If you have been reading about 细胞因子 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 2026-02-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
Recommended storage for the dry powder is a freezer near minus twenty degrees Celsius, kept desiccated and away from light. Once dissolved, the peptide is less stable and is usually held at two to eight degrees Celsius for short intervals or frozen for longer storage. Stability studies focus on the acetylated terminus and the disulfide linkage because those features define the intact molecule. Common degradation routes include cysteine oxidation, deamidation of asparagine or glutamine side chains, and slow formation of higher-molecular-weight species.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white lyophilized powder | Visual description varies by batch |
| Solubility | Freely soluble in water | Aqueous buffers are commonly used |
| Typical storage temperature | -20 °C or below for powder | Reconstituted liquid kept at 2-8 °C short term |
| Purity method | Reversed-phase HPLC | Value derived from peak area integration |
| Identity method | Mass spectrometry | Confirms mass and sequence integrity |
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
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.
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
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.
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.
Oscar Tiegs' scientific interests and contributions ranged from the physiological analysis of nervous and muscular action to invertebrate embryology, his studies being comparable to the very best work the last century. He repeatedly turned from one area of research to another, only to return again. He was a dedicated practiser of descriptive morphology during a period when the majority of biologists were turning to experimentation. Typically, even his first research paper, was to describe something unusually interesting, namely that the male of the echiuroid worm exhibits a greater degree of degeneration than other species, the tissues fusing with those of its female partner and the host. He briefly made some helminthological investigations, for example with hookworm, and monogeneans before moving to the newly created Department of Zoology at the University of Adelaide in 1922.
In 1991, the Proceeds of Crime (Money Laundering) Act was brought into force in Canada to give legal effect to the former FATF Forty Recommendations by establishing record keeping and client identification requirements in the financial sector to facilitate the investigation and prosecution of money laundering offences under the Criminal Code and the Controlled Drugs and Substances Act. In 2000, the Proceeds of Crime (Money Laundering) Act was amended to expand the scope of its application and to establish a financial intelligence unit with national control over money laundering, namely FINTRAC. In December 2001, the scope of the Proceeds of Crime (Money Laundering) Act was again expanded by amendments enacted under the Anti-Terrorism Act with the objective of deterring terrorist activity by cutting off sources and channels of funding used by terrorists in response to 9/11. The Proceeds of Crime (Money Laundering) Act was renamed the Proceeds of Crime (Money Laundering) and Terrorist Financing Act. In December 2006, the Proceeds of Crime (Money Laundering) and Terrorist Financing Act was further amended, in part, in response to pressure from the FATF for Canada to tighten its money laundering and financing of terrorism legislation.
=== Pharmacokinetics === The bioavailability of quercetin in humans after oral intake is very low, with one study concluding it must be less than 1%. Intravenous injection of quercetin shows a rapid decay in concentration described by a two-compartment model (initial half-life of 8.8 minutes, terminal half-life of 2.4 hours). Because it undergoes rapid and extensive metabolism, the biological effects presumed from in vitro studies are unlikely to apply in vivo. Quercetin supplements in the aglycone form are less bioavailable than the quercetin glycoside often found in foods, especially red onions. Ingestion with high-fat foods may increase bioavailability compared to ingestion with low-fat foods, and carbohydrate-rich foods may increase absorption of quercetin by stimulating gastrointestinal motility and colonic fermentation. Whereas quercetin has been shown to be a potent anti-inflammatory compound in a variety of in vitro and in vivo bioassay models, oral quercetin in human subjects has not exhibited the desired effects. Because of low solubility and poor bioavailability of quercetin, derivatives have been synthesized to overcome these challenges and enhance its biological activity, leading to compounds with improved properties for possible therapeutic applications.
=== Cystic fibrosis and CFTR === Cystic fibrosis is an autosomal recessive genetic disorder of the CFTR protein which reduces chloride and sodium ion transport through the cell membrane, causing thicker than normal mucus secretions. The CFTR protein is found in epithelial cells of the lung, liver, pancreas, digestive tract, and reproductive tracts. CFTR has a role in the production of mucus, sweat, and digestive fluids. The thickened mucus can lead to inflammation, respiratory infections, and clogged ducts.
Sources: en.wikipedia.org
=== Superficial bundles === Superficial neurovascular bundles do not include arteries, and consist primarily of capillaries and nerves. Because capillaries function as the sites for substance exchange between interstitial fluid and blood, they tend to have large surface area and short diffusion path. Normally, capillaries consist of a central lumen lined with an endothelium, a single layer of smooth epithelial cells.
Food and Drug Administration (FDA) on 24 July 2015, and evolocumab (Repatha, Amgen), approved on 27 August 2015; both were also authorised in the European Union in 2015. Inclisiran (Leqvio, Novartis), a small interfering RNA (siRNA) that reduces PCSK9 production in the liver and is administered by twice-yearly injection, was subsequently approved by the European Medicines Agency in December 2020 and by the FDA in December 2021. PCSK9 inhibitors have been shown to significantly reduce LDL-C levels and increase HDL-C levels significantly. They were found to lower the incidence of myocardial infarction and stroke in individuals at high cardiovascular risk (over 15% using PREDICT cardiovascular disease calculator), such as those with at least five risk factors, established cardiovascular disease, or hereditary lipid disorders without cardiovascular risk factor, but not in those at low to moderate risk. A 2023 meta-analysis has indicated that alirocumab may reduce all-cause mortality, whereas evolocumab has no significant effect on all-cause mortality. The efficacy of bococizumab remains unclear, as its development was discontinued by Pfizer in 2016. The most recent guidelines for cholesterol management from the American Heart Association and American College of Cardiology now provide guidance for when PCSK9 inhibitors should be considered, particularly focusing on cases in which maximally tolerated statin and ezetimibe fail to achieve goal LDL reduction. A possible side effect of the monoclonal antibody might be irritation at the injection site.
=== Arabati Baba Teḱe controversy === In 2002, a group of armed members of the Islamic Religious Community of Macedonia (ICM), a Sunni group that is the legally recognized organisation which claims to represent all Muslims in North Macedonia, unlawfully entered the Bektashi Order's Arabati Baba Teḱe in an attempt to reclaim this tekke as a mosque although the facility has never functioned as such. Subsequently, the Bektashi Order of North Macedonia sued the government for failing to restore the tekke to the Bektashis, pursuant to a law passed in the early 1990s returning properties previously nationalized under the Yugoslav government. The law, however, deals with restitution to private citizens, rather than religious communities. The ICM claim to the tekke is based upon their contention to represent all Muslims in North Macedonia; and indeed, they are one of two Muslim organizations recognized by the government, both Sunni. The Bektashi community filed for recognition as a separate religious community with the Macedonian government in 1993, which has refused to recognize them.
April 12: Decree stating no woman accused of a capital crime can be tried until verified she is not pregnant, with provisions for verification, temporary reprieves, or penalty adjustments. May 23: Decree barring women from political assemblies and gatherings of more than five. October 25: Bonuses for certain requisitioned port workers during wartime are paid directly to wives. 1798
Commonly served on a Sunday or any other special occasion, it can be done in a kettle BBQ or a conventional oven. Typical preparation involves covering the leg of lamb with butter, pushing rosemary sprigs into incisions cut in the leg, and sprinkling rosemary leaves on top. The lamb is then roasted for two hours at 180 °C (350 °F) and typically served with carrots and potato (also roasted), green vegetables and gravy. In Indonesia, lamb is popularly served as lamb satay and lamb curry. Both dishes are cooked with various spices from the islands, and served with either rice or lontong. A version of lamb and bamboo shoot curry is the specialty of Minang cuisine, although similar dishes can be found in Thai cuisine. In Mexico, lamb is the meat of choice for barbacoa, in which the lamb is roasted or steamed wrapped in maguey leaves underground. In Japan, although lamb is not traditionally consumed in most of the country, on the northern island of Hokkaido and in the northeastern Tohoku regions, a hot-pot dish called jingisukan (i.e. "Genghis Khan") is popular. In that dish, thin-sliced lamb is cooked over a convex skillet alongside various vegetables and mushrooms in front of the diners, then dipped in soy-sauce-based dipping sauces and eaten. It was so named because lamb is popular in Mongolia (see "Sheep meat consumption" above).
Sources: en.wikipedia.org
Cold storage slows the chemical degradation reactions that occur in solution. Lyophilized powder is more stable than reconstituted liquid and tolerates longer storage periods. Repeated temperature cycling should still be avoided because it can drive aggregation and loss of material.
Mass spectrometry is the standard confirmation of molecular mass and acetylation state. Chromatography establishes purity but does not identify the molecule on its own. The two techniques are normally applied together during verification.
No, because the reported value reflects the detection method and wavelength used, which vary between laboratories. A number stated without method details cannot be compared directly with another supplier's figure. Requesting the chromatogram and the method conditions is a common way to interpret it.
Reconstituted solutions are typically kept refrigerated at two to eight degrees Celsius when used within a short window, or frozen in aliquots for longer periods. Repeated freeze-thaw cycles are avoided because they can reduce recovery of intact peptide.