The short version of thymosin alpha 1 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-20. Anything still debated is marked as such rather than presented as settled.
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.
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 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.
| 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 |
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.
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.
Identity and purity are usually checked by reverse-phase high-performance liquid chromatography, which separates the intact chain from truncated products, together with mass spectrometry for confirmation of the expected mass. Peptide mapping after enzymatic digestion and amino acid analysis add sequence-level evidence. Release testing also covers water content, residual solvents, and counter-ions, all of which influence measured mass and stability. Related-peptide limits are commonly expressed as a percentage of total peak area, with individual unspecified impurities held below a lower threshold.
The lyophilized peptide is a white to off-white powder that dissolves freely in water and in aqueous buffers near neutral pH. Because the molecule carries a net negative charge under physiological conditions, saline and phosphate solutions are the usual vehicles, while strongly acidic media are avoided. Stock solutions are commonly divided into small aliquots so that repeated freezing and thawing can be limited, since cycling may encourage aggregation. Solubility in organic solvents is poor and those solvents are seldom used as primary diluents.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
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.
== Awards and honors == Sheiner received the Oscar B. Hunter Award, the highest honor of the American Society for Clinical Pharmacology and Therapeutics (ASCPT), in 2004. He was given an Honorary Doctorate from Uppsala University, Sweden in 1995 and received the Rawls Palmer Progress in Medicine Award of the ASCPT in 1989. Posthumously, several awards have been named in Sheiner's honor, including the International Society of Pharmacometrics (ISoP) Lewis B. Sheiner Lecturer Award and the ASCPT's Sheiner-Beal Pharmacometrics Award.
=== Birds === Birds' unique circulatory lungs also promote efficient use of oxygen at low partial pressures of O2. These two adaptations reinforce each other and account for birds' remarkable high-altitude performance. This was specifically found in hummingbirds that inhabit the Andes. Hummingbirds already expend a lot of energy and thus have high oxygen demands and yet Andean hummingbirds have been found to thrive in high altitudes. Non-synonymous mutations in the hemoglobin gene of multiple species living at high elevations (Oreotrochilus, A. castelnaudii, C. violifer, P. gigas, and A. viridicuada) have caused the protein to have less of an affinity for inositol hexaphosphate (IHP), a molecule found in birds that has a similar role as 2,3-BPG in humans; this results in the ability to bind oxygen in lower partial pressures.
== Diagnosis == The diagnosis of JIA can be difficult, in part because joint pain in children is so common and may be from many causes other than JIA. The characteristic feature of arthritis is joint swelling which is sometimes – but not always – associated with pain. The presence of joint stiffness is another typical feature, particularly when present in the morning and improving with activity. No single test can confirm a diagnosis of JIA: a combination of presenting signs and symptoms, blood tests, and if necessary medical imaging, is used to make the diagnosis. The blood tests may measure levels of inflammatory markers, as well as the presence of specific immune markers which may include anti-nuclear antibody, HLA-B27, rheumatoid factor and anti–citrullinated protein antibody. These serological markers may be negative in children with JIA, and are often present in healthy children; as such they should not be interpreted in isolation but in the context of the clinical presentation. Many children with JIA have normal blood work. X-rays may be required to ensure that the joint pain and swelling is not from a fracture, cancer, infection, or congenital abnormality. In some cases, fluid from the joint can be aspirated and analysed to assist in making a diagnosis. This test can assist by ruling out other causes of arthritis such as infection.
SPECIAL obtains spatial localization from only a single dimension with pre-excitation inversion pulses (cycled on and off every other repetition time [TR]), making it a two-cycle sequence. The use of the preinversion pulse to remove one refocusing pulse (as compared with PRESS) is what allows SPECIAL to achieve a short TE, reaching a minimum of 2.2 msec on a preclinical scanner in rat brain while being able to recover the full signal and as low as 6 msec on a clinical 3T scanner. The largest drawback of SPECIAL and SPECIAL-sLASER is that they are two-cycle schemes, and systematic variations between cycles will manifest in their difference spectrum. Lipid contamination is a particularly large problem with SPECIAL and similar sequences. The state-of-the-art localization sequence is sLASER, which utilizes two pairs of adiabatic refocusing pulses. This has recently been recommended by consensus. The first is through OVS, which will reduce the contamination of lipid signals that originate from outside the voxel, although this comes at the cost of an increase in SAR. The second is not to set the amplitude of the pre-excitation inversion pulse to zero every other TR, but instead to shift the location of this ISIS plane such that the excited volume for the off condition is outside the object. This has been shown to greatly reduce lipid contamination, speculated to have arisen from the interaction between the RF pulse and lipid compartments due to incomplete relaxation, magnetization transfer, or the homonuclear Overhauser effect, although the exact mechanism remains unknown.
Sources: en.wikipedia.org
As a result of research of Gericke's claims by order of the Director of the California Agricultural Experiment Station of the University of California, Claude Hutchison, Dennis Hoagland and Daniel Arnon wrote a classic 1938 agricultural bulletin, The Water Culture Method for Growing Plants Without Soil, one of the most important works on solution culture ever, which made the claim that hydroponic crop yields were no better than crop yields obtained with good-quality soils. Ultimately, crop yields would be limited by factors other than mineral nutrients, especially light and aeration of the culture medium. However, in the introduction to his landmark book on soilless cultivation, published two years later, Gericke pointed out that the results published by Hoagland and Arnon in comparing the yields of experimental plants in sand, soil and solution cultures, were based on several systemic errors ("...these experimenters have made the mistake of limiting the productive capacity of hydroponics to that of soil. Comparison can be only by growing as great a number of plants in each case as the fertility of the culture medium can support.").
Environmentally friendly – reuses leftover leather without need for extra farming and use of resources Product consistency – no natural defects and minimal batch to batch variation High cutting yield – cost efficient and reducing waste Possible drawbacks include:
==== MeSH D12.776.503.280.249 – collectins ==== MeSH D12.776.503.280.249.500 – mannose-binding lectin MeSH D12.776.503.280.249.600 – pulmonary surfactant-associated protein a MeSH D12.776.503.280.249.625 – pulmonary surfactant-associated protein d
=== Availability === Flutamide is marketed widely throughout the world, including in the United States, Canada, Europe, Australia, New Zealand, South Africa, Central and South America, East and Southeast Asia, India, and the Middle East.
In reaction, APHIS introduced more strict regulations for pharming field trials in the US in 2003. In 2005, Anheuser-Busch threatened to boycott rice grown in Missouri because of plans by Ventria Bioscience to grow pharm rice in the state. A compromise was reached, but Ventria withdrew its permit to plant in Missouri due to unrelated circumstances. The industry has slowly recovered, by focusing on pharming in simple plants grown in bioreactors and on growing GM crops in greenhouses. Some companies and academic groups have continued with open-field trials of GM crops that produce drugs. In 2006 Dow AgroSciences received USDA approval to market a vaccine for poultry against Newcastle disease, produced in plant cell culture – the first plant-produced vaccine approved in the U.S.
Sources: en.wikipedia.org
At atmospheric levels of ambient CO2 the table indicates that the solution will be slightly alkaline with a maximum CaCO3 solubility of 47 mg/L. As ambient CO2 partial pressure is reduced below atmospheric levels, the solution becomes more and more alkaline. At extremely low PCO2, dissolved CO2, bicarbonate ion, and carbonate ion largely evaporate from the solution, leaving a highly alkaline solution of calcium hydroxide, which is more soluble than CaCO3. For PCO2 = 10−12 atm, the [Ca2+][OH−]2 product is still below the solubility product of Ca(OH)2 (8×10−6). For still lower CO2 pressure, Ca(OH)2 precipitation will occur before CaCO3 precipitation. As ambient CO2 partial pressure increases to levels above atmospheric, pH drops, and much of the carbonate ion is converted to bicarbonate ion, which results in higher solubility of Ca2+. The effect of the latter is especially evident in day-to-day life of people who have hard water. Water in aquifers underground can be exposed to levels of CO2 much higher than atmospheric. As such, water percolates through calcium carbonate rock, the CaCO3 dissolves according to one of the trends above. When that same water then emerges from the tap, in time, it comes into equilibrium with CO2 levels in the air by outgassing its excess CO2. The calcium carbonate becomes less soluble as a result, and the excess precipitates as lime scale. This same process is responsible for the formation of stalactites and stalagmites in limestone caves.
Cardiology Clinical genetics Clinical pharmacology Endocrinology Gastroenterology and hepatology General medicine Geriatric medicine Haemotology Immunology and allergy Infectious diseases Medical oncology Nephrology Neurology Nuclear medicine Respiratory and sleep medicine Rheumatology
=== Inlet for liquids === A now well established setup for the controlled evaporation and subsequent analysis of liquids with PTR-MS has been published in 2013 by Fischer et al. As the authors saw the main application of their setup in the calibration of PTR-MS instruments via aqueous standards, they named it "Liquid Calibration Unit (LCU)". The LCU sprays a liquid standard into a gas stream at well-defined flow rates via a purpose-built nebulizer (optimized for reduced probability of clogging and high tolerance to salts in the liquid). The resulting micro-droplets are injected into a heated (> 100 °C) evaporation chamber. This concept offers two main advantages: (i) the evaporation of compounds is enhanced by the enlarged surface area of the droplets and (ii) compounds which are dissociated in water, such as acids (or bases), experience a shift in pH value when the water evaporates from a droplet. This in turn reduces dissociation and supports total evaporation of the compound. The resulting continuous gas flow containing the analytes can be directly introduced into a PTR-MS instrument for analysis.
== Etymology == The word vegetable was first recorded in English in the early 15th century. It comes from Old French, and was originally applied to all plants; the word is still used in this sense in biological contexts. It derives from Medieval Latin vegetabilis "growing, flourishing" (i.e. of a plant), a semantic change from a Late Latin meaning "to be enlivening, quickening". The meaning of "vegetable" as a "plant grown for food" was not established until the 18th century. In 1767, the word was specifically used to mean a "plant cultivated for food, an edible herb or root". The year 1955 saw the first use of the shortened, slang term "veggie". As an adjective, the word vegetable is used in scientific and technical contexts with a different and much broader meaning, namely of "related to plants" in general, edible or not—as in vegetable matter, vegetable kingdom, vegetable origin, etc.
In 2023, the most opioid overdose deaths were among White Americans (47,754), followed by African Americans (16,481), Latinos (11,310), Native Americans (1,170), and Asians (695). While media attention has often focused on the uptick of deaths among middle class White Americans, the heroin overdose death rate among African Americans has gone up more than 200 percent since 2010. Among Latinos, it climbed nearly 140 percent. The prevalence of rural opioid overdose deaths per 100,000 within the USA was highest for Native Americans, followed by non-Hispanic Whites, Black, Hispanic, and Asian/Pacific Islander individuals. During the first and second wave of the opioid epidemic, White American people were most affected by opioid overdose. While all groups were affected in the third and fourth wave of the epidemic, White Americans and non-Hispanic Black individuals saw the greatest rise in deaths. Native Americans and Alaska Natives experienced a five-fold increase in opioid-overdose deaths between 1999 and 2015, with Native Americans having the highest increase of any demographic group. With the belief that there would be a low risk of addiction, Indian Health Service physicians, like doctors nationwide, readily prescribed opioids. In addition, structural health care deficiencies from the provider and cultural beliefs against receiving care from the patient, as well as inadequate community support structures for substance misuse, contributed to high mortality rates. In 2015, American Indians/Alaska Natives had the greatest drug overdose mortality rates of any U.S.
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.
It is a 28-amino-acid peptide originally purified from a bovine thymic extract and later produced synthetically. It is studied mainly for its effects on immune cell function.