Cystic fibrosis (CF) is a fatal, inherited disease found in humans and characterized by buildup of thick, sticky mucus, particularly in the respiratory and digestive tracts. The abnormally thick mucus prevents the pancreas from functioning normally; it often leads to digestive problems and chronic lung infections. Cystic fibrosis is most prevalent in Caucasian individuals, and approximately 1 in every 29 individuals in the US is a carrier for the mutated CF gene. There are an estimated 30,000 reported cystic fibrosis cases in the US, and 70,000 reported cases worldwide, although the international number is undoubtedly low due to underreporting or early deaths.
Mesenchyme is a type of animal tissue comprised of loose cells embedded in a mesh of proteins and fluid, called the extracellular matrix. The loose, fluid nature of mesenchyme allows its cells to migrate easily and play a crucial role in the origin and development of morphological structures during the embryonic and fetal stages of animal life. Mesenchyme directly gives rise to most of the body's connective tissues, from bones and cartilage to the lymphatic and circulatory systems. Furthermore, the interactions between mesenchyme and another tissue type, epithelium, help to form nearly every organ in the body.
The 1981 Adolescent Family Life Act, or AFLA, is a US federal law that provides federal funding to public and nonprofit private organizations to counsel adolescents to abstain from sex until marriage. AFLA was included under the Omnibus Reconciliation Act of 1981, which the US Congress signed into law that same year. Through the AFLA, the US Department of Health and Human Services, or HHS, funded a variety of sex education programs for adolescents to address the social and economic ramifications associated with pregnancy and childbirth among unmarried adolescents. AFLA received several criticisms for directly emphasizing and funding abstinence-only education programs from religious organizations. However, when US citizen Chan Kendrick brought the case Bowen v. Kendrick before the Supreme Court in 1988, the Court upheld that AFLA was constitutional. Although numerous evaluations have shown minimal scientific evidence supporting abstinence-only education, as of 2020, the federal government still provides funding for such programs through AFLA.
Nuclear transplantation is a method in which the nucleus of a donor cell is relocated to a target cell that has had its nucleus removed (enucleated). Nuclear transplantation has allowed experimental embryologists to manipulate the development of an organism and to study the potential of the nucleus to direct development. Nuclear transplantation, as it was first called, was later referred to as somatic nuclear transfer or cloning.
Estrogen plays a key role in the regulation of gene transcription. This is accomplished by its ability to act as a ligand and to bind to specific estrogen receptor (ER) molecules, such as ERα and ERβ, which act as nuclear transcription factors. There are three major nuclear estrogen receptor protein domains: the estrogen binding domain, the protein interaction domain, and the DNA binding domain. The domain responsible for the regulation of transcription is the DNA binding domain, which binds to DNA sequences called estrogen-responsive elements (EREs), found in enhancer regions of specific genes. By the binding of estrogen or an estrogen mimic to these enhancers, the target genes become activated and the proteins produced are involved in numerous cellular processes. With an estrogen mimic or xenoestrogen, such as diethylstilbestrol (DES), the negative regulation of certain genes during embryonic development can be devastating to the developing anatomy, especially the reproductive system.
The Game of Life, or just Life, is a one-person game that was created by the English mathematician John Horton Conway in the late 1960s. It is a simple representation of birth, death, development, and evolution in a population of living organisms, such as bacteria. Martin Gardner popularized the Game of Life by writing two articles for his column "Mathematical Games" in the journal Scientific American in 1970 and 1971. There exist several websites that provide the Game of Life as a download or as an online game.
In 1881 British opthalmologist Warren Tay made an unusual observation. He reported a cherry-red spot on the retina of a one-year-old patient, a patient who was also showing signs of progressive degeneration of the central nervous system as manifested in the child's physical and mental retardation. This cherry-red spot is a characteristic that would eventually come to be associated with metabolic neurological disorders like Sandhoff, GM-1, Niemann-Pick, and, to the credit of Tay, the lysosomal storage disorder known as Tay-Sachs disease. Tay shares the disease's title with New York neurologist Bernard Sachs, who described the cellular changes present in the disease as well as its potential for heritability, shortly after Tay's observation. Sachs also noted the higher occurrence of the disease in Jews of eastern and central European descent as well as the typical pattern of the disease, including early blindness, severe retardation, and death in early childhood.
Tissue engineering is a field of regenerative medicine that integrates the knowledge of scientists, physicians, and engineers into the construction or reconstruction of human tissue. Practitioners of tissue engineering seek to repair, replace, maintain, and enhance the abilities of a specific tissue or organ by means of living cells. More often than not stem cells are the form of living cells used in this technology. Tissue engineering is one of the disciplines involved in translating knowledge of developmental biology into the clinical setting. One focus that this field has taken is the understanding of tissue and organ development during embryogenesis, as this knowledge will open avenues to new applications of this technology.
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. HIV weakens the immune system and can be passed from a pregnant woman to her fetus in utero, or in the womb. In 1984, scientist Marty St. Clair and her team determined that zidovudine could help treat HIV. Zidovudine was the first medicine discovered to help treat HIV and prevent the transmission of HIV from affected pregnant women to fetuses in the womb by blocking the virus from passing through the placenta.
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. When mitochondria fail to fulfill those functions properly in the cell, many different maladies, including death, can occur. Humans inherit mitochondria from the mother through the egg cell, and all the mtDNA molecules in a person are identical to each other. But the mutation rate is much higher in the mtDNA than in nuclear DNA, and some individuals may have more than one type of mtDNA. As egg cells develop, they divide via a process called meiosis. As egg cells divide, mitochondria of different types can randomly segregate in some new cells but not in others. As a result, two offspring from the same female might differ in their types of mitochondria. Random amounts of the two mitochondria types can lead to some offspring inheriting a mitochondrial disease or developmental abnormalities while others are normal.