Boyce BF, Xing L Functions of RANKL/RANK/OPG in bone modeling and remodeling. Arch Biochem Biophys. 2008 May 15;473(2):139-46. doi: 10.1016/j.abb.2008.03.018. Epub 2008 Mar 25. Review.
Gorny G, Shaw A, Oursler MJ IL-6, LIF, and TNF-alpha regulation of GM-CSF inhibition of osteoclastogenesis in vitro. Exp Cell Res. 2004 Mar 10;294(1):149-58.
Hofbauer LC, Hicok KC, Chen D, Khosla S Regulation of osteoprotegerin production by androgens and anti-androgens in human osteoblastic lineage cells. Eur J Endocrinol. 2002 Aug;147(2):269-73.
Kearns AE, Khosla S, Kostenuik PJ Receptor activator of nuclear factor kappaB ligand and osteoprotegerin regulation of bone remodeling in health and disease. Endocr Rev. 2008 Apr;29(2):155-92. Epub 2007 Dec 5. Review.
Michael H, Härkönen PL, Väänänen HK, Hentunen TA Estrogen and testosterone use different cellular pathways to inhibit osteoclastogenesis and bone resorption. J Bone Miner Res. 2005 Dec;20(12):2224-32. Epub 2005 Aug 1.
Pepene CE, Crisan N, Coman I Elevated serum receptor activator of nuclear factor kappa B ligand and osteoprotegerin levels in late-onset male hypogonadism. Clin Invest Med. 2011 Aug 1;34(4):E232.
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.
