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Displaying 326 - 350 of 614 items.

Inducing Fertilization and Development in Sand Dollars

Sand dollars are common marine invertebrates in the phylum Echinodermata and share the same class (Echinoidea) as sea urchins. They have served as model laboratory organisms for such embryologists as Frank Rattray Lillie and Ernest Everett Just. Both Lillie and Just used Echinarachnius parma for their studies of egg cell membranes and embryo development at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, in the early 1900s.

Format: Articles

Subject: Processes

John Tyler Bonner (1920- )

The establishment and growth of developmental-evolutionary biology owes a great debt to the work of John Tyler Bonner. Bonner's studies of cellular slime molds have shed light on some of the big questions of biology including the origins of multicellularity and the nature of morphogenesis. The second child of Lilly Marguerite Stehli and Paul Bonner, John Tyler was born 12 May 1920 in New York City and spent his early years in Locust Valley, Long Island (late 1920s), France (1930), and London (1932).

Format: Articles

Subject: People

"The Potency of the First Two Cleavage Cells in Echinoderm Development. Experimental Production of Partial and Double Formations" (1891-1892), by Hans Driesch

Hans Adolf Eduard Driesch was a late-nineteenth and early-twentieth century philosopher and developmental biologist. In the spring of 1891 Driesch performed experiments using two-celled sea urchin embryos, the results of which challenged the then-accepted understanding of embryo development. Driesch showed that the cells of an early embryo, when separated, could each continue to develop into normal larval forms.

Format: Articles

Subject: Experiments, Publications

"Proliferation, Differentiation and Degeneration in the Spinal Ganglia of the Chick Embryo under Normal and Experimental Conditions" (1949), by Viktor Hamburger and Rita Levi-Montalcini

In this paper Viktor Hamburger and Rita Levi-Montalcini collaborated to examine the effects of limb transplantation and explantation on neural development. In 1947 Hamburger invited Levi-Montalcini to his lab at Washington University in St. Louis to examine this question. Independently, each had previously arrived at opposing conclusions based on the same data.

Format: Articles

Subject: Experiments

"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

“Of Pregnancy and Progeny” (1980), by Norbert Freinkel

Norbert Freinkel’s lecture Of Pregnancy and Progeny was published by the American Diabetes Association’s journal Diabetes in December of 1980. In the lecture, Freinkel argued that pregnancy changes the way that the female body breaks down and uses food. Through experiments that involved pregnant women as well as infants, Freinkel established the body’s maternal metabolism and how it affects both the mother and the infant. Freinkel’s main focus of research in the latter part of his life was diabetes, specifically in pregnant women.

Format: Articles

Subject: Publications

Menstrual Tampon

Menstrual tampons are feminine hygiene devices, usually made of absorbent cotton, that are temporarily inserted into the vagina for absorbing a woman’s blood during menstruation. In 1931, Earl Haas invented the menstrual tampon most commonly used in the twenty-first century. Later, Gertrude Tendrich produced the first commercial tampon brand, Tampax, using Haas’s patented design. Tendrich and Haas’s tampon was made of tightly compacted absorbent cotton, shaped like a bullet, and had a string attached at the base that allowed for easy removal from the woman’s body.

Format: Articles

Subject: Technologies

Horatio Robinson Storer (1830–1922)

Horatio Robinson Storer was a surgeon and anti-abortion activist in the 1800s who worked in the field of women’s reproductive health and led the Physicians’ Crusade Against Abortion in the US. Historians credit Storer as being one of the first physicians to distinguish gynecology, the study of diseases affecting women and their reproductive health, as a separate subject from obstetrics, the study of pregnancy and childbirth.

Format: Articles

Subject: People, Reproduction, Religion

Neonatal Respiratory Distress Syndrome and Its Treatment with Artificial Surfactant

Neonatal respiratory distress syndrome, previously called hyaline membrane disease, is a respiratory disease affecting premature newborns. Neonatal respiratory distress syndrome involves shallow breathing, pauses between breaths that last a few seconds, or apnea, and a bluish tinge to the infant’s skin. The syndrome occurs when microscopic sacs called alveoli in infant lungs do not produce surfactant, a liquid that coats the inside of the lungs and helps them inflate during breathing.

Format: Articles

Subject: Disorders

Wilhelm Ludvig Johannsen (1857-1927)

Wilhelm Ludvig Johannsen studied plants and helped found the field of genetics, contributing methods and concepts to the study of heredity around the turn of the twentieth century in Denmark. His experiments on heredity and variation in plants influenced the methods and techniques of geneticists, and his distinction between the genotype of an organism-its hereditary disposition-and its phenotype-its observable characteristics-remains at the core of contemporary biology. Johannsen criticized biological explanations that relied on concepts such as vitalism and teleology.

Format: Articles

Subject: People

"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

History of the Monash IVF Research Program from 1971 to 1989

In 1971, a group of researchers founded the Monash IVF Research Program with the mission to discover how in vitro fertilization, or IVF, techniques could become a treatment for infertility in both men and women. The program included researcher Carl Wood and colleagues John Leeton, Alex Lopata, Alan Trounson, and Ian Johnston at the Queen Victoria Medical Center and Royal Women’s Hospital in Melbourne, Australia. Since the program’s establishment in 1971, the Monash IVF Research Program has helped to develop and implement many IVF technologies still used in clinical practice as of 2020.

Format: Articles

Subject: Organizations, Reproduction

Rock-Menkin Experiments

Dr. John Rock, a doctor of obstetrics and gynecology in Boston, and Miriam Menkin, Rock s hired lab technician, were the first researchers to fertilize a human egg outside of a human body in February of 1944. Their work was published on 4 August 1944 in an issue of Science in an article entitled "In Vitro Fertilization and Cleavage of Human Ovarian Eggs." This experiment marked the first time in history that a human embryo was produced outside of the human body, proving that in vitro fertilization was possible in humans.

Format: Articles

Subject: Experiments, Reproduction

Pope Sixtus V (1520-1590)

Known for dropping a long-held distinction in the Catholic Church between the animated and unanimated fetus, Felice Peretti was born in Grottamare, Italy, in 1521, son of a Dalmatian gardener. In his early years, Peretti worked as a swineherd, but soon became involved in the local Minorite convent in Montalto, where he served as a novice at the age of twelve. He went on to study in Montalto, Ferrara, and Bologna, continuing his devotion to religious life, and in 1547 Peretti was ordained as priest in the city of Siena.

Format: Articles

Subject: People, Religion, Reproduction

Humanae Vitae (1968), by Pope Paul VI

The "Humanae Vitae," meaning "Of Human Life" and subtitled "On the Regulation of Birth," was an encyclical promulgated in Rome, Italy, on 25 July 1968 by Pope Paul VI. This encyclical defended and reiterated the Roman Catholic Church's stance on family planning and reproductive issues such as abortion, sterilization, and contraception. The document continues to have a controversial reputation today, as its statements regarding birth control strike many Catholics as unreasonable.

Format: Articles

Subject: Religion, Reproduction

Regeneration

Regeneration is a fascinating phenomenon. The fact that many organisms have the capacity to regenerate lost parts and even remake complete copies of themselves is difficult to fathom; so difficult, in fact, that for a very long time people were reluctant to believe regeneration actually took place. It seemed unbelievable that some organisms could re-grow lost limbs, organs, and other body parts. If only we could do the same!

Format: Articles

Subject: Processes

"Cell Deaths in Normal Vertebrate Ontogeny" (1951), by Alfred Glücksmann

The review article “Cell Deaths in Normal Vertebrate Ontogeny” (abbreviated as “Cell Deaths”) was published in Biological Reviews of the Cambridge Philosophy Society in 1951. The author, Alfred Glücksmann, was a German developmental biologist then working at the Strangeways Research Laboratory, Cambridge, England. In “Cell Deaths,” Glücksmann summarizes observations about cell death in normal vertebrate development that he had compiled from literature published during the first half of the twentieth century.

Format: Articles

Subject: Publications

Ian Wilmut (1944- )

British embryologist Sir Ian Wilmut, best known for his work in the field of animal genetic engineering and the successful cloning of sheep, was born 7 July 1944 in Hampton Lucy, England. The family later moved to Scarborough, in the north of the country, to allow his father to accept a teaching position. There Wilmut met Gordon Whalley, head of the biology department at Scarborough High School for Boys, which Wilmut attended.

Format: Articles

Subject: People

Caspar Friedrich Wolff (1734-1794)

Caspar Friedrich Wolff is most famous for his 1759 doctoral dissertation, Theoria Generationis, in which he described embryonic development in both plants and animals as a process involving layers of cells, thereby refuting the accepted theory of preformation: the idea that organisms develop as a result of the unfolding of form that is somehow present from the outset, as in a homunculus. This work generated a great deal of controversy and discussion at the time of its publication but was an integral move in the reemergence and acceptance of the theory of epigenesis.

Format: Articles

Subject: People

Andrew Francis Dixon (1868-1936)

Andrew Francis Dixon studied human anatomy and egg cells at the turn of the twentieth century in Ireland and Great Britain. Dixon studied the sensory and motor nervous system of the face, the cancellous bone tissue of the femur, supernumerary kidneys, and the urogenital system. In 1927 Dixon described a mature human ovarian follicle. This follicle, Dixon noted, contained an immature human egg cell (oocyte) with a visible first polar body and the beginnings of the second polar body.

Format: Articles

Subject: People

Shoukhrat Mitalipov and Masahito Tachibana’s Mitochondrial Gene Replacement in Primate Offspring and Embryonic Stem Cells (2009)

Shoukhrat Mitalipov, Masahito Tachibana, and their team of researchers replaced the mitochondrial genes of primate embryonic stem cells via spindle transfer. Spindle replacement, also called spindle transfer, is the process of removing the genetic material found in the nucleus of one egg cell, or oocyte, and placing it in another egg that had its nucleus removed. Mitochondria are organelles found in all cells and contain some of the cell’s genetic material. Mutations in the mitochondrial DNA can lead to neurodegenerative and muscle diseases.

Format: Articles

Subject: Experiments

“Mothers’ Anxiety During Pregnancy Is Associated with Asthma in Their Children” (2009), by Hannah Cookson, Raquel Granell, Carol Joinson, Yoav Ben-Shlomo, and A. John Henderson

In 2009, A. John Henderson and colleagues published “Mothers’ Anxiety During Pregnancy Is Associated with Asthma in Their Children,” hereafter, “Mothers’ Anxiety,” in The Journal of Allergy and Clinical Immunology. Previous studies had shown that maternal stress during pregnancy affects children’s health during childhood. The researchers explored the association of asthma in children with maternal anxiety during pregnancy. The cause of asthma is often unknown.

Format: Articles

Subject: Theories, Reproduction, Publications, Disorders

The Business of Being Born (2008)

In 2008, Barranca Productions released a documentary called The Business of Being Born, detailing the topic of childbirth. Ricki Lake and Abby Epstein produced and directed the documentary. The documentary explores pregnancy related healthcare in the US, including the history of midwives and obstetrics. The film also discusses potential consequences of medicalized childbirth common in the twenty-first century. The Business of Being Born provides viewers with information about home-births, midwives, and the positive and negative aspects of going to the hospital for childbirth.

Format: Articles

Subject: Outreach

“Survival of Mouse Embryos Frozen to -196 ° and -269 °C” (1972), by David Whittingham, Stanley Leibo, and Peter Mazur

In 1972, David Whittingham, Stanley Leibo, and Peter Mazur published the paper, “Survival of Mouse Embryos Frozen to -196 ° and -269 °C,” hereafter, “Survival of Mouse Embryos,” in the journal Science. The study marked one of the first times that researchers had successfully cryopreserved, or preserved and stored by freezing, a mammalian embryo and later transferred that embryo to a live mouse who gave birth to viable offspring. Previously, scientists had only been successful cryopreserving single cells, like red blood cells.

Format: Articles

Subject: Experiments, Publications

Johannes Holtfreter (1901-1992)

Johannes Holtfreter made important discoveries about the properties of the organizer discovered by Hans Spemann. Although he spent much time away from the lab over many years, he was a productive researcher. His colleagues noted that the time he spent away helped revitalize his ideas. He is credited with the development of a balanced salt medium to allow embryos to develop; the discovery that dead organizer tissue retains inductive abilities; and the development of specification, competence, and distribution of fate maps in the developing frog embryo.

Format: Articles

Subject: People