The short version of 鼻内给药 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-30 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 whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
| 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 |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
{\displaystyle {\begin{aligned}a[{\text{Bq/g}}]&={\frac {4.17\times 10^{23}[{\text{mol}}^{-1}]}{t_{1/2}[{\text{year}}]\times 365\times 24\times 60\times 60[{\text{s/year}}]\times M}}\\[1ex]&\approx {\frac {1.32\times 10^{16}[{\text{mol}}^{-1}{\cdot }{\text{s}}^{-1}{\cdot }{\text{year}}]}{t_{1/2}[{\text{year}}]\times M[{\text{g/mol}}]}}.\end{aligned}}}
== Adverse effects == To reduce the risk of developing ketoacidosis (a serious condition where the body produces high levels of blood acids called ketones) after surgery, the FDA has approved changes to the prescribing information for SGLT2 inhibitor diabetes medications, recommending they be temporarily stopped before scheduled surgery. Empagliflozin should each be stopped at least three days before scheduled surgery. Symptoms of ketoacidosis include nausea, vomiting, abdominal pain, tiredness, and trouble breathing.
We won't see the rebirth of the Warsaw Pact and the Soviet Union." Chairman of the Islamic Committee of Russia Geydar Dzhemal stated that there was no difference between the Georgian-Ossetian conflict and the conflict in Chechnya. Former Prime Minister of Russia Mikhail Kasyanov stated in late September: "The trampling of the foundations of the Constitution of Russia leads to an aggressive foreign policy. A vivid example of this is the Russian-Georgian conflict. Instead of fulfilling the peacekeeping mandate, the Russian authorities gave the order to launch a full-scale war." Former Prime Minister of Estonia Mart Laar stated in late September 2008 that he personally saw that it was South Ossetia that attacked first when it began heavy shelling of the Georgian villages.
Sources: en.wikipedia.org
=== Tropoelastin precursors === Elastin is made by linking together many small soluble precursor tropoelastin protein molecules (50-70 kDa), to make the final massive, insoluble, durable complex. The unlinked tropoelastin molecules are not normally available in the cell, since they become crosslinked into elastin fibres immediately after their synthesis by the cell and export into the extracellular matrix. Each tropoelastin consists of a string of 36 small domains, each weighing about 2 kDa in a random coil conformation. The protein consists of alternating hydrophobic and hydrophilic domains, which are encoded by separate exons, so that the domain structure of tropoelastin reflects the exon organization of the gene. The hydrophilic domains contain Lys-Ala (KA) and Lys-Pro (KP) motifs that are involved in crosslinking during the formation of mature elastin. In the KA domains, lysine residues occur as pairs or triplets separated by two or three alanine residues (e.g. AAAKAAKAA) whereas in KP domains the lysine residues are separated mainly by proline residues (e.g. KPLKP). The hydrophobic domains of tropoelastin are enriched in non-polar amino acids, particularly glycine, valine, proline, and alanine, whereas its lysine-rich domains provide sites for enzymatic cross-linking during the formation of mature elastin.
=== Bone morphogenetic proteins === Key growth factors in endochondral skeletal differentiation include bone morphogenetic proteins (BMPs) that determine to a major extent where chondrocyte differentiation occurs and where spaces are left between bones. The system of cartilage replacement by bone has a complex regulatory system. BMP2 also regulates early skeletal patterning. Transforming growth factor beta (TGF-β), is part of a superfamily of proteins that include BMPs, which possess common signaling elements in the TGF beta signaling pathway. TGF-β is particularly important in cartilage differentiation, which generally precedes bone formation for endochondral ossification. An additional family of essential regulatory factors is the fibroblast growth factors (FGFs) that determine where skeletal elements occur in relation to the skin
=== Sony Computer Entertainment === In 1997, Ueda joined Sony Computer Entertainment Japan. He began work on Ico, being granted his own unit as the studio had little experience in developing games on their own (mostly the Ape Escape series) due to their focus on assisting third-party developers. After Ico, Ueda and his small team started work on Shadow of the Colossus. In February 2007, Japanese gaming magazine Famitsu reported that Ueda and his team were working on a game for the PlayStation 3. No details about the unnamed title were revealed. In 2008, in the August edition of PlayStation Magazine, Sony Worldwide Studios boss Shuhei Yoshida commented that both Ico and Shadow of the Colossus took 4 years to develop as a hint that the game was under production, but was not close to release. The game was revealed at E3 2009 as The Last Guardian, the trailer for which suggests a saga involving elements of both Ico and Shadow of the Colossus wherein a young boy resembling Ico partners up with a colossus-sized companion to complete puzzles. Ueda later confirmed The Last Guardian to be related to the two previous installments. In an interview with G4tv.com in 2009 he expressed admiration for the method of cut-scene story-telling in Valve's Half-Life 2, and when questioned directly expressed an interest in making a first-person game.
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。
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.