If you have been reading about tuftsin and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-10-22. 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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
| 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 |
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
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.
This method incorporated a parallelized, adapter/ligation-mediated, bead-based sequencing technology and served as the first commercially available "next-generation" sequencing method, though no DNA sequencers were sold to independent laboratories.
A catecholamine (; abbreviated CA), most typically a 3,4-dihydroxyphenethylamine, is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine. Catechol can be either a free molecule or a substituent of a larger molecule, where it represents a 1,2-dihydroxybenzene group. Catecholamines are derived from the amino acid tyrosine, which is derived from dietary sources as well as synthesis from phenylalanine. Catecholamines are water-soluble and are 50% bound to plasma proteins in circulation. Included among catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response. Tyrosine is created from phenylalanine by hydroxylation by the enzyme phenylalanine hydroxylase. Tyrosine is also ingested directly from dietary protein. Catecholamine-secreting cells use several reactions to convert tyrosine serially to L-DOPA and then to dopamine. Depending on the cell type, dopamine may be further converted to norepinephrine or even further converted to epinephrine. Various stimulant drugs (such as a number of substituted amphetamines) are catecholamine analogues.
Gomphrena globosa, commonly known as globe amaranth, is an edible plant from the family Amaranthaceae. The round-shaped flower inflorescences are a visually dominant feature and cultivars have been propagated to exhibit shades of magenta, purple, red, orange, white, pink, and lilac. Within the flowerheads, the true flowers are small and inconspicuous. Gomphrena globosa is native to Central America including regions Panama, and Guatemala, but is now grown globally. As a tropical annual plant, G. globosa blooms continuously throughout summer and early fall. It is very heat tolerant and fairly drought resistant, but grows best in full sun and regular moisture. The plant fixes carbon through the C4 pathway. At maturity, the flowerheads are approximately 4 centimetres (1.6 in) long and the plant grows up to 24 inches (61 cm) in height. Gomphrena globosa is an outcrossing species that is pollinated by butterflies, bees, and other insects. Floral volatiles likely play a significant role in the reproductive success of the plant by promoting the attraction of pollinators.
==== Symptomatic treatment ==== Medications used to treat the cognitive symptoms of AD rather than the underlying cause include: four acetylcholinesterase inhibitors (tacrine, rivastigmine, galantamine, and donepezil) and memantine, an NMDA receptor antagonist. The acetylcholinesterase inhibitors are intended for those with mild to severe AD, whereas memantine is intended for those with moderate or severe Alzheimer's disease. The benefit from their use is small. Reduction in the activity of the cholinergic neurons is a well-known feature of AD. Acetylcholinesterase inhibitors are employed to reduce the rate at which the body breaks down acetylcholine (ACh), thereby increasing the concentration of ACh in the brain and combating the loss of ACh caused by the death of cholinergic neurons. Evidence supports medical efficacy in mild to moderate AD, and somewhat in the advanced stage. This does not extend to delaying symptom onset. Memantine is a noncompetitive NMDA receptor antagonist first used as an anti-influenza agent. It acts on the glutamatergic system by blocking NMDA receptors and inhibiting their overstimulation by glutamate. Memantine has been reported to have a small benefit in the treatment of moderate to severe AD. The combination of memantine and donepezil has been reported to be "of statistically significant but clinically marginal effectiveness". An extract of Ginkgo biloba known as EGb 761 has been used for treating AD and other neuropsychiatric disorders. Its use is approved throughout Europe.
Sources: en.wikipedia.org
Chest trauma leading to aortic dissection can be divided into two groups based on cause: blunt chest trauma (commonly seen in car accidents) and iatrogenic. Iatrogenic causes include trauma during cardiac catheterization or due to an intra-aortic balloon pump. Aortic dissection may be a late sequela of heart surgery. About 18% of individuals who present with an acute aortic dissection have a history of open-heart surgery. Individuals who have undergone aortic valve replacement for aortic insufficiency are at particularly high risk because aortic regurgitation causes increased blood flow in the ascending aorta. This can cause dilatation and weakening of the walls of the ascending aorta. In December 2018, the U.S. Food and Drug Administration (FDA) issued a warning that fluoroquinolones may increase the risk of aortic aneurysm and aortic dissection, particularly in older adults and in patients with hypertension, Marfan syndrome, Ehlers-Danlos syndrome, atherosclerosis, peripheral vascular disease, or a history of aneurysms. Syphilis only potentially causes aortic dissection in its tertiary stage.
=== Maturation of the electrical properties of the action potential === A neuron's ability to generate and propagate an action potential changes during development. How much the membrane potential of a neuron changes as the result of a current impulse is a function of the membrane input resistance. As a cell grows, more channels are added to the membrane, causing a decrease in input resistance. A mature neuron also undergoes shorter changes in membrane potential in response to synaptic currents. Neurons from a ferret lateral geniculate nucleus have a longer time constant and larger voltage deflection at P0 than they do at P30. One consequence of the decreasing action potential duration is that the fidelity of the signal can be preserved in response to high frequency stimulation. Immature neurons are more prone to synaptic depression than potentiation after high frequency stimulation. In the early development of many organisms, the action potential is actually initially carried by calcium current rather than sodium current. The opening and closing kinetics of calcium channels during development are slower than those of the voltage-gated sodium channels that will carry the action potential in the mature neurons. The longer opening times for the calcium channels can lead to action potentials that are considerably slower than those of mature neurons. Xenopus neurons initially have action potentials that take 60–90 ms. During development, this time decreases to 1 ms. There are two reasons for this drastic decrease.
Adverse effects have been documented from vitamin B6 dietary supplements, but never from food sources. Even though it is a water-soluble vitamin and is excreted in the urine, doses of pyridoxine in excess of the dietary upper limit (UL) over long periods cause painful and ultimately irreversible neurological problems. The primary symptoms are pain and numbness of the extremities. In severe cases, motor neuropathy may occur with "slowing of motor conduction velocities, prolonged F wave latencies, and prolonged sensory latencies in both lower extremities", causing difficulty in walking. Sensory neuropathy typically develops at doses of pyridoxine in excess of 1,000 mg per day. As noted above, in 2023 the European Food Safety Commission set an adult UL at 12 mg/day. While Australia has set an upper limit of 50 mg/day, the Therapeutic Goods Administration requires a label warning about peripheral neuropathy if the daily dose is predicted to exceed 10 mg/day.
Metabolic flux analysis (MFA) using stable isotope labeling is an important tool for explaining the flux of certain elements through the metabolic pathways and reactions within a cell. An isotopic label is fed to the cell, then the cell is allowed to grow utilizing the labeled feed. For stationary metabolic flux analysis the cell must reach a steady state (the isotopes entering and leaving the cell remain constant with time) or a quasi-steady state (steady state is reached for a given period of time). The isotope pattern of the output metabolite is determined. The output isotope pattern provides valuable information, which can be used to find the magnitude of flux, rate of conversion from reactants to products, through each reaction. The figure demonstrates the ability to use different labels to determine the flux through a certain reaction. Assume the original metabolite, a three carbon compound, has the ability to either split into a two carbon metabolite and one carbon metabolite in one reaction then recombine or remain a three carbon metabolite. If the reaction is provided with two isotopes of the metabolite in equal proportion, one completely labeled (blue circles), commonly known as uniformly labeled, and one completely unlabeled (white circles). The pathway down the left side of the diagram does not display any change in the metabolites, while the right side shows the split and recombination. As shown, if the metabolite only takes the pathway down the left side, it remains in a 50–50 ratio of uniformly labeled to unlabeled metabolite.
=== Identifying Translated mRNA Regions === By using specific drugs, ribosome profiling can identify initiating regions of mRNA, elongating regions, and areas of translation stalling. Initiating regions can be detected by adding harringtonine or lactidomycin to prevent any further initiation. This allows the starting codon of the mRNAs throughout the cell lysate to be analyzed, which has been used to determine non-AUG sequences that do initiate translation. The other elongating regions can be detected by adding antibiotics like cycloheximide that inhibit translocation, chloramphenicol that inhibits transfer of peptides within the ribosome, or non-drug means like thermal freezing. These elongation freezing methods allow for the kinetics of translation to be analyzed. Since multiple ribosomes can translate a single mRNA molecule to speed up the translation process, RiboSeq demonstrates the protein coding regions within the mRNA and how quickly this is done depending on the mRNA being sequenced. This also allows for ribosome profiling to show pause sites within the transcriptome at specific codons. These sites of slow or paused translation are demonstrated by an increase in ribosome density and these pauses can link specific proteins with their roles within the cell.
Sources: en.wikipedia.org
Additionally, ketone bodies can be anti-inflammatory. Some kinds of cancer cells are unable to use ketone bodies, as they do not have the necessary enzymes to engage in ketolysis. It has been proposed that actively engaging in behaviors that promote ketogenesis could help manage the effects of some cancers.
In 66 AD, the Roman tribune Neapolitanus met with King Agrippa II in Iamnia, to inform him of his mission to investigate the situation in Jerusalem, following Florus' seizure of Temple funds and clashes between Jews and Roman troops. Later, in spring 68 AD, after the Roman army under Vespasian quelled the insurrection in Galilee, the army marched upon Iamnia and Azotus, taking both towns and stationing garrisons within them. Following the failure of the revolt and the destruction of the Second Temple, Judaism underwent significant reform in Yavne. According to rabbinic tradition, Rabbi Yohanan ben Zakkai and his disciples were permitted to settle in Iamnia during the outbreak of the war, after ben Zakkai, realizing that Jerusalem was about to fall, departed the city and sought the permission of Vespasian, commander of the Roman forces, to settle in Yavne and teach his disciples. Upon the fall of Jerusalem, his school functioned as a Sanhedrin. It was also theorized for some time to have been the site of a supposed Council of Jamnia that established the rabbinic Jewish biblical canon (although current scholarship largely rejects the theory that such a council in fact occurred). According to the Jerusalem Talmud (Berakhot 1:4), when the rabbis argued over some fine point of Jewish law, a Divine voice (Hebrew: bat ḳol) was heard in Yavne, ruling in favor of the School of Hillel.
=== University technology transfer === Despite the ethical, academic, commercial, and therapeutic controversies surrounding the identity and efficacy of "tethelin" itself (see below), Robertson's (1917) assignment of his tethelin patent to the University of California is universally treated as a landmark precedent event in the development of university technology transfer. In the ensuing years, the emergence of the concept of "intellectual property", driven by the theories and influence of Henri Bergson (the (August 1922) inaugural chairman of the League of Nations Committee on Intellectual Cooperation), made the already complex "paper vs. patent" issue even more fiercely contested, due to the significantly increased number of patents and the number of universities involved, and the extent to which a university's ever-increasing move towards commercialization not only reduced that institution's focus on the production of knowledge, but also privatised the knowledge that its researchers produced (PS.1):
An estimated 150 babies were born in Gaza per day since the start of the conflict. A pediatric doctor at the Emirati Hospital in Rafah, stated the number of premature babies born in Gaza had risen sharply. Newborn babies receiving specialized care in Israel and the West Bank while their mothers were trapped in Gaza. Oxfam stated newborn babies were dying from preventable diseases such as infection, hypothermia, diarrhea, and dehydration. By mid-December, parents were struggling to feed newborn babies, as mothers had insufficient nutrition to breastfeed. Newborn babies born during the conflict died in airstrikes, though some were rescued from the rubble. A UNOCHA representative stated she had met a woman forced to give birth in the street, and that the baby had died. One woman reported being unable to bathe her newborns more than ten days after their birth, due to the lack of clean water. Mothers reported extreme difficulty locating or affording milk and diapers for their newborns. In December 2023, an Israeli shell struck the largest fertility clinic in Gaza; the explosion knocked the lids off five liquid nitrogen tanks, causing temperature within the tanks to rise and destroying more than 4,000 embryos and 1,000 specimens of unfertilized eggs and sperm. According to Bahaeldeen Ghalayini, the obstetrician and gynaecologist who founded the clinic, the corner of the building was hit by a single shell, destroying the ground floor embryology lab; he does not know whether the strike was intentional or not.
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.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.