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Displaying 151 - 175 of 309 items.

"Contributions to the Development of the Embryo. On the Artificial Production of One of the First Two Blastomeres, and the Later Development (Postgeneration) of the Missing Half of the Body" (1888), by Wilhelm Roux

Wilhelm Roux was an influential figure in the early history of experimental embryology. Although he originally studied medicine, he was invited to be a Privatdozentur, or unsalaried lecturer, at the Anatomical Institute in Breslau (Wroclaw), Poland, in 1879. He spent the next ten years at this institute, working his way from Dozent to associate professor and finally, in 1889, to director for his own institute, Institut für Entwicklungsgeschichte, or Institute for Developmental History and Mechanics.

Format: Articles

Subject: Experiments

Facial Abnormalities of Fetal Alcohol Syndrome (FAS)

Prenatal exposure to alcohol (ethanol) results in a continuum of physical, neurological, behavioral, and learning defects collectively grouped under the heading Fetal Alcohol Spectrum Disorder (FASD). Fetal Alcohol Syndrome (FAS) was first defined in 1973 as a condition characterized by pre- and postnatal growth deficiencies, facial abnormalities, and defects of the central nervous system. The pattern of facial defects that occur as a result of ethanol exposure during development primarily affects the midline of the face, altering morphology of the eyes, nose, and lips.

Format: Articles

Subject: Disorders, Reproduction

Hwang Woo-suk's Use of Human Eggs for Research 2002-2005

Hwang Woo-suk, a geneticist in South Korea, claimed in Science magazine in 2004 and 2005 that he and a team of researchers had for the first time cloned a human embryo and that they had derived eleven stem cell lines from it. Hwang was a professor at Seoul National University in Seoul, South Korea. In the Science articles, Hwang stated that all of the women who donated eggs to his laboratory were volunteers who donated their eggs (oocytes) without receiving any compensation in return. In 2006, Hwang admitted that many of the results were fabricated.

Format: Articles

Subject: Legal, Ethics, Reproduction

Francesco Redi (1626-1698)

Francesco Redi, son of Florentine physician Cecilia de' Ghinci and Gregorio Redi, was born in Arezzo, Italy, on 18 February 1626. He studied philosophy and medicine at the University of Pisa, graduating on 1 May 1647. A year later, Redi moved to Florence and registered at the Collegio Medico. There he served at the Medici Court as both the head physician and superintendent of the ducal pharmacy and foundry. Redi was also a member of the Accademia del Cimento, which flourished from 1657-1667. It was during this decade that Redi produced his most important works.

Format: Articles

Subject: People

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

Interspecies SCNT-derived Humanesque Blastocysts

Since the 1950s, scientists have developed interspecies blastocysts in laboratory settings, but not until the 1990s did proposals emerge to engineer interspecies blastocysts that contained human genetic or cellular material. Even if these embryos were not permitted to mature to fetal stages, their ethical and political status became debated within nations attempting to use them for research.

Format: Articles

Subject: Theories

“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

Dickey-Wicker Amendment, 1996

The Dickey-Wicker Amendment is an amendment attached to the appropriations bills for the Departments of Health and Human Services, Labor, and Education each year since 1996 restricting the use of federal funds for creating, destroying, or knowingly injuring human embryos. The Dickey-Wicker Amendment began as a rider (another name for an amendment) attached to House Resolution (H.R.) 2880. H.R.

Format: Articles

Subject: Legal

Effects of Prenatal Alcohol Exposure on Ocular Development

Maternal consumption of alcohol (ethanol) can result in a range of alcohol-induced developmental defects. In humans, those collective birth defects are called Fetal Alcohol Spectrum Disorders, with the most severe manifestation being Fetal Alcohol Syndrome (FAS). FAS is defined by pre- and post-natal growth retardation, minor facial abnormalities, and deficiencies in the central nervous system (CNS). The eye and ocular system development is particularly susceptible to the effects of prenatal alcohol exposure and can result in visual impairment or blindness.

Format: Articles

Subject: Disorders, Reproduction

"Experiments in Plant Hybridization" (1866), by Johann Gregor Mendel

During the mid-nineteenth century, Johann Gregor Mendel experimented with pea plants to develop a theory of inheritance. In 1843, while a monk in the Augustian St Thomas's Abbey in Brünn, Austria, now Brno, Czech Repubic, Mendel examined the physical appearance of the abbey's pea plants (Pisum sativum) and noted inconsistencies between what he saw and what the blending theory of inheritance, a primary model of inheritance at the time, predicted.

Format: Articles

Subject: Experiments

De Formatione Ovi et Pulli (1621), by Girolamo Fabrici

The embryological treatise De formatione ovi et pulli (On the Formation of the Egg and of the Chick) was written by anatomist and embryologist Girolamo Fabrici and published in Padua posthumously in 1621. The book was edited by Joahannes Prevotius and is separated into two parts that describe Fabrici's observations and assumptions on embryology and combine the traditional knowledge of his predecessors with his own first-hand anatomical observations.

Format: Articles

Subject: Publications

Studies in Spermatogenesis (1905), by Nettie Maria Stevens

Studies in Spermatogenesis is a two volume book written by Nettie Maria Stevens, and published by the Carnegie Institution of Washington in 1905 and 1906. In the books Stevens explains the research she conducted on chromosomal sex determination in the sperm and egg cells of insect species while at Bryn Mawr College, near Philadelphia, Pennsylvania. Studies in Spermatogenesis described early examples of chromosomal XY sex-determination.

Format: Articles

Subject: Publications

Shoukhrat Mitalipov and Masahito Tachibana's Mitochondrial Gene Replacement Therapy Technique

In 2009, Shoukhrat Mitalipov, Masahito Tachibana, and their team of researchers developed the technology of mitochondrial gene replacement therapy to prevent the transmission of a mitochondrial disease from mother to offspring in primates. Mitochondria contain some of the body's genetic material, called mitochondrial DNA. Occasionally, the mitochondrial DNA possesses mutations.

Format: Articles

Subject: Technologies

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

"Alternative Sources of Human Pluripotent Stem Cells" (2005), by Leon Kass and the President’s Council on Bioethics

Human pluripotent stem cells are valued for their potential to form numerous specialized cells and for their longevity. In the US, where a portion of the population is opposed to destruction of human embryos to obtain stem cells, what avenues are open to scientists for obtaining pluripotent cells that do not offend the moral sensibilities of a significant number of citizens?

Format: Articles

Subject: Publications, Ethics

Clinica Para Madres (1934-1950)

The Clinica Para Madres (Mother’s Clinic) opened in Tucson, Arizona, in December of 1934 as the first birth control clinic in Arizona. After moving to Tucson, birth control activist Margaret Sanger, along with a group of local philanthropic women, founded the clinic to provide Arizona women with contraception. During the early 1900s in the US, contraception was illegal under the federal Comstock Act. Additionally, many viewed contraception and sex as obscene and not to be discussed in public or outside of marriage.

Format: Articles

Subject: Organizations, Reproduction, Outreach

Title X Family Planning Program (1970–1977)

The Family Planning Services and Public Research Act of 1970, often called Title X Family Planning Program, is a US federal law that provides federal funding for family planning services to low income or uninsured families. The US federal government passed the law, Public Law 91-572, in 1970 as an amendment to the Public Health Services Act of 1944. The Act created the Office of Population Affairs (OPA) under the Secretary of Health, Education, and Welfare (here called the Secretary).

Format: Articles

Subject: Reproduction, Legal

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

Karl Wilhelm Theodor Richard von Hertwig (1850-1937)

Karl Wilhelm Theodor Richard von Hertwig is an important figure in the history of embryology for his contributions of artificial hybridization of sea urchin eggs and the formulation of his coelom theory. He was born 23 September 1850 in Friedelberg, Germany, to Elise Trapp and Carl Hertwig. Richard and his older brother Oscar began their studies at Jena under the direction of Ernst Haeckel from 1868 to 1871. In 1872 Hertwig became a lecturer in zoology at Jena while Oscar lectured in anatomy and embryology.

Format: Articles

Subject: People

Embryonic Differentiation in Animals

Embryonic differentiation is the process of development during which embryonic cells specialize and diverse tissue structures arise. Animals are made up of many different cell types, each with specific functions in the body. However, during early embryonic development, the embryo does not yet possess these varied cells; this is where embryonic differentiation comes into play. The differentiation of cells during embryogenesis is the key to cell, tissue, organ, and organism identity.

Format: Articles

Subject: Processes

"Drama of Life Before Birth" (1965), by Life Magazine and Lennart Nilsson

Life Magazine's 1965 cover story "Drama of Life Before Birth" featured photographs of embryos and fetuses taken by Swedish photojournalist Lennart Nilsson to document the developmental stages of a human embryo. Included in this article was the first published image of a living fetus inside its mother's womb. Prior to this, embryos and fetuses were observed, studied, and photographed outside of women's bodies as non-living specimens.

Format: Articles

Subject: Publications, Outreach, Reproduction

Mitochondrial Diseases in Humans

Mitochondrial diseases in humans result when the small organelles called mitochondria, which exist in all human cells, fail to function normally. The mitochondria contain their own mitochondrial DNA (mtDNA) separate from the cell's nuclear DNA (nDNA). The main function of mitochondria is to produce energy for the cell. They also function in a diverse set of mechanisms such as calcium hemostasis, cell signaling, regulation of programmed cell death (apoptosis), and biosynthesis of heme proteins that carry oxygen.

Format: Articles

Subject: Disorders, 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

The First Successful Cloning of a Gaur (2000), by Advanced Cell Technology

Advanced Cell Technology (ACT), a stem cell biotechnology company in Worcester, Massachusetts, showed the potential for cloning to contribute to conservation efforts. In 2000 ACT researchers in the United States cloned a gaur (Bos gaurus), an Asian ox with a then declining wild population. The researchers used cryopreserved gaur skin cells combined with an embryo of a domestic cow (Bos taurus). A domestic cow also served as the surrogate for the developing gaur clone.

Format: Articles

Subject: Experiments

Albrecht von Haller (1708-1777)

Victor Albrecht von Haller was an 18th century scientist who did extensive work in the life sciences, including anatomy and physiology, botany, and developmental biology. His embryological work consisted of experiments in understanding the process of generation, and led him to adopt the model of preformationism called ovism (the idea that the new individual exists within the maternal egg prior to conception). Haller was born in Bern, Switzerland, on 16 October, 1708. His mother was Anna Maria Engel, and his father was Niklaus Emanuel Haller.

Format: Articles

Subject: People