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Displaying 1901 - 1925 of 2008 items.

Acid Dissolution of Fossil Dinosaur Eggs

Acid dissolution is a technique of removing a fossil from the surrounding rock matrix in which it is encased by dissolving that matrix with acid. Fossilized bone, though strong enough to be preserved for thousands or millions of years, is often more delicate than rock. Once a fossil is discovered, scientists must remove the fossil from its surroundings without damaging the fossil itself.

Format: Articles

Subject: Technologies

The Mustard Operation

The Mustard Operation is a surgical technique to correct a heart condition called the transposition of the great arteries (TGA). TGA is a birth defect in which the placement of the two arteries, the pulmonary artery, which supplies deoxygenated blood to the lungs, and the aorta, which takes oxygenated blood to the body are switched. William Thornton Mustard developed the operation later named for him and in 1963 operated on an infant with TGA, and ameliorated the condition, at the Hospital for Sick Children in Toronto, Canada.

Format: Articles

Subject: Technologies, Disorders

John Hunter (1728–1793)

John Hunter studied human reproductive anatomy, and in eighteenth century England, performed one of the earliest described cases of artificial insemination. Hunter dissected thousands of animals and human cadavers to study the structures and functions of organ systems. Much of his anatomical studies focused on the circulatory, digestive, and reproductive systems. He helped to describe the exchange of blood between pregnant women and their fetuses. Hunter also housed various natural collections, as well as thousands of preserved specimens from greater than thirty years of anatomy work.

Format: Articles

Subject: People, Reproduction

Gonzales v. Carhart (2007)

In Gonzales v. Carhart (2007), the US Supreme Court held in a five-to-four decision that the 2003 Partial-Birth Abortion Ban Act passed by the US Congress was constitutional. Although the Court previously ruled in Stenberg v. Carhart (2000) that a Nebraska law that prohibited partial-birth abortions was unconstitutional, Gonzales reversed this decision. Gonzales created the precedent that anyone who delivers and kills a living fetus could be subject to legal consequences, unless he or she performed the procedure to save the life of the mother.

Format: Articles

Subject: Legal, Reproduction

Clinical Tests of Estrogen Injections on Women with Abnormal Menstrual Cycles During the Early 1920s by Jean Paul Pratt and Edgar Allen

In the early twentieth century US, Jean Paul Pratt and Edgar Allen conducted clinical experiments on women who had abnormal menstrual cycles. During the clinical tests, researchers injected the hormone estrogen into their patients to alleviate their menstrual ailments, which ranged from irregular cycles to natural menopause. The hormone estrogen plays a prominent role in the menstrual cycle by signaling the tissue lining the uterus (endometrium) to thicken in preparation for possible pregnancy.

Format: Articles

Subject: Experiments

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

Harald zur Hausen's Experiments on Human Papillomavirus Causing Cervical Cancer (1976–1987)

From 1977 to 1987, Harald zur Hausen led a team of researchers across several institutions in Germany to investigate whether the human papillomavirus (HPV) caused cervical cancer. Zur Hausen's first experiment tested the hypothesis that HPV caused cervical cancer rather than herpes simplex virus type 2 (HSV-2), the then accepted cause. His second and third experiments detailed methods to identify two previously unidentified HPV strains, HPV 16 and HPV 18, in cervical cancer tumor samples. The experiments showed that HPV 16 and 18 DNA were present in cervical tumor samples.

Format: Articles

Subject: Experiments

Alexandre Lion’s Incubator Charities in Europe (1894–1898)

Alexandre Lion established incubator charities in the late 1890s in France to promote his infant incubator. Lion’s infant incubators kept premature infants warm and improved their chances of survival, but were expensive and not widely used. In order to promote his new technology, Lion displayed incubators that carried premature infants in storefronts and at fairs and expositions throughout Europe. After the public began paying admission to view the infants and incubators, the expositions became incubator charities. Admission fees went directly to the care of the premature infants.

Format: Articles

Subject: Organizations

"The Familial Factor in Toxemia of Pregnancy" (1968), by Leon C. Chesley, et al.

In the 1950s and 1960s, researchers Leon Chesley, John Annitto, and Robert Cosgrove investigated the possible familial factor for the conditions of preeclampsia and eclampsia in pregnant women. Preeclampsia and eclampsia, which are related to high blood pressure, have unknown causes and affect at least five percent of all pregnancies.

Format: Articles

Subject: Reproduction, Experiments, Disorders

"'Doing the Month': Confinement and Convalescence of Chinese Women After Childbirth" (1978), by Barbara L.K. Pillsbury

In 1978 Social Science and Medicine published Barbara L.K. Pillsbury's article, 'Doing the Month': Confinement and Convalescence of Chinese Women After Childbirth, which summarized the results of Pillsbury's study on Chinese childbirth customs. Pillsbury, a professor of cultural anthropology at San Diego State University in San Diego, California, conducted over eighty interviews with people in Taiwan and China, including civilians, herbalists, and physicians over a four-month period in 1975.

Format: Articles

Subject: Publications

Infant Mortality: Results of a Field Study in Johnstown, PA., Based on Births in One Calendar Year (1915), by Emma Duke

The book Infant Mortality: Results of a Field Study in Johnstown, PA., Based on Births in One Calendar Year (1915), written by Emma Duke, detailed one of the first infant mortality field studies conducted by the US Children's Bureau. In the study, Duke and her colleagues collected information about over one thousand infants in the city of Johnstown, Pennsylvania. They used that information, along with interviews conducted with the families of the infants, to identify factors that affected infant mortality rates in the community.

Format: Articles

Subject: Experiments, Publications

"Vietnam Veterans' Risks for Fathering Babies with Birth Defects" (1984), by J. David Erickson et al.

In 1984, J. David Erickson and his research team published the results of a study titled 'Vietnam Veterans' Risks for Fathering Babies with Birth Defects' that indicated that Vietnam veterans were at increased risk of fathering infants with serious congenital malformations, or birth defects.

Format: Articles

Subject: Publications

Ignaz Philipp Semmelweis (1818-1865)

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.

Format: Articles

Subject: People

Martius Flap Procedure to Repair Obstetric Fistulas

The Martius flap procedure is a surgical procedure used to treat obstetric fistulas in women. Heinrich Martius developed the procedure in twentieth century Germany to treat women with urinary incontinence caused by stress, and later doctors used it to repair obstetric fistulas. Fistulas occur in pregnant women when a hole is torn between the vagina and the urinary tract (called vesicovaginal) or the vagina and the rectum (called rectovaginal). The hole, or fistula, occurs in the tissue separating two organs and therefore obstetric fistulas result in either urinary or fecal incontinence.

Format: Articles

Subject: Technologies, Disorders

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

The Apgar Score (1953-1958)

In 1952 Virginia Apgar, a physician at the Sloane Women’s Hospital in New York City, New York, created the Apgar score as a method of evaluating newborn infants’ health to determine if they required medical intervention. The score included five separate categories, including heart rate, breathing rate, reaction to stimuli, muscle activity, and color. An infant received a score from zero to two in each category, and those scores added up to the infant’s total score out of ten. An infant with a score of ten was healthy, and those with low scores required medical attention at birth.

Format: Articles

Subject: Technologies, Processes

“Elective Induction of Labor” (1955), by Edward Bishop

In 1955, obstetrician Edward Bishop, a physician specializing in childbirth, published the article “Elective Induction of Labor,” in which he proposed the best conditions for pregnant women to elect to induce, or begin, labor. Elective induction of labor requires an obstetrician to administer a drug to help a pregnant woman to start her contractions, and to rupture the fluid-filled sac surrounding the fetus called the amniotic sac.

Format: Articles

Subject: Reproduction, Publications

Gene Transfer Strategy Used to Treat Tay - Sachs Disease (2005), by Sabata Martino’s Research Group

In the early 2000s, Sabata Martino and a team of researchers in Italy and Germany showed that they could reduce the symptoms of Tay-Sachs in afflicted mice by injecting them with a virus that infected their cells with a gene they lacked. Tay-Sachs disease is a fatal degenerative disorder that occurs in infants and causes rapid motor and mental impairment, leading to death at the ages of three to five. In gene therapy, researchers insert normal genes into cells that have missing or defective genes in order to correct genetic disorders.

Format: Articles

Subject: Experiments

Neonatal Jaundice

Neonatal jaundice is the yellow discoloration of the skin and eyes due to elevated bilirubin levels in the bloodstream of a newborn. Bilirubin is a byproduct of the breakdown of red blood cells. Jaundiced infants are unable to process bilirubin at a normal rate or they have an abnormally high amount of bilirubin in their bloodstream, resulting in a buildup of the yellow colored bilirubin. That build up is called hyperbilirubinemia and is the cause of jaundice.

Format: Articles

Subject: Disorders

The Effectiveness of Phototherapy in Premature Infants (1968)

In 1968, pediatric researchers Jerold Lucey, Mario Ferreiro, and Jean Hewitt conducted an experimental trial that determined that exposure to light effectively treated jaundice in premature infants. The three researchers published their results in 'Prevention of Hyperbilirubinemia of Prematurity by Phototherapy' that same year in Pediatrics. Jaundice is the yellowing of the skin and eyes due to the failure of the liver to break down excess bilirubin in the blood, a condition called hyperbilirubinemia.

Format: Articles

Subject: Experiments

Transposition of the Great Arteries (TGA)

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.

Format: Articles

Subject: Disorders

Dandy-Walker Syndrome

Dandy-Walker Syndrome is a congenital brain defect in humans characterized by malformations to the cerebellum, the part of the brain that controls movement, and to the ventricles, the fluid-filled cavities that surround the cerebellum. The syndrome is named for physicians Walter Dandy and Arthur Walker who described associated signs and symptoms of the syndrome in the 1900s. The malformations often develop during embryonic stages.

Format: Articles

Subject: Disorders

Arthur Earl Walker (1907-1995)

Arthur Earl Walker was a medical researcher and physician who studied the brain and neurosurgery in the United States during the twentieth century. Walker examined the connections of the thalamus to the rest of the brain and how the thalamus coordinates sensory signals. The thalamus is a cluster of nerve cells located between the two hemispheres of the brain and it is responsible for consciousness and sensory interpretation.

Format: Articles

Subject: People

Hydrocephalus During Infancy

Hydrocephalus is a congenital or acquired disorder characterized by the abnormal accumulation of cerebrospinal fluid within the cavities of the brain, called ventricles. The accumulation of cerebrospinal fluid, the clear fluid surrounding the brain and spinal cord, causes an abnormal widening of the ventricles. The widening creates potentially harmful pressure on the tissues of the brain that can result in brain damage or death.

Format: Articles

Subject: Disorders