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.

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.

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.

The Golgi staining technique, also called the black reaction after the stain's color, was developed in the 1870s and 1880s in Italy to make brain cells (neurons) visible under the microscope. Camillo Golgi developed the technique while working with nervous tissue, which required Golgi to examine cell structure under the microscope. Golgi improved upon existing methods of staining, enabling scientists to view entire neurons for the first time and changing the way people discussed the development and composition of the brain's cells. Into the twenty-fist century, Golgi's staining method continued to inform research on the nervous system, particularly regarding embryonic development.

William Hunter’s Anatomia Uteri Humani Gravidi Tabulis Illustrata (The Anatomy of the Human Gravid Uterus Exhibited in Figures), hereafter called The Human Gravid Uterus, is an anatomical atlas depicting the pregnant form through both engravings and descriptions. William Hunter, an anatomist working in England during the eighteenth century, compiled the work based on observations from his dissections of pregnant women. The collection of thirty-four copper plate illustrations details the anatomy of the pregnant human womb (gravid uterus), and includes depictions of unborn fetuses at various stages of development. Hunter compiled The Human Gravid Uterus to provide an objective anatomical depiction of pregnancy and development at a time when midwifery and obstetrics were becoming prominent fields of medical practice in England.

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.

Fetal surgeries are a range of medical interventions performed in utero on the developing fetus of a pregnant woman to treat a number of congenital abnormalities. The first documented fetal surgical procedure occurred in 1963 in Auckland, New Zealand when A. William Liley treated fetal hemolytic anemia, or Rh disease, with a blood transfusion. Three surgical techniques comprise many fetal surgeries: hysterotomy, or open abdominal surgery performed on the woman; fetoscopy, for which doctors use a fiber-optic endoscope to view and make repairs to abnormalities in the fetus; and percutaneous fetal theray, for which doctors use a catheter to drain excess fluid. As the sophistication of surgical and neonatal technology advanced in the late twentieth century, so too did the number of congenital disorders fetal surgeons treated, such as mylomeningeocele, blocked urinary tracts, twin-to-twin transfusion syndrome, polyhydramnios, diaphragmatic hernia, tracheal occlusion, and other anomalies. Many discuss the ethics of fetal surgery, as many consider it contentious, as fetal surgery risks both the developing fetus and the pregnant woman, and at times it only marginally improves patient outcomes. Some argue, however, that as more advanced diagnostic equipment and surgical methods improve, advanced clinical trials in a few conditions may demonstrate more benefits than risks to both pregnant women and fetuses.

The arterial switch operation, also called the Jatene procedure, is an operation in which surgeons redirect the flow of blood through abnormal hearts. In 1975, Adib Jatene conducted the first successful arterial switch operation on a human infant. The arterial switch operation corrects a condition called transposition of the great arteries, abbreviated TGA, also called transposition of the great vessels, abbreviated TGV. TGA occurs when the pulmonary artery, which supplies deoxygenated blood to the lungs, and the aorta, which takes oxygenated blood to the body, are switched, or transposed. The switch between the aorta and pulmonary artery results in dangerously low levels of oxygen, a condition called cyanosis, in newborn infants, which causes them to die if a surgeon does not correct it.

The term Fetal Alcohol Syndrome (FAS) was first published in 1973 in an article published in the British medical journal The Lancet. In that article, a group of pediatricians and psychiatrists at the University of Washington Medical School helped to define the morphological defects and developmental delays that can affect children born to alcoholic mothers. Those observations include pre- and post-natal growth deficiencies, minor facial abnormalities, and damage to the developing brain that can result in behavioral, learning, and cognitive abnormalities.

The Cell in Development and Inheritance, by Edmund Beecher Wilson, provided a textbook introduction to cell biology for generations of biologists in the twentieth century. In his book, Wilson integrated information about development, inheritance, chromosomes, organelles, and the structure and functions of cells. First published in 1896, the book started with 371 pages, grew to 483 pages in the second edition that appeared in 1900, and expanded to 1,231 pages by the third and final edition in 1925. Wilson dedicated the book to the cell biologist Theodor Boveri, whose work established the roles of chromosomes in cell division. With its explanations and many illustrations and diagrams, The Cell in Development and Inheritance enabled embryologists to better understand development in terms of cell structure and function.