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Displaying 276 - 300 of 614 items.

United States v. University Hospital (1984)

The US 2nd Circuit Court of Appeals' 1984 decision United States v. University Hospital, State University Hospital of New York at Stony Brook set a significant precedent for affirming parental privilege to make medical decisions for handicapped newborns, while limiting the ability of the federal government to intervene. The ruling stemmed from the 1983 case involving an infant born with severe physical and mental congenital defects; the infant was only identified as Baby Jane Doe.

Format: Articles

Subject: Legal, Reproduction

Images of Embryos in Life Magazine in the 1950s

Embryonic images displayed in Life magazine during the mid-twentieth century serve as a representation of technological advances and the growing public interest in the stages of embryological development. These black-and-white photographs portray skeletal structures and intact bodies of chicken embryos and human embryos and fetuses obtained from collections belonging to universities and medical institutions.

Format: Articles

Subject: Outreach, Publications, Reproduction

"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

Johann Friedrich Meckel, the Younger (1781-1833)

Johann Friedrich Meckel studied abnormal animal and human anatomy in nineteenth century Germany in an attempt to explain embryological development. During Meckel's lifetime he catalogued embryonic malformations in multiple treatises. Meckel's focus on malformations led him to develop concepts like primary and secondary malformations, atavism, and recapitulation- all of which influenced the fields of medicine and embryology during the nineteenth and twentieth centuries.

Format: Articles

Subject: People

Endoscopy

Endoscopy is a medical procedure that enables the viewing and biopsy of, and surgery on, internal tissues and organs. Endoscopic examinations are characterized by the introduction of a tube containing a series of lenses into the body through either an incision in the skin or a natural opening or cavity. During the mid-twentieth century, photographer Lennart Nilsson used endoscopes to capture the now-familiar images of embryos and fetuses.

Format: Articles

Subject: Technologies, Reproduction

Samuel Randall Detwiler (1890-1957)

Samuel Randall Detwiler was an embryologist who studied neural development in embryos and vertebrate retinas. He discovered evidence for the relationship between somites and spinal ganglia, that transplanted limbs can be controlled by foreign ganglia, and the plasticity of ganglia in response to limb transplantations. He also extensively studied vertebrate retinas during and after embryonic development.

Format: Articles

Subject: People

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

The Formation of Reticular Theory

In the nineteenth century, reticular theory aimed to describe the properties of neurons, the specialized cells which make up the nervous system, but was later disconfirmed by evidence. Reticular theory stated that the nervous system was composed of a continuous network of specialized cells without gaps (synapses), and was first proposed by researcher Joseph von Gerlach in Germany in 1871.

Format: Articles

Subject: Theories

Curt Jacob Stern (1902-1981)

Curt Jacob Stern studied radiation and chromosomes in humans and fruit flies in the United States during the twentieth century. He researched the mechanisms of inheritance and of mitosis, or the process in which the chromosomes in the nucleus of a single cell, called the parent cell, split into identical sets and yield two cells, called daughter cells. Stern worked on the Drosophila melanogaster fruit fly, and he provided early evidence that chromosomes exchange genetic material during cellular reproduction.

Format: Articles

Subject: People

“Revival of Spermatozoa after Dehydration and Vitrification at Low Temperatures” (1949), by Christopher Polge, Audrey Ursula Smith, and Alan Sterling Parkes

In the 1949 article “Revival of Spermatozoa after Dehydration and Vitrification at Low Temperatures,” researchers Christopher Polge, Audrey Ursula Smith, and Alan Sterling Parkes demonstrated that glycerol prevents cells from dying while being frozen. Polge and his colleagues discussed several procedures in which they had treated sperm cells from various species with glycerol, froze those cells, and then observed the physiological effects that freezing had on the treated sperm. The researchers concluded that glycerol safely preserves sperm samples from a variety of species.

Format: Articles

Subject: Publications

"Experimental Studies on Congenital Malformations" (1959), by James G. Wilson

The article Experimental Studies on Congenital Malformations was published in the Journal of Chronic Diseases in 1959. The author, James G. Wilson, studied embryos and birth defects at the University of Florida Medical School in Gainesville, Florida. In his article, Wilson reviewed experiments on birds and mammals from the previous forty years to provide general principles and guidelines in the study of birth defects and teratogens, which are things that cause birth defects.

Format: Articles

Subject: Publications

The Blastoderm in Chicks During Early Gastrulation

This image shows a chicken (Gallus gallus) embryo undergoing gastrulation in stage four (18-19 hrs after laying) according to the Hamburger-Hamilton staging series. At this point in time the chicken embryo is a blastoderm (shown in blue). The first magnification of the embryo shows that the blastoderm cell layers have thickened to form the primitive streak and Hensen's node. The primitive streak extends from the posterior (P) region to the anterior (A) region. The second rectangular magnification shows the blastoderm cross-sectioned through the primitive streak.

Format: Graphics

Subject: Processes, Organisms, Theories

Walter Jakob Gehring (1939-2014)

Walter Jakob Gehring discovered the homeobox, a DNA segment found in a specific cluster of genes that determine the body plan of animals, plants, and fungi. Gehring identified the homeobox in 1983, with the help of colleagues while isolating the Antennapedia (Antp) gene in fruit flies (Drosophila) at the University of Basel in Basel, Switzerland. Hox genes, a family of genes that have the homeobox, determine the head-to-tail (anterior-posterior) body axis of both vertebrates and invertebrates.

Format: Articles

Subject: People

"A Genomic Regulatory Network for Development" (2002), by Eric H. Davidson, et al.

In 2002 Eric Davidson and his research team published 'A Genomic Regulatory Network for Development' in Science. The authors present the first experimental verification and systemic description of a gene regulatory network. This publication represents the culmination of greater than thirty years of work on gene regulation that began in 1969 with 'A Gene Regulatory Network for Development: A Theory' by Roy Britten and Davidson. The modeling of a large number of interactions in a gene network had not been achieved before.

Format: Articles

Subject: Publications

Treatment of Anemia during Pregnancy (1931), by Lucy Wills

In 1931, physician Lucy Wills conducted a study of nutritional deficiencies that caused anemia in pregnant women in Bombay, India, later renamed Mumbai. Anemia is a lack of healthy red blood cells in the blood. Wills published the results of her study in the medical article 'Treatment of ‘Pernicious Anaemia of Pregnancy' and 'Tropical Anaemia'' in the British Medical Journal in 1931. Wills's research contributed to knowledge of anemia and the possible causes associated with the disease, such as the symptoms of fatigue and irritability.

Format: Articles

Subject: Experiments

CRISPR Acquired Resistance Against Viruses (2007)

In 2007, Philippe Horvath and his colleagues explained how bacteria protect themselves against viruses at Danisco, a Danish food company, in Dangé-Saint-Romain, France. Horvath and his team worked to improve the lifespan of bacteria cultures for manufacturing yogurt and ice cream. Specifically, they focused on bacteria’s resistance to bacteriophages, or viruses that infect bacteria. Horvath and his colleagues found that the bacteria used to culture yogurt, Streptococcus thermophilus, has an adaptive immune system that can target specific viruses that have previously infected the bacteria.

Format: Articles

Subject: Experiments

Rh Incompatibility in Pregnancy

Rh incompatibility occurs when a pregnant woman whose blood type is Rh-negative is exposed to Rh-positive blood from her fetus, leading to the mother s development of Rh antibodies. These antibodies have the potential to cross the placenta and attach to fetal red blood cells, resulting in hemolysis, or destruction of the fetus 's red blood cells. This causes the fetus to become anemic, which can lead to hemolytic disease of the newborn. In severe cases, an intrauterine blood transfusion for the fetus may be required to correct the anemia.

Format: Articles

Subject: Processes, Disorders, Reproduction

In Vitro Fertilization

In vitro fertilization (IVF) is an assisted reproductive technology (ART) initially introduced by Patrick Steptoe and Robert Edwards in the 1970s to treat female infertility caused by damaged or blocked fallopian tubes. This major breakthrough in embryo research has provided large numbers of women the possibility of becoming pregnant, and subsequent advances have dramatically increased their chances. IVF is a laboratory procedure in which sperm and egg are fertilized outside the body; the term "in vitro" is Latin for "in glass."

Format: Articles

Subject: Technologies, Reproduction

Theodor Heinrich Boveri (1862-1915)

Theodor Boveri investigated the mechanisms of heredity. He developed the chromosomal theory of inheritance and the idea of chromosomal individuality. Boveri sought to provide a comprehensive explanation for the hereditary role and behavior of chromosomes. He hoped that his experiments would also help to distinguish the roles of the nucleus and the cytoplasm in embryogenesis. Boveri was particularly interested in how offspring are shaped by the attributes of their parents.

Format: Articles

Subject: People

Clifford Grobstein (1916-1998)

Clifford Grobstein was a traditional, influential, and highly innovative biologist of the mid-twentieth century, gifted with many character facets and pragmatic talents. His early adulthood passion of linking classical embryology with developmental anatomy and medicine was joined by his later pursuit of combining research ethics and science education with public policy.

Format: Articles

Subject: People

"Visualizing Human Embryos" (1999), by Bradley Richard Smith

In March 1999 Bradley Richard Smith, a professor at the University of Michigan, unveiled the first digital magnetic resonance images of human embryos. In his article "Visualizing Human Embryos for Scientific American," Smith displayed three-dimensional images of embryos using combinations of Magnetic Resonance Microscopy (MRM), light microscopy, and various computer editing. He created virtual embryo models that it is possible to view as dissections, animations, or in their whole 3D form. Smith's images constitute a new way of visualizing embryos.

Format: Articles

Subject: Outreach, Publications

Bernard Sachs (1858-1944)

Bernard Sachs studied nervous system disorders in children in the
United States during the nineteenth and twentieth centuries. In the
late 1880s, Sachs described the fatal genetic neurological disorder
called amaurotic family idiocy, later renamed Tay-Sachs disease. The
disorder degrades motor skills as well as mental abilities in
affected individuals. The expected lifespan of a child with
Tay-Sachs is three to five years. In addition to working on
Tay-Sachs disease, Sachs described other childhood neurological and

Format: Articles

Subject: People

Friedrich Tiedemann (1781-1861)

Friedrich Tiedemann studied the anatomy of humans and animals in the nineteenth century in Germany. He published on zoological subjects, on the heart of fish, the anatomy of amphibians and echinoderms, and the lymphatic and respiratory system in birds. In addition to his zoological anatomy, Tiedemann, working with the chemist Leopold Gmelin, published about how the digestive system functioned.

Format: Articles

Subject: People

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

Spermism

Spermism was one of two models of preformationism, a theory of embryo generation prevalent in the late seventeenth through the end of the eighteenth century. Spermist preformationism was the belief that offspring develop from a tiny fully-formed fetus contained within the head of a sperm cell. This model developed slightly later than the opposing ovist model because sperm cells were not seen under the microscope until about 1677.

Format: Articles

Subject: Theories