Search

Displaying 151 - 175 of 327 items.

Rosalind Elsie Franklin (1920-1958)

Rosalind Elsie Franklin worked with X-ray crystallography at King's College London, UK, and she helped determine the helical structure of DNA in the early 1950s. Franklin's research helped establish molecular genetics, a field that investigates how heredity works on the molecular level. The discovery of the structure of DNA also made future research possible into the molecular basis of embryonic development, genetic disorders, and gene manipulation.

Format: Articles

Subject: People

Stanley Paul Leibo (1937–2014)

Stanley Paul Leibo studied the cryopreservation of embryos in the US in the twentieth century. Cryopreservation is a method of preserving biological material through freezing. Early in his career, Leibo collaborated with other scientists to study why cells were oftentimes injured during freezing. Later, Leibo and his team accomplished one of the first successful births using previously-frozen mammalian embryos.

Format: Articles

Subject: People, Technologies

Zhang Lizhu (1921- )

Zhang Lizhu is a Chinese gynecologist and researcher. For most of her career, she worked in the Peking Medical College Third Hospital, renamed in 2000, Peking University Third Hospital. There, she led a team of researchers and physicians in the study of human in vitro fertilization (IVF) and embryo transfer (ET) technology. Zhang and her colleagues contributed to the birth of the first test-tube baby in Mainland China in 1988.

Format: Articles

Subject: People, Reproduction

Robert Alan Good (1922-2003)

Robert Alan Good was an American physician and scientific researcher who explored the cellular mechanisms of immunity. His research and discoveries earned him the label of "father of modern immunology." Though his work in immunology is considered his greatest scientific achievement, Good is also well known for his work with tissue engineering. From his research on immunology, Good was able to perform the first successful allogeneic (donor and recipient are unrelated) bone marrow transplant.

Format: Articles

Subject: People

John Bertrand Gurdon (1933- )

Sir John Bertrand Gurdon further developed nuclear transplantation, the technique used to clone organisms and to create stem cells, while working in Britain in the second half of the twentieth century. Gurdon's research built on the work of Thomas King and Robert Briggs in the United States, who in 1952 published findings that indicated that scientists could take a nucleus from an early embryonic cell and successfully transfer it into an unfertilized and enucleated egg cell.

Format: Articles

Subject: People

Leonard Colebrook (1883–1967)

Leonard Colebrook was a physician who researched bacteria and infections in England during the twentieth century. In 1936, Colebrook deployed the antibiotic Prontosil to treat puerperal fever, a disorder that results from bacterial infections in the uterine tracts of women after childbirth or abortions. Colebrook also advanced care for burn patients by advocating for the creation of burn units in hospitals and by using antisepsis medication for burn wound infections. Colebrook’s work on treatments for puerperal fever reduced cases of puerperal fever throughout the world.

Format: Articles

Subject: People

Roger Wolcott Sperry (1913–1994)

Roger Wolcott Sperry studied the function of the nervous system in the US during the twentieth century. He studied split-brain patterns in cats and humans that result from separating the two hemispheres of the brain by cutting the corpus callosum, the bridge between the two hemispheres of the brain. He found that separating the corpus callosum the two hemispheres of the brain could not communicate and they performed functions as if the other hemisphere did not exist. Sperry studied optic nerve regeneration through which he developed the chemoaffinity hypothesis.

Format: Articles

Subject: People

Harald zur Hausen (1936–)

Harald zur Hausen studied viruses and discovered that certain strains of the human papilloma virus (HPV), a sexually transmitted disease, can cause cervical cancer, in Europe during the twentieth and twenty-first centuries. Zur Hausen spent his research career identifying the viruses that cause diseases, particularly cancer-causing viruses (oncoviruses). He primarily focused on HPV and cervical cancer. Zur Hausen hypothesized that HPV was cancerous and discovered that two strains, HPV 16 and 18, caused cervical cancer.

Format: Articles

Subject: People

Julia Barlow Platt (1857-1935)

Julia Barlow Platt studied neural crests in animal embryos and became involved in politics in the US during the nineteenth and twentieth centuries. She researched how body and head segments formed in chicks (Gallus gallus) and spiny dogfish (Squalus acanthias). Platt observed that in the mudpuppy (Necturus maculosus), the coordinated migration of neural crest cells in the embryo produced parts of the nervous system, bones, and connective tissues in the head.

Format: Articles

Subject: People

Torsten Wiesel (1924– )

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.

Format: Articles

Subject: People

Walter Schiller (1887–1960)

Walter Schiller studied the causes of diseases in the US and Austria in the early twentieth century and in 1928, invented the Schiller test, or a way to diagnose early cervical cancer in women. Cervical cancer is the uncontrollable division of cells in the cervix, or lower part of the uterus. While living in Austria until his emigration to escape the Nazis in 1937, Schiller concluded that there was a form of cervical cancer, later named carcinoma in situ, that physicians could detect earlier than when tumors start to appear.

Format: Articles

Subject: People

Georges Cuvier (1769-1832)

Georges Cuvier, baptized Georges Jean-Leopold Nicolas-Frederic Cuvier, was a professor of anatomy at the National Museum of Natural History in Paris, France, through the late eighteenth and early nineteenth centuries. Scholars recognize Cuvier as a founder of modern comparative anatomy, and as an important contributor to vertebrate paleontology and geology. Cuvier studied the form and function of animal anatomy, writing four volumes on quadruped fossils and co-writing eleven volumes on the natural history of fish with Achille Valenciennes.

Format: Articles

Subject: People

William Thornton Mustard (1914-1987)

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.

Format: Articles

Subject: People, Disorders, Disorders

Jérôme Lejeune (1926−1994)

Jérôme Lejeune was a French physician and researcher who studied genetics and developmental disorders. According to the Jérôme Lejeune Foundation, in 1958, Lejeune discovered that the existence of an extra twenty-first chromosome, a condition called Trisomy 21, causes Down Syndrome. Down Syndrome is a condition present in an individual since birth and is characterized by physical and developmental anomalies such as small ears, a short neck, heart defects, and short height as children and adults.

Format: Articles

Subject: People

Ernst Heinrich Philipp August Haeckel (1834-1919)

Ernst Heinrich Philipp August Haeckel was a prominent comparative anatomist and active lecturer in the late nineteenth and early twentieth centuries. He is most well known for his descriptions of phylogenetic trees, studies of radiolarians, and illustrations of vertebrate embryos to support his biogenetic law and Darwin's work with evolution. Haeckel aggressively argued that the development of an embryo repeats or recapitulates the progressive stages of lower life forms and that by studying embryonic development one could thus study the evolutionary history of life on earth.

Format: Articles

Subject: People

Camillo Golgi (1843–1926)

Camillo Golgi studied the central nervous system during the late nineteenth and early twentieth centuries in Italy, and he developed a staining technique to visualize brain cells. Called the black reaction, Golgi’s staining technique enabled him to see the cellular structure of brain cells, called neurons, with much greater precision. Golgi also used the black reaction to identify structures within animal cells like the internal reticular apparatus that stores, packs, and modifies proteins, later named the Golgi apparatus in his honor.

Format: Articles

Subject: People

Richard Woltereck (1877-1944)

Richard Woltereck was a German zoologist and hydrobiologist who studied aquatic animals and extended the concept of Reaktionsnorm (norm of reaction) to the study of genetics. He also provided some of the first experimental evidence for the early twentieth-century embryological theory of heredity known as cytoplasmic inheritance. Through experiments on the water flea, Daphnia, Woltereck investigated whether variation produced by environmental impacts on development could play a role in heredity and evolution.

Format: Articles

Subject: People

Hilde Mangold (1898-1924)

Hilde Mangold, previously Hilde Proescholdt, was a German embryologist and physiologist who became well known for research completed with Hans Spemann in the 1920s. As a graduate student, Mangold assisted Spemann and together they discovered and coined the term the "organizer." The organizer discovery was a crucial contribution to embryology that led to further understanding of the pattern of embryo differentiation of amphibians.

Format: Articles

Subject: People

Eugen Steinach (1861–1944)

Eugen Steinach researched sex hormones and their effects on mammals in the late nineteenth and early twentieth centuries in Europe. He experimented on rats by removing their testicles and implanting them elsewhere in their bodies, and he found that the testes interstitial cells produce male sex hormones. He developed the Steinach Rejuvenation Procedure, which he claimed could rejuvenate men by increasing their production of sex hormones. Steinach’s work on female sex hormones and on ovarian extracts led to the development of the first standardized injectable estrogen.

Format: Articles

Subject: People

William John Little (1810–1894)

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.

Format: Articles

Subject: People, Disorders

Milan Vuitch (1915–1993)

Milan Vuitch was an abortion provider in the twentieth century, who performed thousands of abortions in Washington, DC, at a time when abortions were legal only if they preserved the life or health of the pregnant woman. Vuitch was a frequent critic of Washington DC’s anti-abortion law and was arrested multiple times for providing abortions that were not considered necessary to preserve the pregnant woman’s life. After several arrests, Vuitch challenged the law under which he had been arrested, and his case made its way to the Supreme Court in Vuitch v. United States.

Format: Articles

Subject: People

August Friedrich Leopold Weismann (1834-1914)

August Friedrich Leopold Weismann studied how the traits of organisms developed and evolved in a variety of organisms, mostly insects and aquatic animals, in Germany in the late nineteenth and early twentieth centuries. Weismann proposed the theory of the continuity of germ-plasm, a theory of heredity. Weismann postulated that germ-plasm was the hereditary material in cells, and parents transmitted to their offspring only the germ-plasm present in germ-cells (sperm and egg cells) rather than somatic or body cells.

Format: Articles

Subject: People

Lynn Petra Alexander Sagan Margulis (1938-2011)

Lynn Petra Alexander Sagan Margulis was an American biologist, whose work in the mid-twentieth century focused on cells living together in a mutually advantageous relationship, studied cells and mitochondria in the US during the second half of the twentieth century. She developed a theory for the origin of eukaryotic cells, that proposed two kinds of structures found in eukaryotic cells mitochondria in animals, and plastids in plantsÑwere once free-living bacteria that lived harmoniously and in close proximity to larger cells, a scenario called symbiosis.

Format: Articles

Subject: People, Theories

Virginia Apgar (1909–1974)

Virginia Apgar worked as an obstetrical anesthesiologist, administering drugs that reduce women’s pain during childbirth, in the US in the mid-twentieth century. In 1953, Apgar created a scoring system using five easily assessable measurements, including heart rate and breathing rate, to evaluate whether or not infants would benefit from medical attention immediately after birth. Apgar’s system showed that infants who were previously set aside as too sick to survive, despite low Apgar scores, could recover with immediate medical attention.

Format: Articles

Subject: People, Reproduction

Mary-Claire King (1946– )

Mary-Claire King studied genetics in the US in the twenty-first century. King identified two genes associated with the occurrence of breast cancer, breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2). King showed that mutated BRCA1 and BRCA2 genes cause two types of reproductive cancer, breast and ovarian cancer. Because of King’s discovery, doctors can screen women for the inheritance of mutated BRCA1 and BRCA2 genes to evaluate their risks for breast and ovarian cancer.

Format: Articles

Subject: People