This is a working overview of Heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-12-29 and is reviewed periodically as new material appears.
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.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
=== Other === A relationship between intra-operative blood transfusion and cancer recurrence has been observed in colorectal cancer. In lung cancer intra-operative blood transfusion has been associated with earlier recurrence of cancer, worse survival rates and poorer outcomes after lung resection. Suppression of the immune system by blood transfusion has been implicated as playing a role in more than 10 different cancer types, through mechanisms involving the innate and adaptive immune system. Five major mechanisms for this include the lymphocyte-T set, myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), natural killer cells (NKCs), and dendritic cells (DCs). Blood transfusion may modulate the activity of antitumor CD8+ cytotoxic T lymphocytes (CD8+/CTL), temporal response of Tregs, and the STAT3 signaling pathway. The role of the antitumor immune response in cancer therapeutics was explored historically through the use of bacteria to enhance the antitumor immune response and more recently in cellular Immunotherapy. However, the impact of transfusion-related immunomodulation (TRIM) on cancer progression has not been definitively established and requires further study. In retrospective studies, blood transfusion has been associated with worse outcomes after cytoreductive surgery and HIPEC. However, correlation does not prove causation, and transfused patients often have more complicated surgeries and more underlying cardiopulmonary disease compared to untransfused patients; conclusions should be based on prospective randomized controlled trials.
=== Exon-skipping === Antisense oligonucleotides (oligos), structural analogs of DNA, are the basis of a potential treatment for 10% of people with Duchenne muscular dystrophy. The compounds allow faulty parts of the dystrophin gene to be skipped when it is transcribed to RNA for protein production, permitting a still-truncated but more functional version of the protein to be produced. It is also known as nonsense suppression therapy. Two kinds of antisense oligos, 2'-O-methyl phosphorothioate oligos (such as drisapersen) and morpholino oligos (such as eteplirsen), have tentative evidence of benefit and are being studied. Eteplirsen is targeted to skip exon 51. "As an example, skipping exon 51 restores the reading frame of ~ 15% of all the boys with deletions. It has been suggested that by having 10 AONs to skip 10 different exons it would be possible to deal with more than 70% of all DMD boys with deletions." This represents about 1.5% of cases.
1993/584) National Blood Authority (Establishment and Constitution) Order 1993 (S.I. 1993/585) National Blood Authority Regulations 1993 (S.I. 1993/586) Central Blood Laboratories Authority (Revocation) Order 1993 (S.I. 1993/587) Nurses, Midwives and Health Visitors Act 1992 (Commencement No. 1) Order 1993 (S.I. 1993/588) Registration of Births, Deaths and Marriages (Fees) (Amendment) (No. 2) Order 1993 (S.I. 1993/589) United Kingdom Central Council for Nursing, Midwifery and Health Visiting (Term of Office of Members) Order 1993 (S.I. 1993/590) Recovery of Maintenance (United States of America) Order 1993 (S.I. 1993/591) Social Security (Northern Ireland) Order 1993 (S.I. 1993/592) Reciprocal Enforcement of Maintenance Orders (Hague Convention Countries) Order 1993 (S.I. 1993/593) Reciprocal Enforcement of Maintenance Orders (Republic of Ireland) Order 1993 (S.I. 1993/594) European Communities (Designation) Order 1993 (S.I. 1993/595) Veterinary Surgeons Qualifications (EEC Recognition) (Amendment) Order 1993 (S.I. 1993/596) Home Guard (Amendment) Order 1993 (S.I. 1993/597) Naval, Military and Air Forces etc. (Disablement and Death) Service Pensions Amendment Order 1993 (S.I. 1993/598) Continental Shelf (Designation of Areas) Order 1993 (S.I. 1993/599)
Carbapenem-resistant Enterobacteriaceae (CRE) or carbapenemase-producing Enterobacteriaceae (CPE) are gram-negative bacteria that are resistant to the carbapenem class of antibiotics, considered the drugs of last resort for such infections. They are resistant because they produce an enzyme called a carbapenemase that disables the drug molecule. The resistance can vary from moderate to severe. Enterobacteriaceae are common gastrointestinal commensals and infectious agents. Experts fear CRE as the new "superbug". The bacteria can kill up to half of patients who get bloodstream infections. Tom Frieden, former head of the Centers for Disease Control and Prevention has referred to CRE as "Nightmare bacteria". Examples of enzymes found in certain types of CRE are KPC (Klebsiella pneumoniae carbapenemase) and NDM (New Delhi Metallo-beta-lactamase). KPC and NDM are enzymes that break down carbapenems and make them ineffective. Both of these enzymes, as well as the enzyme VIM (Verona Integron-Mediated Metallo-β-lactamase) have also been reported in Pseudomonas.
There were proposals to extend this corridor 7 miles to Chapel Hill with light rail technology. However, in 2006 Triangle Transit deferred implementation indefinitely when the Federal Transit Administration declined to fund the program due to low ridership projections. The region's two metropolitan planning organizations appointed a group of local citizens in 2007 to reexamine options for future transit development in light of Triangle Transit's problems. The Special Transit Advisory Commission (STAC) retained many of the provisions of Triangle Transit's original plan but recommended adding new bus services and raising additional revenues by adding a new local half-cent sales tax to fund the project. Greyhound Lines provides an inter-city bus service to Durham, Charlotte, Richmond, Washington, D.C., Atlanta, and other cities.
Sources: en.wikipedia.org
==== English-language ==== A 2013 systematic review of the English-language case reports found that serious adverse events associated with acupuncture are rare, but that acupuncture is not without risk. Between 2000 and 2011 the English-language literature from 25 countries and regions reported 294 adverse events. The majority of the reported adverse events were relatively minor, and the incidences were low. For example, a prospective survey of 34,000 acupuncture treatments found no serious adverse events and 43 minor ones, a rate of 1.3 per 1000 interventions. Another survey found there were 7.1% minor adverse events, of which 5 were serious, amid 97,733 acupuncture patients. The most common adverse effect observed was infection (e.g. mycobacterium), and the majority of infections were bacterial in nature, caused by skin contact at the needling site. Infection has also resulted from skin contact with unsterilized equipment or with dirty towels in an unhygienic clinical setting. Other adverse complications included five reported cases of spinal cord injuries (e.g. migrating broken needles or needling too deeply), four brain injuries, four peripheral nerve injuries, five heart injuries, seven other organ and tissue injuries, bilateral hand edema, epithelioid granuloma, pseudolymphoma, argyria, pustules, pancytopenia, and scarring due to hot-needle technique.
=== Enzyme substitutes === In 2018, the FDA approved an enzyme substitute called pegvaliase which metabolizes phenylalanine. It is for adults who are poorly managed on other treatments. Tetrahydrobiopterin (BH4) (a cofactor for the oxidation of phenylalanine) when taken by mouth can reduce blood levels of this amino acid in some people.
Yeast is used in winemaking, where it converts the sugars present (glucose and fructose) in grape juice (must) into ethanol. Yeast is normally already present on grape skins. Fermentation can be done with this endogenous "wild yeast", but this procedure gives unpredictable results, which depend upon the exact types of yeast species present. For this reason, a pure yeast culture is usually added to the must; this yeast quickly dominates the fermentation. The wild yeasts are repressed, which ensures a reliable and predictable fermentation. Most added wine yeasts are strains of S. cerevisiae, though not all strains of the species are suitable. Different S. cerevisiae yeast strains have differing physiological and fermentative properties, therefore the actual strain of yeast selected can have a direct impact on the finished wine. Significant research has been undertaken into the development of novel wine yeast strains that produce atypical flavour profiles or increased complexity in wines. The growth of some yeasts, such as Zygosaccharomyces and Brettanomyces, in wine can result in wine faults and subsequent spoilage. Brettanomyces produces an array of metabolites when growing in wine, some of which are volatile phenolic compounds. Together, these compounds are often referred to as "Brettanomyces character", and are often described as "antiseptic" or "barnyard" type aromas. Brettanomyces is a significant contributor to wine faults within the wine industry. Researchers from the University of British Columbia, Canada, have found a new strain of yeast that has reduced amines.
== Health risks == Acrolein is toxic and is a strong irritant for the skin, eyes, and nasal passages. The main metabolic pathway for acrolein is the alkylation of glutathione. The WHO suggests a "tolerable oral acrolein intake" of 7.5 μg per day per kg of body weight. Although acrolein occurs in French fries (and other fried foods), the levels are only a few μg per kg, meaning that one would have to consume more than their body weight in fries every day to surpass the limit set by the WHO. In response to occupational exposures to acrolein, the US Occupational Safety and Health Administration has set a permissible exposure limit at 0.1 ppm (0.25 mg/m3) at an eight-hour time-weighted average. Acrolein acts in an immunosuppressive manner and may promote regulatory cells, thereby preventing the generation of allergies on the one hand, but also increasing the risk of cancer. Acrolein was identified as one of the chemicals involved in the 2019 Kim Kim River toxic pollution incident.
Sources: en.wikipedia.org
1993/3140) New Possibilities National Health Service Trust Dissolution Order 1993 (S.I. 1993/3141) Combined Probation Areas (Kent) Order 1993 (S.I. 1993/3142) Cayman Islands (Constitution) (Amendment) Order 1993 (S.I. 1993/3143) Child Abduction and Custody (Parties to Conventions) Order 1993 (S.I. 1993/3144) Hong Kong (Legislative Powers) (Amendment) Order 1993 (S.I. 1993/3145) Criminal Justice (Confiscation) (Northern Ireland) Order 1993 (S.I. 1993/3146) Criminal Justice Act 1988 (Designated Countries and Territories) (Amendment) (No. 2) Order 1993 (S.I. 1993/3147) Criminal Justice (International Co–operation) Act 1990 (Enforcement of Overseas Forfeiture Orders) (Amendment) (No. 2) Order 1993 (S.I. 1993/3148) Environmentally Sensitive Areas (Machair of the Uists and Benbecula, Barra and Vatersay) Designation Order 1993 (S.I. 1993/3149) Environmentally Sensitive Areas (Shetland Islands) Designation Order 1993 (S.I. 1993/3150) Registration of Births, Deaths and Marriages (Fees) (Scotland) Order 1993 (S.I. 1993/3151) Marriage Fees (Scotland) Regulations 1993 (S.I. 1993/3152) Registration of Births, Deaths, Marriages and Divorces (Fees) (Scotland) Regulations 1993 (S.I. 1993/3153) Maximum Number of Judges (Scotland) Order 1993 (S.I. 1993/3154) Criminal Justice (International Co-operation) Act 1990 (Enforcement of Overseas Forfeiture Orders) (Scotland) Amendment (No.2) Order 1993 (S.I. 1993/3155) Confiscation of the Proceeds of Drug Trafficking (Designated Countries and Territories) (Scotland) Amendment (No.2) Order 1993 (S.I.
The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the United States. For women and men of ages 15 and older, the PRIs are set respectively at 650 and 750 μg RE/day. PRI for pregnancy is 700 μg RE/day, for lactation 1300/day. For children of ages 1–14 years, the PRIs increase with age from 250 to 600 μg RE/day. These PRIs are similar to the US RDAs. The EFSA reviewed the same safety question as the United States, and set ULs at 800 for ages 1–3, 1100 for ages 4–6, 1500 for ages 7–10, 2000 for ages 11–14, 2600 for ages 15–17 and 3000 μg/day for ages 18 and older for preformed vitamin A, i.e., not including dietary contributions from carotenoids.
== Soluble TCR == A soluble TCR is a TCR that has been made water-soluble using protein engineering. Such a protein is based on changing an existing TCR's chains to remove the transmembrane portions, leaving only the extracellular part. A number of techniques from protein engineering are then used to stabilize the complex and improve its binding characteristics. A soluble TCR can be used as an antigen-binding module, much like how monoclonal antibodies are used in medicine. Their advantage over antibodies is that they make use of the MHC/HLA display mechanism, allowing them to detect not only extracellular antigens, but also fragments of intracellular ones. On the other hand, they also face some restrictions in terms of applicable HLA genotypes due to them being made to target the complex of a MHC protein with the antigen fragment. One idea for overcoming this restriction is to instead target monomorphic HLA-like molecules such as HLA-E, MHC-related protein 1 (MR1) and cluster of differentiation 1 a, b, c and d (CD1a, CD1b, CD1c or CD1d). An example of a protein derived from soluble TCR is tebentafusp, approved by the US FDA in 2022. This designed protein contains a soluble TCR (αβ) targeting a fragment of gp100 presented by HLA-A*02:01 connected to a ScFv that binds CD3. As a result it causes T cells to activate in the vicinity of cells that present gp100, acting as a molecular glue (a bi-specific T-cell engager in the broad sense). It is only applicable to people with the HLA-A*02:01 genotype.
== Modern experimental pathology == As new research techniques, such as electron microscopy, immunohistochemistry, and molecular biology have expanded the means by which biomedical scientists can study disease, the definition and boundaries of investigative pathology have become less distinct. In the broadest sense, nearly all research which links manifestations of disease to identifiable processes in cells, tissues, or organs can be considered experimental pathology.
=== Blue Men of Lurgan === The "blue men of Lurgan" were a pair of Lurgan men suffering from what was described as "familial idiopathic methemoglobinemia" who were treated by James Deeny in 1942. Deeny, who would later become the Chief Medical Officer of the Republic of Ireland, prescribed a course of ascorbic acid and sodium bicarbonate. In case one, by the eighth day of treatments, there was a marked change in appearance, and by the twelfth day of treatment, the patient's complexion was normal. In case two, the patient's complexion reached normality over a month-long duration of treatment.
Sources: en.wikipedia.org
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.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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.