免疫组织 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-10-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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.
| 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 |
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.
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 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.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
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.
== Awards and recognitions == Rex has been named one of the top 100 hospitals in the country by Thomson (2008) and named one of the Best Places to Work in Healthcare by Modern Healthcare (2008). In 2014, Rex was recognized as the hospital with the best patient interactions in the state of North Carolina. In a study done by an independent company, Axial Exchange, Rex was ranked highest based on readmissions, patient satisfaction, and self care tools and education. In 2010, it was named a Bariatric Center of Excellence by the American Society for Bariatric Surgery. Rex was the first hospital in the Triangle, and one of only 10 in North Carolina to receive Magnet Recognition, which places Rex nurses among the top two percent in the country.
== Effects on global climate == In climate change science, ENSO is known as one of the internal climate variability phenomena. The other two main ones are Pacific decadal oscillation and Atlantic multidecadal oscillation. La Niña impacts the global climate and disrupts normal weather patterns, which can lead to intense storms in some places and droughts in others. El Niño events cause short-term (approximately 1 year in length) spikes in global average surface temperature while La Niña events cause short term cooling. Therefore, the relative frequency of El Niño compared to La Niña events can affect global temperature trends on decadal timescales.
A relatively short-range dating technique is based on the decay of uranium-234 into thorium-230, a substance with a half-life of about 80,000 years. It is accompanied by a sister process, in which uranium-235 decays into protactinium-231, which has a half-life of 32,760 years. While uranium is water-soluble, thorium and protactinium are not, and so they are selectively precipitated into ocean-floor sediments, from which their ratios are measured. The scheme has a range of several hundred thousand years. A related method is ionium–thorium dating, which measures the ratio of ionium (thorium-230) to thorium-232 in ocean sediment.
=== Given name === Reta Beebe (born 1936), American astronomer, author and popularizer of astronomy Reta Cowley (1910–2004), Canadian painter Reta Jo Lewis (born 1953), American Director of Congressional Affairs, an attorney, diplomat Reta Mays (born 1975), American serial killer Reta Shaw (1912–1982), American character actress Reta Trotman (born 1989), New Zealand racing cyclist
Nicotine is widely used recreationally through tobacco products, electronic cigarettes, and nicotine pouches, and, as of 2024, 1.2 billion people worldwide use tobacco products. It is highly addictive and hard to discontinue. Nicotine is often used compulsively, and dependence can develop within days. Recreational drug users commonly use nicotine for its mood-altering effects. Recreational nicotine products include chewing tobacco, cigars, cigarettes, e-cigarettes, snuff, pipe tobacco, snus, and nicotine pouches. Alcohol infused with nicotine is called nicotini.
Sources: en.wikipedia.org
== History == In 1628, English physician William Harvey discovered that blood circulates around the body. Soon thereafter, the first blood transfusion was attempted. In 1665 another English doctor Richard Lower successfully used blood transfusion between dogs to keep them alive. Karl Landsteiner is recognized as the father of transfusion medicine. Landsteiner is credited with the first classification of human blood into the four types (A, B, AB, O) of the ABO blood group system.
== Medical uses == Nalbuphine is indicated for the relief of moderate to severe pain. It can also be used as a supplement to balanced anesthesia, for preoperative and postoperative analgesia, and for obstetrical analgesia during labor and delivery. However, a 2014 Cochrane Systematic Review concluded that from the included studies, there was limited evidence to demonstrate that "0.1 to 0.3 mg/kg nalbuphine compared to placebo might be an effective postoperative analgesic" for pain treatment in children. Further research is therefore needed to compare nalbuphine with other postoperative opioids. In addition to relieving pain, nalbuphine has been shown to reduce morphine-induced pruritus (itching). Pruritus is a common side effect of morphine and other pure μ-opioid receptor (MOR) agonists. A systematic review of clinical trials concluded that nalbuphine is effective in counteracting morphine-induced pruritus, likely through central nervous system mechanisms. Evidence suggests that κ-opioid receptor (KOR) activation can counteract MOR-mediated effects in the brain. This interaction may have broader implications for central nervous system disorders, including potential applications in treating Parkinson's disease, where KOR agonism and MOR antagonism have been shown to reduce levodopa-induced dyskinesia and normalize striatal function. Morphine-induced pruritus may also result from histamine release by mast cells in the skin. Both MORs and KORs are expressed in skin nerves and keratinocytes, indicating potential peripheral mechanisms for opioid-induced pruritus.
== History == 2,3-Dihydro-LSD was first described in the scientific literature by Charles Gorodetzky and Harris Isbell at the Addiction Research Center of the National Institute of Mental Health (subsequently part of the National Institute on Drug Abuse) by 1964. However, it had first been synthesized and studied in animals by Botand Berde and Rudolph Bircher at Sandoz Pharmaceuticals, but their findings were unpublished. Sandoz Pharmaceuticals supplied the 2,3-dihydro-LSD used by Gorodetzky and Isbell in their clinical study.
President-elect Joe Biden announces he will elevate the White House Office of Science and Technology Policy to a Cabinet-level position, making its nominated director Eric Lander the first biologist in the Cabinet, if confirmed by the U.S. Senate. January 17 – Riley June Williams, a 22-year-old woman suspected of stealing House Speaker Nancy Pelosi's laptop during the January 6 Capitol riot, is charged by the FBI with intent to sell the device to Russian foreign intelligence services. January 18 Vice President-elect Kamala Harris resigns from her U.S. Senate seat. Her chosen successor, former California Secretary of State Alex Padilla, becomes the first Latino to represent California in the Senate. The 1776 Report is released by the 1776 Commission. January 19 COVID-19 pandemic: Nationwide COVID-19 deaths surpass 400,000. On his final full day in office, President Trump issues pardons for 144 people. New York State Office of Court Administration employee Brendan Hunt is arrested by the FBI for encouraging public executions of members of the U.S. Congress on social media. January 20 Joe Biden is sworn in as the 46th president of the United States. Kamala Harris becomes the first woman, first Asian American, and first African American to become Vice President of the United States. Donald Trump becomes the first outgoing president to boycott his successor's inauguration since Andrew Johnson in 1869.
Sources: en.wikipedia.org
Classification seeks to describe the diversity of bacterial species by naming and grouping organisms based on similarities. Bacteria can be classified on the basis of cell structure, cellular metabolism or on differences in cell components, such as DNA, fatty acids, pigments, antigens and quinones. While these schemes allowed the identification and classification of bacterial strains, it was unclear whether these differences represented variation between distinct species or between strains of the same species. This uncertainty was due to the lack of distinctive structures in most bacteria, as well as lateral gene transfer between unrelated species. Due to lateral gene transfer, some closely related bacteria can have very different morphologies and metabolisms. To overcome this uncertainty, modern bacterial classification emphasises molecular systematics, using genetic techniques such as guanine cytosine ratio determination, genome-genome hybridisation, as well as sequencing genes that have not undergone extensive lateral gene transfer, such as the rRNA gene. Classification of bacteria is determined by publication in the International Journal of Systematic Bacteriology, and Bergey's Manual of Systematic Bacteriology. The International Committee on Systematic Bacteriology (ICSB) maintains international rules for the naming of bacteria and taxonomic categories and for the ranking of them in the International Code of Nomenclature of Bacteria. Historically, bacteria were considered a part of the Plantae, the plant kingdom, and were called "Schizomycetes" (fission-fungi).
=== Prevention of atrial fibrillation === In 2005, meta-analysis results showed that angiotensin receptor blockers and angiotensin converting enzyme inhibitors considerably reduce the risk of atrial fibrillation in patients with coexisting heart failure and systolic left ventricular dysfunction. Specifically, an analysis of the CHARM study showed benefits for Candesartan in reducing new occurrences of atrial fibrillation in patients with heart failure and reduced left ventricular function. While these studies have demonstrated a potential additional benefit for candesartan when used in patients with systolic left ventricular dysfunction, additional studies are required to further elucidate the role of candesartan in the prevention of atrial fibrillation in other population groups.
The structure of the native state is generally assumed to be determined by its amino acid sequence (Anfinsen's dogma). This is a thermodynamic principle which states that the native structure is a unique, stable and kinetically accessible minimum of the free energy. The thermodynamic path going from unfolded to the native state is typically visualized as a free energy landscape in the form of a folding funnel. The forces driving the folding is a combination of hydrophobic interacts, hydrogen bonding, van der Waals forces and Coloumb interactions. During folding, the number hydrophobic side-chains exposed to water is minimized, which is known as hydrophobic collapse, causing them to collapse into the core of the protein. This causes most globular proteins to have hydrophilic side-chains outwards on the surface exposed to solvent and hydrophobic side-chains in the core.
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。
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.