The insulin-like growth factors (IGFs) are proteins with high sequence similarity to insulin. IGFs are part of a complex system that cells use to communicate with their physiologic environment. This complex system consists of two cell-surface receptors, two ligands, a family of seven high-affinity IGF-binding proteins, as well as associated IGFBP degrading enzymes, referred to collectively as proteases.
Hirsutism is excessive body hair on parts of the body where hair is normally absent or minimal. The word is from early 17th century: from Latin hirsutus meaning "hairy". It usually refers to a male pattern of hair growth in a female that may be a sign of a more serious medical condition, especially if it develops well after puberty. Cultural stigma against hirsutism can cause much psychological distress and social difficulty. Discrimination based on facial hirsutism often leads to the avoidance of social situations and to symptoms of anxiety and depression.
Growth hormone deficiency (GHD), or hyposomatotropism, is a medical condition resulting from not enough growth hormone (GH). Generally the most noticeable symptom is that an individual attains a short height. Newborns may also present low blood sugar or a small penis size. In adults there may be decreased muscle mass, high cholesterol levels, or poor bone density.
Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a hormone similar in molecular structure to insulin which plays an important role in childhood growth, and has anabolic effects in adults. In the 1950s IGF-1 was called "sulfation factor" because it stimulated sulfation of cartilage in vitro, and in the 1970s due to its effects it was termed "nonsuppressible insulin-like activity" (NSILA).
Acanthosis nigricans is a medical sign characterised by brown-to-black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds, such as the posterior and lateral folds of the neck, the armpits, groin, navel, forehead and other areas.
Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it is called androgen-binding protein (ABP).
Insulin-like growth factor 2 (IGF-2) is one of three protein hormones that share structural similarity to insulin. The MeSH definition reads: "A well-characterized neutral peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like and mitogenic activities. The growth factor has a major, but not absolute, dependence on somatotropin. It is believed to be a major fetal growth factor in contrast to insulin-like growth factor 1 (IGF-1), which is a major growth factor in adults."
The insulin-like growth factor 1 (IGF-1) receptor is a protein found on the surface of human cells. It is a transmembrane receptor that is activated by a hormone called insulin-like growth factor 1 (IGF-1) and by a related hormone called IGF-2. It belongs to the large class of tyrosine kinase receptors. This receptor mediates the effects of IGF-1, which is a polypeptide protein hormone similar in molecular structure to insulin. IGF-1 plays an important role in growth and continues to have anabolic effects in adults – meaning that it can induce hypertrophy of skeletal muscle and other target tissues. Mice lacking the IGF-1 receptor die late in development, and show a dramatic reduction in body mass. This testifies to the strong growth-promoting effect of this receptor.
Laron syndrome (LS), also known as growth hormone insensitivity or growth hormone receptor deficiency (GHRD), is an autosomal recessive disorder characterized by a lack of insulin-like growth factor 1 production in response to growth hormone. It is usually caused by inherited growth hormone receptor (GHR) mutations.
Insulin-like growth factor-binding protein 3, also known as IGFBP-3, is a protein that in humans is encoded by the IGFBP3 gene. IGFBP-3 is one of six IGF binding proteins that have highly conserved structures and bind the insulin-like growth factors IGF-1 and IGF-2 with high affinity. IGFBP-7, sometimes included in this family, shares neither the conserved structural features nor the high IGF affinity. Instead, IGFBP-7 binds IGF1R, which blocks IGF-1 and IGF-2 binding, resulting in apoptosis.
Insulin-like growth factor-binding protein 2 is a protein that in humans is encoded by the IGFBP2 gene.
Insulin-like growth factor-binding protein 4 is a protein that in humans is encoded by the IGFBP4 gene.
Autoimmune hypophysitis is defined as inflammation of the pituitary gland due to autoimmunity.
Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female's life.
Cyril Y. Bowers, M.D., emeritus professor of medicine at Tulane University School of Medicine, attended medical school at the University of Oregon and did an internship at the University of Washington. He then studied biochemistry at Cornell University and attended the postgraduate school of medicine at the University of Pennsylvania. From 1961-2004 he was the director of the Section of Endocrinology & Metabolism in the department of medicine at Tulane University School of Medicine. Bowers has served on the editorial board of several endocrine journals, was a member of the National Institute of Diabetes and Digestive and Kidney Diseases Study Section for eight years and has written over 400 articles in peer-reviewed journals, including chapters in books and over 200 abstracts.
Leonid Poretsky is a Russian-born American endocrinologist. His research interests include mechanisms of insulin action in the ovary, endocrinological aspects of AIDS, and clinical outcomes in diabetes. He has authored over 150 publications and has served on the National Institutes of Health's review committees and on the editorial boards of the Journal of Clinical Endocrinology and Metabolism and other endocrine journals.
Pierre De Meyts is a Belgian physician and biochemist known for his research on fine chemical and kinetic aspects of ligand-receptor interaction, subunit assembly, and specific metabolic effects of hormones typically causing receptor tyrosine kinase activation such as insulin and insulin-like growth factors (IGFs). He has also studied receptor signalling for other peptide hormones such as growth hormone and relaxin, and key pathophysiological aspects of diabetes mellitus. De Meyts held professorial posts for over three decades at several European and United States institutions and currently is an emeritus professor in the Science Faculty at the Université catholique de Louvain. While living in Denmark (1990-2010) he occupied executive research positions at Novo Nordisk. De Meyts is also known as a science cartoonist.
Hormonal breast enhancement or augmentation is a highly experimental potential medical treatment for the breasts in which hormones or hormonal agents such as estrogen, progesterone, growth hormone (GH), and insulin-like growth factor 1 (IGF-1) are utilized or manipulated to produce breast enlargement in women. It is a possible alternative or supplement to surgical breast augmentation with breast implants or fat transfer and other means of medical breast enlargement.
Steven Grinspoon is an American physician who is a Professor of Medicine at Harvard Medical School, Chief of the Massachusetts General Hospital (MGH), and Metabolism Unit and Director of the Nutrition and Obesity Research Center at Harvard. In addition, he is the MGH Endowed Chair in Neuroendocrinology and Metabolism. His work investigates the neuroendocrine regulation of body composition, and physiological consequences of fat distribution on cardiovascular disease and inflammation. In 2015, he became the Principal Investigator of the NIH-funded Nutrition Obesity Research Center at Harvard.
