If you have been reading about telomerase 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 2026-02-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
I hit him over the head with my 'rod of iron' (a section of the rear axle of an automobile)." Karriem recalled his children sobbed and begged him, "please, Daddy, don't do it, don't do it!" On November 22, press coverage included a picture of the "Voodoo house" where the slaying had occurred. It was revealed that he had taken on the name "Karriem", referring to "Harris" as his 'slave name'. His son has likewise been renamed Hasabas. Hasabas, age 12, and daughter Ruby, 9, had been forced to witness the ritual. Press reported: "With an insane light in his eyes, he admitted that he had planned to seek out and kill Judges Edward J. Jeffries and Arthur E Gordon for the purpose of propitiating jungle gods." Karriem also reported wanting to kill a 21 year old social worker who had cut him from welfare rolls. Karriem was compared to the Ahfed Abdullah, formerly James Moaning, described as psychopathic, who had gained entrance to the Mayor's home in the delusional belief that the Mayor was responsible for the government of Haiti. On November 23, press discussed police access to a temple on Hasting Street using a secret password, their raid on the temple, and their arrest of leader Ugan Ali, described as 'God of the Asiatics', after he admitted to having taught Karriem. Police initiated a manhunt for Fard and another leader, Ugan Ali, who were arrested and questioned. Karriem was deemed insane and committed to a mental hospital. "The society cannot be blamed for anything he did", Ali was quoted as saying in the Detroit News.
== Effects on pharmacokinetics == Those experiencing poverty-related infectious diseases (PRDs) such as malaria and tuberculosis are also likely to be malnourished. Malnutrition can affect the pharmacokinetics of various drugs used to treat PRDs by changing a drug's bioavailability, distribution, and elimination. To optimize the treatment of those diseases, there needs to be more research into how severe malnutrition, specifically kwashiorkor, can affect treatment response.
Tralokinumab sold under the brand names Adtralza (EU/UK) and Adbry (US) among others, is a human monoclonal antibody used for the treatment of atopic dermatitis. Tralokinumab targets the cytokine interleukin 13. The most common side effects include upper respiratory tract infections (colds and other infections of the nose and throat), reactions at the injection site, and redness and discomfort in the eye. Tralokinumab was approved for medical use in the European Union and in the United Kingdom in June 2021. It was approved for medical use in the United States in December 2021. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication.
=== Anti-jamming technologies === The British had been aware that the Germans would determine the purpose of the system and attempt to interfere with it, and had designed in a variety of features and methods in order to address some of these issues even as the first stations were being built. The most obvious of these was CH's ability to operate on different frequencies, which was added to allow the stations to avoid any sort of continuous-broadcast interference on their operating frequency. Additionally, the Interference Rejection Unit, or IFRU, allowed the output of the intermediate stages of the amplifiers to be clipped in an attempt to finely tune the receiver to the station's own signals and help reject broadband signals. More complex was a system built into the CH displays, implemented in order to remove spurious signals from unsynchronized jamming pulses. It consisted of two layers of phosphor in the CRT screen, a quick-reacting layer of zinc sulphide below, and a slower "afterglow" layer of zinc cadmium sulphide on top. During normal operation the bright blue signal from the zinc sulphide was visible, and its signal would activate the yellow zinc cadmium sulphide layer, causing an "averaged" signal to be displayed in yellow. To filter out jamming pulses, a yellow plastic sheet was placed in front of the display, rendering the blue display invisible and revealing the dimmer yellow averaged signal. This is the reason many radars from the War through to the 1960s have yellow displays.
Sources: en.wikipedia.org
== Manufacturing == Paper-based microfluidic devices can be manufactured based on the dimensions, i.e. 2D and 3D. To fabricate 2D paper-based microfluidics, variations of methods, such as wax printing, inkjet printing, photolithography, flexographic printing, plasma treatment, laser treatment, etching (microfabrication), screen printing, digital light processing (DLP) 3-D printer, and wax screening, have been employed. Further lamination of multiple paper microfluidics creates pseudo-3D microfluidics that could provide an additional dimension of the fluidic network and increase the complexity. Each technique aims to create hydrophobic physical barriers on hydrophilic paper that passively transport aqueous solutions. Biological and chemical reagents must then be deposited selectively along the device by either dipping the substrate into a reagent solution or locally spotting a reagent onto the substrate.
== Career == Beginning in the late 1970s, at Columbia University, Wigler, Richard Axel and Saul Silverstein developed methods for engineering animal cells. These methods are the basis for many discoveries in mammalian genetics, and the means for producing protein therapeutics such as those used to treat heart disease, cancer and strokes. After moving to CSHL, Wigler continued his studies of gene transfer into mammalian cells, exploring the integration of foreign DNA and its stability of expression in host cells, demonstrating the inheritance of DNA methylation patterns, and isolating the first vertebrate genes, and first human oncogenes, using DNA transfer and genetic selection. His laboratory was among the group that first showed the involvement of members of the RAS gene family in human cancer, and that point mutations can activate the oncogenic potential of cellular genes. Wigler's laboratory was the first to demonstrate that some regulatory pathways have been so conserved in evolution that yeast can be used as a host to study the function of mammalian genes and in particular genes involved in signal transduction pathways and cancer. This led to deep insights into RAS function, eventually solving the RAS biochemical pathway in yeast and humans, and demonstrating the multifunctional nature of this important oncogene. From this work in fungi new cellular mechanisms were recognized for "insulating" signal transduction pathways with protein scaffolds that reduce cross-talk and for processing and localization of proteins.
At the hearing, he said that he "found Judge Jackson to be smart, well-versed in the law, and extraordinarily deft and artful in her ability to speak at length without saying anything of substance on critical questions—especially the limits of judicial power and the importance of judicial restraint", adding, "I don't agree with the judge on where, based on her opinions, she draws the limits of judicial power, and I don't think she places as great an importance as I do on judicial restraint in a Madisonian system of checks and balances and separation of powers, and, for that reason, I will be voting no." On July 27, 2022, Kennedy voted against the Chips and Science Act, a bill regarding semiconductor production. He called the bill "a subsidy to Big Tech", adding, "These are extraordinary American companies that Congress just helped, but they're very profitable, and the supply of chips is growing now. My concern is the amount of money. For that amount, we could have doubled the R&D tax credit for every company in America." On August 7, 2022, Kennedy voted against the Inflation Reduction Act, calling it a "massive tax-and-spending bill". While the bill was being amended, Kennedy attempted to include an amendment he drafted with Senator Raphael Warnock to cap the price of insulin at $35 per month; the amendment did not receive the 60 votes needed to be included.
"Victims as Defenders: African Troops in the Rhodesian Defence System 1890–1980". Small Wars & Insurgencies. 2 (2): 240–275. doi:10.1080/09592319108422981. Molomo, Mpho G. (2009). "The Link between Sustainable Development and Security in Botswana". In Cawthra, Gavin (ed.). African Security Governance: Emerging Issues. Tokyo: United Nations University Press. pp. 131–156. ISBN 9789280811773. Melson, C. D. (2005). "Top Secret War: Rhodesian Special Operations". Small Wars and Insurgencies. 16 (1): 57–82. doi:10.1080/0959231042000322567. S2CID 145455177. Moorcraft, Paul L.; McLaughlin, Peter (1982). Chimurenga! The War in Rhodesia, 1965-1980. A Military history. Marshalltown, South Africa: Sygma/Collins. ISBN 0620062142. Moorcraft, P. L.; McLaughlin, P. (2010). The Rhodesian War: A Military History. Stackpole Books. ISBN 9780811707251. Morse, Stephen A. (2006). "Historical Perspectives of Microbial Bioterrorism". In Anderson, Burt; Friedman, Herman; Bendinelli, Mauro (eds.). Microorganisms and Bioterrorism. New York City: Springer. pp. 15–30. ISBN 9780387281568. O'Brien, Kevin (September 2001). "Counter-Intelligence for counter-revolutionary warfare: The South African police security branch 1979–1990". Intelligence and National Security. 16 (3): 27–59. doi:10.1080/02684520412331306200. S2CID 153561623. Palmer, Robin (October 1983). "Review: From Zimbabwe to Azania? A Review Article". African Affairs. 82 (329): 574–578. doi:10.1093/oxfordjournals.afraf.a097565. JSTOR 721219. Prokosh, Eric, ed. (1994). "Disappearances" and Political Killings: Human Rights Crisis of the 1990s.
The medical anthropologist Charles Leslie writes that Chinese, Greco-Arabic, and Indian traditional medicines were all grounded in systems of correspondence that aligned the organization of society, the universe, and the human body and other forms of life into an "all-embracing order of things". Each of these traditional systems was organized with such qualities as heat and cold, wet and dry, light and darkness, qualities that also align the seasons, compass directions, and the human cycle of birth, growth, and death. They provided, Leslie continued, a "comprehensive way of conceiving patterns that ran through all of nature," and they "served as a classificatory and mnemonic device to observe health problems and to reflect upon, store, and recover empirical knowledge," but they were also "subject to stultifying theoretical elaboration, self-deception, and dogmatism." The doctrines of Chinese medicine are rooted in books such as the Yellow Emperor's Inner Canon and the Treatise on Cold Damage, as well as in cosmological notions such as yin–yang and the five phases. The Compendium of Materia Medica dates back to around 1,100 BCE when only a few dozen drugs were described. By the end of the 16th century, the number of drugs documented had reached close to 1,900. And by the end of the last century, published records of CMM had reached 12,800 drugs." Starting in the 1950s, these precepts were standardized in the People's Republic of China, including attempts to integrate them with modern notions of anatomy and pathology.
Sources: en.wikipedia.org
According to Kardashev, in order to capture the significant radiation of an advanced civilization emitted by a megastructure (such as a Dyson sphere), a radio telescope with a diameter larger than that of the Earth would have to be placed in orbital space. Kardashev concluded by predicting that the search for extraterrestrial civilizations would lead to positive results in the [then] next decade, giving humanity access to a vast amount of information about the Universe and its evolution over a period of several billion years.
Solute carrier family 25 member 39 is a protein that in humans is encoded by the SLC25A39 gene. The protein has been shown to be necessary for the import of the major antioxidant glutathione into the mitochondria.
=== Ultraviolet (UV) inactivation === UV rays can damage the DNA of living organisms by creating nucleic acid dimers. However, the damages are usually not important due to low penetration of UVs through living tissues. UV rays can be used, however, to inactivate viruses since virus particules are small and the UV rays can reach the genetic material, inducing the dimerisation of nucleic acids. Once the DNA dimerised, the virus particules cannot replicate their genetic material which prevent them from spreading. UV light in combination with riboflavin has been shown to be effective in reducing pathogens in blood transfusion products. Riboflavin and UV light damages the nucleic acids in viruses, bacteria, parasites, and donor white blood cells rendering them unable to replicate and cause disease.
== Single-player mods == Afraid of Monsters - A mod released in 2005 centered around David Leatherhoff, a drug addict who, after admitting himself to a hospital for help following intense hallucinations, finds the hospital and city to be full of monsters that he must fend off.A refurbished Director's Cut version of the mod was released in 2007. Azure Sheep - A mod released in 2001 where the player controls Barney searching Black Mesa for his colleague Kate, codenamed Azure Sheep. After rescuing her, Kate functions as an AI companion for the rest of the mission. The mod was said to be similar to Half-Life: Blue Shift. It received positive reviews from PC Zone, Incite PC Games, 3DActionPlanet, and Planet Half-Life. In 2019, a first part of a remake for Black Mesa was released. Chemical Existence – The player is Reese Max who must navigate a city in a warzone with mutant creatures, gang members, and the military forces. Cry of Fear – The spiritual successor of Afraid of Monsters, it puts the player in the shoes of Simon, who must make his way back home through the city of Stockholm while facing various nightmarish monsters along the way. It features a co-op mode. Though initially a mod, it was later released as a free standalone game on 25 April 2013, via Steam. Escape from Woomera – An unfinished point-and-click adventure game, intended to critique the treatment of mandatorily detained asylum seekers in Australia as well as the Australian government's attempt to impose a media blackout on the detention centers.
Sources: en.wikipedia.org
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
Small studies with human participants have been reported, chiefly in Russian-language journals, but they are limited in size and design. No large randomised controlled trial with published results is available.