Healthy Aging — Does Human Skeletal Muscle Possess an Epigenetic Memory of Testosterone?
Citation(s)
Egner IM, Bruusgaard JC, Eftestol E, Gundersen K A cellular memory mechanism aids overload hypertrophy in muscle long after an episodic exposure to anabolic steroids. J Physiol. 2013 Dec 15;591(24):6221-30. doi: 10.1113/jphysiol.2013.264457. Epub 2013 Oct 28.
Sharples AP, Turner DC Skeletal muscle memory. Am J Physiol Cell Physiol. 2023 Jun 1;324(6):C1274-C1294. doi: 10.1152/ajpcell.00099.2023. Epub 2023 May 8.
Turner DC, Seaborne RA, Sharples AP Comparative Transcriptome and Methylome Analysis in Human Skeletal Muscle Anabolism, Hypertrophy and Epigenetic Memory. Sci Rep. 2019 Mar 12;9(1):4251. doi: 10.1038/s41598-019-40787-0.
Wen Y, Dungan CM, Mobley CB, Valentino T, von Walden F, Murach KA Nucleus Type-Specific DNA Methylomics Reveals Epigenetic "Memory" of Prior Adaptation in Skeletal Muscle. Function (Oxf). 2021 Aug 5;2(5):zqab038. doi: 10.1093/function/zqab038. eCollection 2021.
Does Human Skeletal Muscle Possess an Epigenetic Memory of Testosterone?
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.