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"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?
Subject: Publications, Ethics
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.
Embryo Blotting Paper Models
Anatomical models have always been a mainstay of descriptive embryology. As the training of embryologists grew in the late 1800s, so too did the need for large-scale teaching models. Embryo wax models, such as those made by Adolf Ziegler and Gustav Born, were popular in the latter part of the nineteenth century and the early twentieth century as a way to visualize, in three dimensions, the fine detail of embryos without the aid of a microscope.
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.
Allan Charles Wilson (1934-1991)
Allan C. Wilson studied genes, proteins, and body structures of animals and humans in the US during the second half of the twentieth century. Wilson also studied human evolution. Although morphology and behaviors of humans (Homo sapiens) and great apes differ, Wilson found that they have biochemical and genetic similarities. Wilson and his colleagues calculated the time period of humans' and African apes' common ancestor.
David Starr Jordan (1851-1931)
David Starr Jordan studied fish and promoted eugenics in the US during the late nineteenth and early twentieth centuries. In his work, he embraced Charles Darwin s theory of evolution and described the importance of embryology in tracing phylogenic relationships. In 1891, he became the president of Stanford University in Stanford, California. Jordan condemned war and promoted conservationist causes for the California wilderness, and he advocated for the eugenic sterilization of thousands of Americans.
Subject: People, Reproduction
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.
The endothelium is the layer of cells lining the blood vessels in animals. It weighs more than one kilogram in adult humans, and it covers a surface area of 4000 to 7000 square meters. The endothelium is the cellular interface between the circulating blood and underlying tissue. As the medium between these two sets of tissues, endothelium is part of many normal and disease processes throughout the body.
George Wells Beadle (1903-1989)
George Wells Beadle studied corn, fruit flies, and funguses in the US during the twentieth century. These studies helped Beadle earn the 1958 Nobel Prize in Physiology or Medicine. Beadle shared the prize with Edward Tatum for their discovery that genes help regulate chemical processes in and between cells. This finding, initially termed the one gene-one enzyme hypothesis, helped scientists develop new techniques to study genes and DNA as molecules, not just as units of heredity between generations of organisms.
Lynn Petra Alexander Sagan Margulis (1938-2011)
Lynn Petra Alexander Sagan Margulis was an American biologist, whose work in the mid-twentieth century focused on cells living together in a mutually advantageous relationship, studied cells and mitochondria in the US during the second half of the twentieth century. She developed a theory for the origin of eukaryotic cells, that proposed two kinds of structures found in eukaryotic cells mitochondria in animals, and plastids in plantsÑwere once free-living bacteria that lived harmoniously and in close proximity to larger cells, a scenario called symbiosis.
Harry Hamilton Laughlin (1880-1943)
Harry Hamilton Laughlin helped lead the eugenics
movement in the United States during the early twentieth century.
The US eugenics movement of the early twentieth century sought to
reform the genetic composition of the United States population through
sterilization and other restrictive reproductive measures. Laughlin
worked as superintendent and assistant director of the Eugenics
Research Office (ERO) at Cold Spring Harbor Laboratory in Cold
Spring Harbor, New York, alongside director Charles Davenport.
Subject: People, Reproduction
Telomerase in Human Development
Telomerase is an enzyme that regulates the lengths of telomeres in the cells of many organisms, and in humans it begins to function int the early stages of embryonic development. Telomeres are repetitive sequences of DNA on the ends of chromosomes that protect chromosomes from sticking to each other or tangling. In 1989, Gregg Morin found that telomerase was present in human cells. In 1996, Woodring Wright and his team examined human embryonic cells and found that telomerase was active in them. Scientists manipulate telomerase in cells to give cells the capacity to replicate infinitely.
Edgar Allen (1892–1943)
Edgar Allen identified and outlined the role of female sex hormones and discovered estrogen in the early 1900s in the US. In 1923, Allen, through his research with mice, isolated the primary ovarian hormone, later renamed estrogen, from ovarian follicles and tested its effect through injections in the uterine tissues of mice. Allen’s work on estrogen, enabled researchers to further study hormones and the endocrine system.
Irving Freiler Stein Sr. (1887–1976)
Irving Freiler Stein Sr. was a physician who studied women’s reproductive health during the twentieth century in the United States. In partnership with his colleague, Michael Leventhal, Stein identified a women’s reproductive disorder related to elevated male sex hormones, or androgens. The syndrome was originally called Stein-Leventhal syndrome and later known as polycystic ovarian syndrome. While studying the syndrome, Stein also helped establish a treatment for the condition, through the surgical removal of ovarian tissues.
The Food and Drug Administration’s Pregnancy and Lactation Labeling Rule (2014)
In 2014, the United States Food and Drug Administration published the Pregnancy and Lactation Labeling Rule to amend previous guidelines for the prescription of drugs for pregnant and lactating women. The 2014 Pregnancy and Lactation Labeling Rule was intended to increase the safety and efficacy of prescription drugs by making drug labels easier for physicians to understand and utilize.
Gail Roberta Martin (1944– )
In the twentieth and early twenty-first centuries, Gail Roberta Martin specialized in biochemistry and embryology, more specifically cellular communication and the development of organs. In 1981, she named any cell taken from inside a human embryo at the blastocyst stage an “embryonic stem cell”. During development, an embryo goes through the blastocyst stage just before it implants in the uterus. Embryonic stem cells are useful for experiments because they are self-renewing and able to develop into almost any cell type in the body.
Boston Women’s Health Book Collective, later Our Bodies Ourselves (1969–)
The Boston Women’s Health Book Collective was a women’s health organization headquartered in Boston, Massachusetts, that published the informational book Our Bodies Ourselves, which sold over 4.5 million copies. Initially called the Doctor’s Group, the Collective formed in response to the insufficiency of women-specific health information during the late 1960s and early 1970s. Members of the organization participated in the women’s liberation movement in Boston, Massachusetts, and conducted research on women’s health using resources such as medical textbooks.
“Annual Research Review: Prenatal Stress and the Origins of Psychopathology: An Evolutionary Perspective” (2011), by Vivette Glover
In 2011, fetal researcher Vivette Glover published “Annual Research Review: Prenatal Stress and the Origins of Psychopathology: An Evolutionary Perspective,” hereafter, “Prenatal Stress and the Origins of Psychopathology,” in the Journal of Child Psychology and Psychiatry. In that article, Glover explained how an evolutionary perspective may be useful in understanding the effects of fetal programming. Fetal programming is a hypothesis that attempts to explain how factors during pregnancy can affect fetuses after birth.
Subject: Theories, Reproduction, Disorders
Priscilla White (1900–1989)
Priscilla White studied
the treatment of diabetes in mothers, pregnant women, and
children during the twentieth century in the US. White began
working with children with Type 1 diabetes in 1924 at Elliott
Proctor Joslin’s practice in Boston, Massachusetts. Type 1
diabetes is an incurable disease where the pancreas produces
little to no insulin. Insulin is a hormone that allows the body
to use sugar from food for energy and store sugars for future
use. Joslin and White co-authored many publications on children
Beatrice Mintz (1922–2022)
Beatrice Mintz is a brilliant researcher who has developed techniques essential for many aspects of research on mouse development. She produced the first successful mouse chimeras and meticulously characterized their traits. She has worked with various cancers and produced viable mice from the cells of a teratoma. Mintz participated in the development of transgenic mice by the incorporation of foreign DNA into a mouse genome.
"The Contagiousness of Puerperal Fever” (1843), by Oliver Wendell Holmes
In 1843, physician Oliver Wendell Holmes wrote and published The Contagiousness of Puerperal Fever, an essay about puerperal fever, a disease that occurs mainly as a result of bacterial infection in the uterine tract of women after giving birth or undergoing an abortion. In the essay, Holmes argues that puerperal fever is spread through birth attendants like physicians and midwives who make contact with the disease and carry it from patient to patient. The article was published in The New England Quarterly Journal of Medicine and Surgery in 1843.
Evelyn Lorraine Rothman (1932–2007)
Evelyn Lorraine Rothman advocated for women’s reproductive rights and invented at-home kits for women’s health concerns in the late twentieth century in Los Angeles, California. Rothman provided women in the Los Angeles area with the means to perform self-examinations, pregnancy tests, and abortions on their own without assistance from a medical professional. Along with Carol Downer, Rothman cofounded the Federation of Feminist Health Centers in Los Angeles, California, and spent her career educating women on reproductive health.
The Hedgehog Signaling Pathway in Vertebrates
The hedgehog signaling pathway is a mechanism that regulates cell growth and differentiation during embryonic development, called embryogenesis, in animals. The hedgehog signaling pathway works both between cells and within individual cells.
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.
Subject: People, Reproduction
Ignacio Vives Ponseti (1914-2009)
Ignacio Vives Ponseti developed a noninvasive method for treating congenital club foot in the US during the late 1940s. Congenital club foot is a birth deformity in which one or both of an infant's feet are rotated inward beneath the ankle, making normal movement rigid and painful. Ponseti developed a treatment method, later called the Ponseti method, that consisted of a series of manipulations and castings of the club foot performed in the first few months of life.