The short version of chronic hepatitis B fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-19. Anything still debated is marked as such rather than presented as settled.
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.
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.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
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.
| 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 |
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.
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.
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.
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.
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.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
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.
=== 3: Primary Active Transporters === 3.A: P-P-bond-hydrolysis-driven transporters (a.k.a. ATP-driven pumps, or transport ATPases): ATP-binding cassette transporter (ABC transporter), such as MDR, CFTR V-type ATPase; ( "V" related to vacuolar ). P-type ATPase; ( "P" related to phosphorylation), such as: Na+/K+-ATPase Plasma membrane Ca2+ ATPase Proton pump F-type ATPase; ("F" related to factor), including: mitochondrial ATP synthase, chloroplast ATP synthase1 3.B: Decarboxylation-driven transporters 3.C: Methyltransfer-driven transporters 3.D: Oxidoreduction-driven transporters 3.E: Light absorption-driven transporters, such as rhodopsin
The G protein-coupled receptor kinases (GRKs) are protein kinases that phosphorylate only active GPCRs. G-protein-coupled receptor kinases (GRKs) are key modulators of G-protein-coupled receptor (GPCR) signaling. They constitute a family of seven mammalian serine-threonine protein kinases that phosphorylate agonist-bound receptor. GRKs-mediated receptor phosphorylation rapidly initiates profound impairment of receptor signaling and desensitization. Activity of GRKs and subcellular targeting is tightly regulated by interaction with receptor domains, G protein subunits, lipids, anchoring proteins and calcium-sensitive proteins. Phosphorylation of the receptor can have two consequences:
Insoluble accumulations of β-amyloid peptide in brain regions related to memory and cognition are a defining characteristic of Alzheimer's disease (AD). SNX8 has a neuroprotective role related to AD: it enhances the non-amyloidogenic APP pathway and, hence, reduces the Aβ plaques and deposit accumulations and suppresses cognitive impairment caused by AD. Some studies found that SNX8 levels were drastically lower in patients with AD. Furthermore, it has been demonstrated that SNX8 overexpression mediated by adeno-associated virus (AVV) reduced Aβ levels and reversed cognitive impairment in AD mice. It is also important mentioning that a pair of polymorphisms (rs2286206 and rs10249052) within the human SNX8 gene locus have also been associated with late-onset AD.
Sources: en.wikipedia.org
The IFP was the third-largest party until it was unseated by the EFF and is one of the few parties to have consecutive representation in parliament since democracy in 1994. The IFP apart from the ANC was part of the National Government for 10 years. The IFP champions the rights of traditional leaders and advocates for policies which favour free markets. The party is opposed to socialism and communist policies. Because the ANC had such a large majority in parliament, smaller parties are constantly forming alliances and coalitions in order to act as a stronger opposition to the ANC-run legislative and executive branches. In the 2024 South African general election, support for the ruling African National Congress (ANC) significantly declined; the ANC remained the largest party but lost the parliamentary majority that it had held since the inaugural post-apartheid election in 1994. The centrist Democratic Alliance (DA) remained in second place with a slight increase. uMkhonto we Sizwe (MK) A left-wing populist party founded 6 months prior to the 2024 election and led by former president Jacob Zuma came in third place. Most of the ANC's loss of support flowed into the MK, while the DA saw some gains, and the EFF lost some support (and its status as the third-largest party in parliament).
The mouse has since been used extensively as a model organism and is associated with many important biological discoveries of the 20th and 21st centuries. The Jackson Laboratory in Bar Harbor, Maine is currently one of the world's largest suppliers of laboratory mice, supplying around 3 million mice a year. The laboratory is also the world's source for more than 8,000 strains of genetically defined mice and is home of the Mouse Genome Informatics database.
Utilizing both the freeze-casting and salting-out processing techniques on poly(vinyl alcohol) hydrogels to induce hierarchical morphologies and anisotropic mechanical properties. Directional freezing of the hydrogels helps to align and coalesce the polymer chains, creating anisotropic array honeycomb tube-like structures while salting out the hydrogel yielded out a nano-fibril network on the surface of these honeycomb tube-like structures. While maintaining a water content of over 70%, these hydrogels' toughness values are well above those of water-free polymers such as polydimethylsiloxane (PDMS), Kevlar, and synthetic rubber. The values also surpass the toughness of natural tendon and spider silk.
Sources: en.wikipedia.org
Furthermore, Oxgr1 gene knockout mice drinking sodium bicarbonate-rich water developed metabolic alkalosis (body tissue pH levels higher than normal) that was associated with blood bicarbonate levels significantly higher and blood chloride levels significantly lower than those in control mice drinking the sodium bicarbonate-rich water. Several other studies confirmed these findings and reported that cells in the proximal tubules of mice synthesize α-ketoglutarate and either broke it down thereby reducing its urine levels or secreted it into the tubules' lumens thereby increasing its urine levels. Another study showed that a) In silico computer simulations strongly suggested that α-ketoglutarate bound to mouse OXGPR1; b) suspensions of canal duct cells isolated from the collecting ducts, loops of Henle, vasa recta, and interstitium of mouse kidneys raised their cytosolic ionic calcium, i.e., Ca2+ levels in response to α-ketoglutarate but this response (which is an indicator of cell activation) was blocked by pretreating the cells with montelukast; and c) compared to mice not treated with streptozotocin, streptozotocin-induced diabetic mice (an animal disease model of diabetes) urinated only a small amount of the ionic sodium (Na+) that they drank or received by intravenous injections; montelukast reversed this defect in the streptozotocin-pretreated mice.
July 12: Law concerning freedom of higher education (for boys). July 24: "Women of ill repute" are kept away from the gendarmerie. 1879 August 9: Law establishing primary teacher training colleges: each department is required to have one, with a version for training male teachers and another for training female teachers—destined for communal schools. December 5: Decree organizing the General Inspectorate of Administrative Services of the Ministry of the Interior; among the planned measures is the creation of a post for a female general inspector—her salary is lower than that of her male counterparts; this general inspector is particularly in charge of inspecting girls' penal institutions and women's establishments. 1880
Becky's absence is written as her dropping out of high school to elope with Mark and moving to Minneapolis. Producers, however, wanted the character to return but, with Goranson unavailable, they recast the role with Canadian actress Sarah Chalke. Chalke appeared as Becky starting mid-Season 6 and all of Season 7. Goranson returned as Becky for Season 8. When Goranson's school schedule occasionally conflicted with her filming schedule, Chalke filled in. Goranson, not wanting to put the show through more scheduling conflicts, declined to sign on for Season 9 so Chalke returned full time. In the series revival, Goranson once again played Becky. In Season 10, Goranson, as Becky, and Chalke, as a character named Andrea, meet and comment on how much they resemble one another. The Andrea character hires Becky to be her surrogate; this arrangement fails due to Becky's age (she is 43) making it unlikely she can conceive. In Season 1 of The Conners, which deals with life after Roseanne's death from an accidental opiate overdose, Becky, who never expected to get pregnant, announces she is expecting. The child's father, Becky's restaurant coworker Emilio, is an undocumented immigrant from Mexico and unable to help out financially, as he is a small-wage earner. With her family's support, Becky proceeds with the pregnancy. Becky likes but does not love Emilio, though she later warms to him and accepts his being part of her and her child's lives; Dan hires him as a drywall worker at his construction business, and Jackie tutors him in English.
This term can then define the residual enzymatic activity present when the inhibitor is interacting with individual enzymes in the population. However the inclusion of this term has the added value of allowing for the possibility of activation if the secondary Vmax term turns out to be higher than the initial term. To account for the possibly of activation as well the notation can then be rewritten replacing the inhibitor "I" with a modifier term (stimulator or inhibitor) denoted here as "X".
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.