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Displaying 201 - 225 of 1054 items.

“An Extended Family with a Dominantly Inherited Speech Disorder” (1990), by Jane A. Hurst et al.

In 1990, researcher Jane Hurst and her colleagues published “An Extended Family With a Dominantly Inherited Speech Disorder,” in which they proposed that a single gene was responsible for a language disorder across three generations of a family. Affected individuals of the family, called the KE family, had difficulty producing, expressing and comprehending speech. Hurst and her team studied the KE family and the disorder at the Department of Clinical Genetics at the Great Ormond Street Hospital for Children in London, England.

Format: Articles

Subject: Publications, Disorders

George Nicholas Papanicolaou (1883–1962)

George Nicholas Papanicolaou developed the Pap test in the United States during the twentieth century. The Pap test is a diagnostic procedure used to test for cervical cancer in women. Papanicolaou’s work helped improve the reproductive health of women by providing an effective means of identifying precancerous cells and improving the likelihood of early treatment and survival of cervical cancer.

Format: Articles

Subject: People, Reproduction

"Sheep Cloned by Nuclear Transfer from a Cultured Cell Line" (1996), by Keith Campbell, Jim McWhir, William Ritchie, and Ian Wilmut

In 1995 and 1996, researchers at the Roslin Institute in Edinburgh, Scotland, cloned mammals for the first time. Keith Campbell, Jim McWhir, William Ritchie, and Ian Wilmut cloned two sheep, Megan and Morag, using sheep embryo cells. The experiments indicated how to reprogram nuclei from differentiated cells to produce live offspring, and that a single population of differentiated cells could produce multiple offspring. They reported their results in the article 'Sheep Cloned by Nuclear Transfer from a Cultured Cell Line' in March 1996.

Format: Articles

Subject: Experiments

Dorothy Andersen (1901–1963)

Dorothy Andersen studied cystic fibrosis in the United States during the early 1900s. In 1935, Andersen discovered lesions in the pancreas of an infant during an autopsy, which led her to classify a condition she named cystic fibrosis of the pancreas. In 1938, Andersen became the first to thoroughly describe symptoms of the medical condition cystic fibrosis.

Format: Articles

Subject: People

"Human Factor IX Transgenic Sheep Produced by Transfer of Nuclei from Transfected Fetal Fibroblasts" (1997), by Angelika E. Schnieke, et al.

In the 1990s, researchers working at the Roslin Institute in Edinburgh, Scotland, performed cloning experiments in collaboration with PPL Therapeutics in Roslin, Scotland, on human coagulation factor IX, a protein. The team of scientists used the methods identified during the Dolly experiments to produce transgenic livestock capable of producing milk containing human blood clotting factor IX, which helps to treat a type of hemophilia.

Format: Articles

Subject: Experiments

Etienne Stephane Tarnier (1828–1897)

Etienne Stephane Tarnier was a physician who worked with premature infants in France during the nineteenth century. He worked at the Maternité Port-Royal in
Paris, France, a hospital for poor pregnant women. Tarnier developed and introduced prototypes of
infant incubators to the Maternité in 1881. Tarnier's incubators became standard in neonatal care,
especially for premature infants, enabling doctors to save many such infants that previously would
have died.

Format: Articles

Subject: People

Truman William Brophy (1848–1928)

Truman William Brophy developed a cleft palate surgical repair, later called the Brophy Operation, in the late nineteenth century US. The procedure improved facial aesthetics and speech in cleft palate patients. A cleft palate occurs during development when the palatal bones in the roof of the mouth don't completely fuse, leaving an opening, or cleft, in the upper lip and mouth. Brophy's cleft repair used compression inside and outside of the mouth to push the palatal bones into normal alignment shortly after birth.

Format: Articles

Subject: People, Disorders

Leonardo da Vinci (1452-1519)

Leonardo da Vinci was born on 15 April 1452, the illegitimate son of a young peasant girl by the name of Caterina and Ser Piero da Vinci, a well-renowned Florentine notary. Leonardo lived in Italy in the town of Vinci until his late teens and received a simple education in reading and writing as well as some training in mathematics and engineering. Although he was socially excluded by birthright from almost every profession and prohibited from attending any formal university, Leonardo went on to become a celebrated scientist, artist, and engineer.

Format: Articles

Subject: People

Barbara McClintock (1902-1992)

Barbara McClintock worked on genetics in corn (maize) plants and spent most of her life conducting research at the Cold Spring Harbor Laboratory in Laurel Hollow, New York. McClintock's research focused on reproduction and mutations in maize, and described the phenomenon of genetic crossover in chromosomes. Through her maize mutation experiments, McClintock observed transposons, or mobile elements of genes within the chromosome, which jump around the genome. McClintock received the Nobel Prize for Physiology or Medicine in 1983 for her research on chromosome transposition.

Format: Articles

Subject: People

Edward Drinker Cope (1840-1897)

Edward Drinker Cope studied fossils and anatomy in the US in the late nineteenth century. Based on his observations of skeletal morphology, Cope developed a novel mechanism to explain the law of parallelism, the idea that developing organisms successively pass through stages resembling their ancestors. Others had proposed the addition of new body forms at the end of an individual organism's developed as a mechanism through which new species arose, but those proposals relied on changes in the lengths of gestation or incubation.

Format: Articles

Subject: People

John Craig Venter (1946- )

John Craig Venter helped map the genomes of humans, fruitflies, and other organisms in the US in the late 1990s and early 2000s, and he helped develop an organism with a synthetic genome. In February 2001, Venter and his team published a human genome sequence after using a technique known as Expressed Sequence Tags, or ESTs. Venter worked to bridge commercial investment with scientific research. Venter founded a number of private companies, including the for-profit Celera Genomics, headquartered in Alameda, California, as well as research institutes, such as the not-for-profit J.

Format: Articles

Subject: People

De Monstruorum Causis, Natura et Differentiis (On the Reasons, Nature and Differences of Monsters) (1616), by Fortunio Liceti

In 1616 in Padua, Italy, Fortunio Liceti, a professor of natural philosophy and medicine, wrote and published the first edition of De Monstruorum Causis, Natura et Differentiis (On the Reasons, Nature, and Differences of Monsters), hereafter De monstruorum. In De monstruorum, Liceti chronologically documented cases of human and animal monsters from antiquity to the seventeenth century. During the seventeenth century, many people considered such monsters as frightening signs of evil cursed by spiritual or supernatural entities.

Format: Articles

Subject: Theories

Emma Goldman (1869–1940)

Emma Goldman was a traveling public speaker and writer known for her anarchist political views as well as her opinions on contraception and birth limiting in the late nineteenth century in the United States. Goldman identified as an anarchist, which she explained as being part of an ideology in which people use violence to provoke or demand social and political change. Goldman was involved in many anarchist social groups and published the anarchist magazine Mother Earth.

Format: Articles

Subject: People

Lysogenic Bacteria as an Experimental Model at the Pasteur Institute (1915-1965)

Lysogenic bacteria, or virus-infected bacteria, were the primary experimental models used by scientists working in the laboratories of the Pasteur Institute in Paris, France, during the 1950s and 1960s. Historians of science have noted that the use of lysogenic bacteria as a model in microbiological research influenced the scientific achievements of the Pasteur Institute's scientists.

Format: Articles

Subject: Organisms, Experiments

Agent Orange Birth Defects

Sprayed extensively by the US military in Vietnam, Agent Orange contained a dioxin contaminant later found to be toxic to humans. Despite reports by Vietnamese citizens and Vietnam War veterans of increased rates of stillbirths and birth defects in their children, studies in the 1980s showed conflicting evidence for an association between the two. In 1996, the US National Academy of Sciences reported that there was evidence that suggested dioxin and Agent Orange exposure caused spina bifida, a birth defect in which the spinal cord develops improperly.

Format: Articles

Subject: Disorders

Stafford Leak Warren (1896–1981)

Stafford Leak Warren studied nuclear medicine in the United States during the twentieth century. He used radiation to make images of the body for diagnosis or treatment and developed the mammogram, a breast imaging technique that uses low-energy X-rays to produce an image of breasts. Mammograms allow doctors to diagnose breast cancer in its early and most treatable stages.

Format: Articles

Subject: People

Fetal Alcohol Syndrome (FAS)

The concept Fetal Alcohol Syndrome (FAS) refers to a set of birth defects that occur in children born to mothers who abused alcohol during pregnancy. The alcohol-induced defects include pre- and post-natal growth deficiencies, minor facial abnormalities, and damage to the developing central nervous system (CNS).

Format: Articles

Subject: Disorders

In re Agent Orange Product Liability Litigation (1979-1984)

In the legal case In re Agent Orange Product Liability Litigation of the early 1980s, US military veterans of the Vietnam War sued the US chemical companies that had produced the herbicide Agent Orange, and those companies settled with US veterans out of court. Agent Orange contains dioxin, a chemical later shown to disrupt the hormone system of the body and to cause cancer. As veterans returned to the US from Vietnam, scientists further confirmed that exposure to Agent Orange caused a variety of cancers in veterans and developmental problems in the veterans' children.

Format: Articles

Subject: Legal, Ethics

The Debate over DNA Replication Before the Meselson-Stahl Experiment (1953–1957)

Between 1953 and 1957, before the Meselson-Stahl experiment verified semi-conservative replication of DNA, scientists debated how DNA replicated. In 1953, James Watson and Francis Crick proposed that DNA was composed of two helical strands that wound together in a coil. Their model suggested a replication mechanism, later termed semi-conservative replication, in which parental DNA strands separated and served as templates for the replication of new daughter strands.

Format: Articles

Subject: Theories

Alejandro Sánchez Alvarado (1964- )

Alejandro Sánchez Alvarado is a Professor of Neurobiology and Anatomy at the University of Utah School of Medicine and is also a Howard Hughes Medical Institute Investigator. Born in Caracas, Venezuela, 24 February 1964, Sánchez Alvarado left his home to pursue education in the United States, where he received a Bachelor of Science in molecular biology and chemistry from Vanderbilt University in 1986 and a Doctorate in pharmacology and cell biophysics at the University of Cincinnati College of Medicine in 1992.

Format: Articles

Subject: People

Stem Cell Tourism

When James Thomson of the University of Wisconsin announced in 1998 that he had derived and cultured human embryonic stem cells(hESCs), Americans widely believed-and accepted-that stem cells would one day be the basis of a multitude of regenerative medical techniques. Researchers promised that they would soon be able to cure a variety of diseases and injuries such as cancer, diabetes, Parkinson's, spinal cord injuries, severe burns, and many others. But it wasn't until January 2009 that the Food and Drug Administration approved the first human clinical trials using hESCs.

Format: Articles

Subject: Theories, Ethics

Max Ludwig Henning Delbruck (1906–1981)

Max Ludwig Henning Delbrick applied his knowledge of theoretical physics to biological systems such as bacterial viruses called bacteriophages, or phages, and gene replication during the twentieth century in Germany and the US. Delbrück demonstrated that bacteria undergo random genetic mutations to resist phage infections. Those findings linked bacterial genetics to the genetics of higher organisms. In the mid-twentieth century, Delbrück helped start the Phage Group and Phage Course in the US, which further organized phage research.

Format: Articles

Subject: People

Nuclear Magnetic Resonance Imaging to Visualize Fetal Abnormalities

Nuclear magnetic resonance imaging (MRI) is a technique to create a three-dimensional image of a fetus. Doctors often use MRIs to image a fetuses after an ultrasound has detected an, or has been inconclusive about an, abnormality. In 1983 researchers in Scotland first used MRI to visualize a fetus. MRIs showed a greater level of fetal detail than ultrasound images, and researchers recognized the relevance of this technique as a means to gather information about fetal development and growth.

Format: Articles

Subject: Technologies, Technologies, Reproduction

Benjamin Harrison Willier (1890-1972)

Benjamin Harrison Willier is considered one of the most versatile embryologists to have ever practiced in the US. His research spanned most of the twentieth century, a time when the field of embryology evolved from being a purely descriptive pursuit to one of experimental research, to that of incorporating molecular biology into the research lab. Willier was born on 2 November 1890 near Weston, Ohio to Mary Alice Ricard. He spent his childhood doing farming chores and running the farm while his father, David Willier worked as a banker.

Format: Articles

Subject: People

Wolbachia

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

Format: Articles

Subject: Organisms