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Semicarbazide-cadmium Therapy
Semicarbazide-cadmium therapy was an experimental cancer therapy that was tested in several clinical trials in the Soviet Union during the 1960s. Semicarbazide is an irreversible inhibitor of semicarbazide-sensitive amine oxidase (SSAO), an enzyme possibly involved in exacerbation of inflammation. Cadmium is a heavy metal and can also induce apoptosis. The first study in humans was an open pilot trial conducted in Russia in 1957-1962. It was also patented in Russia. This method was successfully used for treatment of patients in later stages of lung, intestinal, and brest cancer, melanoma, and some other cancer types. The Experiments were accompanied by organizational problems (conflict between soviet authorities and scientists). Method The method involved the use of the following preparations: semicarbazide hydrochloride, urea, and cadmium halides. Additionally, stable isotopes of gadolinium, as gadolinium oxides, can be used, in addition to other drugs. Semicarbazide Cli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicarbazide
Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea. Synthesis The compound prepared by treating urea with hydrazine:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. . :OC(NH2)2 + N2H4 → OC(NH2)(N2H3) + NH3 A further reaction can occur to give carbohydrazide: :OC(NH2)(N2H3) + N2H4 → OC(N2H3)2 + NH3 Derivatives Semicarbazide is frequently reacted with aldehydes and ketones to produce semicarbazones via a condensation reaction. This is an example of imine formation resulting from the reaction of a primary amine with a carbonyl group. The reaction is useful because semicarbazones, like oximes and 2,4-DNPs, typically have high melting points and crystallize, facilitating purification or identification of reaction products. Properties Semicarbazide products (semicarbazones and thiosemicarbazones) are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicarbazide-sensitive Amine Oxidase
Primary-amine oxidase, also known as semicarbazide-sensitive amine oxidase (SSAO), is an enzyme () with the systematic name ''primary-amine:oxygen oxidoreductase (deaminating)''. This enzyme catalyses the following chemical reaction : RCH2NH2 + H2O + O2 \rightleftharpoons RCHO + NH3 + H2O2 These enzymes are copper quinoproteins (2,4,5-trihydroxyphenylalanine quinone). Like monoamine oxidase (MAO), SSAO can deaminate short-chain primary amines, but is insensitive to MAO inhibitors. Semicarbazide inhibits the enzyme, in addition to other hydrazines, hydroxylamine and propargylamine. However, hydrazines are weak inhibitors and stronger inhibitors have been developed. SSAO is found in the smooth muscle of blood vessels and various other tissues. The physiological function of SSAO is not well understood. Development of blood vessels, lipolysis regulation, and detoxication are suggested. It may function as a scavenger enzyme to assist MAO. However, the oxidation process generates har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of its compounds, and like mercury, it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals, in that they do not have partly filled ''d'' or ''f'' electron shells in the elemental or common oxidation states. The average concentration of cadmium in Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate. Cadmium occurs as a minor component in most zinc ores and is a byproduct of zinc production. Cadmium was used for a long time as a corrosion-resistant plating on steel, and cadmium compounds are used as red, orang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heavy Metal (chemistry)
upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as metals with relatively high density, densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical property, chemical behaviour. More specific definitions have been published, but none of these have been widely accepted. The definitions surveyed in this article encompass up to 96 out of the 118 known chemical elements; only mercury, lead and bismuth meet all of them. Despite this lack of agreement, the term (plural or singular) is widely used in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicarbazide
Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea. Synthesis The compound prepared by treating urea with hydrazine:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. . :OC(NH2)2 + N2H4 → OC(NH2)(N2H3) + NH3 A further reaction can occur to give carbohydrazide: :OC(NH2)(N2H3) + N2H4 → OC(N2H3)2 + NH3 Derivatives Semicarbazide is frequently reacted with aldehydes and ketones to produce semicarbazones via a condensation reaction. This is an example of imine formation resulting from the reaction of a primary amine with a carbonyl group. The reaction is useful because semicarbazones, like oximes and 2,4-DNPs, typically have high melting points and crystallize, facilitating purification or identification of reaction products. Properties Semicarbazide products (semicarbazones and thiosemicarbazones) are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidative Stress
Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily Detoxification, detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal redox state of cells can cause toxic effects through the production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA. Oxidative stress from Cellular respiration, oxidative metabolism causes base damage, as well as DNA damage (naturally occurring), strand breaks in DNA. Base damage is mostly indirect and caused by the reactive oxygen species generated, e.g., O2− (superoxide radical), OH (hydroxyl radical) and H2O2 (hydrogen peroxide). Further, some reactive oxidative species act as cellular messengers in redox signaling. Thus, oxidative stress can cause disruptions in normal mechanisms of cellular signaling. In humans, oxidative stress is thought to be involved in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke. Although the public generally associates carcinogenicity with synthetic chemicals, it is equally likely to arise from both natural and synthetic substances. Carcinogens are not necessarily immediately toxic; thus, their effect can be insidious. Carcinogens, as mentioned, are agents in the environment capable of contributing to cancer growth. Carcinogens can be categorized into two different types: activation-dependent and activation-independent, and each nature impacts their level ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitogen
A mitogen is a small bioactive protein or peptide that induces a cell to begin cell division, or enhances the rate of division (mitosis). Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen. The mechanism of action of a mitogen is that it triggers signal transduction pathways involving mitogen-activated protein kinase (MAPK), leading to mitosis. The cell cycle Mitogens act primarily by influencing a set of proteins which are involved in the restriction of progression through the cell cycle. The G1 checkpoint is controlled most directly by mitogens: further cell cycle progression does not need mitogens to continue. The point where mitogens are no longer needed to move the cell cycle forward is called the "restriction point" and depends on cyclins to be passed.Bohmer et al. "Cytoskeletal Integrity Is Required throughout the Mitogen Stimulation Phase of the Cell Cycle and Mediates the Anchorage-dependent Expression of Cyclin DI". January 1996, Molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazine Sulfate
Hydrazine sulfate, more properly hydrazinium hydrogensulfate, is a salt of the cation hydrazinium and the anion bisulfate (hydrogensulfate), with the formula or more properly . It is a white, water-soluble solid at room temperature. Hydrazine sulfate has a number of uses in chemical laboratories and in the chemical industry, including analytical chemistry and the synthesis of organic compounds. In those uses it is usually preferred to pure hydrazine, because it is not volatile and is less susceptible to atmospheric oxidation on storage. Preparation The compound can be prepared by treating an aqueous solution of hydrazine () with sulfuric acid (). Laboratory and industrial uses Besides its general use as a safe source of hydrazine, the compound is used as a catalyst in making fibers out of acetate, in the analysis and synthesis of minerals, and testing for arsenic in metals. Medical uses Hydrazine sulfate can be used as a fungicide and antiseptic. Hydrazine sulfate ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Cancer Treatments
Experimental cancer treatments are mainstream medical therapies intended to treat cancer by improving on, supplementing or replacing conventional methods (surgery, chemotherapy, radiation, and immunotherapy). However, researchers are still trying to determine whether these treatments are safe and effective treatments. Experimental cancer treatments are normally available only to people who participate in formal research programs, which are called ''clinical trials''. Occasionally, a seriously ill person may be able to access an experimental drug through an expanded access program. Some of the treatments have regulatory approval for treating other conditions. Health insurance and publicly funded health care programs normally refuse to pay for experimental cancer treatments. The entries listed below vary between theoretical therapies to unproven controversial therapies. Many of these treatments are alleged to help against only specific forms of cancer. It is not a list of tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Medicine
The history of medicine is both a study of medicine throughout history as well as a multidisciplinary field of study that seeks to explore and understand medical practices, both past and present, throughout human societies. More than just history and medicine, this field of study incorporates learnings from across disciplines such as anthropology, economics, health sciences, sociology, and politics to better understand the institutions, practices, people, professions, and social systems that have influenced and shaped medicine throughout the ages. As a documentation of medicine over time, the history of medicine shows how societies have changed in their approach to illness and disease from ancient times to the present. Early medical traditions include those of Babylon, China, Egypt and India. The Hippocratic Oath was written in ancient Greece in the 5th century BCE, and is a direct inspiration for oaths of office that physicians swear upon entry into the profession today. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
