The short version of T-alpha-1 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-27. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C129H215N33O55 | Calculated for the acetylated 28-residue peptide |
| Appearance | White to off-white powder | Lyophilized solid recovered from aqueous buffer |
| Solubility | Freely soluble in water | Typically dissolved in water or buffer before use |
| Typical storage | -20 C or below, desiccated | Protect from light and avoid repeated freeze-thaw cycles |
| Identity testing | Reverse-phase HPLC with mass spectrometry | Retention time and measured mass confirm the sequence |
Identity and purity are normally confirmed by reversed-phase high-performance liquid chromatography and mass spectrometry. The expected mass for the acetylated 28-residue peptide is close to 3108 daltons, and a mass shift indicates a modification or truncation. Peptide mapping after enzymatic digestion can resolve sequence-level questions. Counter-ion content, water content, and residual solvents are separate quality attributes that a certificate of analysis may or may not report. Aggregation is monitored by size-exclusion chromatography when relevant.
Thymosin alpha-1 is supplied as a lyophilized powder in most research settings. The solid dissolves readily in water and in common aqueous buffers, and it is typically reconstituted shortly before use. Solutions are clear and colourless at ordinary working concentrations. Because the peptide is hygroscopic, weighing and reconstitution are usually performed with minimal exposure to ambient air. Aliquots are prepared to avoid repeated freeze-thaw cycles, and working solutions are kept cold.
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 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.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
Practical handling focuses on limiting adsorption and contamination. The peptide dissolves readily in water, and dilute solutions tend to adhere to plastic and glass surfaces, so an inert carrier protein or a defined buffer can reduce losses in laboratory work. Workers also record the counter-ion form, since an acetate or trifluoroacetate salt changes the mass balance of the weighed powder. Documentation of lot number, purity value, and storage history supports reproducibility when results from different laboratories are compared.
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
Peripheral nerves are more likely to be damaged, but the effects of the damage are not as widespread as seen in injuries to the spinal cord. Treatments are currently in clinical trials to repair severed nerves, with early success. Stem cells induced to a neural fate injected in to a severed nerve. Within four weeks, regeneration of previously damaged stem cells and completely formed nerve bundles were observed. Stem cells are also in clinical phases for treatment in ophthalmology. Hematopoietic stem cells have been used to treat corneal ulcers of different origin of several horses. These ulcers were resistant to conventional treatments available, but quickly responded positively to the stem cell treatment. Stem cells were also able to restore sight in one eye of a horse with retinal detachment, allowing the horse to return to daily activities.
=== Broken specimens === Broken specimens are reattached to the herbaria sheet using thinly cut strips of archival pre-gummed linen tape. Detached materials such as seeds or leaves are placed in an acid-free card fragment packet, which is secured onto the sheet with the original specimen.
A "stop" traffic sign with three 3D military drones painted on by Banksy is unveiled. The artwork has an anti-war theme believed to be relating to the Gaza war. However, it is stolen one hour after its unveiling in Peckham, London. 23 December The Metropolitan Police launches an investigation after a street sign in Peckham, London featuring the work of Banksy is stolen. A man is arrested on suspicion of theft and criminal damage during the first day of investigation. An increase in environmental activists being referred to the Prevent terrorism programme is reported, following the recent rise in disruptive climate protests. 24 December A second man is arrested on suspicion of theft and criminal damage after a road sign featuring work by street artist Banksy was stolen. Home Secretary James Cleverly apologises for a joke about his wife in which he said, "a little bit of Rohypnol in her drink every night" is "not really illegal", just hours after the Home Office announced plans to crack down on spiking. Two teenagers die and three others are injured in a three-car crash in Cramlington, Northumberland. The warmest Christmas Eve since 1997 is recorded, with temperatures of up to 15.3 °C (59.5 °F). British businessman Sir Jim Ratcliffe agrees a deal worth an estimated £1.3bn to buy a 25% share in Manchester United. The Ministry of Defence confirms that HMS Trent will take part in joint military exercises in Guyana in early 2024 as Venezuela renews its claims in the Guyana–Venezuela territorial dispute.
== In fungi == There are a variety of saprophytic and parasitic organisms that have evolved the habit of growing into their substrates as thin strands for extracellular digestion. This is most typical of the "true" fungi, but it has also evolved in Actinomycetota (Bacteria), oomycetes (which are part of the stramenopile grouping, as are kelp), parasitic plants, and rhizocephalans (parasitic barnacles). Slime molds are traditionally classified as fungi, but molecular-phylogeny work has revealed that most slime molds are not very close to Fungi proper and similar organisms, and that their slime-mold habit has originated several times. Mycetozoa (Amoebozoa), Labyrinthulomycetes (Stramenopiles), Phytomyxea and Guttulinopsis vulgaris (Rhizaria), Acrasidae (Heterolobosea), Fonticula alba (Opisthokonta), and Myxobacteria (Bacteria). Mycetozoa itself contains myxogastrids, dictyostelids, and protostelids, likely with separate origins, with protostelids themselves likely originating several times. Specialized forms of osmotrophy are found in unrelated fungi and animals.
=== Technology safety === In 2011, an independent security researcher, Jay Radcliffe, revealed a security vulnerability in a Medtronic insulin pump at the computer security conference Black Hat Briefings, allowing an attacker to take control of the pump. Medtronic responded by assuring users of the full safety of its devices. In 2008, a team of computer security researchers was able to take remote control of a Medtronic cardiac implant. The team, using an unused implant in a lab, was able to control the electrical shocks delivered by the defibrillator component and even glean patient data from the device. In February 2020, Medtronic recalled around 322,000 MiniMed insulin pumps with faulty pump retainer rings, which had been correlated to death and around 2,000 injuries.
Sources: en.wikipedia.org
Vasodilators—calcium channel blockers, such as the dihydropyridines nifedipine or amlodipine, preferably slow-release preparations—are often first-line treatment. They have the common side effects of headache, flushing, and ankle edema, but these are not typically of sufficient severity to require cessation of treatment. The limited evidence available shows that calcium-channel blockers are only slightly effective in reducing how often attacks happen, but some studies have found that CCBs may decrease the severity of attacks, pain, and disability associated with Raynaud's phenomenon. People whose disease is secondary to erythromelalgia often cannot use vasodilators for therapy, as they trigger "flares", causing the extremities to become burning red due to too much blood supply. People with severe disease prone to ulceration or large artery thrombotic events may be prescribed aspirin. Sympatholytic agents, such as the alpha-adrenergic blocker prazosin, may provide temporary relief to secondary Raynaud's phenomenon. Angiotensin receptor blockers, such as Losartan, or ACE inhibitors may aid blood flow to the fingers, and there is some evidence that angiotensin receptor blockers (often losartan) reduce frequency and severity of attacks, and possibly better than nifedipine. The prostaglandin iloprost is used to manage critical ischemia and pulmonary hypertension in Raynaud's phenomenon, and the endothelin receptor antagonist bosentan is used to manage severe pulmonary hypertension and prevent finger ulcers in scleroderma.
Voltage-gated ion channels are capable of producing action potentials because they can give rise to positive feedback loops: the membrane potential controls the state of the ion channels, and the state of the ion channels controls the membrane potential. Thus, in some situations, a rise in the membrane potential can cause ion channels to open, thereby causing a further rise in the membrane potential. An action potential occurs when this positive feedback cycle proceeds explosively. The time and amplitude trajectory of the action potential are determined by the biophysical properties of the voltage-gated ion channels that produce it. Several types of channels capable of producing the positive feedback necessary to generate an action potential do exist. Voltage-gated sodium channels are responsible for the fast action potentials involved in nerve conduction. Slower action potentials in muscle cells and some types of neurons are generated by voltage-gated calcium channels. Each of these types comes in multiple variants, with different voltage sensitivity and different temporal dynamics. The most intensively studied type of voltage-dependent ion channels comprises the sodium channels involved in fast nerve conduction. These are sometimes known as Hodgkin-Huxley sodium channels because they were first characterized by Alan Hodgkin and Andrew Huxley in their Nobel Prize-winning studies of the biophysics of the action potential, but can more conveniently be referred to as NaV channels.
=== Cladogram === Below is a phylogenetic tree of the phylum. Lines of the cladogram show evolutionary relationships between the major groups of extinct taxa, which are denoted with a dagger (†), and extant taxa.
What caused the sizable deficit increases during and shortly after the Great Recession? The CBO reported that the deficit expansion was mainly due to the economic downturn rather than policy choices. Revenue fell while social safety net spending increased for programs such as unemployment compensation and food stamps, as more families qualified for benefits. From 2008 to 2009, the large deficit increase was also driven by spending on stimulus and bailout programs. Should the Bush tax cuts of 2001 and 2003 be allowed to expire in 2010 as scheduled? Ultimately, the Bush tax cuts were allowed to expire for the highest income taxpayers only as part of the American Taxpayer Relief Act of 2012. Should significant deficits be continued or should fiscal austerity be implemented? While the deficit jumped from 2008 to 2009, by 2014 it had fallen to its historical average relative to the size of the economy (GDP). This was due to the recovering economy, which had increased tax revenue. In addition, tax increases were implemented on higher-income taxpayers, while military and non-military discretionary spending were reduced or restrained (sequestered) as part of the Budget Control Act of 2011.
Unlabeled antibody is incubated in the presence of its antigen (sample) A sufficient incubation period is provided to allow the antibodies to bind to the antigens. The sample is then passed through the Scavenger container. This can be a test tube or a specifically designed flow through channel. The surface of the Scavenger container or channel has "Scavenger Antigens" bound to it. These can be identical or sufficiently similar to the primary antigens that the free antibodies will bind. The Scavenger container must have sufficient surface area and sufficient time to allow the Scavenger Antigens to bind to all the excess Antibodies introduced into the sample. The sample, that now contains the tagged and bound antibodies, is passed through a detector. This device can be a flow cytometer or other device that illuminates the tags and registers the response. This test allows multiple antigens to be tagged and counted at the same time. This allows specific strains of bacteria to be identified by two (or more) different color tags. If both tags are present on a cell, then the cell is that specific strain. If only one is present, it is not. This test is done, generally, one test at a time and cannot be done with the microtiter plate. The equipment needed is usually less complicated and can be used in the field.
Sources: en.wikipedia.org
=== Dexamethasone suppression test === The dexamethasone suppression test involves administering dexamethasone, a synthetic glucocorticoid, to the horse, and measuring its serum cortisol levels before and 19–24 hours after injection. In a normal horse, dexamethasone administration results in negative feedback to the pituitary, resulting in decreased ACTH production from the pars distalis and, therefore, decreased synthesis of cortisol at the level of the adrenal gland. A horse with PPID, which has an overactive pars intermedia not regulated by glucocorticoid levels, does not suppress ACTH production and, therefore, cortisol levels remain high. False negatives can occur in early disease. Additionally, dexamethasone administration may increase the risk of laminitis in horses already prone to the disease. For these reasons, the dexamethasone suppression test is currently not recommended for PPID testing.
== Enzymes == Glycogen phosphorylase with Pyridoxal phosphate as prosthetic group Alpha-1,4 → alpha-1,4 glucan transferase Alpha-1,6-glucosidase Phosphoglucomutase Glucose-6-phosphatase (absent in muscles)
== Structure == Three distinct fiber types have been identified within the dermis: oxytalan, elaunin, and elastic fibers. The most superficial of these, the oxytalan fibers, are extremely slender and oriented perpendicularly to the dermoepidermal junction. They arise from a plexus exhibiting the staining properties of elaunin fibers, which in turn are contiguous with the thicker elastic fibers of the reticular dermis. Electron microscopy shows that oxytalan fibers consist of bundles of tubular microfibrils measuring approximately 10–12 nm in diameter. In deeper dermal layers, these bundles contain a central amorphous substance. Elaunin fibers contain only small amounts of this amorphous material, whereas in elastic fibers it is abundant and densely compacted. The structure of Elaunin fibers allows for repeated stretching or pressure because they are made up of microfibrils and small amounts of elastic fibers (Sawada et al, 2006.) These elaunin fibers have moderate tissue elasticity and plays an important role by allowing tissues such as skin and mucosa to stretch during everyday movements without becoming permanently damaged. Additionally, the fibers support blood vessels by maintaining the shape of vessel lumen, especially during sudden or repeated changes in pressure. The flexibility of elaunin fibers allows for a certain level of stretch that is still strong enough to support moving tissues but does not recoil like fully developed elastic fibers do.
==== Endothelial keratoplasty ==== Endothelial keratoplasty replaces the patient's endothelium with a transplanted disc of posterior stroma/Descemets/endothelium (DSEK) or Descemets/endothelium (DMEK). This relatively new procedure has revolutionized treatment of disorders of the innermost layer of the cornea (endothelium). Unlike a full-thickness corneal transplant, the surgery can be performed with one or no sutures. Patients may recover functional vision in days to weeks, as opposed to up to a year with full thickness transplants. However, an Australian study has shown that despite its benefits, the loss of endothelial cells that maintain transparency is much higher in DSEK compared to a full-thickness corneal transplant. The reason may be greater tissue manipulation during surgery, the study concluded. During surgery the patient's corneal endothelium is removed and replaced with donor tissue. With DSEK, the donor includes a thin layer of stroma, as well as endothelium, and is commonly 100–150 μm thick. With DMEK, only the endothelium is transplanted. In the immediate postoperative period the donor tissue is held in position with an air bubble placed inside the eye (the anterior chamber). The tissue self-adheres in a short period and the air is adsorbed into the surrounding tissues. Complications include displacement of the donor tissue requiring repositioning ("refloating"). This is more common with DMEK than DSEK. Folds in the donor tissue may reduce the quality of vision, requiring repair. Rejection of the donor tissue may require repeating the procedure.
Anti-obesity medication or weight loss medications are pharmacological agents that reduce excess body fat and cause weight loss. These medications alter one of the fundamental processes of weight regulation, by: reducing appetite and consequently energy intake, increasing energy expenditure, redirecting nutrients from adipose to lean tissue, or interfering with the absorption of calories. Weight loss drugs have been developed since the early twentieth century, and many have been banned or withdrawn from the market due to adverse effects, including deaths; other drugs proved ineffective. Although many earlier drugs were stimulants such as amphetamines, in the early 2020s, GLP-1 receptor agonists became popular for weight loss. As of 2023, the medications liraglutide, naltrexone/bupropion, orlistat, semaglutide, tirzepatide and phentermine/topiramate are approved by the US Food and Drug Administration (FDA) for weight management in combination with reduced-calorie diet and increased physical activity. Medications to treat obesity may be considered in those with a body mass index above 30, or above 27 with obesity related complications (such as hypertension, hyperlipidemia, cardiovascular disease, or obstructive sleep apnea). As of 2022, no medication has been shown to be as effective at long-term weight reduction as bariatric surgery.
Sources: en.wikipedia.org
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.
No. The two peptides share part of a name but differ in length, sequence, and net charge. Literature searches that treat them as one compound return misleading results.
Solid-phase peptide synthesis is the usual route, and recombinant expression has also been described. Both approaches produce material matching the natural sequence.
It corresponds to a fragment of the larger protein prothymosin alpha, which is present in many tissues. The isolated 28-amino-acid peptide was originally obtained from thymus preparations, and the pharmaceutical product is synthesized rather than extracted. The term therefore describes both a natural fragment and a manufactured drug substance.