Intranasal delivery raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-10-13 and is reviewed periodically as new material appears.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or below | For lyophilized powder, long term |
| Common analytical method | Reverse-phase HPLC | Usually paired with mass spectrometry |
| Typical reported purity | At or above 95 percent by area | Research-grade material |
| Aqueous solubility | High | Solutions used in laboratory assays |
| Moisture sensitivity | Hydrolyzes in solution | Aseptic handling reduces degradation |
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.
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.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
== Medical uses == Lebrikizumab is indicated for the treatment of moderate-to-severe atopic dermatitis in adults and adolescents aged twelve years of age and older with a body weight of at least 40 kilograms (88 lb) who are candidates for systemic therapy.
=== Changes that occur during the onset of gingivitis and periodontitis and its role in bleeding on probing === Following the infiltration of bacteria and its products within the sulcular epithelium, the inflammatory response triggers the release of matrix metalloproteinases which cause collagen destruction. Studies suggest that this mechanism is through the activation of Toll-Like Receptors (TLRs, such as TLR-9) which are present on epithelial cells upon binding with bacterial products (such as lipopolysaccharides, unmyelinated CpG motifs). The expression of these collagenolytic matrix metalloproteinases like MMP-13 and activated NF-κB subunit p65 (a type of transcription factor) was more commonly present in periodontitis tissue compared to gingivitis tissue, indicating that the extent of connective tissue destruction accelerates with the progression of the disease. As an effort to curb the incoming bacterial invasion, the basal cells of the sulcular epithelium, being triggered by the ongoing inflammation, proliferate in hopes to maintain an intact barrier against the bacteria and their products. Due to the ongoing inflammation, engorgement of vessels and vasodilation occurs at the underlying connective tissue of the sulcular epithelium. The concurrent destruction of the collagen will then result in the thinning or ulceration of the sulcular epithelium, making the engorged and more abundant blood capillaries more susceptible to rupture upon innocuous mechanical stimuli (such as those during toothbrushing, probing, flossing, eating).
Enzyme-catalyzed proximity labeling (PL), also known as proximity-based labeling, is a laboratory technique that labels biomolecules, usually proteins or RNA, proximal to a protein of interest. By creating a gene fusion in a living cell between the protein of interest and an engineered labeling enzyme, biomolecules spatially proximal to the protein of interest can then be selectively marked with biotin for pulldown and analysis. Proximity labeling has been used for identifying the components of novel cellular structures and for determining protein-protein interaction partners, among other applications.
== Personal life == Since his playing career ended, Bagwell has spent much of his time with his family while sporadically taking coaching and special assignment positions for the Astros. He is married to Rachel Bagwell, his third wife, with whom he has five children in a blended family. Rachel had three children prior to meeting Jeff. Before his marriage to Rachel, Jeff had two daughters, Blake and Bryce. Bagwell married his first wife, model Shaune Bagwell (née Stauffer), in 1992. He later married Ericka Bagwell, with whom he had his two daughters. Rachel Bagwell was the widow of Greater Houston-area hand surgeon Dr. Michael Brown, the owner and founder of Brown Hand Center. In spite of his professional success, Bagwell has stated that he "doesn't enjoy too much of the spotlight" that follows. While giving a tribute to him during the retirement ceremony of his uniform number, longtime friend and former teammate Brad Ausmus noted several little-known facts. "He liked soccer as much as ... baseball" while growing up in Connecticut. He hit three fewer home runs than his boyhood idol, Carl Yastrzemski, who hit 452. "His baseball card says he's six feet tall. He's closer to 5' 10"." Both Bagwell and Ausmus hit 32 triples in their careers. After his playing career, Bagwell was seen with significantly longer hair. Remarked Ausmus, "I want to confirm he does not have hair extensions." In January 2015, Bagwell reportedly sold his home in the Memorial neighborhood of Houston.
Sources: en.wikipedia.org
Alfred Ellis Wilhelmi (1910–1994) was an American endocrinologist recognized for contributing to the understanding of anterior pituitary hormones. Born in Lakewood, Ohio, Wilhelmi attended Cleveland public schools. Wilhelmi earned a B.S. degree in premedical sciences from Western Reserve University in 1933. He then attended Oxford University as a Rhodes Scholar, where he obtained a B.A. in 1933 and Ph.D. in animal physiology in 1937. He then joined Yale University's Biochemistry Department, rising to the position of Professor in 1950. Wilhelmi chaired the Department of Biochemistry at Emory University School of Medicine from 1950 to 1977. In 1960, he was named Charles Howard Candler Professor of Biochemistry. In 1979, he received Emory's Thomas Jefferson award for service to the university and community. Wilhelmi also was President of the Endocrine Society from 1968 to 1969. During his career, he published over 80 articles in scientific journals.
== Uranium-230 == Uranium-230 is an artificial isotope of uranium with a half-life of 20.8 days. It has potential to be used in targeted alpha therapy. It is prepared from decay of protactinium-230, which is produced from proton irradiation of thorium targets.
Lilly's biosynthetic recombinant insulin, branded as Humulin, was introduced in 1983. In 1985, Axel Ullrich sequenced the human insulin receptor, further enhancing the understanding of insulin's biological mechanisms. By 1988, Novo Nordisk produced synthetic recombinant human insulin, which further improved insulin availability and consistency.
Amino acids are a key nutrient in ecosystems. Some are essential to animals, meaning that these organisms cannot synthesize them de novo. Instead, animals rely on their diet to acquire these molecules, creating strong interdependencies between animals and organisms with complete amino acid synthesis capabilities. In a study of bacteria and archaea at Antarctica's McMurdo Dry Valleys, the distribution of 13C between their amino acids reflected the biosynthetic pathways employed by these organisms. Autotrophs and heterotrophs had distinct isotopic fingerprints, as did organisms that employed alternatives to the citric acid cycle to ferment or produce acetate. Plants, fungi, and bacteria are also distinguishable by their amino acid carbon isotopes. The compositions of the essential amino acids, which have more complex biosynthetic pathways, are particularly informative. Lysine, isoleucine, leucine, threonine, and valine all had significantly different δ13C values between at least two of these groups. The fungi and bacteria in this study were grown on amino acid-free media to ensure that all the amino acids were synthesized by the organisms of interest. Bacteria and fungi can also scavenge amino acids from the environment, complicating the interpretation of data from field samples. Nevertheless, researchers have successfully used these differences to identify the sources of amino acids in food webs. Terrestrial and marine producers in a mangrove forest had different patterns of 13C enrichment in their amino acids.
However, the results of the 2012 presidential elections gave the PS wins in both districts with a smaller margin in the 7th (Hollande: 51.71% / Sarkozy: 48.29%) than in the 8th (Hollande 64.21% / Sarkozy: 35.79%).
Sources: en.wikipedia.org
== Nomenclature == Various fairly standardized abbreviations for vaccine names have developed, although the standardization is by no means centralized or global. For example, the vaccine names used in the United States have well-established abbreviations that are also widely known and used elsewhere. An extensive list of them provided in a sortable table and freely accessible is available at a US Centers for Disease Control and Prevention web page. The page explains that "The abbreviations [in] this table (Column 3) were standardized jointly by staff of the Centers for Disease Control and Prevention, ACIP Work Groups, the editor of the Morbidity and Mortality Weekly Report (MMWR), the editor of Epidemiology and Prevention of Vaccine-Preventable Diseases (the Pink Book), ACIP members, and liaison organizations to the ACIP." Some examples are "DTaP" for diphtheria and tetanus toxoids and acellular pertussis vaccine, "DT" for diphtheria and tetanus toxoids, and "Td" for tetanus and diphtheria toxoids. At its page on tetanus vaccination, the CDC further explains that "Upper-case letters in these abbreviations denote full-strength doses of diphtheria (D) and tetanus (T) toxoids and pertussis (P) vaccine. Lower-case "d" and "p" denote reduced doses of diphtheria and pertussis used in the adolescent/adult-formulations.
=== Outside mainland China === PRC Customs said exports of dairy products and eggs in 2007 were valued at US$359 million, a year-on-year increase of 90 per cent. Since the news of the melamine contamination began to circulate, at least 25 countries stopped importing Chinese dairy products. A number of countries had imposed blanket bans on Chinese milk products or its derivatives—among which were Bangladesh, Bhutan, Brunei, Burundi, Cameroon, Chile, Colombia, Dominican Republic, Gabon, India, Côte d'Ivoire, Maldives, Mali, Mexico, Nepal, Papua New Guinea, Paraguay, South Korea, Suriname, Tanzania, Togo, and the United Arab Emirates —joining Indonesia, Taiwan, Japan, Singapore and Malaysia which had also imposed specific bans on Chinese dairy products which tested positive for melamine.
== Treatment == Treatment for LNS is symptomatic. Gout can be treated with allopurinol to control excessive amounts of uric acid. Kidney stones may be treated with lithotripsy, a technique for breaking up kidney stones using shock waves or laser beams. There is no standard treatment for the neurological symptoms of LNS. Some may be relieved with the drugs carbidopa/levodopa, diazepam, phenobarbital, or haloperidol. It is essential that the overproduction of uric acid be controlled in order to reduce the risk of nephropathy, nephrolithiasis, and gouty arthritis. The drug allopurinol is utilized to stop the conversion of oxypurines into uric acid, and prevent the development of subsequent arthritic tophi (produced after having chronic gout), kidney stones, and nephropathy, the resulting kidney disease. Allopurinol is taken orally, at a typical dose of 3–20 mg/kg per day. The dose is then adjusted to bring the uric acid level down into the normal range (<3 mg/dL). Most affected individuals can be treated with allopurinol all through life. No medication is effective in controlling the extrapyramidal motor features of the disease. Spasticity, however, can be reduced by the administration of baclofen or benzodiazepines. There has previously been no effective method of treatment for the neurobehavioral aspects of the disease. Even children treated from birth with allopurinol develop behavioral and neurologic problems, despite never having had high serum concentrations of uric acid.
In Urgenda v State of Netherlands the Dutch Supreme Court held the Dutch government must reduce greenhouse gas emissions by 25% before 2020, following the IPCC 2007 minimum recommendations, and that failure to do so would violate the right to life and home in ECHR articles 2 and 8. In the Klimaschutz case, the German Constitutional Court held that the German government must speed up its climate protection measures to protect the rights to life, and the environment under the Grundgesetz 1949, articles 2 and 20a. However the EU and member states have so far failed to codify liability to prevent pollution and climate damage by corporations that profit, and the EU Emissions Trading System has failed to adequately price carbon for the damage it causes (prices traded under €98 per metric ton until the end of 2022).
Sources: en.wikipedia.org
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.
Lyophilized powder is usually kept frozen and protected from moisture. Solutions are less stable and are often used promptly or divided into aliquots to avoid repeated freeze-thaw cycles. Exact shelf-life values depend on purity and handling.
No. A purity figure derived from chromatographic area does not prove the amino acid sequence. Identity requires an orthogonal method such as mass spectrometry or sequencing. Truncated or isomerized peptides can co-elute with the target compound.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.