This is a working overview of 免疫组织, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-24 and is reviewed periodically as new material appears.
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。
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。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
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.
=== South Ossetia === The Government of South Ossetia in Tskhinvali called for Russian help to prevent "genocide" when the Georgian bombardment began, saying that Tskhinvali was under "the most frightful fire".
The amount of alcohol on the breath can be measured, without requiring drawing blood, by blowing into a breathalyzer, resulting in a breath alcohol content (BrAC). The BrAC specifically correlates with the concentration of alcohol in arterial blood, satisfying the equation BACarterial = BrAC × 2251 ± 46. Its correlation with the standard BAC found by drawing venous blood is less strong. Jurisdictions vary in the statutory conversion factor from BrAC to BAC, from 2000 to 2400. Many factors may affect the accuracy of a breathalyzer test, but they are the most common method for measuring alcohol concentrations in most jurisdictions.
In 1961, Peter Mitchell proposed chemiosmosis as a cell's primary system of energy conversion. The mechanism, now ubiquitous in living cells, powers energy conversion in micro-organisms and in the mitochondria of eukaryotes, making it a likely candidate for early life. Mitochondria produce adenosine triphosphate (ATP), the energy currency of the cell used to drive cellular processes such as chemical syntheses. The mechanism of ATP synthesis involves a closed membrane in which the ATP synthase enzyme is embedded. The energy required to release strongly bound ATP has its origin in protons that move across the membrane. In modern cells, those proton movements are caused by the pumping of ions across the membrane, maintaining an electrochemical gradient. In the first organisms, the gradient could have been provided by the difference in chemical composition between the flow from a hydrothermal vent and the surrounding seawater, or perhaps meteoric quinones that were conducive to the development of chemiosmotic energy across lipid membranes if at a terrestrial origin.
Sources: en.wikipedia.org
Phenibut also binds to and blocks α2δ subunit-containing VDCCs, similarly to gabapentin and pregabalin, and hence is a gabapentinoid. Both (R)-phenibut and (S)-phenibut display this action with similar affinity (Ki = 23 and 39 μM, respectively). It is often claimed on websites about nootropics and elsewhere on the internet that phenibut increases dopamine. Three papers published in Russian by Soviet scientists in 1979, 1986, and 1990 report that phenibut increases dopamine in the striatum of rats and in the mouse brain. The mechanism underlying this putative effect is unclear. Structurally, phenibut can also be considered a derivative of phenethylamine, and some research suggests that phenibut antagonizes the action of phenethylamine.
Less kidney toxicity has been reported with liposomal formulations (such as AmBisome) and it has become preferred in patients with preexisting renal injury. The integrity of the liposome is disrupted when it binds to the fungal cell wall, but is not affected by the mammalian cell membrane, so the association with liposomes decreases the exposure of the kidneys to amphotericin B, which explains its less nephrotoxic effects. In addition, electrolyte imbalances such as hypokalemia and hypomagnesemia are also common. In the liver, increased liver enzymes and hepatotoxicity (up to and including fulminant liver failure) are common. In the circulatory system, several forms of anemia and other blood dyscrasias (leukopenia, thrombopenia), serious cardiac arrhythmias (including ventricular fibrillation), and even frank cardiac failure have been reported. Skin reactions are also possible, with rash & itching occurring in about 17% of patients, in rare cases it can cause a serious skin reaction known as Drug rash with eosinophilia and systemic symptoms (DRESS). In very rare instances, amphotericin B has also been shown to cause reversible ototoxicity causing tinnitus, vertigo, and temporary hearing loss. While there have been only a few reported cases, the hearing loss was temporary in all of them, with hearing showing improvement two weeks after discontinuing the drug. The analogue AM-2-19 has been engineered to be less toxic to the kidneys.
=== Environmental pollution === Considering the complex interactions between humans, animals and the environment, it is also important to consider the environmental aspects and contributors to antimicrobial resistance. One of these factors is human and hospital waste, which is a substantial contributor to environmental antimicrobial resistance (AMR). It is estimated that around 50–80% of antibiotics are passed unmetabolized in urine and 4–30% in feces, causing large quantities of active antibiotics to enter sewage systems. Sewage environments contain high levels of antimicrobial-resistant bacteria (ARB), antimicrobial resistance genes (ARGs), and mobile genetic elements such as plasmids, which enable rapid gene exchange. Wastewater treatment plants (WWTPs) are typically not designed to remove AMR; in some cases, multidrug-resistant species such as Escherichia, Shigella, and Klebsiella can increase twofold in treated wastewater. Methicillin-resistant Staphylococcus aureus (MRSA) has also been detected in both raw and treated sewage. Agriculture is also a major contributor to environmental AMR. Manure from livestock (such as cattle, sheep, etc.) contains residual antibiotics, which enter the soil as farmers usually use it as fertilizer. These are typically at levels of 1–10 mg/kg, and also contain ARBs and ARGs. One megaton of antibiotics has been estimated to have entered global soils through manure application. Pathogens can survive in soil for up to 10 years and on plant surfaces for up to 1 year, thereby enabling long-term environmental continuation of AMR.
Sources: en.wikipedia.org
== Adverse effects == Protamine has been reported to cause allergic reactions in patients who are allergic to fish, diabetics using insulin preparations containing protamine, and vasectomized or infertile men. These occur at rates ranging from 0.28% to 6%. Avoiding rapid infusion of protamine sulfate and pre-treating at-risk patients with histamine receptor antagonists (H1 and H2) and steroids may minimize these reactions. A 5 to 10 mg test dose is recommended following pretreatment before administering the full dose.
Revenues in the world liquid chromatography market, specifically, are expected to grow from $3.4 billion in 2007 to $4.7 billion in 2013, with a slight decrease in spending expected in 2008 and 2009 from the worldwide economic slump and decreased or stagnant spending. The pharmaceutical industry alone accounts for 35% of all the HPLC instruments in use. The main source of growth in LC stems from biosciences and pharmaceutical companies.
Narrated by Heather Couper, produced by Stuart Carter, made by Pioneer Productions 5 December Serious Fun, about Sim City; the video game industry was 20bn, bigger than film industry; Peter Main of Nintendo; Japanese musician Dai Satō; Japanese games designer Shigeru Miyamoto, and how the 3-D effect on games was achieved through polygon rendering, such as the polygon mesh; games designer Ed Annunziata; Lucy Bradshaw (game developer) of Electronic Arts, of California, who developed SimCity in 1989; software engineer Craig Reynolds (computer graphics) of Electronic Arts; sports commentator John Madden, appearing in the EA Sports game Madden NFL; a wire-frame model of a face had around four thousand polygons; sequencing the voice with the movement of the face was done with a software package called KISS; the British Syndicate (1993 video game); Ron Martinez of Spectrum HoloByte, and their game Star Trek: The Next Generation – A World for All Seasons; Paul Rioux of Sega. Directed by Sheila Hayman, made by Tra La La 12 December End of a Dynasty, about the execution of the Romanov family on 17 July 1918 at Yekaterinburg in Sverdlovsk Oblast. Directed by Julian Nott, made by Peninsula Films
=== Cancer treatment === Pardaxin inhibits proliferation and induces apoptosis of human cancer cell lines. Its 33-amino acid structure contains many cationic and amphipathic amino acids. This makes it easier for it to interact with anionic membranes, such as those in tumor cells, which are inherently more acidic because of the acidic environment created by more glycolysis. Pardaxin initiates caspase-dependent and caspase-independent apoptosis in human cervical carcinoma cells. Pardaxin triggers reactive oxygen species (ROS). ROS production disrupts protein folding and induces the unfolded protein response (UPR). This causes stress on the endoplasmic reticulum, which releases calcium. This leads to an increase in mitochondrial calcium, dropping its membrane potential. The pore permeability changes, and Cytochrome c (Cyt c) is released. Cyt c activates the caspase chain that leads to apoptosis. ROS also activates the JNK pathway. JNK is phosphorylated, which leads to the phosphorylation of AP-1 (transcription factor consisting of cFOS and Cjun). This results in the activation of caspases as well. ROS also causes a caspase independent pathway that results in apoptosis. When the mitochondrial membrane potential changes, apoptosis-inducing factors (AIFs) are also released. These trigger apoptosis when they enter the nucleus, not needing to involve caspases.
Sources: en.wikipedia.org
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。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
The lyophilized powder is kept refrigerated at 2 to 8 degrees Celsius and protected from light. Reconstituted solutions should be used promptly. Freezing and thawing repeatedly is avoided.