Embryo Project Encyclopedia Articles

William Thornton Mustard was a surgeon in Canada during the twentieth century who developed surgical techniques to treat children who had congenital heart defects. Mustard has two surgeries named after him, both of which he helped to develop. The first of these surgeries replaces damaged or paralyzed muscles in individuals who have polio, a virus that can cause paralysis. The other technique corrects a condition called the transposition of the great arteries (TGA) that is noticed at birth. Surgeons worldwide adopted that technique, leading to increased survival rates in infants afflicted with the condition. Mustard also published over 100 articles on congenital heart defects, surgical techniques, and the preparation of an artificial heart lung machine. Mustard helped perform the first blood transfusion of a newborn whose red blood cells (RBCs) had degraded, a condition called hemolytic anemia. Throughout his career, Mustard developed surgical techniques that increased the survival rates of infants and children with congenital and developmental disorders.

Published in 1971, Adenocarcinoma of the Vagina: Association of Maternal Stilbestrol Therapy with Tumor Appearance in Young Women, by Arthurs L. Herbst and colleagues, was the first piece of literature connecting maternal use of the drug diethylstilbestrol (DES), also called stilbestrol, with the development of a rare and severe form of vaginal cancer in young women. Diethylstilbestrol was later classified as an endocrine disruptor, a substance that disrupts the hormonal function of the body in those exposed to it during development or later in life. After Herbst and his team established the connection between DES and the occurrence of breast cancer, cervical cancer, infertility, and reproductive abnormalities, the US federal government banned use the drug for pregnant women. The article was published in the New England Journal of Medicine.

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. Despite the wide use of diethylstilbestrol to treat a variety of hormonal problems like miscarriages during pregnancy and menopause, Dodds argued against the use of synthetic substances in the human body due to their unknown effects. Just before Dodds's death, his hypotheses were confirmed when researchers showed that people exposed to diethylstilbestrol often developed cancer. Dodds was one of the first researchers to investigate the endocrine or hormone system in humans, and his research led to the creation of other synthetic hormones used in contraceptive pills and hormone replacements.

Ignaz Philipp Semmelweis demonstrated that the use of disinfectants could reduce the occurrence of puerperal fever in patients in nineteenth century Austria. Puerperal fever is a bacterial infection that can occur in the uterine tract of women after giving birth or undergoing an abortion. Semmelweis determined that puerperal fever is contagious and argued that the unhygienic practices of physicians, like examining patients after performing autopsies, caused the spread of puerperal fever. He showed that if physicians washed their hands with a chloride solution before they attended patients, then they prevented those patients from developing puerperal fever. Despite being widely criticized during his lifetime, Semmelweis's research on the contagiousness of puerperal fever set a precedent for many scientists, and contributed to preventing the spread of puerperal fever.

Scientists use cerebral organoids, which are artificially produced miniature organs that represent embryonic or fetal brains and have many properties similar to them, to help them study developmental disorders like microcephaly. In human embryos, cerebral tissue in the form of neuroectoderm appears within the first nine weeks of human development, and it gives rise to the brain and spinal cord. In the twenty-first century, Juergen Knoblich and Madeleine Lancaster at the Institute of Molecular Biotechnology in Vienna, Austria, grew cerebral organoids from pluripotent stem cells as a model to study developmental disorders in embryonic and fetal brains. One such disorder is microcephaly, a condition in which brain size and the number of neurons in the brain are abnormally small. Scientists use cerebral organoids, which they've grown in labs, because they provide a manipulable model for studying how neural cells migrate during development, the timing of neural development, and how genetic errors can result in developmental disorders.

Transposition of the great arteries or TGA is a potentially fatal congenital heart malformation where the pulmonary artery and the aorta are switched. The switch means that the aorta, which normally carries oxygenated blood, carries deoxygenated blood. There are two types of the malformation, d-TGA where no oxygen reaches the body and l-TGA where some oxygenated blood circulates. In the US, the Centers for Disease Control estimate that about 1,901 infants are born each year with TGA, or about one for every 2,000 births. Throughout history, physicians classified TGA as a condition that causes blue babies and hypothesized it was a fatal condition. With the development of corrective surgeries, studies on the causes of TGA, and improved prenatal diagnosis have allowed for the survival rate for those with TGA to approach almost one hundred percent.

William Withey Gull studied paraplegia, anorexia, and hormones as a physician in England during the nineteenth century. In addition to caring for patients, he described the role of the posterior column of the spinal cord in paraplegia, and he was among the first to describe the conditions of anorexia and of hypochondria. He also researched the effects of thyroid hormone deficiencies in women who had malfunctioning thyroid glands. Gull's research on thyroid hormone confirmed that chemicals in the body directly affect health, and he contributed to the foundation of endocrinology, the scientific field for the study of hormones.

Adib Jatene in Brazil was the first surgeon to successfully perform the arterial switch operation in 1975. The operation corrected a heart condition in infants called transposition of the great arteries (TGA). Left untreated, infants with TGA die, as their blood cannot supply oxygen to their bodies. Jatene’s operation became widely used to correct the condition. Aside from medical research, Jatene worked for years in politics and education, serving as Brazil’s minister of health and teaching thoracic surgery at the University of São Paulo.

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. In his later career Greene formed the Thyroid Club of London that brought together specialists in the emerging field on endocrinology. Greene’s research on progesterone and thyroid helped researchers study how of the endocrine system functions in women’s reproductive health.

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. Menstruation is the monthly series of changes a woman's body undergoes in preparation for the possibility of pregnancy. Dalton and Greene described how progesterone affected women during different phases of their menstrual cycles. The paper convinced many about the phenomenon of PMS, and docotors and scientists adopted Dalton's and Green's term. The paper furthered research about the role of hormones in physiology and of conditions linked to the reproductive system.