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Hormesis
Hormesis is a two-phased dose-response relationship to an environmental agent whereby low-dose amounts have a beneficial effect and high-dose amounts are either inhibitory to function or toxic. Within the hormetic zone, the biological response to low-dose amounts of some stressors is generally favorable. An example is the breathing of oxygen, which is required in low amounts (in air) via respiration in living animals, but can be toxic in high amounts, even in a managed clinical setting. In toxicology, hormesis is a dose-response phenomenon to xenobiotics or other stressors. In physiology and nutrition, hormesis has regions extending from low-dose deficiencies to homeostasis, and potential toxicity at high levels. Physiological concentrations of an agent above or below homeostasis may adversely affect an organism, where the hormetic zone is a region of homeostasis of balanced nutrition. In pharmacology, the hormetic zone is similar to the therapeutic window. In the context of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormesis — Two Sides Of The Same Coin
Hormesis is a two-phased dose-response relationship to an environmental agent whereby low-dose amounts have a beneficial effect and high-dose amounts are either inhibitory to function or toxic. Within the hormetic zone, the biological response to low-dose amounts of some stressors is generally favorable. An example is the breathing of oxygen, which is required in low amounts (in air) via Respiration (physiology), respiration in living animals, but can be toxic in high amounts, even in a managed clinical setting. In toxicology, hormesis is a dose-response phenomenon to xenobiotics or other stressors. In physiology and nutrition, hormesis has regions extending from low-dose deficiencies to homeostasis, and potential toxicity at high levels. Physiological concentrations of an agent above or below homeostasis may adversely affect an organism, where the hormetic zone is a region of homeostasis of balanced nutrition. In pharmacology, the hormetic zone is similar to the therapeutic wind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arndt–Schulz Rule
Arndt–Schulz rule or Schulz' law is a claimed law concerning the effects of pharmaca or poisons in various concentrations. It states that: That is to say, highly diluted pharmaca or poisons enhance life processes, while strong concentrations may inhibit these processes and even terminate them. The rule was named after Hugo Paul Friedrich Schulz and Rudolf Arndt. The latter originally formulated it in 1888. However, the exceptions to the rule are so numerous that it can not be considered a general law. For instance, many paralysing substances have no exciting effect in weak doses, and what constitutes a weak, medium, or strong stimulus is highly individual, as pointed out by Arndt himself. The rule is no longer cited in modern pharmacology texts, having been supplanted by the theory of hormesis. Scientific basis for homeopathy This rule has been claimed by some homeopaths as supporting their hypotheses. However, this rule does not apply to the extremely high dilutions typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dose–response Relationship
The dose–response relationship, or exposure–response relationship, describes the magnitude of the Stimulus–response model, response of an organism, as a Function (mathematics), function of exposure (or Dose (biochemistry), doses) to a Stimulus (physiology), stimulus or stressor (usually a chemical) after a certain exposure time. Dose–response relationships can be described by dose–response curves. This is explained further in the following sections. A stimulus response function or stimulus response curve is defined more broadly as the response from any type of stimulus, not limited to chemicals. Motivation for studying dose–response relationships Studying dose response, and developing dose–response models, is central to determining "safe", "hazardous" and (where relevant) beneficial levels and dosages for drugs, pollutants, foods, and other substances to which humans or other organisms are exposed. These conclusions are often the basis for public policy. The Unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homeopathy
Homeopathy or homoeopathy is a pseudoscientific system of alternative medicine. It was conceived in 1796 by the German physician Samuel Hahnemann. Its practitioners, called homeopaths or homeopathic physicians, believe that a substance that causes symptoms of a disease in healthy people can cure similar symptoms in sick people; this doctrine is called ''similia similibus curentur'', or "like cures like". Homeopathic preparations are termed ''remedies'' and are made using homeopathic dilution. In this process, the selected substance is repeatedly diluted until the final product is chemically indistinguishable from the diluent. Often not even a single molecule of the original substance can be expected to remain in the product. Between each dilution homeopaths may hit and/or shake the product, claiming this makes the diluent "remember" the original substance after its removal. Practitioners claim that such preparations, upon oral intake, can treat or cure disease. All relevant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapeutic Window
The therapeutic index (TI; also referred to as therapeutic ratio) is a quantitative measurement of the relative safety of a drug with regard to risk of overdose. It is a comparison of the amount of a therapeutic agent that causes toxicity to the amount that causes the therapeutic effect. The related terms therapeutic window or safety window refer to a range of doses optimized between efficacy and toxicity, achieving the greatest therapeutic benefit without resulting in unacceptable side-effects or toxicity. Classically, for clinical indications of an approved drug, TI refers to the ratio of the dose of the drug that causes adverse effects at an incidence/severity not compatible with the targeted indication (e.g. toxic dose in 50% of subjects, TD) to the dose that leads to the desired pharmacological effect (e.g. efficacious dose in 50% of subjects, ED). In contrast, in a drug development setting TI is calculated based on plasma exposure levels. In the early days of pharmaceut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Dose Makes The Poison
"The dose makes the poison" ( 'only the dose makes the poison') is an adage intended to indicate a basic principle of toxicology. It is credited to Swiss physician Paracelsus who expressed the following classic toxicology maxim: This is often condensed to: "The dose makes the poison" or in Latin, . It means that a substance can produce the harmful effect associated with its toxic properties only if it reaches a susceptible biological system within the body in a high enough concentration (i.e., dose). The principle relies on the finding that all chemicals—even water and oxygen—can be toxic if too much is eaten, drunk, or absorbed. "The toxicity of any particular chemical depends on many factors, including the extent to which it enters an individual’s body." This finding also provides the basis for public health standards, which specify maximum acceptable concentrations of various contaminants in food, public drinking water, and the environment. The idea also describe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mithridatism
Mithridatism is the practice of protecting oneself against a poison by gradually self-administering non-lethal amounts. The word is derived from Mithridates VI, the king of Pontus, who so feared being poisoned that he regularly ingested small doses, aiming to develop immunity. Background Mithridates VI's father, Mithridates V, was assassinated by poisoning by a conspiracy among his attendants. After this, Mithridates VI's mother held regency over Pontus (a Hellenistic kingdom, 281 BC–62 AD) until a male heir came of age. Mithridates was in competition with his brother for the throne and his mother began to favor his brother. Supposedly, during his youth, he began to suspect plots against him at his own mother's orders and was aware of her possible connection with his father's death. He then began to notice pains in his stomach during his meals and suspected his mother had ordered small amounts of poison to be added to his food to slowly kill him off. With other assassination a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electuaries
An electuary is a medicine consisting of a powder or other ingredient mixed with something sweet such as honey to make it more palatable."The Doctor and the Buccaneer: Sir Hans Sloane's Case History of Sir Henry Morgan, Jamaica, 1688" by Richard B. Sheridan, '''', Vol. 41, No. 1 (January 1986), pp. 76-87. In German and Swiss cultures, electuary ( or ) is also more generally a thickened juice and honey preparation with a thick, viscous consistency that is used in for culinary purposes, such as a (bread) spread ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Calabrese
Edward J. Calabrese is an American toxicologist and professor in the department of environmental health sciences at the University of Massachusetts Amherst. He is the editor emeritus of the scientific journal '' Dose-Response''. Education Calabrese grew up in Bridgewater, Massachusetts. He received his B.S. from Bridgewater State College in 1968 and his M.A. and Ph.D. from the University of Massachusetts Amherst in 1972 and 1973, respectively. Academic career Calabrese began working at the University of Massachusetts Amherst in 1976. Research Early in his career, Calabrese conducted research on carcinogens. However, he is best known for his research into, and championing of, hormesis Hormesis is a two-phased dose-response relationship to an environmental agent whereby low-dose amounts have a beneficial effect and high-dose amounts are either inhibitory to function or toxic. Within the hormetic zone, the biological response to ..., which he has called "the fundamental dose-response ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chester M
Chester is a cathedral city in Cheshire, England, on the River Dee, Wales, River Dee, close to the England–Wales border. With a built-up area population of 92,760 in 2021, it is the most populous settlement in the borough of Cheshire West and Chester. It is also the historic county town of Cheshire and the List of Cheshire settlements by population, second-largest settlement in Cheshire after Warrington. Chester was founded in 79 AD as a "Castra, castrum" or Roman Empire, Roman fort with the name Deva Victrix during the reign of Emperor Vespasian. One of the main army camps in Roman Britain, Deva later became a major civilian settlement. In 689, Æthelred of Mercia, King Æthelred of Mercia founded the Minster Church of West Mercia, which later became Chester's first cathedral, and the Angles (tribe), Angles extended and strengthened the walls to protect the city against the Danes (Germanic tribe), Danes. Chester was one of the last cities in England to Norman conquest of Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudolph Arndt
Rudolf Gottfried Arndt (31 March 1835 – 29 January 1900) was a German psychiatrist from Bialken, district of Marienwerder. Biography Arndt studied in Greifswald and Halle. As a student, his instructors included Felix von Niemeyer (1820–1871), Heinrich Adolf von Bardeleben (1819–1895), and Heinrich Philipp August Damerow (1798–1866). He was conferred doctor of medicine on 20 February 1860. From 1861 he maintained a private practice, and also participated in the Second Schleswig War (1864), Austro-Prussian War (1866) and Franco-Prussian War (1870–71). In 1867 he obtained his habilitation, subsequently serving as director of the ''Irren-Heil- und Pflege-Anstalt'' in Greifswald. In 1873 he became an associate professor of psychiatry at Greifswald. He died of angina pectoris. He is known today for the " Arndt-Schulz rule", a pharmacologic principle of homeopathy that is named in conjunction with German chemist Hugo Schulz (1853-1932). He is also remembered for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugo Schulz
Hugo Paul Friedrich Schulz (August 6, 1853 – July 13, 1932) was a German pharmacologist from Wesel, Rhenish Prussia. He studied medicine in the universities of Heidelberg and Bonn, where he did scientific work in the physiological institute of Eduard Friedrich Wilhelm Pflüger (1829-1910). In 1877 he earned his doctorate, and afterwards worked in the pharmacological institute of Karl Binz (1832-1913) at Bonn. In 1883 he was appointed professor of pharmacology at the University of Greifswald. Schulz is known for his research of a phenomenon known as hormesis, showing that the effect of toxins in small doses can be the opposite of their effect in large doses. He demonstrated this in experiments using chemical compounds on yeast cells. From his research came the " Arndt-Schulz rule", a law concerning dosages in toxicology, named along with Dr. Rudolf Arndt (1835-1900). Schulz published a number of works in the field of pharmacology, including the well-regarded ''Pharmakothera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
