Everything below concerns Toll-like receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | ≈3,108 Da | Synthetic 28-residue peptide |
| Amino acid count | 28 | N-terminal serine carries an acetyl group |
| Appearance | White to off-white powder | Lyophilized solid |
| Water solubility | Freely soluble | Dissolves in aqueous buffer |
| Common synonyms | Thymalfasin; Tα1 | Thymalfasin is the international nonproprietary name |
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
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。
The lyophilized peptide is generally stable for extended periods when kept cold and dry. Once dissolved, aqueous solutions are less stable; hydrolysis, oxidation, and aggregation can degrade the material. Storage at -20 °C or lower slows these processes. Repeated freeze-thaw cycles are best avoided because they can promote aggregation. The exact shelf life depends on formulation, pH, and concentration, so stability studies are typically performed for each specific product.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
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.
Like most short peptides, thymosin alpha-1 is susceptible to hydrolysis under strongly acidic or basic conditions and to oxidation when exposed to air over long periods. The acetylated amino terminus blocks one common degradation route, which contributes to the molecule's relative robustness in solution. Lyophilized material generally retains potency for extended periods when kept cold and dry. Once reconstituted, aqueous solutions are less stable and are typically used within a defined window rather than held indefinitely at ambient temperature.
Routine handling calls for storage of the lyophilized powder at refrigerated temperatures, away from light, in a sealed container. Working solutions are often prepared in sterile water or buffer and kept cold between uses. Repeated freeze-thaw cycles are generally avoided because they can promote aggregation and loss of material. Laboratories usually record lot number, reconstitution date, and storage conditions so that any change in behavior can be traced to a specific preparation.
Reverse-phase high-performance liquid chromatography is the standard technique for assessing purity and concentration, because the peptide's hydrophobicity allows clean separation from related impurities. Mass spectrometry confirms molecular identity and detects sequence errors or truncations. Amino acid analysis and peptide mapping supply additional structural confirmation when required. Chromatographic purity values reported on certificates of analysis describe the proportion of the main peak and do not by themselves establish biological activity.
GlcA = β-D-glucuronic acid, IdoA = α-L-iduronic acid, IdoA(2S) = 2-O-sulfo-α-L-iduronic acid, GlcNAc = 2-deoxy-2-acetamido-α-D-glucopyranosyl, GlcNS = 2-deoxy-2-sulfamido-α-D-glucopyranosyl, GlcNS(6S) = 2-deoxy-2-sulfamido-α-D-glucopyranosyl-6-O-sulfate One unit of heparin (the "Howell unit") is an amount approximately equivalent to 0.002 mg of pure heparin, which is the quantity required to keep 1 ml of cat's blood fluid for 24 hours at 0 °C.
Diphenoxylate (Lomotil, R-1132) is a centrally active opioid drug of the phenylpiperidine series that is used as a combination drug, prescribed in the United States under the trade name Lomotil, with atropine for the treatment of diarrhea. Diphenoxylate is an opioid and acts by slowing intestinal contractions; the atropine is present to prevent drug abuse and overdose. It should not be given to children due to the risk that they will stop breathing and should not be used in people with Clostridioides difficile infection.
=== Elimination === Bicalutamide is eliminated in feces (43%) and urine (34%), whereas its metabolites are eliminated in approximately equal proportions in urine and bile. It is excreted to a substantial extent in its unmetabolized form, with both bicalutamide and its metabolites excreted mainly as glucuronide conjugates.
=== SGLT inhibition === McGuire is known for his research on sodium-glucose cotransporter-2 (SGLT2) and SGLT1/2 inhibitors. McGuire has had consultancy and/or trial leadership roles for all SGLT inhibitors presently available for clinical use in the US, and he has contributed to iterative meta-analyses of randomized CVOT trials data on SGLT2 and SGLT1/2 inhibitors. These analyses found that SGLT inhibitors reduce the risk of MACE, hospitalization for heart failure, and progression of chronic kidney disease. The benefits were consistent across patients with and without type 2 diabetes and across varying levels of cardiovascular and kidney risk.
Sources: en.wikipedia.org
However, because of how quickly their revolts would further radicalize the lower classes, the Creoles quickly stopped supporting general violent insurrection because they benefitted from social change that occurred through the systems of the Spanish crown. Institutional change ensured stability by supporting the political institutions that allowed for the creation of a wealthy Creole class and further adapting those institutions to meet demands, rather than propose a radical shift in the complete make-up of socioeconomic life and traditions. However, institutional change did not come as anticipated and further spurred on the radicalization of Spanish-American social classes towards independence.
A hormonal intrauterine device (IUD), also known as an intrauterine system (IUS) with progestogen and sold under the brand name Mirena among others, is an intrauterine device that releases a progestogenic hormonal agent such as levonorgestrel into the uterus. It is used for birth control, heavy menstrual periods, and to prevent excessive build of the lining of the uterus in those on estrogen replacement therapy. It is one of the most effective forms of birth control with a one-year failure rate around 0.2%. The device is placed in the uterus and lasts three to eight years. Fertility often returns quickly following removal. Side effects include irregular periods, benign ovarian cysts, pelvic pain, and depression. Rarely uterine perforation may occur. Use is not recommended during pregnancy but is safe with breastfeeding. The IUD with progestogen is a type of long-acting reversible birth control. It works by thickening the mucus at the opening of the cervix, stopping the buildup of the lining of the uterus, and occasionally preventing ovulation. The IUD with levonorgestrel was first approved for medical use in 1990 in Finland and in the United States in 2000. It is on the World Health Organization's List of Essential Medicines.
=== Diaphragm check valve === A diaphragm check valve uses a flexing rubber diaphragm positioned to create a normally-closed valve. Pressure on the upstream side must be greater than the pressure on the downstream side by a certain amount, known as the pressure differential, for the check valve to open allowing flow. Once positive pressure stops, the diaphragm automatically flexes back to its original closed position. This type is used in respirators (face masks) with an exhalation valve.
== Career at Genentech == Because of the Kleiner and Perkins investment, Swanson and Boyer dissolved their partnership and created the legal entity Genentech. Kleiner and Perkins provided $100,000 on the May closing, and acquired 20,000 shares of preferred stock from Genentech. Swanson was made the president and treasurer of Genentech, and received a $2,500 per month salary, along with 25,000 shares. This marked the end of Swanson's unemployment, and the beginning of his career at Genentech. With funding secured, and the organizational structure formed, the first logical step forward was to begin experimenting with the procedure for the synthesis of insulin. Since Genentech lacked any laboratories of its own, the Boyer lab, as well as two other labs in the San Francisco area, were to be subcontracted to carry out the experiments. However, the scientists quickly realized that a step wise approach would be more practical; rather than immediately engineer a bacterium that synthesized insulin, they would engineer a bacterium that could synthesize somatostatin, a smaller hormone. Swanson resisted at first, since he believed that “If you are going to go for something, go for the real thing.” the "real thing" being insulin, in this case. He eventually agreed, albeit grudgingly. With a new research goal set up, Swanson proceeded to establish official research agreements with the institutions. He set up research agreements with the University of California and the City of Hope. Then, in early 1977, Swanson began a second round of funding, to jumpstart the somatostatin research.
Specifically, flutamide and particularly its major metabolite hydroxyflutamide inhibit enzymes in the mitochondrial electron transport chain in hepatocytes, including respiratory complexes I (NADH ubiquinone oxidoreductase), II (succinate dehydrogenase), and V (ATP synthase), and thereby reduce cellular respiration via ATP depletion and hence decrease cell survival. Inhibition of taurocholate (a bile acid) efflux has also been implicated in flutamide-induced hepatotoxicity. In contrast to flutamide and hydroxyflutamide, which severely compromise hepatocyte cellular respiration in vitro, bicalutamide does not significantly do so at the same concentrations and is regarded as non-mitotoxic. It is thought that the nitroaromatic group of flutamide and hydroxyflutamide enhance their mitochondrial toxicity; bicalutamide, in contrast, possesses a cyano group in place of the nitro moiety, greatly reducing the potential for such toxicity. The hepatotoxicity of flutamide appears to depend on hydrolysis of flutamide catalyzed by an arylacetamide deacetalyse enzyme. This is analogous to the hepatotoxicity that occurs with the withdrawn paracetamol (acetominophen)-related medication phenacetin. In accordance, the combination of paracetamol (acetaminophen) and flutamide appears to result in additive to synergistic hepatotoxicity, indicating a potential drug interaction. Hepatotoxicity with flutamide may be cross-reactive with that of cyproterone acetate.
Sources: en.wikipedia.org
=== Treatment === To treat the food, it is exposed to a radioactive source for a set period of time to achieve a desired dose. Radiation may be emitted by a radioactive substance, or by X-ray and electron beam accelerators. Special precautions are taken to ensure the food stuffs never come in contact with the radioactive substances and that the personnel and the environment are protected from radiation exposure. Irradiation treatments are typically classified by dose (high, medium, and low), but are sometimes classified by the effects of the treatment (radappertisation, radicidation and radurisation). Food irradiation is sometimes referred to as "cold pasteurisation" or "electronic pasteurisation" because ionising the food does not heat it to high temperatures during the process, and the effect is similar to pasteurisation. The term "cold pasteurisation" is controversial because the term may be used to disguise the fact that the food has been irradiated, and pasteurisation and irradiation are fundamentally different processes.
where [A] = [H3PO4] + [H2PO−4] + [HPO2−4] + [PO3−4] is the total acid concentration. Thus phosphoric acid is more efficient than a monoacid since at the final almost neutral pH, the second dissociated state concentration [HPO2−4] is not negligible (see phosphoric acid).
Surgical technique – the septal mucosal flap The surgeon cuts the anteriorly based septal mucosal tissue-flap as widely as possible, and then releases it with a low, posterior back-cut; but only as required to allow the rotation of the tissue-flap into the nasal wound.
=== Tertiary structure === GALE structure has been resolved for a number of species, including E. coli and humans. GALE exists as a homodimer in various species. While subunit size varies from 68 amino acids (Enterococcus faecalis) to 564 amino acids (Rhodococcus jostii), a majority of GALE subunits cluster near 330 amino acids in length. Each subunit contains two distinct domains. An N-terminal domain contains a 7-stranded parallel β-pleated sheet flanked by α-helices. Paired Rossmann folds within this domain allow GALE to tightly bind one NAD+ cofactor per subunit. A 6-stranded β-sheet and 5 α-helices comprise GALE's C-terminal domain. C-terminal residues bind UDP, such that the subunit is responsible for correctly positioning UDP-glucose or UDP-galactose for catalysis.
Sources: en.wikipedia.org
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.
It is usually described as an immunomodulatory peptide rather than a classic hormone. It acts on immune cells through receptor pathways. No single endocrine organ target defines its function.
Several countries, including Italy and China, allow it for specific indications. The FDA has not approved it as a drug in the United States. Availability depends on local regulation.
Cool storage below freezing is usual for long-term retention, with a desiccant and protection from light. Portions are often split before first use to avoid repeated handling.