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Androgen Insensitivity Syndrome
Androgen Insensitivity Syndrome (AIS) is a human disorder in which an individual's genetic sex (genotype) differs from that individual's observable secondary sex characteristics (phenotypes). A fetus with AIS is genetically male with a 46,XY genotype. The term 46,XY refers to the chromosomes found in most cells of the fetus. Most cells have a total of 46 autosomes, or non-sex chromosomes, and a pair sex chromosomes, XX for genetic females, or XY for genetic males.
Charles Raymond Greene (1901–1982)
Charles Raymond Greene studied hormones and the effects of environmental conditions such as high-altitude on physiology in the twentieth century in the United Kingdom. Green researched frostbite and altitude sickness during his mountaineering expeditions, helping to explain how extreme environmental conditions effect respiration. Greene’s research on hormones led to a collaboration with physician Katarina Dalton that culminated in the development of the theory that progesterone caused premenstrual syndrome, a theory that became the basis for later research on the condition.
Irving Freiler Stein Sr. (1887–1976)
Irving Freiler Stein Sr. was a physician who studied women’s reproductive health during the twentieth century in the United States. In partnership with his colleague, Michael Leventhal, Stein identified a women’s reproductive disorder related to elevated male sex hormones, or androgens. The syndrome was originally called Stein-Leventhal syndrome and later known as polycystic ovarian syndrome. While studying the syndrome, Stein also helped establish a treatment for the condition, through the surgical removal of ovarian tissues.
Symptoms Associated with Polycystic Ovarian Syndrome (PCOS)
Polycystic ovarian syndrome or PCOS is one of the most common reproductive conditions in women, and its symptoms include cystic ovaries, menstrual irregularities, and elevated androgen or male sex hormone levels. During the 1930s, Irving Freiler Stein and Michael Leventhal identified the syndrome and its symptoms. Women who experience symptoms of PCOS may also experience secondary symptoms, including infertility and diabetes. Though estimates vary and the causes of the syndrome are not clear as of 2017, PCOS affects approximately ten percent of women of reproductive age.
US Endocrine Disruptor Screening Program
In 1996, the US Congress mandated that the US Environmental Protection Agency (EPA) create and regulate the Endocrine Disruptor Screening Program. The program tests industrial and agricultural chemicals for hormonal impacts in humans and in wildlife that may disrupt organisms' endocrine systems. The endocrine system regulates the release of small amounts of chemical substances called hormones to keep the body functioning normally.
Amenorrhea as a Menstrual Disorder
Amenorrhea is considered a type of abnormal menstrual bleeding characterized by the unexpected absence of menstrual bleeding, lasting three months or longer. Menstrual bleeding typically happens approximately once a month when blood and endometrial tissue, or tissue lining the inside of the uterus, sheds from the uterus through the vagina. Menstruation is expected to stop with pregnancy, breastfeeding, and menopause, or the natural cessation of the menstrual cycle at an older age.
Subject: Disorders, Reproduction
Embryonic Sex Differentiation and Sex Hormones (1947), by Carl R. Moore
In 1947, Carl Richard Moore, a researcher at the University of Chicago, in Chicago, Illinois, wrote Embryonic Sex Differentiation and Sex Hormones, which was published in the same year as a first-edition monograph. In the book, Moore argues that regulation of sex differentiation in mammals is not controlled by sex hormones secreted by embryonic sex organs (gonads), but is controlled by non-hormonal genetic factors.
Subject: Publications, Experiments
Hermaphrodites and the Medical Invention of Sex (1998), by Alice Domurat Dreger
Hermaphrodites and the Medical Invention of Sex, by historian of science Alice Domurat Dreger, was published in 1998 by Harvard University Press. In the book, Dreger describes how many doctors and scientists treated human hermaphrodites from the late nineteenth century to the early twentieth century. She states that during this time period, many physicians and scientists struggled to determine the nature sex, and to support a classification of sex as male or female, many physicians and scientists resorted to viewing a person's gonads for identification of his or her sex.
Subject: Publications, Theories, Disorders
Clomiphene citrate, more commonly known by its brand names Clomid and Serophene, is a medication prescribed to women to stimulate ovulation in order to treat infertility. It stimulates ovulation in women who do not ovulate or ovulate irregularly. This drug was created by Dr. Frank Palopoli in 1956 while he worked for Merrell Company. It first successfully induced ovulation in women in 1961 and was approved by the Federal and Drug Administration (FDA) in 1967.
The Effects of Bisphenol A on Embryonic Development
Bisphenol A (BPA) is an organic compound that was first synthesized by Aleksandr Dianin, a Russian chemist from St. Petersburg, in 1891. The chemical nomenclature of BPA is 2,2-bis (4-hydroxyphenyl) propane. The significance of this synthesized compound did not receive much attention until 1936, when two biochemists interested in endocrinology, Edward Dodds and William Lawson, discovered its ability to act as an estrogen agonist in ovariectomized, estrogen-deficient rats.
Subject: Disorders, Reproduction
Theodora (Theo) Emily Colborn (1927-2014)
Theodora Colborn studied how chemicals affect organisms as they develop and reproduce during the twentieth and twenty first centuries in the US. By the 1940s, researchers had reported that chemicals from agricultural and industrial processes affected how wild organisms developed, but in 1991, Colborn organized the Wingspread Conference in Racine, Wisconsin, at which a group of scientists classed these chemicals as environmentally harmful substances. Colborn and her colleagues called those chemicals endocrine disruptors, as they mimic or block the body's endocrine system.
Diethylstilbestrol (DES) in the US
Diethylstilbestrol (DES) is an artificially created hormone first synthesized in the late 1930s. Doctors widely prescribed DES first to pregnant women to prevent miscarriages, and later as an emergency contraceptive pill and to treat breast cancer. However, in 1971, physicians showed a link between DES and vaginal cancer during puberty in the children of women who had taken DES while pregnant. Consequently, the US Food and Drug Administration (FDA) banned its use during pregnancy.
Subject: Reproduction, Technologies
"The Premenstrual Syndrome" (1953), by Raymond Greene and Katharina Dalton
In 1953, Raymond Greene and Katharina Dalton, who were doctors in the UK, published The Premenstrual Syndrome in the British Medical Journal. In their article, Dalton and Greene established the term premenstrual syndrome (PMS). The authors defined PMS as a cluster of symptoms that include bloating, breast pain, migraine-headache, fatigue, anxiety, depression, and irritability. The article states that the symptoms begin one to two weeks before menstruation during the luteal phase of the menstrual cycle, and they disappear upon the onset of the menstrual period.
Subject: Publications, Reproduction
"Experimental Studies on Congenital Malformations" (1959), by James G. Wilson
The article Experimental Studies on Congenital Malformations was published in the Journal of Chronic Diseases in 1959. The author, James G. Wilson, studied embryos and birth defects at the University of Florida Medical School in Gainesville, Florida. In his article, Wilson reviewed experiments on birds and mammals from the previous forty years to provide general principles and guidelines in the study of birth defects and teratogens, which are things that cause birth defects.
Temperature-Dependent Sex Determination in Reptiles
The sex of a reptile embryo partly results from the production of sex hormones during development, and one process to produce those hormones depends on the temperature of the embryo's environment. The production of sex hormones can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination, also called genetic or chromosomal sex determination, an organism's genes determine which hormones are produced.
Edward Charles Dodds (1899-1973)
Edward Charles Dodds researched the function and effects of natural and artificial hormones on the endocrine system in England during the twentieth century. Though he first worked with hormones such as insulin, Dodds focused on the effects of estrogen in the body and how to replicate those effects with artificial substances. In 1938, along with chemist Robert Robinson, Dodds synthesized the first synthetic estrogen called diethylstilbestrol.
Carl Richard Moore (1892-1955)
Carl Richard Moore was a professor and researcher at the University of Chicago in Chicago, Illinois who studied sex hormones in animals from 1916 until his death in 1955. Moore focused on the role of hormones on sex differentiation in offspring, the optimal conditions for sperm production, and the effects of vasectomy or testicular implants on male sex hormone production. Moore's experiments to create hermaphrodites in the laboratory contributed to the theory of a feedback loop between the pituitary and fetal gonadal hormones to control sex differentiation.
Bacteria of the genus Wolbachia are
bacteria that live within the cells of their hosts. They infect a
wide range of arthropods (insects, arachnids, and crustaceans) and
some nematodes (parasitic roundworms). Scientists estimate that
Wolbachia exist in between seventeen percent and seventy-six percent of
arthropods and nematodes. The frequency of the bacteria makes them
one of the most widespread parasites. In general, they are divided
into five groups, from A to E, depending of the species of their
Sex Determination in Humans
In humans, sex determination is the process that determines the biological sex of an offspring and, as a result, the sexual characteristics that they will develop. Humans typically develop as either male or female, primarily depending on the combination of sex chromosomes that they inherit from their parents. The human sex chromosomes, called X and Y, are structures in human cells made up of tightly bound deoxyribonucleic acid, or DNA, and proteins.