A practical reference on Neurotrophic signalling: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-17. Anything still debated is marked as such rather than presented as settled.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
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.
==== Empyema ==== Untreated cholecystitis can lead to worsened inflammation and infected bile that can lead to a collection of pus inside the gallbladder, also known as empyema. The symptoms of empyema are similar to uncomplicated cholecystitis but greater severity: high fever, severe abdominal pain, more severely elevated white blood count.
The subject of study in biochemistry is the chemical processes in living organisms, and its history involves the discovery and understanding of the complex components of life and the elucidation of pathways of biochemical processes. Much of biochemistry deals with the structures and functions of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules; their metabolic pathways and flow of chemical energy through metabolism; how biological molecules give rise to the processes that occur within living cells; it also focuses on the biochemical processes involved in the control of information flow through biochemical signalling, and how they relate to the functioning of whole organisms. Over the last 40 years the field has had success in explaining living processes such that now almost all areas of the life sciences from botany to medicine are engaged in biochemical research. Among the vast number of different biomolecules, many are complex and large molecules (called polymers), which are composed of similar repeating subunits (called monomers). Each class of polymeric biomolecule has a different set of subunit types. For example, a protein is a polymer whose subunits are selected from a set of twenty or more amino acids, carbohydrates are formed from sugars known as monosaccharides, oligosaccharides, and polysaccharides, lipids are formed from fatty acids and glycerols, and nucleic acids are formed from nucleotides.
=== Cancer progression and metastasis === ITGA1 has emerged as an important mediator of pancreatic ductal adenocarcinoma (PDAC) progression. In PDAC and pancreatic intraepithelial neoplasia (PanIN), increased ITGA1 expression has been associated with aggressive disease features as well as poor prognosis of patients. Because ITGA1 is increased in premalignant lesions and encodes a cell-surface receptor, it has been proposed as a potential biomarker for early disease detection and as a therapeutic target. The ITGA1-collagen signaling axis contributes to tumor progression by regulating extracellular matrix interactions, invasion, metastatic dissemination, and resistance to chemotherapies. Increased expression of ITGA1-associated collagen ligands including type IV and type VI collagen, is also associated with aggressive tumor features, including higher tumor grade, TP53 mutation status, and erlotinib resistance. Overexpression of ITGA1 has similarly been found in other malignancies like melanoma, prostate cancer, bladder cancer, hepatocellular carcinoma, and multiple myeloma, where it is associated with invasive phenotypes, metastatic behavior and tumor progression. This association supports the identification of ITGA1 as a potential biomarker and therapeutic target across multiple cancer types.
== Treatment == For patients with VWD type 1 and VWD type 2A, desmopressin is available as different preparations, recommended for use in cases of trauma, or in preparation for dental or surgical procedures. Desmopressin stimulates the release of VWF from the Weibel–Palade bodies of endothelial cells, thereby increasing the levels of VWF (as well as coagulant factor VIII) three- to five-fold. Desmopressin is also available as a preparation for intranasal administration (Stimate) and as a preparation for intravenous administration. Desmopressin is contraindicated in VWD type 2b because of the risk of aggravated thrombocytopenia and thrombotic complications. Desmopressin is probably not effective in VWD type 2M and is rarely effective in VWD type 2N. It is totally ineffective in VWD type 3. Regular preventative infusions of desmopressin to keep vWF levels normal (outside of planned surgical procedures or trauma) is not recommended. However, in very small limited studies, preventative desmopressin infusions have been shown to prevent bleeding episodes in severe VWD. For women with heavy menstrual bleeding, estrogen-containing oral contraceptive medications are effective in reducing the frequency and duration of the menstrual periods. Estrogen and progesterone compounds available for use in the correction of menorrhagia include ethinylestradiol, levonorgestrel, drospirenone and cyproterone.
Before the introduction of the basic chromium species in tanning, several steps are required to produce a tannable hide. The pH must be very acidic when the chromium is introduced to ensure that the chromium complexes are small enough to fit between the fibers and residues of the collagen. Once the desired level of penetration of chrome into the substance is achieved, the pH of the material is raised again to facilitate the process. This step is known as basification. In the raw state, chrome-tanned skins are greyish-blue, so are referred to as wet blue. Chrome tanning is faster than vegetable tanning (taking less than a day for this part of the process) and produces a stretchable leather which is excellent for use in handbags and garments. After application of the chromium agent, the bath is treated with sodium bicarbonate in the basification process to increase the pH to 3.8–4.0, inducing cross-linking between the chromium and the collagen. The pH increase is normally accompanied by a gradual temperature increase up to 40 °C. Chromium's ability to form such stable bridged bonds explains why it is considered one of the most effective tanning compounds. Chromium-tanned leather can contain between 4 and 5% of chromium. This efficiency is characterized by its increased hydrothermal stability of the skin, and its resistance to shrinkage in heated water.
Sources: en.wikipedia.org
=== Chalcogenides and pnictides === Sulfides, selenides and tellurides of curium have been obtained by treating curium with gaseous sulfur, selenium or tellurium in vacuum at elevated temperature. Curium pnictides of the type CmX are known for nitrogen, phosphorus, arsenic and antimony. They can be prepared by reacting either curium(III) hydride (CmH3) or metallic curium with these elements at elevated temperature.
==== Indigenous Americans ==== Aztec paintings, Central American temples, and the great burial mounds in the Southern United States are frequently adorned with depictions of rattlesnakes, often within the symbols and emblems of the most powerful deities. The Feathered Serpent of Mesoamerican religion was depicted as having the combined features of the quetzal and rattlesnake. The Ancient Maya considered the rattlesnake to be a "vision serpent" that acted as a conduit to the "otherworld". Rattlesnakes are a key element in Aztec mythology and were widely represented in Aztec art, including sculptures, jewelry, and architectural elements.
==== Campaign on the Min River and final retreat to Xikang (July–October 1933) ==== Liu's defensive line on the west bank of the Min River did not last long, and Liu Xiang's forces crossed it at several points. Morale within the 24th Army collapsed, and desertion was rampant. Liu finally decided to retreat to Mingshan, which guarded the entrance to Ya'an. It was in Ya'an that Liu hoped to reorganize his forces, but he was pursued even here, narrowly escaping with his life after artillery shelled his headquarters. Liu retreated even further into Xikang proper, entering the Ningyuan region. Because Xikang was a desolate country, with few hopes of earning provisions or pay, he voluntarily let many of his officers and soldiers leave the army. Liu later said the loss of most of his army was the "greatest grievance" of his life. It was at this point where Liu Wenhui telegraphed an apology to his nephew and declared his support for Sichuanese unification. He had also gotten his eldest brother to appeal on his behalf. Liu Xiang also relented, recognizing that fully eliminating Liu Wenhui's forces could leave an opening for Deng Xihou and others in Sichuan to gain power. Judging that his uncle was no longer a threat, Liu Xiang ordered his commander Li Hongkun to retreat from Ya'an on 8 October, clearing the way for Liu Wenhui to return to the town on 24 October and ending the Two-Liu War. In the aftermath of the war, Liu Wenhui was left with his remaining possessions in Xikang, having lost the entire Sichuan basin to Liu Xiang.
The ethical principle of primum non-nocere ("first, do no harm") guides the trial, and if an investigator believes the study treatment may be harming subjects in the study, the investigator can stop participating at any time. On the other hand, investigators often have a financial interest in recruiting subjects, and could act unethically to obtain and maintain their participation. The local investigators are responsible for conducting the study according to the study protocol, and supervising the study staff throughout the duration of the study. The local investigator or his/her study staff are also responsible for ensuring the potential subjects in the study understand the risks and potential benefits of participating in the study. In other words, they (or their legally authorized representatives) must give truly informed consent. Local investigators are responsible for reviewing all adverse event reports sent by the sponsor. These adverse event reports contain the opinions of both the investigator (at the site where the adverse event occurred) and the sponsor, regarding the relationship of the adverse event to the study treatments. Local investigators also are responsible for making an independent judgment of these reports, and promptly informing the local IRB of all serious and study treatment-related adverse events. When a local investigator is the sponsor, there may not be formal adverse event reports, but study staff at all locations are responsible for informing the coordinating investigator of anything unexpected.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.