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Displaying 451 - 471 of 471 items.

The Role of the Notch Signaling Pathway in Myogenesis

Among other functions, the Notch signaling pathway forestalls the process of myogenesis in animals. The Notch signaling pathway is a pathway in animals by which two adjacent cells within an organism use a protein named Notch to mechanically interact with each other. Myogenesis is the formation of muscle that occurs throughout an animal's development, from embryo to the end of life. The cellular precursors of skeletal muscle originate in somites that form along the dorsal side of the organism.

Format: Articles

Subject: Theories, Processes

August Friedrich Leopold Weismann (1834-1914)

August Friedrich Leopold Weismann studied how the traits of organisms developed and evolved in a variety of organisms, mostly insects and aquatic animals, in Germany in the late nineteenth and early twentieth centuries. Weismann proposed the theory of the continuity of germ-plasm, a theory of heredity. Weismann postulated that germ-plasm was the hereditary material in cells, and parents transmitted to their offspring only the germ-plasm present in germ-cells (sperm and egg cells) rather than somatic or body cells.

Format: Articles

Subject: People

Dizhou Tong (1902-1979)

Dizhou Tong, also called Ti Chou Tung, studied marine animals and helped introduce and organize experimental embryology in China during the twentieth century. He introduced cellular nuclear transfer technology to the Chinese biological community, developed methods to clone organisms from many marine species, and investigated the role of cytoplasm in early development. Tong's administrative and scientific leadership in the fields of marine, cellular, and developmental biology contributed to China's experimental embryology research programs.

Format: Articles

Subject: People

"Ethical Issues in Human Stem Cell Research: Executive Summary" (1999), by the US National Bioethics Advisory Commission

Ethical Issues in Human Stem Cell Research: Executive Summary was published in September 1999 by The US National Bioethics Advisory Commission in response to a national debate about whether or not the US federal government should fund embryonic stem cell research. Ethical Issues in Human Stem Cell Research recommended policy to US President William Clinton's administration, which advocated for federal spending on the use of stem research on stem cells that came from embryos left over from in vitro fertilization (IVF) fertility treatments.

Format: Articles

Subject: Legal, Ethics

Mesoderm

Mesoderm is one of the three germ layers, groups of cells that interact early during the embryonic life of animals and from which organs and tissues form. As organs form, a process called organogenesis, mesoderm interacts with endoderm and ectoderm to give rise to the digestive tract, the heart and skeletal muscles, red blood cells, and the tubules of the kidneys, as well as a type of connective tissue called mesenchyme. All animals that have only one plane of symmetry through the body, called bilateral symmetry, form three germ layers.

Format: Articles

Subject: Processes

Robert Lanza (1956- )

During the twentieth and twenty-first centuries, Robert Paul Lanza studied embryonic stem cells, tissues,
and endangered species as chief scientific officer of Advanced Cell
Technology, Incorporated in Worcester, Massachusetts. Lanza's team cloned
the endangered species of gaur Bos gaurus.
Although the gaur did not survive long, Lanza successfully cloned
another cow-like creature, called the banteng
(Bos
javanicus). Lanza also worked on cloning human embryos
to harvest stem cells, which could be used to treat dieases. While

Format: Articles

Subject: People

Endoscopic Fetoscopy

Endoscopic fetoscopy is a minimally invasive surgical procedure performed during pregnancy that allows physicians to view the fetus in-utero. Physicians use endoscopic fetoscopy to evaluate, diagnose, and treat fetal abnormalities. Physicians use an endoscope, or a thin, flexible surgical device with a light attached to its end, to perform endoscopic fetoscopy procedures. In 1954, Björn Westin performed the first endoscopic fetoscopy in Sweden.

Format: Articles

Subject: Technologies

Heart of a Dog (1925), by Mikhail Bulgakov

Собачье сердце (Heart of a Dog) is a novella written in 1925 by author and playwright Mikhail Bulgakov in Moscow, USSR, later Russia. An early English translation was published in 1968. Heart of a Dog tells the story of a stray dog named Sharik, who is found by a surgeon, and undergoes extensive surgery for experimental purposes to create a New Soviet man, someone committed to the ideals of communism in the Soviet Union.

Format: Articles

Subject: Publications

California Proposition 71 (2004)

The California Stem Cell Research and Cures Act, also called Proposition 71, was a ballot
initiative proposed by California voters in 2004 to allocate three billion dollars of state
funds for stem cell research over ten years. Endorsed by California scientists and
patient-advocates, Prop 71 passed on 2 November 2004, amending the state constitution to make
stem cell research a constitutional right. In addition, Prop 71 led to the creation of the
California Institute for Regenerative Medicine (CIRM), in San Francisco, California to allocate

Format: Articles

Subject: Legal

Ian Hector Frazer (1953– )

Ian Hector Frazer studied the human immune system and vaccines in Brisbane, Australia, and helped invent and patent the scientific process and technology behind what later became the human papillomavirus, or HPV, vaccinations. According to the Centers for Disease Control and Prevention of the US, or CDC, HPV is the most common sexually transmitted infection, and can lead to genital warts, as well as cervical, head, mouth, and neck cancers.

Format: Articles

Subject: People

Ovarian Hyperstimulation Syndrome (OHSS) Caused by Fertility Treatment

Ovarian hyperstimulation syndrome, abbreviated OHSS, is an atypical reaction that women may experience in response to excessive hormones, and often occurs during fertility treatments. OHSS is typically triggered by hormonal medications designed to mature eggs in the ovaries, which can cause blood vessels within the ovaries to leak fluid. Sometimes that can lead to painful tenderness or swelling. In severe cases of OHSS, that fluid can leak into the abdominal cavity in large amounts, causing vomiting, blood clots, and severe pain.

Format: Articles

Subject: Reproduction

Agent Orange as a Cause of Spina Bifida

Spina bifida is a birth defect that affects the spines of developing fetuses and infants, and research in the 20th century indicated that chemicals in the herbicide Agent Orange likely lead to the birth defect. People with spina bifida can have nerve damage, paralysis, and mental disabilities. During the Vietnam War in the 1960s, the US military employed Agent Orange and other herbicides to destroy enemy crops and forest cover until 1970.

Format: Articles

Subject: Disorders

Ernest John Christopher Polge (1926-2006)

Twentieth-century researcher Ernest John Christopher Polge studied the reproductive processes of livestock and determined a method to successfully freeze, thaw, and utilize viable sperm cells to produce offspring in animals. In 1949, Polge identified glycerol as a cryoprotectant, or a medium that enables cells to freeze without damaging their cellular components or functions. Several years later, Polge used glycerol in a freezing process called vitrification, which enabled him to freeze poultry sperm, thaw that sperm, and use it to fertilize vertebrate embryos.

Format: Articles

Subject: People

Essay: Review of Icons of Life: A Cultural History of Human Embryos

To Lynn M. Morgan, the Mary E. Woolley Professor of Anthropology at Mt. Holyoke College, nothing says life more than a dead embryo. In her easily readable book, Icons of Life: A Cultural History of Human Embryos, Morgan brings together cultural phenomena, ethics, and embryology to show that even dead embryos and fetuses have their own stories to tell. As an anthropologist, Morgan is interested in many things, including the science of embryology and its history. But she also wants to know how culture influences our views on embryos and the material practices that accompany their study.

Format: Essays and Theses

Subject: Publications

The Inheritance of Acquired Characteristics (1924), by Paul Kammerer

The Inheritance of Acquired Characteristics is a book published in 1924, written by Paul Kammerer, who studied developmental biology in Vienna, Austria, in the early twentieth century. The Inheritance of Acquired Characteristics summarizes Kammerer's experiments, and explains their significance. In his book, Kammerer aims to explain how offspring inherit traits from their parents. Some scholars criticized Kammerer's reports and interpretations, arguing that they were inaccurate and misleading, while others supported Kammerer's work.

Format: Articles

Subject: Publications, Theories

"Reproductive Options for HIV-Serodiscordant Couples” (2006) by Pablo Barreiro, Ann Duerr, Karen Beckerman, and Vincent Soriano

In July 2006, scientist Pablo Barreiro and colleagues published “Reproduction Options for HIV-Serodiscordant Couples,” in which they recommended methods for human immunodeficiency virus, or HIV, serodiscordant couples to procreate. An HIV-serodiscordant couple is one in which one partner is HIV-positive, meaning they carry HIV, and the other is HIV-negative, meaning they do not carry the virus. HIV is a virus that can spread by sexual contact and it attacks the immune system, causing a person with the virus to have weakened responses to illnesses.

Format: Articles

Subject: Publications

Zidovudine or azidothymidine

In 1964, Jerome Horwitz synthesized the drug zidovudine, commonly abbreviated ZDV, otherwise known as azidothymidine, or AZT, at Wayne State University School of Medicine in Detroit, Michigan. Horwitz and his colleagues originally developed zidovudine to treat cancers caused by retroviruses. In 1983, Nobel Prize in Physiology or Medicine recipients Françoise Barré-Sinoussi and Luc Montagnier discovered a new retrovirus, the human immunodeficiency virus, or HIV, at the Pasteur Institute in Paris, France.

Format: Articles

Subject: Processes

Peter Mazur (1928–2015)

Peter Mazur was a researcher in the US who developed new ways of preserving biological material by freezing it, a process called cryopreservation. If done correctly, cryopreservation enables scientists to store or study biological material for an extended period of time. If done incorrectly, cryopreservation can easily harm or destroy biological material. Mazur worked to find the best ways to cryopreserve different cells, embryos, and organs in order to minimize the damage caused by freezing.

Format: Articles

Subject: People

Essay: Homology

Homology is a central concept of comparative and evolutionary biology, referring to the presence of the same bodily parts (e.g., morphological structures) in different species. The existence of homologies is explained by common ancestry, and according to modern definitions of homology, two structures in different species are homologous if they are derived from the same structure in the common ancestor.

Format: Essays and Theses

Subject: Processes

Agent Orange Birth Defects

Sprayed extensively by the US military in Vietnam, Agent Orange contained a dioxin contaminant later found to be toxic to humans. Despite reports by Vietnamese citizens and Vietnam War veterans of increased rates of stillbirths and birth defects in their children, studies in the 1980s showed conflicting evidence for an association between the two. In 1996, the US National Academy of Sciences reported that there was evidence that suggested dioxin and Agent Orange exposure caused spina bifida, a birth defect in which the spinal cord develops improperly.

Format: Articles

Subject: Disorders

"Vietnam Veterans' Risks for Fathering Babies with Birth Defects" (1984), by J. David Erickson et al.

In 1984, J. David Erickson and his research team published the results of a study titled 'Vietnam Veterans' Risks for Fathering Babies with Birth Defects' that indicated that Vietnam veterans were at increased risk of fathering infants with serious congenital malformations, or birth defects.

Format: Articles

Subject: Publications