This is a working overview of 鼻内给药, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-15 and is reviewed periodically as new material appears.
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
In post-WW1 Hungary, arsenic extracted by boiling fly paper was used in an estimated 300 murders by the Angel Makers of Nagyrév. In imperial China, arsenic trioxide and sulfides were used in murder, as well as for capital punishment for members of the royal family or aristocracy. Forensic studies have determined that the Guangxu Emperor (d. 1908) was murdered by arsenic, most likely ordered by the Empress Dowager Cixi or Generalissimo Yuan Shikai. Likewise, in ancient Korea, and particularly in the Joseon Dynasty, arsenic-sulfur compounds had been used as a major ingredient of sayak (사약; 賜藥), which was a poison cocktail used in capital punishment of high-profile political figures and members of the royal family. Due to social and political prominence of the condemned, many of these events were well-documented, often in the Annals of Joseon Dynasty; they are sometimes portrayed in historical television miniseries because of their dramatic nature. Arsenic-contaminated beer poisoned over 6,000 people in the Manchester area of England in 1900, and is thought to have killed at least 70 victims. Mass arsenic poisoning due to naturally occurring arsenic in drinking water was first noted by Dr. Abel Ayerza in Córdoba, Argentina in a paper published in 1918. One of the worst incidents of arsenic poisoning via well water occurred in Bangladesh with the mass installation of tube wells following Bangladesh's independence in 1971. The World Health Organization called this the "largest mass poisoning of a population in history" and was recognized as a major public health concern.
===== United Kingdom ===== In the UK, semaglutide is available on NHS prescription for diabetes at nominal or no cost to the individual. It is also available for obesity, limited to treatment for two years.
=== Immunostimulatory CpG motifs === Plasmid DNA itself appears to have an adjuvant effect on the immune system. Bacterially derived DNA can trigger innate immune defence mechanisms, the activation of dendritic cells and the production of TH1 cytokines. This is due to recognition of certain CpG dinucleotide sequences that are immunostimulatory. CpG stimulatory (CpG-S) sequences occur twenty times more frequently in bacterially derived DNA than in eukaryotes. This is because eukaryotes exhibit "CpG suppression" – i.e. CpG dinucleotide pairs occur much less frequently than expected. Additionally, CpG-S sequences are hypomethylated. This occurs frequently in bacterial DNA, while CpG motifs occurring in eukaryotes are methylated at the cytosine nucleotide. In contrast, nucleotide sequences that inhibit the activation of an immune response (termed CpG neutralising, or CpG-N) are over represented in eukaryotic genomes. The optimal immunostimulatory sequence is an unmethylated CpG dinucleotide flanked by two 5’ purines and two 3’ pyrimidines. Additionally, flanking regions outside this immunostimulatory hexamer must be guanine-rich to ensure binding and uptake into target cells. The innate system works with the adaptive immune system to mount a response against the DNA encoded protein. CpG-S sequences induce polyclonal B-cell activation and the upregulation of cytokine expression and secretion. Stimulated macrophages secrete IL-12, IL-18, TNF-α, IFN-α, IFN-β and IFN-γ, while stimulated B-cells secrete IL-6 and some IL-12.
Sources: en.wikipedia.org
== Physiology == The primary function of the blood-brain barrier is to protect the brain and keep it isolated from harmful toxins that are potentially in the blood stream. It accomplishes this because of its structure, as is usual in the body that structure defines its function. The tight junctions between the endothelial cells prevent large molecules and many ions from passing between the junction spaces. This forces molecules to go through the endothelial cells to enter the brain tissue, meaning that they must pass through the cell membranes of the endothelial cells. Because of this, the only molecules that can easily transverse the blood–brain barrier are very lipid-soluble ones. These are not the only molecules that can transverse the blood–brain barrier; glucose, oxygen and carbon dioxide are not lipid-soluble but are actively transported across the barrier, to support the normal cellular function of the brain. The fact that molecules have to fully transverse the endothelial cells makes them a perfect barricade to unspecified particles from entering the brain, working to protect the brain at all costs. Also, because most molecules are transported across the barrier, it does a very effective job of maintaining homeostasis for the most vital organ of the human body.
The AGA does not recommend extensive pre-procedural testing, including repeated measurements of PT/INR or platelet count, before patients with stable cirrhosis undergo common gastrointestinal procedures. Nor do they suggest the routine use of blood products, such as platelets, for bleeding prevention. Cirrhosis is stable when there are no changes in baseline abnormalities of coagulation lab values. For patients with stable cirrhosis and low platelet count undergoing common low-risk procedures, the AGA does not recommend the routine use of thrombopoietin receptor agonists for bleeding prevention. In hospitalized patients who meet standard guidelines for clot prevention, the AGA suggests standard prevention. The AGA does not recommend routine screening for portal vein thrombosis. If there is a portal vein thrombosis, the AGA suggests treatment by anticoagulation. In the case of cirrhosis with atrial fibrillation, the AGA recommends using anticoagulation over no anticoagulation.
== Naturally occurring molecular knots == Organic molecules containing knots may fall into the categories of slipknots or pseudo-knots. They are not considered mathematical knots because they are not a closed curve, but rather a knot that exists within an otherwise linear chain, with termini at each end. Knotted proteins are thought to form molecular knots during their tertiary structure folding process, and knotted nucleic acids generally form molecular knots during genomic replication and transcription, though details of knotting mechanism continue to be disputed and ambiguous. Molecular simulations are fundamental to the research on molecular knotting mechanisms. Knotted DNA was found first in single-stranded, circular, bacterial DNA, though double-stranded circular DNA has been found to also form knots. Naturally knotted RNA has not yet been reported. A number of proteins containing naturally occurring molecular knots have been identified. The knot types found to be naturally occurring in proteins are the
Sources: en.wikipedia.org
An upper endoscopy with biopsy of the duodenum (beyond the duodenal bulb) or jejunum is performed to obtain multiple samples from the duodenum. Not all areas may be equally affected; if biopsies are taken from healthy bowel tissue, the result would be a false negative. Even in the same bioptic fragment, different degrees of damage may be present. Most people with coeliac disease have a small intestine that appears to be normal on endoscopy before the biopsies are examined. Endoscopic features of coeliac disease include scalloping of the small bowel folds (pictured), fissures, a mosaic pattern to the mucosa, prominence of the submucosa blood vessels, and a nodular pattern to the mucosa. Capsule endoscopy (CE) allows identification of typical mucosal changes observed in coeliac disease and may be used as an alternative to endoscopy in those who cannot or do not want one.
Butyrfentanyl or butyrylfentanyl is a potent short-acting synthetic opioid analgesic drug. It is an analog of fentanyl with around one quarter of its potency. One of the first mentions of this drug can be found in document written by The College on Problem of Drug Dependence, where it is mentioned as N-butyramide fentanyl analog. This document also states that the article describing its clinical effects (analgesic studies, μ-, δ-, κ-opioid receptor binding, and in vitro measures of drug efficacy, antinociceptive, and narcotic properties) was published in 1987. It is an agonist for the μ-opioid receptors. Butyrfentanyl has no current legitimate clinical applications; however, it is being sold as a designer drug. Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea, and potentially serious respiratory depression which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.
For instance, oxycodone and diamorphine may be tested, both sedative analgesics. If such a test is not requested specifically, the more general test (in the preceding case, the test for opioids) will detect most of the drugs of a class, but the employer or physician will not have the benefit of the identity of the drug. Employment-related test results are relayed to a medical review office (MRO) where a medical physician reviews the results. If the result of the screen is negative, the MRO informs the employer that the employee has no detectable drug in the urine, typically within 24 hours. However, if the test result of the immunoassay and GC-MS are non-negative and show a concentration level of parent drug or metabolite above the established limit, the MRO contacts the employee to determine if there is any legitimate reason—such as a medical treatment or prescription. On-site instant drug testing is a more cost-efficient method of effectively detecting substance use amongst employees, as well as in rehabilitation programs to monitor patient progress. These instant tests can be used for both urine and saliva testing. Although the accuracy of such tests varies with the manufacturer, some kits have rates of accuracy correlating closely with laboratory test results.
Sources: en.wikipedia.org
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.