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Malcolm Steinberg
Malcolm Saul Steinberg (June 1, 1930 - February 7, 2012) was an American biologist who proposed the differential adhesion hypothesis as a mechanism explaining cell sorting during embryogenesis and cancer. Steinberg proposed that when cells form distinct tissues, specific cell-cell adhesion between cells from the same tissue can drive the separation. He further proposed that a difference in level of cell adhesion molecules expression between two cell types was sufficient to drive the separation. He confirmed these predictions in a model system in which adhesion between cells of a cultured line of mouse cells was controlled by genetic expression levels of cadherin. Steinberg pioneered work in characterizing the physical properties of cells and tissues. He proposed that cell-cell adhesion drives tissue rounding up and, comparing tissues to liquids, he proposed that tissues have a surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the mini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biologist
A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual cell, a multicellular organism, or a community of interacting populations. They usually specialize in a particular branch (e.g., molecular biology, zoology, and evolutionary biology) of biology and have a specific research focus (e.g., studying malaria or cancer). Biologists who are involved in basic research have the aim of advancing knowledge about the natural world. They conduct their research using the scientific method, which is an empirical method for testing hypotheses. Their discoveries may have applications for some specific purpose such as in biotechnology, which has the goal of developing medically useful products for humans. In modern times, most biologists have one or more academic degrees such as a bachelor's degree plus an advanced degree like a master's degree or a doctorate. Like other scientists, biologists can be fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Adhesion Hypothesis
Differential adhesion hypothesis (DAH) is a hypothesis that explains cellular movement during morphogenesis with thermodynamic principles. In DAH tissues are treated as liquids consisting of mobile cells whose varying degrees of surface adhesion cause them to reorganize spontaneously to minimize their interfacial free energy. Put another way, according to DAH, cells move to be near other cells of similar adhesive strength in order to maximize the bonding strength between cells and produce a more thermodynamically stable structure. In this way the movement of cells during tissue formation, according to DAH, parodies the behavior of a mixture of liquids. Although originally motivated by the problem of understanding cell sorting behavior in vertebrate embryos, DAH has subsequently been applied to explain several other morphogenic phenomena. Background The origins of DAH can be traced back to a 1955 study by Philip L. Townes and Johannes Holtfreter. In this study Townes and Holtfreter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryogenesis
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor diet, lack of physical activity or excessive drinking of alcohol. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. In the developing world, 15% of cancers are due to infections such as ''Helicobacter pylori'', hepatitis B, hepatitis C, human papillomavirus infection, Epstein–Barr virus and human immunodeficiency virus (HIV). These factors act, at least partly, by changing the genes of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Adhesion Molecules
Cell adhesion molecules (CAMs) are a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion. In essence, CAMs help cells stick to each other and to their surroundings. CAMs are crucial components in maintaining tissue structure and function. In fully developed animals, these molecules play an integral role in generating force and movement and consequently ensuring that organs are able to execute their functions normally. In addition to serving as "molecular glue", CAMs play important roles in the cellular mechanisms of growth, contact inhibition, and apoptosis. Aberrant expression of CAMs may result in a wide range of pathologies, ranging from frostbite to cancer. Structure CAMs are typically single-pass transmembrane receptors and are composed of three conserved domains: an intracellular domain that interacts with the cytoskeleton, a transmembrane domain, and an extrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadherin
Cadherins (named for "calcium-dependent adhesion") are a type of cell adhesion molecule (CAM) that is important in the formation of adherens junctions to allow cells to adhere to each other . Cadherins are a class of type-1 transmembrane proteins, and they are dependent on calcium (Ca2+) ions to function, hence their name. Cell-cell adhesion is mediated by extracellular cadherin domains, whereas the intracellular cytoplasmic tail associates with numerous adaptors and signaling proteins, collectively referred to as the cadherin adhesome. The cadherin family is essential in maintaining the cell-cell contact and regulating cytoskeletal complexes. The cadherin superfamily includes cadherins, protocadherins, desmogleins, desmocollins, and more. In structure, they share ''cadherin repeats'', which are the extracellular Ca2+-binding domains. There are multiple classes of cadherin molecules, each designated with a prefix (in general, noting the types of tissue with which it is associated). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adhesion
Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be divided into several types. The intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories of chemical adhesion, dispersive adhesion, and diffusive adhesion. In addition to the cumulative magnitudes of these intermolecular forces, there are also certain emergent mechanical effects. Surface energy Surface energy is conventionally defined as the work that is required to build an area of a particular surface. Another way to view the surface energy is to relate it to the work required to cleave a bulk sample, creating two surfaces. If the new surfaces are identical, the surface energy γ of each surface is equal to half the work of cleavage, W: γ = (1/2)W11. If the surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Tension
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged. At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion). There are two primary mechanisms in play. One is an inward force on the surface molecules causing the liquid to contract. Second is a tangential force parallel to the surface of the liquid. This ''tangential'' force is generally referred to as the surface tension. The net effect is the liquid behaves as if its surface were covered with a stretched elastic membrane. But this analogy must not be taken too far as the tension in an elastic membrane is dependent on the amount of deformation of the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Biologists
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University Faculty
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. It is one of the highest-ranked universities in the world. The institution moved to Newark, New Jersey, Newark in 1747, and then to the current site nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. It is a member of the Ivy League. The university is governed by the Trustees of Princeton University and has an endowment of $37.7 billion, the largest List of colleges and universities in the United States by endowment, endowment per student in the United States. Princeton provides undergraduate education, undergraduate and graduate education, graduate in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Minnesota College Of Biological Sciences Alumni
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". Universities typically offer both undergraduate and postgraduate programs. The first universities in Europe were established by Catholic Church monks. The University of Bologna (), Italy, which was founded in 1088, is the first university in the sense of: *being a high degree-awarding institute. *using the word ''universitas'' (which was coined at its foundation). *having independence from the ecclesiastic schools and issuing secular as well as non-secular degrees (with teaching conducted by both clergy and non-clergy): grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university in medieval life, 1179–1499", McFarland, 2008, , p. 55f.de Ridder-Symoens, Hilde''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amherst College Alumni
Amherst may refer to: People * Amherst (surname), including a list of people with the name * Earl Amherst of Arracan in the East Indies, a title in the British Peerage; formerly ''Baron Amherst'' * Baron Amherst of Hackney of the City of London, a title in the British Peerage Places Australia *Amherst, Victoria Burma * Kyaikkami, Myanmar, formerly known as Amherst Canada * Amherst Cove, Newfoundland and Labrador * Middle Amherst Cove, Newfoundland and Labrador *Upper Amherst Cove, Newfoundland and Labrador * Amherst, Nova Scotia *Amherst Head, Nova Scotia * Amherst Internment Camp, Nova Scotia (1915-1919) *Amherst Point, Nova Scotia * Amherst Shore, Nova Scotia * East Amherst, Nova Scotia *West Amherst, Nova Scotia *Amherst Island, Ontario *Amherst Pointe, Ontario *Amherstburg, Ontario *Amherstview, Ontario *Amherst, Quebec * Saint-Rémi-d'Amherst, Quebec *Amherst Island (Nunavut) United States *Amherst, Colorado *Amherst, Maine * Amherst, Massachusetts *Amherst Center, Massa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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