Intranasal route raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Veterinary pharmacies, sometimes called animal pharmacies, may fall in the category of hospital pharmacy, retail pharmacy or mail-order pharmacy. Veterinary pharmacies stock different varieties and different strengths of medications to fulfill the pharmaceutical needs of animals. Because the needs of animals, as well as the regulations on veterinary medicine, are often very different from those related to people, in some jurisdictions veterinary pharmacy may be kept separate from regular pharmacies.
=== Institutional review boards (IRBs) === Approval by an Institutional Review Board (IRB), or Independent Ethics Committee (IEC), is necessary before all but the most informal research can begin. In commercial clinical trials, the study protocol is not approved by an IRB before the sponsor recruits sites to conduct the trial. However, the study protocol and procedures have been tailored to fit generic IRB submission requirements. In this case, and where there is no independent sponsor, each local site investigator submits the study protocol, the consent(s), the data collection forms, and supporting documentation to the local IRB. Universities and most hospitals have in-house IRBs. Other researchers (such as in walk-in clinics) use independent IRBs. The IRB scrutinizes the study both for medical safety and for protection of the patients involved in the study, before it allows the researcher to begin the study. It may require changes in study procedures or in the explanations given to the patient. A required yearly "continuing review" report from the investigator updates the IRB on the progress of the study and any new safety information related to the study.
=== Sequence similarity === EC categories do not reflect sequence similarity. For instance, two ligases of the same EC number that catalyze exactly the same reaction can have completely different sequences. Independent of their function, enzymes, like any other proteins, have been classified by their sequence similarity into numerous families. These families have been documented in dozens of different protein and protein family databases such as Pfam.
Peyronie's disease (PD) is a benign, acquired penile connective tissue disease characterized by the occurrence of fibrotic plaques within the tunica albuginea—the dense elastic covering of the corpora cavernosa. The plaques cause abnormal curvature, pain, penile deformities (e.g., narrowing or indentation), and usually erectile dysfunction, particularly during erection. The condition typically leads to significant sexual and psychological effects, including difficulty with penetration and lowered self-esteem or evasiveness. Peyronie's disease is most often seen in middle-aged and older men with a median age of onset between 55 and 60 years, however, it has also been reported in adolescents. While the etiology of Peyronie's disease is still uncertain, the leading hypothesis is that it arises from dysregulated wound healing in response to chronic microtrauma of the erect penis. This triggers a cascade of profibrotic molecular pathways—most notably overexpression of transforming growth factor-beta 1 (TGF-β1)—that end in fibroblast proliferation, myofibroblast differentiation, and overproduction of type I collagen. Genetic predisposition is supported by family clustering and linkage with systemic fibrosing disorders such as Dupuytren's contracture. Risk factors include age, penile injury, diabetes mellitus, and cigarette smoking. The prevalence of Peyronie's disease has been projected at 1% to 20% among the general population of men increasing with age and comorbidities such as erectile dysfunction (ED) or connective tissue disease.
Peter S. Tippett (born 1953) is an American physician, researcher, and inventor known for contributions to information security, clinical medicine, and technology. These contributions include the development of the anti-virus program "Corporate Vaccine." Tippett was Vice President of Verizon's Innovations Incubator and Chief Medical Officer for Verizon Enterprise Services from 2009 to 2015. He is currently the Founder and CEO of careMESH Inc.
Sources: en.wikipedia.org
Having returned to the throne and consolidated his power, the Bourbon king unified the two kingdoms he ruled. With the law of 16 December 1816, the Kingdom of the Two Sicilies was born, with Ferdinand as its first monarch, dubbedFerdinand I of the Two Sicilies.
A diplomatic crisis began in 2025 when the Donald Trump's second presidency of the United States administration sought to annex Greenland, an autonomous territory of the Danish Realm—a treaty ally of the United States and co-member of NATO, and a member of the European Union (EU). The crisis intensified in early 2026 when Trump refused to rule out the use of military force for this annexation and threatened a 25% import tax on goods from several European nations unless Denmark ceded the territory to the United States. Denmark's refusal was supported by the EU and several other NATO members, reigniting earlier concerns of a US–EU trade war. Within weeks, Trump backed down, pledging not to use force or tariffs to annex Greenland. Trump had tried to purchase Greenland during his first presidency. After his 2024 re-election, in January 2026, he said "it may be a choice" whether to preserve NATO or seize Greenland, and in Dear Jonas, a letter leaked by Norwegian Prime Minister Jonas Gahr Støre, Trump had said that he "no longer [felt] an obligation to think purely of Peace" after not receiving the Nobel Peace Prize. A report by the Danish Defence Intelligence Service mentioned the United States as a potential threat to national security for the first time in its history, and Danish officials raised concerns about reports that Director of National Intelligence Tulsi Gabbard had assigned agents to spy on Greenland. The Greenlandic and Danish prime ministers rejected any American takeover, saying they would defend Greenland in the event of an attack.
== Literature == Emanuel Gil-Av, Present status of enantiomeric analysis by gas chromatography, J. Mol. Evol. 6 (1975) 131–144. Nelu Grinberg: Emanuel Gil-Av (1916–1996): A man with a legacy, In: Chirality, 1998;10(5):372. Volker Schurig: In Memoriam – Emanuel Gil-Av. In: Journal of High Resolution Chromatography 19 (1996) 462. Volker Schurig: On the Centenary of Emanuel Gil-Av, Former Professor of the Weizmann Institute of Science and Pioneer of Enantioselective Chromatography, Isr. J. Chem. 56 (2016) 890–906.
== External links == Human CSNK1D genome location and CSNK1D gene details page in the UCSC Genome Browser. Overview of all the structural information available in the PDB for UniProt: P48730 (Human Casein kinase I isoform delta) at the PDBe-KB. Overview of all the structural information available in the PDB for UniProt: Q9DC28 (Mouse Casein kinase I isoform delta) at the PDBe-KB.
Sources: en.wikipedia.org
The men had been captured in 2022 during fighting in the Donbas and were released in a series of prisoner exchanges. Latvia pledged 2 million euros ($2.15 million) to support the reconstruction of Chernihiv, according to its City Council. The funds were to be used in projects such as buying school equipment and restoring water and sewage systems. The United States Defense Security Cooperation Agency has authorised the sale of a NASAMS system to Ukraine valued at $285 million.
=== Overdose issues === In 2007, a nurse at Cedars-Sinai Medical Center mistakenly gave the 12-day-old twins of actor Dennis Quaid a dose of heparin that was 1,000 times the recommended dose for infants. The overdose allegedly arose because the labeling and design of the adult and infant versions of the product were similar. The Quaid family subsequently sued the manufacturer, Baxter Healthcare Corp., and settled with the hospital for $750,000. Prior to the Quaid accident, six newborn babies at Methodist Hospital in Indianapolis, Indiana, were given an overdose. Three of the babies died after the mistake. In July 2008, another set of twins born at Christus Spohn Hospital South, in Corpus Christi, Texas, died after an accidentally administered overdose of the drug. The overdose was due to a mixing error at the hospital pharmacy and was unrelated to the product's packaging or labeling. As of July 2008, the exact cause of the twins' death was under investigation. In March 2010, a two-year-old transplant patient from Texas was given a lethal dose of heparin at the University of Nebraska Medical Center. The exact circumstances surrounding her death are still under investigation.
Concerns expressed by some politicians on the subject of salvia reflect those of the media, with comparisons to LSD and particular focus on "protecting our children" being echoed; and with legislative proposals following soon after news stories breaking. Some arguments against salvia have been of a preventative nature, "We need to stop this before it gets to be a huge problem not after it gets to be a huge problem," or of an imitative nature, "The Australians have clearly found a problem with it. There's obviously a risk in people taking it." Concerns about driving while under the influence of salvia have also been expressed. Opponents of more prohibitive measures against salvia argue that such reactions are largely due to an inherent prejudice and a particular cultural bias rather than any actual balance of evidence, pointing out inconsistencies in attitudes toward other more toxic and addictive drugs such as alcohol and nicotine. While not objecting to some form of legal control, in particular with regard to the sale to minors or sale of enhanced high-strength extracts, most salvia proponents otherwise argue against stricter legislation. Those advocating consideration of Salvia divinorum's potential for beneficial use in a modern context argue that more could be learned from Mazatec culture, where salvia is not really associated with notions of drug taking at all and it is rather considered as a spiritual sacrament. In light of this it is argued that Salvia divinorum could be better understood more positively as an entheogen rather than pejoratively as a hallucinogen.
==== Antibody-dependent cell-mediated cytotoxicity (ADCC) ==== Antibody-dependent cell-mediated cytotoxicity (ADCC) requires antibodies to bind to target cell surfaces. Antibodies are formed of a binding region (Fab) and the Fc region that can be detected by immune system cells via their Fc surface receptors. Fc receptors are found on many immune system cells, including NK cells. When NK cells encounter antibody-coated cells, the latter's Fc regions interact with their Fc receptors, releasing perforin and granzyme B to kill the tumor cell. Examples include rituximab, ofatumumab, elotuzumab, and alemtuzumab. Antibodies under development have altered Fc regions that have higher affinity for a specific type of Fc receptor, FcγRIIIA, which can dramatically increase effectiveness.
== Pathway systems == The vast size of the Inca empire made it essential that efficient and effective transportation systems were created and built to assist in the exchanging of goods, services, people, etc. At one point, "their (the Inca) empire eventually extended across western South America from Quito in the north to Santiago in the south, making it the largest empire ever seen in the Americas and the largest in the world at that time (between c. 1400 and 1533 CE)." It is known to have "extended some 3500-4000 km along the mountainous backbone of South America." The trails, roads, and bridges were designed not only to link the empire physically, but these structures also helped the empire to maintain communication.
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.