If you have been reading about Immune modulation 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.
Last reviewed on 2025-11-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white lyophilized powder | Hygroscopic; let the vial equilibrate before opening |
| Solubility | Freely soluble in water and aqueous buffers | Working solutions are often prepared between 0.1 and 1 mg per mL |
| Typical storage temperature | At or below 20 degrees below zero Celsius | Desiccant and sealed vials reduce moisture uptake |
| Routine purity assay | Reversed-phase HPLC with ultraviolet detection | Result reported as percentage of total peak area |
| Identity check | Mass spectrometry with amino acid analysis | Observed mass is compared with the calculated value |
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.
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.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
=== Anion-exchange resins === Formula: R-OH basic Anion resins may be either strongly or weakly basic. Strongly basic anion resins maintain their negative charge across a wide pH range, whereas weakly basic anion resins are neutralized at higher pH levels. Weakly basic resins do not maintain their charge at a high pH because they undergo deprotonation. They do, however, offer excellent mechanical and chemical stability. This, combined with a high rate of ion exchange, make weakly base anion resins well suited for the organic salts. For anion resins, regeneration typically involves treatment of the resin with a strongly basic solution, e.g. aqueous sodium hydroxide. Regenerant strength (1–4 % NaOH) and contact time must be optimized to avoid excessive osmotic stress on the polymer matrix. These anion resins can be regenerated by flushing them with a caustic solution (typically 1–4 % NaOH as mentioned before). During regeneration process, the regenerant chemical is passed through the resin, and trapped negative ions are flushed out, renewing the resin exchange capacity.
catalyst Any element or compound that facilitates an increase in the rate of a chemical reaction but which is not consumed or destroyed during the reaction. It is considered both a reactant and a product of the reaction.
For services to Punjabi and Sikh Heritage, and to Charity. Wayne Ellis Griffiths. Chair, Macmillan's Wales Volunteer Forum and Ambassador and Fundraiser, Velindre Cancer Centre. For services to Fundraising for Cancer Care and Cancer Research. Clare Eluned Frances Gummett. For services to the community in the London Borough of Merton. Eileen Hagan. Volunteer, Blackpool Support Adult Services Unit, Scouts Movement. For services to Young People and to the community in Blackpool. Ian Robert Hague. For services to the community in Sheffield, South Yorkshire. Graham Nelson Hall. Vice President, Nottinghamshire Football Association Ltd. For services to Young People and Sport. Godfrey Williams Harrison. For services to the community in Bude-Stratton, Cornwall. Martin Dymock Harrison. For services to the community in Royal Leamington Spa, Warwickshire and the West Midlands. Stephen Michael Harrison. For services to the Church and to the community in South Petherton, Somerset. Shendl Hastings Harvey (Shendl Russell). Teacher and Dancer, Royal Scottish Official Board of Highland Dancing. For services to Dance. David Kingsley Hastings. Branch Secretary, Royal National Lifeboat Institution Durham Fundraising Branch and Community Presenter. For voluntary services to the Royal National Lifeboat Institution. Nicola June Hawkins. For services to the community in Hastings and Rother, East Sussex. Tracy Hawkins. Assistant Secretary, Special Air Service Regimental Association. For Charitable Services. John Bertram Heasman. President, Dulwich Unit.
Sources: en.wikipedia.org
4 September – Mick Molloy, 85, Olympic long-distance runner (1968). 6 September – Dermot Keogh, 78, historian and author. 8 September – John Kelly, 78, hurler (Cappawhite, Kilruane MacDonaghs, Tipperary senior team, Munster). 19 September Jimmy Brohan, 88, hurler (Blackrock, Cork senior team, Munster). Brendan Devlin, 92, academic. Rónán Mac Aodha Bhuí, 53, broadcaster. 28 September – Michael Gambon, 82, Irish-English actor (Harry Potter, Gosford Park, The King's Speech), pneumonia.
==== Regeneration ==== Once saturated with water, the gel may be regenerated by heating it to about 120 °C (248 °F) for 1–2 hours. Some types of silica gel will "pop" when exposed to enough water. This is caused by breakage of the silica spheres when contacting the water. Regenerating silica gel is important for both economic and environmental reasons. It can be regenerated thermally or chemically. Chemical methods involve the use of desiccating agents or solvents to desorb water from silica gel, though these are generally less practical for routine regeneration. Thermal regeneration can be applied also to packed silica gel beds without opening them, and can be done by conventional heating in an oven at a temperature around 120 °C. Another option for thermal regeneration is by using microwaves to apply heat more evenly and reduce regeneration time compared to conventional ovens, but this process should be tightly controlled to avoid overheating. Yet another option to apply heat is using a solar heater with a compound parabolic concentrator. There are also studies on using ultrasonic waves to remove water molecules from silica gel at 45–90 °C which are lower temperatures than that of conventional heating.
==== Computer tomography ==== In 1972, the first commercial CT scanner for clinical use went into operation at Atkinsons Morley Hospital in London. Its inventor was the English engineer Godfrey Newbold Hounsfield (1919-2004), who shared the 1979 Nobel Prize in Medicine with Allan McLeod Cormack (1924-1998) for his pioneering work in the field of computed tomography. The first steps toward dose reduction were taken in 1989 in the era of single-slice spiral CT. The introduction of multi-slice spiral computed tomography in 1998 and its continuous development made it possible to reduce the dose by means of dose modulation. The tube current is adjusted, for example by reducing the power for images of the lungs compared to the abdomen. The tube current is modulated during rotation. Because the human body has an approximately oval cross-section, radiation intensity is reduced when radiation is delivered from the front or back, and is increased when radiation is delivered from the side. This dose control also depends on the body mass index. For example, the use of dose modulation in the head and neck region reduces total exposure and organ doses to the thyroid and eye lens by up to 50% without significantly compromising diagnostic image quality. The Computed Tomography Dose Index (CTDI) is used to measure radiation exposure during a CT scan. The CTDI was first defined by the Food and Drug Administration (FDA) in 1981. The unit of measurement for the CTDI is the mGy (milli-Gray).
=== Traditional isotope systems === The compounds used as isotopic references have a relatively complex history. The broad evolution of reference materials for the hydrogen, carbon, oxygen, and sulfur stable isotope systems are shown in Figure 1. Materials with red text define the primary reference commonly reported in scientific publications and materials with blue text are those available commercially. The hydrogen, carbon, and oxygen isotope scales are defined with two anchoring reference materials. For hydrogen the modern scale is defined by VSMOW2 and SLAP2, and is reported relative to VSMOW. For carbon the scale is defined by either NBS-19 or IAEA-603 depending on the age of the lab, as well as LSVEC, and is reported relative to VPDB. Oxygen isotope ratios can be reported relative to either the VSMOW or VPDB scales. The isotopic scales for sulfur and nitrogen are both defined for only a single anchoring reference material. For sulfur the scale is defined by IAEA-S-1 and is reported relative to VCDT, while for nitrogen the scale is both defined by and reported relative to AIR.
Sources: en.wikipedia.org
During his visit to Colombia, Pope Francis brought with him a message of peace and paid tribute to the victims of the conflict. The Special Jurisdiction of Peace (Jurisdicción Especial para la Paz, JEP) is the transitional justice component of the Comprehensive System, complying with Colombia's duty to investigate, clarify, prosecute, and punish serious human rights violations and grave breaches of international humanitarian law which occurred during the armed conflict. Its objectives are to satisfy victims' right to justice, offer truth to the public, contribute to the reparation of victims, contribute to the fight against impunity, and adopt decisions which give full legal security to direct and indirect participants in the conflict and contribute to the achievement of a stable and lasting peace. The Special Unit for the Search of Missing Persons in the context and due to the armed conflict (Unidad especial para la búsqueda de personas dadas por desaparecidas en el contexto y en razón del conflicto armado) would be a special high-level unit created following the signature of the final agreement. It would direct and coordinate efforts to search for and locate missing persons, or find their remains so that they may be returned to their families.
== Treatment == Each body is different, and no single formula works for all. People with Lipedema are encouraged to slowly incorporate different treatments into their routine to see what best works for them. The primary goals of treating Lipedema are to: manage inflammation, reduce fibrosis, decrease adipose tissue, improve lymphatic flow, increase mobility, minimize fatigue, manage pain, prioritize emotional and mental health, and promote overall health. Several treatments may be useful including physiotherapy and light exercise which does not put undue stress on the lymphatic system. The two most common conservative treatments are manual lymphatic drainage (MLD) where a therapist gently opens lymphatic channels and moves the lymphatic fluid using hands-on techniques, and compression garments that keep the fluid at bay and assist the sluggish lymphatic flow. Pneumatic compression device or “pump” is useful if there is a lot of swelling or for pain control. The use of surgical techniques is not universal but research has shown positive results in both short-term and long-term studies regarding lymph-sparing liposuction and lipectomy. The studies of the highest quality involve tumescent local anesthesia (TLA), often referred to as simply tumescent liposuction. This can be accomplished via both Suction-Assisted Liposuction (SAL) and Power-Assisted (vibrating) liposuction. The treatment of lipedema with tumescent liposuction may require multiple procedures.
=== Pharmacokinetics === Both nicotinic acid and nicotinamide are rapidly absorbed from the stomach and small intestine. Absorption is facilitated by sodium-dependent diffusion, and at higher intakes, via passive diffusion. Unlike some other vitamins, the percent absorbed does not decrease with increasing dose, so that even at amounts of 3-4 grams, absorption is nearly complete. With a one gram dose, peak plasma concentrations of 15 to 30 μg/mL are reached within 30 to 60 minutes. Approximately 88% of an oral pharmacologic dose is eliminated by the kidneys as unchanged nicotinic acid or nicotinuric acid, its primary metabolite. The plasma elimination half-life of nicotinic acid ranges from 20 to 45 minutes. Nicotinic acid and nicotinamide are both converted into the coenzyme NAD. NAD converts to NADP by phosphorylation in the presence of the enzyme NAD+ kinase. High energy requirements (brain) or high turnover rate (gut, skin) organs are usually the most susceptible to their deficiency. In the liver, nicotinamide is converted to storage nicotinamide adenine dinucleotide (NAD). As needed, liver NAD is hydrolyzed to nicotinamide and nicotinic acid for transport to tissues, there reconverted to NAD to serve as an enzyme cofactor. Excess nicotinic acid is methylated in the liver to N1-methylnicotinamide (NMN) and excreted in urine as such or as the oxidized metabolites N1-methyl-2-pyridone-5-carboxamide and N1-Methyl-4-pyridone-3-carboxamide (2PY and 4PY). Decreased urinary content of these metabolites is a measure of niacin deficiency.
The hydrophobic effect is the observed tendency of nonpolar substances to aggregate in an aqueous solution and to be excluded by water. The word hydrophobic literally means "water-fearing", and it describes the segregation of water and nonpolar substances, which maximizes the entropy of water and minimizes the area of contact between water and nonpolar molecules. In terms of thermodynamics, the hydrophobic effect is the free energy change of water surrounding a solute. A positive free energy change of the surrounding solvent indicates hydrophobicity, whereas a negative free energy change implies hydrophilicity. The hydrophobic effect is responsible for the separation of a mixture of oil and water into its two components. It is also responsible for effects related to biology, including: cell membrane and vesicle formation, protein folding, insertion of membrane proteins into the nonpolar lipid environment and protein-small molecule associations. Hence the hydrophobic effect is essential to life. Substances for which this effect is observed are known as hydrophobes.
=== Experimental methods === The absence of long-range order in liquids is mirrored by the absence of Bragg peaks in X-ray and neutron diffraction. Under normal conditions, the diffraction pattern has circular symmetry, expressing the isotropy of the liquid. Radially, the diffraction intensity smoothly oscillates. This can be described by the static structure factor
Sources: en.wikipedia.org
Aliquots are typically frozen well below zero Celsius and thawed only once, since repeated cycles promote aggregation and loss. Dilution into a neutral buffer limits degradation during short working periods, and prolonged storage at room temperature is avoided.
Research material is commonly offered at 95 percent purity or above by chromatographic area, with some suppliers listing 98 percent. Higher grades usually carry a higher price and are chosen when the assay is sensitive to trace impurities.
Mass spectrometry is the standard check, often paired with amino acid analysis or peptide mapping. A chromatographic retention time alone is generally considered insufficient for structural confirmation.
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。