material.
The name itself causes confusion, because several unrelated thymic peptides share the thymosin label. Thymosin beta-4, for example, is a different molecule with different functions. Naming conventions in the literature also mix descriptive research terms with assigned nonproprietary names, so a reader should confirm which entity a given paper addresses. Clarifying that point is usually the first step in interpreting any claim about this peptide.
Thymosin alpha-1 is a short peptide of 28 amino acid residues first described in the 1970s as a component of thymic extracts. Its N-terminal residue carries an acetyl group, and the sequence is highly conserved across mammalian species. The peptide is not encoded as a standalone gene product; it is released by proteolytic cleavage from the N-terminus of prothymosin alpha, a larger acidic nuclear protein. That precursor relationship places it within a broader family of thymic and immune-associated peptides that have been studied for decades.
The activity of this peptide is generally described as immunomodulatory rather than directly antimicrobial. Experimental work links it to signaling through certain Toll-like receptors on dendritic cells and to downstream maturation of antigen-presenting cells. Reported effects include expansion of T cell subsets, shifts in cytokine profiles, and increased natural killer cell activity. These observations come largely from cell culture and animal models, and the precise receptor-level events in humans remain incompletely characterized.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Residue count | 28 amino acids | Acetyl group on the first residue |
| Approximate molecular mass | 3108 daltons | Calculated from the consensus sequence |
| Origin | Cleavage product of prothymosin alpha | Not encoded as a separate gene product |
| Primary research focus | Immune modulation | Studied in viral hepatitis and as a vaccine adjuvant |
| Common synonyms | Thymalfasin, Tα1, thymosin alpha 1 | Thymalfasin is the assigned nonproprietary name |
Identity and purity are assessed with a small set of standard peptide methods. Reversed-phase high-performance liquid chromatography separates the main peak from truncated or oxidized species, and its area percentage is the usual purity measure. Mass spectrometry confirms the observed molecular mass against the expected value, while amino acid analysis or peptide mapping checks composition and sequence. Specifications for research-grade material are often stated as 95 percent or higher, though the exact limit depends on the supplier and the intended use.
Laboratory supplies of the peptide usually arrive as a lyophilized powder in sealed vials. The powder is hygroscopic, so a vial should be allowed to reach room temperature before it is opened to prevent condensation on the contents. Weighing and transfer are best performed in a low-humidity environment with clean tools. Once dissolved, the solution should be mixed gently rather than vortexed, because foaming and shear can reduce recovery of the peptide.
Storage recommendations center on low temperature, dryness, and protection from repeated freezing and thawing. The intact powder is commonly held at 20 degrees below zero Celsius or colder, while a working solution is divided into single-use aliquots to limit freeze-thaw cycles. Buffered saline or phosphate-buffered saline at neutral pH is frequently used as a diluent. Light sensitivity is not well documented, yet amber vials or foil wrapping are common practice for long-term storage of peptide stocks.
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。
The peptide occurs naturally in thymic tissue and has been detected in serum and other biological fluids. Reported concentrations are low, and reliable measurement generally requires immunoassay or mass spectrometry with an enrichment step. It is released from a larger precursor, prothymosin alpha, by proteolytic cleavage, although the enzymes involved are not fully characterized. Whether circulating levels reflect thymic output specifically remains an open question.
Thymosin alpha 1 is a 28-amino-acid peptide first isolated from thymosin fraction 5, a bovine thymic extract. Its sequence begins with an acetylated serine residue and carries a high proportion of acidic residues, so the molecule has a net negative charge near neutral pH. Despite the shared name, it is unrelated in sequence to the thymosin beta family. Synthetic material prepared by solid-phase peptide synthesis is identical in sequence to the natural peptide.
Several names appear in the literature for this peptide, including thymalfasin and the abbreviation T-alpha-1. Naming conventions differ among research articles, regulatory documents, and supplier catalogs, which complicates literature searches. Both synthetic and recombinant production routes yield a peptide with the same 28-residue sequence as the thymic isolate. Because the thymosin label also covers unrelated peptides, sources should be compared by sequence rather than by name alone.
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 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 plot of v versus [S] above is not linear; although initially linear at low [S], it bends over to saturate at high [S]. Before the modern era of nonlinear curve-fitting on computers, this nonlinearity could make it difficult to estimate KM and Vmax accurately. Therefore, several researchers developed linearisations of the Michaelis–Menten equation, such as the Lineweaver–Burk plot, the Eadie–Hofstee diagram and the Hanes–Woolf plot. All of these linear representations can be useful for visualising data, but none should be used to determine kinetic parameters, as computer software is readily available that allows for more accurate determination by nonlinear regression methods. The Lineweaver–Burk plot or double reciprocal plot is a common way of illustrating kinetic data. This is produced by taking the reciprocal of both sides of the Michaelis–Menten equation. This is a linear form of the Michaelis–Menten equation and produces a straight line with the equation y = mx + c with a y-intercept equivalent to 1/Vmax and an x-intercept of the graph representing −1/KM.
In fact neon is the most electronegative element, but the Pauling scale cannot measure its electronegativity because it does not form covalent bonds with most elements. An element's electronegativity varies with the identity and number of the atoms it is bonded to, as well as how many electrons it has already lost: an atom becomes more electronegative when it has lost more electrons. This sometimes makes a large difference: lead in the +2 oxidation state has electronegativity 1.87 on the Pauling scale, while lead in the +4 oxidation state has electronegativity 2.33.
=== Adolescent mental health === Adolescence is a period when many mental health conditions first appear. Teenagers face major physical, social, and emotional changes that can increase stress and create challenges for their well-being. Research shows that early mental health support helps prevent long-term problems and improves development.
== Release history == Reek of Putrefaction was first released in 1988. When released, Reek of Putrefaction reached No. 6 on the UK Indie Chart, establishing Carcass' earlier grindcore sound. The late BBC Radio 1 DJ John Peel declared it his favourite album of 1988, in an interview for British newspaper The Observer. Reek of Putrefaction was re-released in 1994. In 2002, the album was reissued. The album was re-released in 2008 as part of an ongoing series of Carcass reissues to tie in with their reunion. The main album, along with the demo Flesh Ripping Sonic Torment, is presented as one side of a dualdisc, while the DVD side features the first part of an extended documentary titled The Pathologist's Report Part I: Incubation. Later editions contain the album on a CD and the documentary on a separate DVD. The album is presented in a 12-panel digipak with full lyrics and artwork and is sealed in a white medical bag with sticker, to hide the controversial cover art.
== Further reading == Moss J, Stanley SJ, Oppenheimer NJ (1979). "Substrate specificity and partial purification of a stereospecific NAD- and guanidine-dependent ADP-ribosyltransferase from avian erythrocytes". J. Biol. Chem. 254 (18): 8891–4. doi:10.1016/S0021-9258(19)86783-2. PMID 225315. Moss J, Stanley SJ, Watkins PA (1980). "Isolation and properties of an NAD- and guanidine-dependent ADP-ribosyltransferase from turkey erythrocytes". J. Biol. Chem. 255 (12): 5838–40. doi:10.1016/S0021-9258(19)70705-4. PMID 6247348. Ueda K, Hayaishi O (1985). "ADP-ribosylation". Annu. Rev. Biochem. 54 (1): 73–100. doi:10.1146/annurev.bi.54.070185.000445. PMID 3927821.
Sources: en.wikipedia.org
===== Non-lytic insect cell expression ===== Non-lytic insect cell expression is an alternative to the lytic baculovirus expression system. In non-lytic expression, vectors are transiently or stably transfected into the chromosomal DNA of insect cells for subsequent gene expression. This is followed by selection and screening of recombinant clones. The non-lytic system has been used to give higher protein yield and quicker expression of recombinant genes compared to baculovirus-infected cell expression. Cell lines used for this system include: Sf9, Sf21 from Spodoptera frugiperda cells, Hi-5 from Trichoplusia ni cells, and Schneider 2 cells and Schneider 3 cells from Drosophila melanogaster cells. With this system, cells do not lyse and several cultivation modes can be used. Additionally, protein production runs are reproducible. This system gives a homogeneous product. A drawback of this system is the requirement of an additional screening step for selecting viable clones.
One of the SERRS was a "targeted nanoprobe functionalized with an anti-folate-receptor antibody (αFR-Ab) via a PEG-maleimide-succinimide and using the infrared dye IR780 as the Raman reporter, henceforth referred to as αFR-NP, and a nontargeted probe (nt-NP) coated with PEG5000-maleimide and featuring the IR140 infrared dye as the Raman reporter." These two different mixtures were injected into tumor bearing mice and healthy controlled mice. The mice were imaged with Bioluminescence (BLI) signal that produces light energy within an organism's body. They were also scanned with the Raman microscope in order to be able to see the correlation between the TAS3RS and the BLI map. TAS3RS did not show anything in the healthy mice, but was able to locate the tumor lesions in the infected mice and also able to create a TAS3RS map that could be used as guidance during surgery. TAS3RS shows to be promising in being able to combat ovarian and peritoneal cancer as it allows early detection with high accuracy. This technique can be administered locally, which is an advantage as it does not have to enter the bloodstream and therefore bypassing the toxicity concerns circulating nanoprobes. This technique is also more photostable than fluorochromes because SERRS nanoparticles cannot form from biomolecules and therefore there would not be any false positives in TAS3RS as there is in fluorescence imaging.
In most prokaryotes (archaea, bacteria), a single RNA polymerase species transcribes all types of RNA. RNA polymerase "core" from the bacteria E. coli consists of five subunits: two alpha (α) subunits of 36 kDa, a beta (β) subunit of 150 kDa, a beta prime subunit (β′) of 155 kDa, and a small omega (ω) subunit. A sigma (σ) factor binds to the core, forming the holoenzyme. After transcription starts, the σ factor can unbind and let the core enzyme perform transcription. The core RNA polymerase complex forms a "crab claw" or "clamp-jaw" structure with an internal channel running along the full length. Eukaryotic and archaeal RNA polymerases have a similar core structure and work in a similar manner, although they have many extra subunits. The 2006 Nobel Prize in Chemistry was awarded to Roger D. Kornberg for creating detailed molecular images of RNA polymerase during various stages of the transcription process. All RNAPs contain metal cofactors, in particular zinc and magnesium cations which aid in the transcription process.
As of 2017, lithium was marketed under many brand names worldwide, including Cade, Calith, Camcolit, Carbolim, Carbolit, Carbolith, Carbolithium, Carbonato de Litio, Carboron, Ceglution, Contemnol, Efadermin (Lithium and Zinc Sulfate), Efalith (Lithium and Zinc Sulfate), Elcab, Eskalit, Eskalith, Frimania, Hypnorex, Kalitium, Karlit, Lalithium, Li-Liquid, Licarb, Licarbium, Lidin, Ligilin, Lilipin, Lilitin, Limas, Limed, Liskonum, Litarex, Lithane, Litheum, Lithicarb, Lithii carbonas, Lithii citras, Lithioderm, Lithiofor, Lithionit, Lithium, Lithium aceticum, Lithium asparagicum, Lithium Carbonate, Lithium Carbonicum, Lithium Citrate, Lithium DL-asparaginat-1-Wasser, Lithium gluconicum, Lithium-D-gluconat, Lithiumcarbonaat, Lithiumcarbonat, Lithiumcitrat, Lithiun, Lithobid, Lithocent, Lithotabs, Lithuril, Litiam, Liticarb, Litijum, Litio, Litiomal, Lito, Litocarb, Litocip, Maniprex, Milithin, Neurolepsin, Plenur, Priadel, Prianil, Prolix, Psicolit, Quilonium, Quilonorm, Quilonum, Sedalit, Téralithe, and Theralite. Lithium is available as lithium carbonate in tablets or capsules, and as lithium citrate in liquid form. In the United States, standard release tablets are available in 300 mg. Standard release capsules come in strengths of 150 mg, 300 mg, and 600 mg. Slow release tablets are available in 300 mg and 450 mg. Liquid lithium, in the form of lithium citrate, is available as an 8 mEq/5 mL solution. In the United Kingdom, lithium is available as standard release tablets of 250 mg, while slow release tablets come in 200 mg, 400 mg and 450 mg.
Icatibant, sold under the brand name Firazyr, is a medication for the symptomatic treatment of acute attacks of hereditary angioedema (HAE) in adults with C1-esterase-inhibitor deficiency. It is not effective in angioedema caused by medication from the ACE inhibitor class. It is a peptidomimetic consisting of ten amino acids, which is a selective and specific antagonist of bradykinin B2 receptors.
Sources: en.wikipedia.org
insertional mutagenesis The alteration of a DNA sequence by the insertion of one or more nucleotides into the sequence, either naturally or artificially. Depending on the precise location of the insertion within the target sequence, insertions may partially or totally inactivate or even upregulate a gene product or biochemical pathway, or they may be neutral, leading to no substantive changes at all. Many genetic engineering techniques rely on the insertion of exogenous genetic material into host cells in order to study gene function and expression.
The meeting went from bad to worse, with Thiệu having a meltdown as he broke down in tears and hysterically accused Kissinger of plotting with the Soviet Union and China to betray him, saying he could never accept this peace agreement. Kissinger's statement that "Had we wanted to see you out, there would have been many easier ways by which we could have accomplished this" did not improve the mood. Thiệu later stated that he wanted to punch Kissinger in the face at that meeting. Thiệu refused to sign the peace agreement and demanded very extensive amendments that, as Kissinger reported to Nixon, "verge on insanity". Nixon ordered Kissinger to "push Thiệu as far as possible", but Thiệu refused to sign the peace agreement. Thiệu refused to see Kissinger the next day. Kissinger told one of Thieu's aides, Hoang Duc Nha, on the phone: "I am the special envoy of the President of the United States of America. You know I cannot be treated as an errand boy". Nha replied: "We never considered you an errand boy, but if that's what you think you are, there's nothing I can do about it". As Kissinger returned to Washington, one of his aides recalled: "In twenty-four hours, the bottom fell out". Though Nixon had initially supported Kissinger against Thiệu, two of his most influential advisers, namely his chief of staff, H.R. Haldeman and the Domestic Affairs Adviser John Ehrlichman, urged him to reconsider, arguing that Kissinger had given away too much and that Thiệu's objections had merit.
=== Culinary === The large white mushrooms are edible when young, as are all true puffballs, but they can cause digestive issues if the spores have begun to form—as indicated by the flesh being yellowish or greenish-brown instead of pure white. An overripe puffball will fall apart and release spores when touched or if cut open, and should be discarded. Some people experience a laxative effect from eating this species.
== Preparation of platelet poor plasma == Within 1 hour of blood collection, centrifuge capped citrate (blue top) tube for 15 minutes Using a plastic transfer pipet, remove the top 3/4 of plasma and place it in a plastic centrifuge tube with cap. Centrifuge the plasma (in the plastic centrifuge tube) for another 15 minutes. Using a plastic transfer pipet, remove the top 3/4 into a plastic tube. Do not disturb the plasma in the bottom of the spun tube, where any residual platelets will be. Aliquots with visible red cells or hemolysis (pink plasma) are not acceptable. Freeze plasma immediately. Samples for most laboratory assays should be frozen within 4 hours of collection.
Thomas Cashman, 34, is convicted of shooting dead nine-year-old Olivia Pratt-Korbel in her Liverpool home in August 2022. The Parliamentary Standards Committee recommends that former Scottish National Party MP Margaret Ferrier be suspended from the House of Commons for 30 days for breaching COVID-19 regulations in September 2020 when she took a train home from London following a positive COVID test. 31 March Figures released by the Office for National Statistics show an 0.1% growth in the UK economy for the final three months of 2022, revising previous figures that had suggested no growth over that period. COVID-19 in the UK: The UK Health Security Agency confirms the NHS COVID-19 contact tracing app will close on 27 April following a decline in its use.
Sources: en.wikipedia.org
It is usually classified as an immunomodulatory peptide rather than a classical hormone. It derives from the larger protein prothymosin alpha and acts mainly on immune cells. The thymosin label covers a group of distinct peptides, so the naming can be misleading.
The two share a family name but have different sequences, sizes, and functions. Thymosin beta-4 is a 43-residue peptide associated with actin binding and cell migration. Thymosin alpha-1 is a 28-residue peptide linked mainly to immune signaling.
Thymalfasin is the assigned international nonproprietary name for the synthetic 28-residue peptide. Thymosin alpha-1 is the descriptive research name for the same molecule. Which term appears depends on the context and the regulatory document.
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.