The short version of Intranasal route fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-11-14. Anything still debated is marked as such rather than presented as settled.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Bisulfite sequencing (also known as bisulphite sequencing) is the use of bisulfite treatment of DNA before routine sequencing to determine the pattern of methylation. DNA methylation was the first discovered epigenetic mark, and remains the most studied. In animals it predominantly involves the addition of a methyl group to the carbon-5 position of cytosine residues of the dinucleotide CpG, and is implicated in repression of transcriptional activity. Treatment of DNA with bisulfite converts cytosine residues to uracil, but leaves 5-methylcytosine residues unaffected. Therefore, DNA that has been treated with bisulfite retains only methylated cytosines. Thus, bisulfite treatment introduces specific changes in the DNA sequence that depend on the methylation status of individual cytosine residues, yielding single-nucleotide resolution information about the methylation status of a segment of DNA. Various analyses can be performed on the altered sequence to retrieve this information. The objective of this analysis is therefore reduced to differentiating between single nucleotide polymorphisms (cytosines and thymidine) resulting from bisulfite conversion (Figure 1).
It was around the same time, with the work of Jean-Baptiste Bécœur in particular, that taxidermy became a more serious practice. Louis Dufresne, a taxidermist at the Muséum National d'Histoire Naturelle in France, rediscovered Bécœur's taxidermy process using arsenical soap and made it known through an article in the Nouveau dictionnaire d'histoire naturelle (1803–1804). This technique enabled the museum to build an immense collection of taxidermy birds. In the 19th century, some hunters took their trophies to upholstery shops, where the upholsterers would sew up the animal skins and stuff them with rags and cotton. The term "stuffing" or a "stuffed animal" evolved from this crude form of taxidermy. Professional taxidermists prefer the term "mounting" to "stuffing". More sophisticated cotton-wrapped wire bodies supporting sewn-on cured skins soon followed. Dufresne's methods spread to England in the early 19th century, where updated and non-toxic methods of preservation were developed by some of the leading naturalists of the day, including Rowland Ward and Montague Brown. Ward established one of the earliest taxidermy firms, Rowland Ward Ltd. of Piccadilly. However, the art of taxidermy remained relatively undeveloped, and the specimens remained stiff and unconvincing. Between 1887 and 1894, many naturalist scientists from all over the world went to Costa Rica to research its bird wildlife. At that time, Costa Rica had unique bird species not found in other parts of the world.
Founded in 1945, Wellcome is Hong Kong's longest-established supermarket chain. Since 1964, the company has been wholly owned by Dairy Farm International Holdings following the merger with rival supermarket Dairy Lane. Wellcome has an overall staff of 5,000 in more than 240 stores and serves more than 14 million customers every month. Wellcome was established in 1945 by Mr. Wu Chung-Wai, Mr. Lau Lim and Mr. Ko Yin-Yu. Wellcome established its first store on Ice House Street in Central. The shop specialised in imported products including wines, biscuits, canned food and beverages. Wellcome was the first supermarket to establish a Home Delivery Service division, and an average of 600 customers enjoyed this one-of-a-kind service through orders in person daily. Wellcome was acquired by Dairy Farm(Now DFI Retail Group) in 1964. The company was the first to introduce a "self-service" retailing concept. Customers no longer require the assistance of service staff to get products; they have to select products from the shelf. Wellcome was the first to offer pre-packaged rice products in 1973. In the 1980s, Wellcome launched its first corporate brand "No Frills", offering customers over 300 products at the lowest prices as compared to other products in the same category. Later, Wellcome became the first supermarket to employ Electronic data interchange (EDI) technology to improve the efficiency of operation. Wellcome expanded to Taiwan and acquired Ding Hao supermarket. Wellcome opened its first 24-hour store in Great George Street, Causeway Bay on 23 October 1998.
==== Inflammation ==== When particular GPCRs are activated by their specific chemokines Gβγ directly activates PI3Kγ which is involved in the recruitment of neutrophils that contribute to inflammation. It has been discovered that the inhibition of PI3Kγ significantly reduces inflammation. PI3Kγ is the intended target molecule in the prevention of inflammation as it is the common signalling effector of many different chemokine and receptor types involved in promoting inflammation. Although PI3Kγ is the intended target there are other isoforms of PI3 which perform different functions from PI3Kγ. Since PI3Kγ is specifically regulated by Gβγ, while other isoforms of PI3 are largely regulated by other molecules, inhibiting Gβγ signalling would provide the desired specificity of a therapeutic agent designed to treat inflammation.
electron capture A type of nuclear transformation by which the proton-rich nucleus of an electrically neutral atom absorbs or 'captures' an electron from one of its own inner shells, often those closest to the nucleus, which provokes a reaction that results in a nuclear proton changing into a neutron accompanied by the simultaneous emission of an electron neutrino.
Sources: en.wikipedia.org
Northern Ireland Samuel Paul Henderson, lately Detective Constable, Police Service of Northern Ireland. Nicola Marie Marshall, Detective Superintendent, Police Service of Northern Ireland. Kieran Quinn, Inspector, Police Service of Northern Ireland.
Labcorp Holdings Inc., operating under the brand name Labcorp, headquartered in Burlington, North Carolina, provides laboratory services used for diagnosis and healthcare decisions. It operates one of the largest clinical laboratory networks in the world and has operations in over 100 countries; although its operations are primarily in the U.S. Its Diagnostics Laboratories segment operates 2,000 patient service centers with more than 6,000 in-office phlebotomists in the United States. In addition to healthcare testing such as oncology testing, human immunodeficiency virus (HIV) genotyping and phenotyping, it provides testing for: employment, DNA testing to determine parentage and to determine immigration eligibility, environmental issues, wellness, toxicology, pain management, and medical drug monitoring. It also provides 50 tests that patients can complete at home. It processes over 160 million tests per year. Approximately 10% of this segment’s revenue are from the U.S. Medicare health insurance program. Its Biopharma Laboratory Services segment provides drug development, medical device and diagnostic development services to pharmaceutical, biotechnology, medical device, and diagnostic companies. In 2023, this division provided support to 84% of the new drugs and therapeutic products approved by the Food and Drug Administration. Labcorp performs its largest volume of specialty testing at its Center for Esoteric Testing in Burlington, North Carolina.
== History == The physical principles of ion traps were first explored by F. M. Penning, who observed that electrons released by the cathode of an ionization vacuum gauge follow a long cycloidal path to the anode in the presence of a sufficiently strong magnetic field. Later Wolfgang Paul developed a method to trap ions without magnetic fields that was based on his work with quadrupole mass spectrometers. Ion traps were used in television receivers prior to the introduction of aluminized CRT faces around 1958, to protect the phosphor screen from ions. The ion trap must be delicately adjusted for maximum brightness.
=== More examples === acetaldehyde dehydrogenase alcohol dehydrogenase Delta12-fatty acid dehydrogenase glutamate dehydrogenase (an enzyme that can convert glutamate to α-Ketoglutarate and vice versa). lactate dehydrogenase (used to convert NADH back to NAD+ in anaerobic glycolysis, and in the back reaction to produce NADH) pyruvate dehydrogenase (A common enzyme that feeds the TCA Cycle by converting pyruvate to acetyl CoA, using NAD+. In this reaction, the substrate not only is oxidized but also loses a carbon dioxide molecule, and is attached to the CoA coenzyme.) glucose-6-phosphate dehydrogenase (involved in the pentose phosphate pathway, producing NADPH) glyceraldehyde-3-phosphate dehydrogenase (involved in glycolysis, uses NAD+) sorbitol dehydrogenase TCA cycle examples:
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
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.