Embryo Project Encyclopedia

William John Little was one of the first orthopedic surgeons to research congenital malformations and their causes in the nineteenth century and presented preliminary research on a condition modernly known as cerebral palsy, a condition of varying severity that affects a person’s ability to move. Little worked throughout the United Kingdom for the majority of the time he practiced medicine, and eventually founded one of the first orthopedic infirmaries, the Royal Orthopedic Hospital in London, England. Throughout his career, Little studied congenital malformations, which are medical conditions inherited before birth, as well as how certain medical circumstances during delivery affect the neonate. In 1861, he described a condition with motor, behavioral, and cognitive irregularities in neonates, linked with oxygen deprivation during birth. Little’s research on that condition, originally called Little’s disease, and modernly, spastic cerebral palsy, was one of the first accounts of cerebral palsy in infants.

David Michael Rorvik is a science journalist who publicized advancements in the field of reproductive medicine during the late twentieth century. Rorvik wrote magazine articles and books in which he discussed emerging methods and technologies that contributed to the progression of reproductive health, including sex determination, in vitro fertilization, and human cloning. During that time, those topics were controversial and researchers often questioned Rorvik’s work for accuracy. Rorvik contributed to the field of reproductive medicine by communicating methods of reproductive intervention and contributing to the controversy around new developmental medicine technologies.

Arnaud Fauconnier and Charles Chapron published “Endometriosis and Pelvic Pain: Epidemiological Evidence of the Relationship and Implications,” henceforth “Endometriosis and Pelvic Pain,” in the journal Human Reproduction Update in 2005. In that article, the researchers studied the relationship between pelvic pain and endometriosis. Endometriosis is the growth of endometrium, or tissue that normally lines the inside of the uterus, outside of the uterus. The authors review medical studies in order to determine how much evidence exists that endometriosis causes chronic pelvic pain symptoms. Then, the authors describe specific relationships between different types of endometriotic lesions and pain symptoms. By establishing specific relationships between pain and endometriosis, “Endometriosis and Pelvic Pain” helped healthcare professionals diagnose and treat pelvic pain related to endometriosis.

Screening for Breast Cancer with Mammography is a Cochrane systematic review originally published by Peter Gøtzsche and Karsten Jørgensen in 2001 and updated multiple times by 2013. In the 2013 article, the authors discuss the reliability of the results from different clinical trials involving mammography and provide their conclusions about whether mammography screening is useful in preventing deaths from breast cancer. Mammography is an X-ray technique used to detect abnormalities in breast tissue, such as breast cancer, which affects about twelve percent of women in the world and has a significant risk of mortality. The authors concluded that mammography screenings reduced breast cancer mortality, but resulted in problems such as overdiagnosis and overtreatment of screened women. The article Screening for Breast Cancer with Mammography contributed to the then ongoing controversy about the usefulness of mammography and provided accessible information about mammograms in seven languages.

From 1963 to 1982, researchers in New York City, New York, carried out a randomized trial of mammography screening. Mammography is the use of X-ray technology to find breast cancer at early stages. The private insurance company Health Insurance Plan of Greater New York, or HIP, collaborated with researchers Sam Shapiro, Philip Strax, and Louis Venet on the trial. The researchers’ goal was to determine whether mammography screening reduced breast cancer mortality in women. The study included sixty thousand women aged forty to sixty-four. Half of the women received two annual breast examinations that involved mammography, a breast exam, and an interview. The rest of the women were not invited for annual examinations. After follow up, the researchers found that of the women who received the examinations, thirty percent fewer died from breast cancer than the women who did not receive any examinations. The HIP trial was one of the first large-scale clinical trials to provide evidence that mammography screenings helped prevent breast cancer deaths in women.

George Wells Beadle studied corn, fruit flies, and funguses in the US during the twentieth century. These studies helped Beadle earn the 1958 Nobel Prize in Physiology or Medicine. Beadle shared the prize with Edward Tatum for their discovery that genes help regulate chemical processes in and between cells. This finding, initially termed the one gene-one enzyme hypothesis, helped scientists develop new techniques to study genes and DNA as molecules, not just as units of heredity between generations of organisms. By inducing mutations in organisms while they were in different embryonic stages, Beadle's work on Drosophila and Neurospora led to the analysis of the cell cycle and embryonic development processes.

St. George Jackson Mivart studied animals and worked in England during the nineteenth century. He also proposed a theory of organismal development that he called individuation, and he critiqued Charles Darwin's argument for evolution by natural selection. His work on prosimians, a group of primates excluding apes and monkeys, helped scientists better investigate the Primate group. In his work On the Genesis of Species, Mivart argued that Darwin's theory couldn't explain how specific organismal forms developed and varied, explanations Mivart argued were necessary before Darwin could invoke the mechanism of natural selection to explain the evolution of species. To provide those explanations Mivart proposed theories of individuation and of instinct.

In 1973, Ronald Ericsson developed the Ericsson method, which is a technique used to separate human male sperm cells by their genetic material. Ericsson, a physician and reproduction researcher, developed the method while conducting research on sperm isolation in Berlin, Germany, in the early 1970s. He found that the sperm cells that carry male-producing Y chromosomes move through liquid faster than the cells that carry female-producing X chromosomes. As a result of his findings, Ericsson suggested suspending a semen sample in a viscous liquid made from albumin protein, and collecting only sperm that quickly pass through the liquid. Shortly after Ericsson described his method, researchers demonstrated that it was effective for sex selection. However, later studies contested those results. Despite that, the Ericsson method is still utilized by couples in 2018 as a means of sex selection and was the first sperm separation technique used in combination with artificial insemination to enable people to select the sex of their children.

According to the US National Institutes of Health (NIH), the standard American source on stem cell research, three characteristics of stem cells differentiate them from other cell types: (1) they are unspecialized cells that (2) divide for long periods, renewing themselves and (3) can give rise to specialized cells, such as muscle and skin cells, under particular physiological and experimental conditions. When allowed to grow in particular environments, stem cells divide many times. This ability to proliferate can yield millions of stem cells over several months. As long as the stem cells remain unspecialized, meaning they lack tissue-specific structures, they are able to sustain long-term self-renewal.

Torsten Nils Wiesel studied visual information processing and development in the US during the twentieth century. He performed multiple experiments on cats in which he sewed one of their eyes shut and monitored the response of the cat’s visual system after opening the sutured eye. For his work on visual processing, Wiesel received the Nobel Prize in Physiology or Medicine in 1981 along with David Hubel and Roger Sperry. Wiesel determined the critical period during which the visual system of a mammal develops and studied how impairment at that stage of development can cause permanent damage to the neural pathways of the eye, allowing later researchers and surgeons to study the treatment of congenital vision disorders.