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Displaying 51 - 75 of 101 items.

John Spangler Nicholas (1895-1963)

John Spangler Nicholas, an American biologist, was born on 10 March 1895 in Allegheny, Pennsylvania. He was the only child of Elizabeth Ellen Spangler, a teacher, and Samuel Trauger Nicholas, a Lutheran minister. Nicholas held myriad administrative positions throughout his life and his contributions to biology spanned several sub-disciplines, but his most notable accomplishments were in the field of embryology.

Format: Articles

Subject: People

George Linius Streeter (1873-1948)

George Linius Streeter was born on 12 January 1873 in Johnstown, New York, to Hannah Green Anthony and George Austin Streeter. He completed his undergraduate studies at Union College in 1895 and received his MD degree from the College of Physicians and Surgeons of Columbia University in 1899. At Columbia, Professor George S. Huntington sparked Streeter's interest in anatomy, and Streeter also interned at Roosevelt Hospital in New York City. He then went on to Albany to teach anatomy at the Albany Medical College and to work with neurologist Henry Hun.

Format: Articles

Subject: People

“Traditional postpartum practices and rituals: a qualitative systematic review” (2007), by Cindy-Lee Dennis, Kenneth Fung, Sophie Grigoriadis, Gail Erlick Robinson, Sarah Romans and Lori Ross

In the 2007 paper “Traditional postpartum practices and rituals: a qualitative systematic review,” Toronto-based researchers showed that women from different cultures around the world follow similar postpartum practices after giving birth. At the University of Toronto in Toronto, Canada, Cindy-Lee Dennis, Kenneth Fung, Sophie Grigoriadis, Gail Erlick Robinson, Sarah Romans, and Lori Ross examined fifty-one studies from over twenty countries that focused on traditional postpartum practices.

Format: Articles

Subject: Publications

Franklin Paine Mall (1862-1917)

Franklin Paine Mall was born into a farming family in Belle Plaine, Iowa, on 28 September 1862. While he attended a local academy, an influential teacher fueled Mall's interest in science. From 1880-1883, he studied medicine at the University of Michigan, attaining his MD degree in 1883. William J. Mayo, who later became a famous surgeon and co-founder of the Mayo Clinic in Rochester, Minnesota, was a classmate of Mall's. Throughout his studies at Michigan, he was influenced by Corydon L. Ford, a professor of anatomy, Victor C.

Format: Articles

Subject: People

"A Series of Normal Stages in the Development of the Chick Embryo" (1951), by Viktor Hamburger and Howard L. Hamilton

The developmental stages of the chick embryo were examined by Viktor Hamburger and Howard L. Hamilton in "A Series of Normal Stages in the Development of the Chick Embryo," published in the Journal of Morphology in 1951. These stages were published to standardize the development of the chick based on varying laboratory conditions and genetic differences. The stages Hamburger and Hamilton assigned were determined by the visible features of the chick embryo.

Format: Articles

Subject: Experiments

Ethics of Fetal Surgery

Surgeons sometimes operate on the developing fetuses in utero of pregnant women as a medical intervention to treat a number of congential abnormalities, operations that have ethical aspects. A. William Liley performed the first successful fetal surgery, a blood transfusion, in New Zealand in 1963 to counteract the effects of hemolytic anemia, or Rh disease.

Format: Articles

Subject: Ethics

Wilhelm Johannsen's Genotype-Phenotype Distinction

Wilhelm Johannsen in Denmark first proposed the distinction between genotype and phenotype in the study of heredity in 1909. This distinction is between the hereditary dispositions of organisms (their genotypes) and the ways in which those dispositions manifest themselves in the physical characteristics of those organisms (their phenotypes). This distinction was an outgrowth of Johannsen's experiments concerning heritable variation in plants, and it influenced his pure line theory of heredity.

Format: Articles

Subject: Theories

Gustav Jacob Born (1851-1900)

Gustav Jacob Born was an experimental embryologist whose original work with amphibians served as the platform for his wax-plate method of embryo modeling, heteroblastic (different tissues) and xenoplastic (similar species) transplantation methods, environmental influences on sex ratio studies, and proposed function of the corpus luteum. He was born 22 April 1851 in Kempen, Prussia, but his family moved to the larger city of Görlitz within a year after Born's birth. His father was Marcus Born, a physician and public health officer who practiced in the town of Görlitz.

Format: Articles

Subject: People

"Risks and Benefits of Estrogen Plus Progestin in Healthy, Postmenopausal Women: Principal Results from the Women's Health Initiative Randomized Controlled Trial" (2002), by Jacques Rossouw et al.

In 2002, the Writing Group for the Women's Health Initiative Investigators published the article Risks and Benefits of Estrogen Plus Progestin in Healthy, Postmenopausal Women: Principal Results from the Women's Health Initiative Randomized Controlled Trial in The Journal of the American Medical Association.

Format: Articles

Subject: Publications

Frank Rattray Lillie (1870-1947)

Frank R. Lillie was born in Toronto, Canada, on 27 June 1870. His mother was Emily Ann Rattray and his father was George Waddell Little, an accountant and co-owner of a wholesale drug company. While in high school Lillie took up interests in entomology and paleontology but went to the University of Toronto with the aim of studying ministry. He slowly became disillusioned with this career choice and decided to major in the natural sciences. It was during his senior year that he developed his lifelong interest in embryology.

Format: Articles

Subject: People

Cocaine as a Teratogen

Cocaine use by pregnant women has a variety of effects on the embryo and fetus, ranging from various gastro-intestinal and cardiac defects to tissue death from insufficient blood supply. Thus, cocaine has been termed a teratogen, or an agent that causes defects in fetuses during prenatal development. Cocaine is one of the most commonly used drugs in the US and it has a history of both medical and illegal recreational use. It is a drug capable of a wide array of effects on physical and mental health.

Format: Articles

Subject: Reproduction, Disorders

Frank Rattray Lillie's Study of Freemartins (1914-1920)

Frank Rattray Lillie's research on freemartins from 1914 to 1920 in the US led to the theory that hormones partly caused for sex differentiation in mammals. Although sometimes applied to sheep, goats, and pigs, the term freemartin most often refers to a sterile cow that has external female genitalia and internal male gonads and was born with a normal male twin.

Format: Articles

Subject: Experiments

Theophilus Shickel Painter (1889-1969)

Theophilus Shickel Painter studied the structure and
function of chromosomes in the US during in the early to mid-twentieth century. Painter worked at
the University of Texas at Austin in Austin, Texas. In the 1920s
and 1930s, Painter studied the chromosomes of the salivary gland
giant chromosomes of the fruit fly (Drosophila
melanogaster), with Hermann J. Muller. Muller and Painter
studied the ability of X-rays to cause changes in the chromosomes
of fruit flies. Painter also studied chromosomes in mammals.

Format: Articles

Subject: People

Medical Vibrators for Treatment of Female Hysteria

During the late 1800s through the early 1900s, physicians administered pelvic massages involving clitoral stimulation by early electronic vibrators as treatments for what was called female hysteria. Until the early 1900s, physicians used female hysteria as a diagnosis for women who reported a wide range of complaints and symptoms unexplainable by any other diagnosis at the time. According to historian Rachel Maines, physicians provided pelvic massages for thousands of years to female patients without it being considered erotic or sexually stimulating.

Format: Articles

Subject: Reproduction, Technologies, Ethics

Fetal Surgery

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.

Format: Articles

Subject: Disorders, Ethics, Reproduction

"Genetic Evidence Equating SRY and the Testis-Determining Factor" (1990), by Phillippe Berta et al.

In the late 1980s, Peter Goodfellow in London, UK led a team of researchers who showed that the SRY gene in humans codes a protein that causes testes to develop in embryos. During this time, scientists in London and Paris, including Peter Koompan and John Gubbay, proposed that SRY was the gene on the Y chromosome responsible for encoding the testis-determining factor (TDF) protein. The TDF is a protein that initiates embryo to develop male characteristics.

Format: Articles

Subject: Experiments

Sir Graham Collingwood Liggins (1926-2010)

Sir Graham Collingwood Liggins devoted much of his professional life to obstetric research. Liggins demonstrated that hormones created by the fetus helped initiate labor, rather than hormones originating solely from the mother. Liggins also discovered that cortisol given to pregnant mothers helped delay premature labor, and that it increased the likelihood that premature infants would breathe normally after birth. Prior to cortisol treatment, premature infants often died of respiratory distress syndrome characterized by the inability to inflate immature lungs.

Format: Articles

Subject: People, Reproduction

Julia Bell (1879-1979)

Julia Bell worked in twentieth-century Britain, discovered Fragile X Syndrome, and helped find heritable elements of other developmental and genetic disorders. Bell also wrote much of the five volume Treasury of Human Inheritance, a collection about genetics and genetic disorders. Bell researched until late in life, authoring an original research article on the effects of the rubella virus of fetal development (Congenital Rubella Syndrome) at the age of 80.

Format: Articles

Subject: People

Chang and Eng Bunker (1811–1874)

Chāng (Chang) and Ēn (Eng) Bunker were conjoined twins in the nineteenth century in the United States, the first pair of conjoined twins whose condition was well documented in medical records. A conjoined twins is a rare condition in which two infants are born physically connected to each other. In their youth, the brothers earned money by putting themselves on display as curiosities and giving lectures and demonstrations about their condition. The Bunker brothers toured around the world, including the United States, Europe, Canada, and France, and allowed physicians to examine them.

Format: Articles

Subject: People

Sex-determining Region Y in Mammals

The Sex-determining Region Y (Sry in mammals but SRY in humans) is a gene found on Y chromosomes that leads to the development of male phenotypes, such as testes. The Sry gene, located on the short branch of the Y chromosome, initiates male embryonic development in the XY sex determination system. The Sry gene follows the central dogma of molecular biology; the DNA encoding the gene is transcribed into messenger RNA, which then produces a single Sry protein.

Format: Articles

Subject: Processes

"Male Development of Chromosomally Female Mice Transgenic for Sry gene" (1991), by Peter Koopman, et al.

Early 1990s research conducted by Peter Koopman, John Gubbay, Nigel Vivian, Peter Goodfellow, and Robin Lovell-Badge, showed that chromosomally female (XX) mice embryos can develop as male with the addition of a genetic fragment from the Y chromosome of male mice. The genetic fragment contained a segment of the mouse Sry gene, which is analogous to the human SRY gene. The researchers sought to identify Sry gene as the gene that produced the testis determining factor protein (Tdf protein in mice or TDF protein in humans), which initiates the formation of testis.

Format: Articles

Subject: Experiments

"Hybrids and Chimeras: A Consultation on the Ethical and Social Implications of Creating Human/Animal Embryos in Research" (2007), by the HFEA

To educate its citizens about research into chimeras made from human and non-human animal cells, the United Kingdom's Human Fertilisation Embryology Authority published the consultation piece Hybrids and Chimeras: A Consultation on the Ethical and Social Implications of Creating Human/Animal Embryos in Research, in 2007.

Format: Articles

Subject: Publications

"Hybrids and Chimeras: A report on the findings of the consultation" by the Human Fertilisation and Embryology Authority in October, 2007

In 2007, the Human Fertilisation and Embryology Authority in London, UK, published Hybrids and Chimeras: A Report on the Findings of the Consultation, which summarized a public debate about research on, and suggested policy for, human animal chimeras. The HFEA formulated the report after conducting a series of surveys and debates from earlier in 2007. The HFEA issued a statement in September 2007, followed by an official report published on 1 October 2007. Their report on human-animal chimeras set a worldwide precedent for discussions of the ethical use of those embryos in labs.

Format: Articles

Subject: Publications, Legal, Outreach

William Withey Gull (1816-1890)

William Withey Gull studied paraplegia, anorexia, and hormones as a physician in England during the nineteenth century. In addition to caring for patients, he described the role of the posterior column of the spinal cord in paraplegia, and he was among the first to describe the conditions of anorexia and of hypochondria. He also researched the effects of thyroid hormone deficiencies in women who had malfunctioning thyroid glands.

Format: Articles

Subject: People

David Wildt's Domestic Cat and Cheetah Experiments (1978-1983)

David Wildt's cheetah (Acinonyx jubatus) research from 1978-1983 became the foundation for the use of embryological techniques in endangered species breeding programs. The cheetah is a member of the cat family (Felidae), which includes thirty-seven species. According to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) all Felidae species are currently threatened or endangered, with the exception of the domestic cat (Felinus catus).

Format: Articles

Subject: Experiments