This is a working overview of counter-ion, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-30. Anything still debated is marked as such rather than presented as settled.
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明,它可促进未成熟T细胞向成熟T细胞分化,并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子,从而更有效地呈递抗原。此外,自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体,而是调节宿主免疫应答的强度与方向。
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。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 主要靶细胞 | T细胞、树突状细胞 | 也影响NK细胞 |
| 信号通路 | TLR/MyD88/NF-κB | 部分实验模型 |
| 细胞因子偏向 | Th1型 | 增加IL-2、IFN-γ |
| 给药途径 | 皮下注射 | 临床常用 |
| 半衰期 | 约2小时 | 血浆中较短 |
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.
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.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
Several factors accelerate degradation: alkaline pH, elevated temperature, exposure to oxidants, and the presence of residual moisture. Deamidation of asparagine residues and oxidation of methionine are the most commonly reported degradation routes. Because the peptide lacks disulfide bonds, it does not undergo the thiol-related aggregation seen in some other biologics, but physical aggregation can still occur at high concentration. Stability data are product-specific, and extrapolating shelf life between formulations is not reliable.
Lyophilized thymosin alpha-1 is generally stored at or below minus twenty degrees Celsius, protected from moisture and light. Short-term handling at ambient temperature is possible for dry powder, but reconstituted solutions degrade faster and are usually kept at two to eight degrees Celsius with a defined expiry of days rather than weeks. Repeated freeze-thaw cycles should be avoided because they promote aggregation and loss of potency. Exact limits depend on the formulation and should follow the supplier's documentation.
Ancrod (also known as Viprinex), a serine protease derived from the venom of the Malayan pit vipers, was under development for the treatment of acute ischemic stroke; after Knoll was acquired by Abbott, Abbott licensed the rights to ancrod to Empire Pharmaceuticals, a startup that included a Knoll employee who had worked on ancrod. In 2004 Empire was acquired by Neurobiological Technologies (NTI). Ancrod failed in a Phase III clinical trial in 2008, which led to the demise of NTI.
== Further reading == Shoja, M. M.; Tubbs, R. S.; Loukas, M.; Khalili, M.; Alakbarli, F.; Cohen-Gadol, A. A. (2009). "Vasovagal syncope in the Canon of Avicenna: The first mention of carotid artery hypersensitivity". International Journal of Cardiology. 134 (3): 297–301. doi:10.1016/j.ijcard.2009.02.035. PMID 19332359.
== Sampling and analysis == In common with other mycotoxins, sampling food commodities for zearalenone must be carried out to obtain samples representative of the consignment under test. Commonly used extraction solvents are aqueous mixtures of methanol, acetonitrile, or ethyl acetate followed by a range of different clean-up procedures that depend in part on the food and on the detection method in use. Thin-layer chromatography (TLC) methods and high-performance liquid chromatography (HPLC) are commonly used. The TLC method for zearalenone is: normal phase silica gel plates, the eluent: 90% dichloromethane, 10% v/v acetone; or reverse phase C18 silica plates; the eluent: 90% v/v methanol, 10% water. Zearalenone gives unmistakable blue luminiscence under UV. HPLC alone is not sufficient, as it may often yield false positive results. Today, HPLC-MS/MS analysis is used to quantify and confirm the presence of zearalenone. Typically, the representative sample is commuted and homogenized then few grams are used for extraction with acetonitrile/water mixture. The procedure is the widely used QuEChERS method that quickly and effectively extracts small molecules, like mycotoxins and pesticides, from complex food matrices and animal tissues. The determination step relies on liquid chromatography - mass-spectrometry (LC-MS/MS). Another approach for the analysis of ZEA, without the requirement of expensive instrumentation, is developing specific peptide mimetic with the bioluminescent Gaussia luciferase fused as one protein that can bind specifically to ZEA.
Sources: en.wikipedia.org
== See also == Bioluminescence imaging Gene expression Gene knock-in Gene regulatory network GUS reporter system Molecular cloning Promoter (genetics) Selectable marker Synthetic biology Transcription factor Transfection
The concept of intracellular colloids as an organizing principle for the compartmentalization of living cells dates back to the end of the 19th century, beginning with William Bate Hardy and Edmund Beecher Wilson who described the cytoplasm (then called 'protoplasm') as a colloid. Around the same time, Thomas Harrison Montgomery Jr. described the morphology of the nucleolus, an organelle within the nucleus, which has subsequently been shown to form through intracellular phase separation. WB Hardy linked formation of biological colloids with phase separation in his study of globulins, stating that: "The globulin is dispersed in the solvent as particles which are the colloid particles and which are so large as to form an internal phase", and further contributed to the basic physical description of oil-water phase separation. Colloidal phase separation as a driving force in cellular organisation appealed strongly to Stephane Leduc, who wrote in his influential 1911 book The Mechanism of Life: "Hence the study of life may be best begun by the study of those physico-chemical phenomena which result from the contact of two different liquids. Biology is thus but a branch of the physico-chemistry of liquids; it includes the study of electrolytic and colloidal solutions, and of the molecular forces brought into play by solution, osmosis, diffusion, cohesion, and crystallization." The primordial soup theory of the origin of life, proposed by Alexander Oparin in Russian in 1924 (published in English in 1936) and by J.B.S.
6 August Weather Forecast about weather forecasting in the UK; Swedish Lennart Bengtsson of the European Centre for Medium-Range Weather Forecasts; Alistair Woodroffe and Brian Webster of the Met Office; numerical calculations began in the early 1950s with computers making 10,000 calculations a second but by the mid-1980s it was one billion; Meteosat-2 launched in June 1981; Steven Burke of the London Potato Futures Association; Capt Derek Ralph in a British Caledonian BAC One-Eleven flying to Aberdeen Airport; amateur weatherman Bill Foggitt; the weather centre and Lockheed C-5 Galaxy aircraft at RAF Mildenhall; conservationist Robin Page; narrated by Muriel Gray, directed by John Dollar, made by Uden Associates 13 August Made to Measure, essentially a re-edited, slightly updated edition of the August 1986 episodes on the F1 Ford turbocharged engine, with a few minutes of new content; in May 1987 Peter Collins watches the previous San Marino Grand Prix; Ford Cosworth V6 B187 cars: engine mapping; Dick Scammel, general head of engineering; Martin Walters, chief development engineer; the engine is dismantled, and damage is found; Geoff Goddard, chief racing engine designer; electromagnetic pulses from the engine affected the working of the engine computer circuitry; rogue signals were picked up by the engine computer, so causing erratic fuel injection; French F1 driver Patrick Tambay listens to the sound of the turbo; the turbo pressure would be limited to 2.5 in 1988, before turbos were banned for the 1989 season; the Italian Grand Prix circuit; each team is allowed two sets of qualifying tyres; the tyres on the rear axle warm up before the front axle; the Honda V6 engine could produce 1200 hp; chief designer Rory Byrne, and F1 aerodynamic forces. 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Sherwood Rowland and Mario Molina of the University of California, Irvine found that some chlorine compounds would destroy ozone by making chlorine monoxide, and both received the 1995 Nobel Prize in Chemistry for this discovery; the Chemical Manufacturers' Association (since 2000 the American Chemistry Council) and the National Science Foundation launched a new atmospheric survey at McMurdo Station, led by Susan Solomon of the Earth System Research Laboratories; Jerry D. Mahlman of the Geophysical Fluid Dynamics Laboratory at Princeton was attempting a computer model of the Antarctic atmosphere; Rafe Pomerance of the World Resources Institute; the greenhouse effect, described by James Hansen of the Goddard Institute for Space Studies, who claimed that the Earth's temperature would be 2 degrees higher by 2000, 3 degrees higher by 2010, and 4 to 7 degrees warmer by 2030; Richard E. Benedick. Directed by Linda Harrar, produced by Paula Apsell, made by WGBH, Uden Associates, Television Trust for the Environment and Sveriges Television. Originally a Nova documentary 24 September Dirty Money, about whether the environment can be cleaned up; the UK's first anti-pollution trade fair in March 1987, attended by William Waldegrave; Father Jim Conlon and Portglenone Abbey in N Ireland, with an anaerobic digester, which saved £1000 a month in gas cost, and the manure was sold for £25,000 a year; Mike Flux of ICI; biologist Paul Johnston of Greenpeace, in Teesside; the River Tees was the second-most polluted in the UK, with Douglas Ord of Northumbrian Water; Ken Murphy, and how Greenpeace attempted to block an effluent pipe near Immingham in March 1985; John Elkington, environmental writer; BioTechnica of Llanishen in Cardiff, reclaiming contaminated land on a former highly polluted gasworks site in Lancashire; Jutta Ditfurth; Hans-Georg Peine of BASF AG, and the Sandoz chemical spill in November 1986 in Switzerland; in 1983, ICI founded the first bioplastic company, called Marlborough Biopolymers, which made polyhydroxy butyrate; Dame Anita Roddick of The Body Shop, who worked with Friends of the Earth; Peter Baylis of the NERC Environmental Satellite Laboratory, which began in 1975, in the University of Dundee's Ewing Building, and largely provided the only UK archive of satellite environmental data. Narrated by Bob Peck, produced by Edward Poulter, directed by David Sharp, made by London Scientific Films 1 October Malltime. A US production, produced by Mike Wallington, made by George Haggerty, made by Kai Productions 8 October Anything You Can Do..., about new robotics; the five houses puzzle; Richard Gregory, professor of neuropsychology at the University of Bristol; Roger Mathias of Plessey Radar and the Multi-function Electronically Scanned Adaptive Radar (MESAR), began in 1982; Henry Thompson and speech recognition at the School of Informatics, University of Edinburgh; Robert Kowalski of the Department of Computing, Imperial College London; Margaret Boden of the University of Sussex; J. Michael Brady; Paul Caplin and robotics; Roy Bottomley of Meiko Scientific, and the transputer, developed in the UK; Plessey Laboratories at the Allen Clark Research Centre, and new chemical compounds for computer chip; logic programming and heuristics; the European Eureka Prometheus Project, an expert system. Narrated by Miriam Margolyes, produced by Michael Blakstad, directed by Catherine Robins, made by Workhouse Productions 22 October Command and Control, the chain of command of nuclear weapons; it featured the Air Force Research Laboratory. Directed by Clive Syddall, made by Twenty Twenty Vision 5 November Earthquake Country, about the San Andreas fault; Robert Wallace, chief scientist of the USGS; the 1906 earthquake caused the tectonic planes to move around seven metres; geologist Grove Karl Gilbert; an earthquake in the middle section of the fault was expected for around 1988; a 5.8 earthquake on 8 June 1934; geologist Kerry Sieh and paleoseismology; if an earthquake took place, coordination would be from the Joint Forces Training Base - Los Alamitos; earthquake engineer George W. Housner of Caltech; structural engineer Ray William Clough; earthquake engineer Luis Estava Maraboto of the Engineering Institute of the National Autonomous University of Mexico. Produced by Arabella Woods, directed by John Tchalenko, made by Red Rooster Films 12 November Nature's Technology, about the different types and the modelling of animal locomotion, and legged robots; robotic hands and bioengineer Stephen Jacobsen of the University of Utah; snake-arm robots; the 1986 Adaptive Suspension Vehicle (ASV) of Ohio State University, a hexapod robot, and Vincent Vohnout; active balance and Marc Raibert; the 1965 Walking Truck of General Electric; static stability and the Odex 1 six-legged robot; biomechanics and Robert McNeill Alexander, Professor of Zoology; WABOT-2 of Waseda University, optical music recognition and the NHK Symphony Orchestra of Japan conducted by Yuzo Toyama. Narrated by Adrienne Posta, directed by David Barlow, produced by Karl Sabbagh, made by InCA 19 November Britain Can Make It?, about making kitchen units in the UK and in Germany; the dual system of apprenticeship in Germany; Sig Prais of the National Institute of Economic and Social Research; the Britain Can Make It exhibition, where the fitted kitchen was first introduced in the UK; the Hungarian designer George Fejer was largely responsible for introducing fitted kitchens; Wolfgang Luckhaus of Poggenpohl of Germany, which also developed the fitted kitchen; in the 1960s the Germans introduced chipboard for kitchen manufacturing, which became industry-standard, with wipe-clean melamine resin facing (MFC); Hilary Steedman of the NIESR, and how the Germans built kitchens to order, whereas British companies simply built kitchens, whether ordered or not; Heal's of London introduced German kitchens to the UK in the early 1970s, in a hausfest; the German SieMatic kitchen company; Doug Gregory started The Symphony Group in 1970 after seeing chipboard, developing flatpack kitchen units, the Germans did not make flatpack kitchens, only assembled kitchens; David Love, buying director of MFI, which was helped by the flatpack revolution, but it was all largely an imitation of German products, and was a mostly standard product range; Symphony introduced computer production control in the 1980s, which the Germans had introduced in the early 1970s - this allowed much more variation of manufacturing to order, which was the main German method; employees of Symphony were largely unskilled, but German workers were largely skilled apprentices, who had passed exams in manufacturing; nearly all of German kitchens were built to order, so needed skilled workers; Walter Siekmann, production manager of Poggenpohl; German furniture manufacture was found in East Westphalia (Ostwestfalen); the Germans believed in more thorough technical training, and sold their products all over the world, but British companies had less-thorough training, and did not sell as worldwide as the Germans. Narrated by John Woodvine, directed by David Habakkuk, made by Riverside Television 26 November At the Edge, about the physical limits placed upon fighter pilots when flying high G capable modern aircraft, such as the F16 and the F18. Pilots are subjected to G-LOC in the Aerospace Medicine centrifuge in San Antonio, Texas. Narrated by Ray Brooks, written, produced and directed by Chris Haws, made by InCA
The IUPAC nomenclature (systematic way of naming compounds) for alkanes is based on identifying hydrocarbon chains. Unbranched, saturated hydrocarbon chains are named systematically with a Greek numerical prefix denoting the number of carbons and the suffix "-ane". In 1866, August Wilhelm von Hofmann suggested systematizing nomenclature by using the whole sequence of vowels a, e, i, o and u to create suffixes -ane, -ene, -ine (or -yne), -one, -une, for the hydrocarbons CnH2n+2, CnH2n, CnH2n−2, CnH2n−4, CnH2n−6. In modern nomenclature, the first three specifically name hydrocarbons with single, double and triple bonds; while "-one" now represents a ketone.
Sources: en.wikipedia.org
它促进未成熟T细胞分化并增强成熟T细胞的增殖与细胞因子分泌。这些作用有助于放大抗原特异性免疫应答。
目前认为它可能通过Toll样受体等模式识别受体传递信号,但精确的受体身份和结合机制尚未完全阐明。
不同试验在患者选择、给药方案、联合治疗和终点定义上差异很大。这些异质性使得跨研究比较困难,结论难以统一。
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.