Everything below concerns lyophilization. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
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.
== History == Mitomycin was discovered in 1955 by Japanese scientists in cultures of the microorganism Streptomyces caespitosus. Mitomycin C was isolated as purple crystals by Wakaki and his coworkers from Kyowa Hakko Kogyo in 1956. It was approved based on the results of the OLYMPUS (NCT02793128) multicenter trial involving 71 subjects with low-grade upper urinary tract urothelial cancer (UTUC). These subjects had never undergone treatment (treatment-naïve) or had recurrent low-grade non-invasive UTUC with at least one measurable papillary tumor (a tumor shaped like a small mushroom with its stem attached to the inner lining of an organ) located above the ureteropelvic junction. Subjects received mitomycin gel once a week (mitomycin gel 4 mg per mL instillations via ureteral catheter or nephrostomy tube) for six weeks and, if assessed as a complete response (complete disappearance of the papillary tumor), monthly for up to eleven additional months. Efficacy of mitomycin gel was evaluated using urine cytology (a test to look for abnormal cells in a subjects's urine), ureteroscopy (an examination of the upper urinary tract) and biopsy (if warranted) three months following the initiation of therapy. The primary endpoint was complete response at three months following initiation of therapy. A complete response was found in 41 of the 71 subjects (58%) following six treatments of mitomycin gel administered weekly.
=== Wild birds === Wildlife, including wild and migratory birds, serve as indicators of ecosystem health. They act as a reservoir for zoonotic diseases and antimicrobial-resistant organisms. Birds are a key link between the transmission of zoonotic diseases to human populations. By the same token, increased contact between wild birds and human populations (including domesticated animals), has increased the amount of anti-microbial resistance (AMR) to the bird population. The introduction of AMR to wild birds positively correlates with human pollution and increased human contact. Additionally, wild birds can participate in horizontal gene transfer with bacteria, leading to the transmission of antibiotic-resistant genes (ARG). For simplicity, wild bird populations can be divided into two major categories, wild sedentary birds and wild migrating birds. Wild sedentary bird exposure to AMR is through increased contact with densely populated areas, human waste, domestic animals, and domestic animal/livestock waste. Especially if they are predators, wild, sedentary birds can come into contact with prey that interact more closely with humans. Wild migrating birds interact with sedentary birds in different environments along their migration route. This increases the rate and diversity of AMR across varying ecosystems. Neglect of wildlife in the global discussions surrounding health security and AMR, creates large barriers to true AMR surveillance.
Biomedical sciences are a set of sciences applying portions of natural science or formal science, or both, to develop knowledge, interventions, or technology that are of use in healthcare or public health. Such disciplines as medical microbiology, clinical virology, clinical epidemiology, genetic epidemiology, and biomedical engineering are medical sciences. In explaining physiological mechanisms operating in pathological processes, however, pathophysiology can be regarded as basic science. Biomedical Sciences, as defined by the UK Quality Assurance Agency for Higher Education Benchmark Statement in 2015, includes those science disciplines whose primary focus is the biology of human health and disease and ranges from the generic study of biomedical sciences and human biology to more specialised subject areas such as pharmacology, human physiology and human nutrition. It is underpinned by relevant basic sciences including anatomy and physiology, cell biology, biochemistry, microbiology, genetics and molecular biology, pharmacology, immunology, mathematics and statistics, and bioinformatics. As such the biomedical sciences have a much wider range of academic and research activities and economic significance than that defined by hospital laboratory sciences. Biomedical Sciences are the major focus of bioscience research and funding in the 21st century.
Sources: en.wikipedia.org
=== May === 1 May – 2025 United Kingdom local elections 2 May – Reform UK wins 677 of around 1,600 seats contested in the English local elections, making gains mostly at the expense of the Conservatives. Reform also wins the Runcorn and Helsby by-election and the Lincolnshire mayoral election. The Liberal Democrats gain an extra 160 seats, and control of Oxfordshire County Council, Shropshire County Council and Cambridgeshire County Council. 4 May – Conservative Party leader Kemi Badenoch tells the BBC it would be wrong to think a change of leader would "fix everything" following the party's heavy local election losses, and that the Conservatives will "come out fighting". 5 May – Reform UK is forced to clarify that it will continue to fly county standards from council buildings in councils it controls following controversy after chairman Zia Yusuf said the only flags permitted to fly would be the Union Flag and St George's Flag. Donna Edmunds, elected for Reform UK in Shropshire on 1 May, resigns from the party after she was suspended for tweeting that she intended to defect to another party. 6 May – The UK government says it has no plans to reverse cuts to winter fuel payments despite growing calls from within the Labour Party for it to do so. 8 May – 42 Labour MPs sign a letter calling for changes to proposed cuts to disability benefits. John Swinney says he will not support assisted suicide in Scotland. Carla Denyer says she will not be a candidate in the 2025 Green Party of England and Wales leadership election.
The president is directly elected by popular vote for a renewable six-year term. Requirements for this position, which were enacted by the PAP government, are extremely stringent, such that only a handful of people qualify for the candidacy. These qualifications include that a candidate needs to be a person at least 45 years of age who is no longer a member of a political party, to either have held public office for at least 3 years in a number of specific public service leadership roles, or to have 3 years experience as chief executive of a fully profitable private sector company with at least S$500 million in shareholders' equity, be a resident in Singapore for at least 10 years, not have a criminal record, and more. Candidates must also "satisfy" the Presidential Elections Committee (PEC) that they are a person of integrity, good character and reputation. From 2017, the Constitution requires that presidential elections be "reserved" for a racial community if no one from that ethnic group has been elected to the presidency in the five most recent terms. Only members of that community may qualify as candidates in a reserved presidential election. In the 2017 presidential election, this combination of stringent requirements and a reserved election that required the candidate to be of the 13% Malay ethnic group led to the PEC approving a single candidate for the presidency; Halimah Yacob, considered part of the Malay community, won in an uncontested election. She also became Singapore's first female president.
== Treatment == Solar purpura does not require treatment and may resolve on its own within weeks or months. The lesions may also be permanent. Many people seek treatment for cosmetic purposes. There have been several studies on possible future treatments. A common treatment involves Retinoic acid and other vitamin A derivatives in an attempt to increase dermal thickness and prevent extravasation of red blood cells. The most common treatment is to avoid UV exposure, apply sunscreen, and wear long-sleeved clothing.
Sources: en.wikipedia.org
In the US, the additive is not for direct consumer sale. Lean finely textured beef can constitute up to 15% of ground beef without additional labeling, and it can be added to other meat products such as beef-based processed meats. USDA disallows the use of spinal cord, organ meat such as cow intestines, bones, and connective tissue such as tendons in LFTB. USDA requires the trimmings used to make LFTB to meet the same microbiological standards as other beef. Because of ammonium hydroxide use in its processing, the lean finely textured beef by BPI is not permitted in Canada. Health Canada stated that: "Ammonia is not permitted in Canada to be used in ground beef or meats during their production" and may not be imported, as the Canadian Food and Drugs Act requires that imported meat products meet the same standards and requirements as domestic meat. Canada does allow Cargill's citric acid-produced Finely Textured Meat (FTM) to be "used in the preparation of ground meat" and "identified as ground meat" under certain conditions. Production of mechanically separated meat via use of bones or bone-in cuts of bovine, ovine and caprine animals are prohibited in the European Union.
=== Gene === The human LECT2 gene, LECT2, is located on the long, i.e., "q", arm of chromosome 5 at position q31.1 (notated as 5q31.1). This location is close to several immune modulating genes including interleukins 3, 5, and 9 and granulocyte-macrophage colony stimulating factor. LECT2 is conserved in zebrafish, chicken, rat, mouse, cow. dog, Rhesus monkey, and chimpanzee. Human LECT2 is composed of 4 exons, 3 introns, and ~8,000 base pairs. The gene has numerous single nucleotide variants as well as other variations, two of which (see Pathophysiology section) have been associated with human disease. Human LECT2 has several different transcriptional initiation sights and codes for a mRNA composed of 1,000 to 1,300 ribonucleotides. mRNA for LECT2 is highly expressed in liver tissue and expressed at far lower levels in a wide range of other tssues.
The army was then given reinforcements including 160 new tanks. It then was able to halt the Soviet winter offensive in Southern Russia and then counterattacked in the Third Battle of Kharkov, retaking the city in March 1943. The army saw little or no action over the next three months as both sides built up their strength for the upcoming Battle of Kursk.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.