If you have been reading about chronic hepatitis B 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.
Updated 2025-11-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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 |
|---|---|---|
| Chemical class | Peptide | 28 amino acid residues |
| Molecular weight | Approximately 3108 Da | Depends on acetylation state |
| N-terminal modification | Acetylated | Affects charge and stability |
| Natural source | Fragment of thymosin beta-4 | Cleaved in vivo |
| Sequence length | 28 residues | Synthetic form matches natural |
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.
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.
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.
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 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.
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.
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.
The ionization efficiency of DESI is complex and depends on several parameters such as, surface effects, electrospray parameters, chemical parameters and geometric parameters. Surface effects include chemical composition, temperature and electric potential applied. Electrospray parameters include electrospray voltage, gas and liquid flow rates. Chemical parameters refers to the sprayed solvent composition, e.g. addition of NaCl. Geometric parameters are α, β, d1 and d2 (see figure on the right). Furthermore, α and d1 affect the ionization efficiency, while β and d2 affect the collection efficiency. Results of a test performed on a variety of molecules to determine optimal α and d1 values show that there are two sets of molecules: high molecular weight (proteins, peptides, oligosaccharide etc.) and low molecular weight (diazo dye, stereoids, caffeine, nitroaromatics etc.). The optimal conditions for the high molecular weight group are high incident angles (70–90°) and short d1 distances (1–3 mm). The optimal conditions for the low molecular weight group are the opposite, low incident angles (35–50°) and long d1 distances (7–10 mm). These test results indicate that each group of molecules has a different ionization mechanism; described in detail in the Principle of operation section. The sprayer tip and the surface holder are both attached to a 3D moving stage which allow to select specific values for the four geometric parameters: α, β, d1 and d2.
==== Leptin and osteoarthritis ==== Adipocytes interact with other cells through producing and secreting a variety of signalling molecules, including the cell signalling proteins known as adipokines. Certain adipokines can be considered as hormones, as they regulate the functions of organs at a distance, and several of them have been specifically involved in the physiopathology of joint diseases. In particular, there is one, leptin, which has been the focus of attention for research in recent years. The circulating leptin levels are positively correlated with the Body Mass Index (BMI), more specifically with fatty mass, and obese individuals have higher leptin levels in their blood circulation, compared with non-obese individuals. In obese individuals, the increased circulating leptin levels induce unwanted responses, that is, reduced food intake or losing body weight does not occur as there is a resistance to leptin (ref 9). In addition to the function of regulating energy homeostasis, leptin carries out a role in other physiological functions such as neuroendocrine communication, reproduction, angiogenesis, and bone formation. More recently, leptin has been recognised as a cytokine factor as well as with pleiotropic actions also in the immune response and inflammation. For example, leptin can be found in the synovial fluid in correlation with the body mass index, and the leptin receptors are expressed in the cartilage, where leptin mediates and modulates many inflammatory responses that can damage cartilage and other joint tissues.
In December 1975, attempting to circumvent the restrictions of the banning order, the BPC declared Biko their honorary president. After Biko and other BCM leaders were banned, a new leadership arose, led by Muntu Myeza and Sathasivian Cooper, who were considered part of the Durban Moment. Myeza and Cooper organised a BCM demonstration to mark Mozambique's independence from Portuguese colonial rule in 1975. Biko disagreed with this action, correctly predicting that the government would use it to crack down on the BCM. The government arrested around 200 BCM activists, nine of whom were brought before the Supreme Court, accused of subversion by intent. The state claimed that Black Consciousness philosophy was likely to cause "racial confrontation" and therefore threatened public safety. Biko was called as a witness for the defence; he sought to refute the state's accusations by outlining the movement's aims and development. Ultimately, the accused were convicted and imprisoned on Robben Island. In 1973, Biko had enrolled for a law degree by correspondence from the University of South Africa. He passed several exams, but had not completed the degree at his time of death. His performance on the course was poor; he was absent from several exams and failed his Practical Afrikaans module. The state security services repeatedly sought to intimidate him; he received anonymous threatening phone calls, and gun shots were fired at his house. A group of young men calling themselves 'The Cubans' began guarding him from these attacks.
Sources: en.wikipedia.org
At Arsenal, Wenger has enjoyed a great deal of support and backing from the club board of directors, who demonstrated exceptional faith in the manager and his long-term vision. His arrival at the club prompted a change in their football style – once derided as "boring, boring Arsenal" for a lack of creativity, pundit Alan Hansen described the 2004 team as "quite simply the most fluid, devastating team the British Isles has seen". Brian Clough once quipped: "Arsenal caress a football the way I dreamed of caressing Marilyn Monroe". Wenger himself reflected that his greatest legacy at Arsenal would be the style he implemented. Supporters regularly display banners such as "Arsène knows" and "In Arsène we trust" during home matches, though there became a growing number of protests against his management.
== History == The earliest human activity in Ningxia can be traced back to 30,000 years ago, with remains of the Shuidonggou culture found in Lingwu. As a frontier zone between nomadic pastoralists and sedentary farmers, Ningxia was a frequent seat of war and incursions by non-Chinese tribes. Ningxia and its surrounding areas were incorporated into the Qin as the Beidi Commandery as early as the 3rd century BC. To pacify the region, the imperial government established military colonies to reclaim land. In addition, horse pasturages were founded under the Imperial Stud to safeguard the supply of army horses, as early as the Western Han dynasty (206 BC – AD 9). Throughout the Han dynasty and the Tang dynasty there were several large cities established in the region. The Liang Province rebellion at the end of the Han dynasty affected Ningxia. By the 11th century the Tangut people had established the Western Xia dynasty on the outskirts of the then-Song dynasty. Jews also lived in Ningxia, as evidenced by the fact that in 1489, after a major flood destroyed Torah scrolls in Kaifeng, a replacement set was sent to the Kaifeng Jews by the Ningbo and Ningxia Jewish communities. It then came under Mongol domination after Genghis Khan conquered Yinchuan in the early 13th century. Muslims from Central Asia also began moving into Ningxia from the west. By the late 17th century, Ningxia had become a weaving centre, producing many early Chinese carpets. The Muslim Dungan Revolt of the 19th century affected Ningxia. In 1914, Ningxia was merged with the province of Gansu.
Kenneth D. Tew is a Scottish-American pharmacologist, academic and author. He is a professor in the Department of Cell & Molecular Pharmacology and the John C. West Endowed Chair in Cancer Research at the Medical University of South Carolina. Tew's research primarily focuses on identifying cancer strategies with strong translational potential, particularly in the context of redox pathways, and resistance to various drugs to understand redox mechanisms and their connections to essential signaling pathways. He has authored, co-authored and edited research articles and books such as Preclinical and Clinical Modulation of Anticancer Drugs and Basic Science of Cancer. He is the recipient of the Outstanding Investigator Grant from the National Cancer Institute in 1993, the 2003 American Cancer Society Scientific Research Award and the 2010 Astellas USA Foundation Award from the American Society for Pharmacology and Experimental Therapeutics. Tew is an Elected Fellow of the American Association for the Advancement of Science and the American Society for Pharmacology and Experimental Therapeutics. He is an Executive Editor of Biomedicine & Pharmacotherapy.
Sources: en.wikipedia.org
Most UPS Ground vehicles have no air conditioning, with the exception of tractor-trailers. This has been considered to be a contributing factor to heatstroke and other heat-related health problems in drivers who work in these vehicles for the entire shift. Modern vehicles have improved ventilation systems. On January 29, 2020, UPS invested in Arrival and ordered 10,000 Generation 2 Electric Vehicles.
Kefir ( kə-FEER; alternative spellings: kephir or kefier) is a fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic symbiotic culture. It is prepared by inoculating the milk of cows, goats, or sheep with kefir grains. Kefir is a common breakfast, lunch or dinner drink consumed in countries of West Asia and Central and Eastern Europe. Kefir is consumed at any time of the day, alongside European pastries like zelnik (zeljanica), burek and banitsa/gibanica, and is an ingredient in cold soups.
Alkaloids are separated from their mixture using their different solubility in certain solvents and different reactivity with certain reagents or by distillation. A number of alkaloids are identified from insects, among which the fire ant venom alkaloids known as solenopsins have received greater attention from researchers. These insect alkaloids can be efficiently extracted by solvent immersion of live fire ants or by centrifugation of live ants followed by silica-gel chromatography purification. Tracking and dosing the extracted solenopsin ant alkaloids has been described as possible based on their absorbance peak around 232 nanometers.
=== Degradation === Once an insulin molecule has docked onto the receptor and effected its action, it may be released back into the extracellular environment, or it may be degraded by the cell. The two primary sites for insulin clearance are the liver and the kidney. The liver clears most insulin during first-pass transit, whereas the kidney clears most of the insulin in systemic circulation. Degradation normally involves endocytosis of the insulin-receptor complex, then the action of insulin-degrading enzyme on the B-chain, followed by the disulfide bond being broken by enzymes from the protein disulfide isomerase family. An insulin molecule produced endogenously by the beta cells is estimated to be degraded within about one hour after its initial release into circulation (insulin half-life ~ 4–6 minutes).
Sources: en.wikipedia.org
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.
It is usually described as an immunomodulatory peptide rather than a classical hormone. It does not travel to a single distant organ in the manner of an endocrine hormone. Classification varies across sources, and some texts group it with thymic peptides generally.
The broad outline involves immune cell activation, but the specific molecular steps remain under investigation. Different studies report effects on dendritic cells, T cells, and natural killer cells. No single receptor has been confirmed as the sole mediator.
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.