This is a working overview of tuftsin, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-18. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
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.
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.
By the terms of the 1945 Potsdam Agreement signed by the three victorious Great Powers, the Soviet Union retained most of the territories captured as a result of the Molotov–Ribbentrop Pact of 1939, including western Ukraine and western Belarus, and gained others. Lithuania and the Königsberg area of East Prussia were officially incorporated into the Soviet Union, in the case of the former without the recognition of the Western powers. Poland was compensated with the bulk of Silesia, including Breslau (Wrocław) and Grünberg (Zielona Góra), the bulk of Pomerania, including Stettin (Szczecin), and the greater southern portion of the former East Prussia, along with Danzig (Gdańsk), pending a final peace conference with Germany which eventually never took place. Collectively referred to by the Polish authorities as the "Recovered Territories", they were included in the reconstituted Polish state. With Germany's defeat Poland was thus shifted west in relation to its prewar location, to the area between the Oder–Neisse and Curzon lines, which resulted in a country more compact and with much broader access to the sea.[c] The Poles lost 70% of their pre-war oil capacity to the Soviets, but gained from the Germans a highly developed industrial base and infrastructure that made a diversified industrial economy possible for the first time in Polish history. The flight and expulsion of Germans from what was eastern Germany prior to the war began before and during the Soviet conquest of those regions from the Nazis, and the process continued in the years immediately after the war.
There are more than 300 known compounds in tequila, many of which are produced during the fermentation process, the raw material used, and to a lesser degree during the maturation. The volatile compounds responsible for the flavor and aroma profiles of the tequila are put into a category called organoleptic compounds and are known to increase in concentration with a slower fermentation process. Higher-order alcohols have a strong aroma, and the quantity present in each tequila depends on the carbon:nitrogen ratio and temperature during the cooking and fermentation processes. In general, the longer the controlled fermentation period, the higher yield of esters produced. For example, isovaleraldehyde seems to produce a sweet, cocoa, and chocolate-like flavor. 2 and 3-methylbutanal produce a malty flavor. The agave plant contains many phenolics such as vanillin and syringaldehydes, which present a strong and fruity or herbal aroma. It also contains eugenol, which can deliver a hint of spicy flavor to the tequila. Because the production of tequila involves heating, Maillard browning reactions occur, and furans are produced during the thermal degradation of sugar. The most prominent furanic compounds include 2-furaldehyde and 5-methylfuraldehyde, which can contribute to the smoky flavor of tequila. Guaiacol also seems to contribute to Tequila's smoky flavor. Beta-demascenone contributes to the woody, floral taste of tequila. Volatile compounds that contribute to the overall taste and aroma of tequila can be quantitatively assessed and evaluated by gas chromatography.
The pharmacokinetics of progesterone concerns the pharmacodynamics, pharmacokinetics, and various routes of administration of progesterone. Progesterone is a naturally occurring and bioidentical progestogen, or an agonist of the progesterone receptor, the biological target of progestogens like endogenous progesterone. Progesterone also has antimineralocorticoid and inhibitory neurosteroid activity, whereas it appears to have little or no glucocorticoid or antiandrogenic activity and has no androgenic activity. Because of its progestogenic activity, progesterone has functional antiestrogenic effects in certain tissues such as the uterus, cervix, and vagina. In addition, progesterone has antigonadotropic effects due to its progestogenic activity and can inhibit fertility and suppress sex hormone production. Progesterone differs from progestins (synthetic progestogens) like medroxyprogesterone acetate and norethisterone, with implications for pharmacodynamics and pharmacokinetics as well as efficacy, tolerability, and safety. Progesterone can be taken by mouth, in through the vagina, and by injection into muscle or fat, among other routes. A progesterone vaginal ring and progesterone intrauterine device are also available as pharmaceutical products.
Sources: en.wikipedia.org
== Further reading == Howard JF, Bril V, Vu T, Karam C, Peric S, Margania T, et al. (July 2021). "Safety, efficacy, and tolerability of efgartigimod in patients with generalised myasthenia gravis (ADAPT): a multicentre, randomised, placebo-controlled, phase 3 trial". Lancet Neurol. 20 (7): 526–536. doi:10.1016/S1474-4422(21)00159-9. hdl:10067/1859580151162165141. PMID 34146511. S2CID 235456637.
== Structural classifications of proteins == Protein structures can be grouped based on their structural similarity, topological class or a common evolutionary origin. The Structural Classification of Proteins database and CATH database provide two different structural classifications of proteins. When the structural similarity is large the two proteins have possibly diverged from a common ancestor, and shared structure between proteins is considered evidence of homology. Structure similarity can then be used to group proteins together into protein superfamilies. If shared structure is significant but the fraction shared is small, the fragment shared may be the consequence of a more dramatic evolutionary event such as horizontal gene transfer, and joining proteins sharing these fragments into protein superfamilies is no longer justified. Topology of a protein can be used to classify proteins as well. Knot theory and circuit topology are two topology frameworks developed for classification of protein folds based on chain crossing and intrachain contacts respectively.
This is a methylation reaction in which glycocyamine is converted to creatine. The methyl group comes from the cofactor, S-adenosyl methionine (SAM), which loses its methyl group and becomes S-adenosyl-L-homocysteine (SAH). This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:N-guanidinoacetate methyltransferase. Other names in common use include GA methylpherase, guanidinoacetate methyltransferase, guanidinoacetate transmethylase, methionine-guanidinoacetic transmethylase, and guanidoacetate methyltransferase. It participates in the metabolism of amino acids. Defects in the gene which encodes this protein have been implicated in neurologic syndromes and muscular hypotonia, probably due to creatine deficiency and accumulation of guanidinoacetate in the brain of affected individuals. Two transcript variants encoding different isoforms have been described for this gene.
John Cowan – bass, lead and backing vocals (1993–1995, 2010–present) Marc Russo – saxophones (1998–present) Ed Toth – drums, percussion (2005–present) Marc Quiñones – percussion, backing vocals (2018–present)
Sources: en.wikipedia.org
As President, Johnson steadfastly pursued the Gemini and Apollo programs, promoting them as Kennedy's legacy to the American public. One week after Kennedy's death, he issued Executive Order 11129 renaming the Cape Canaveral and Apollo launch facilities after Kennedy.
=== Respiration === The octopus uses gills as its respiratory surface. The gill is composed of branchial ganglia and a series of folded lamellae. Primary lamellae extend out to form demi branches and are further folded to form the secondary free folded lamellae, which are only attached at their tops and bottoms. The tertiary lamellae are formed by folding the secondary lamellae in a fan-like shape. Water moves slowly in one direction over the gills and lamellae, into the mantle cavity and out of the octopus' funnel. The structure of the octopus' gills allows for a high amount of oxygen uptake; up to 65% in water at 20 °C (68 °F). The thin skin of the octopus accounted for a large portion of oxygen uptake in an in-vitro study; the estimate suggests around 41% of all oxygen absorption is through the skin when at rest. This number is affected by the activity of the animal – the oxygen uptake increases when the octopus is exercising due to its entire body being constantly exposed to water, but the total amount of oxygen absorption through skin is actually decreased to 33% as a result of the metabolic cost of swimming. When the animal is curled up after eating, its absorption through its skin can drop to 3% of its total oxygen uptake. The octopus' respiratory pigment, hemocyanin, also assists in increasing oxygen uptake. Octopuses can maintain a constant oxygen uptake even when oxygen concentrations in the water decrease to around 3.5 kPa (0.51 psi) or 31.6% saturation (standard deviation 8.3%).
Moscow will gain a branch of the Hermitage Museum in 2024. Authorities have agreed on the final project, which will be executed by Hani Rashid, co-founder of the New York-based firm Asymptote Architecture. This firm handled the stock market building in Moscow, the World Business Center Solomon Tower in Busan, and the Strata Tower in Abu Dhabi.
==== Thermoelectrics ==== Adding 0.6% graphene to a mixture of lanthanum and partly reduced strontium titanium oxide produces a strong Seebeck at temperatures ranging from room temperature to 750 °C (compared to 500–750 without graphene). The material converts 5% of the heat into electricity (compared to 1% for strontium titanium oxide.)
In the aftermath of the dissolution of the Soviet Union, Moscow remained the capital city of the newly reconstituted Russian Federation and has experienced continued growth. The northernmost and coldest megacity in the world, Moscow is governed as a federal city, where it serves as the political, economic, cultural, and scientific center of Russia and Eastern Europe. Moscow has one of the world's largest urban economies. Moscow has the second-highest number of billionaires of any city (tied with Hong Kong). The Moscow International Business Center is one of the largest financial centers in the world and features the majority of Europe's tallest skyscrapers. Moscow hosted the 1980 Summer Olympics and co-hosted the 2018 FIFA World Cup. The city contains several UNESCO World Heritage Sites and is known for its display of Russian architecture—particularly in areas such as Red Square, as well as buildings such as Saint Basil's Cathedral and the Moscow Kremlin, which serves as the seat of power of the Government of Russia. Russian companies in various industries are headquartered in Moscow, and the city is served by a comprehensive transit network; this includes four international airports, ten railway terminals, a tram system, a monorail system, and the Moscow Metro, which is the busiest metro system in Europe and one of the largest rapid transit systems in the world. More than 40% of the city's territory is covered by greenery, so it is one of the greenest cities in the world.
Sources: en.wikipedia.org
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.