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Semustine
Semustine (1- (2-Chloroethyl)-3-(trans-4-methylcyclohexyl)- 1-nitrosourea, MeCCNU) is an alkylating nitrosourea compound used in chemotherapy treatment of various types of tumours. Due to its lipophilic property, semustine can cross the blood-brain barrier for the chemotherapy of brain tumours, where it interferes with the cellular DNA of the highly dividing cells. Semustine, just as lomustine, is administered orally. It has been reported that semustine can perform the main mechanism of action at molecular level via the alkylation of DNA nitrogenous bases in duplex by results of inhibition of DNA replication, transcription, and translation by way of alkylation of DNA, under pH-dependent conditions by hydrolysis, forming chloro-carbonium ions. Sufficient evidence was found that treatment with semustine can cause acute leukaemia as a delayed effect in very rare cases. History During the past two decades, massive developments of various categories of anti-cancer drugs have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs) or it may aim to prolong life or to reduce symptoms ( palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''medical oncology''. The term ''chemotherapy'' has come to connote non-specific usage of intracellular poisons to inhibit mitosis (cell division) or induce DNA damage, which is why inhibition of DNA repair can augment chemotherapy. The connotation of the word chemotherapy excludes more selective agents that block extracellular signals (signal transduction). The development of therapies with specific molecular or genetic targets, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lomustine
Lomustine (INN); abbreviated as CCNU; original brand name CeeNU, now marketed as Gleostine) is an alkylating nitrosourea compound used in chemotherapy. It is closely related to semustine and is in the same family as streptozotocin. It is a highly lipid-soluble drug, thus it crosses the blood–brain barrier. This property makes it ideal for treating brain tumors, which is its primary use, although it is also used to treat Hodgkin lymphoma as a second-line option. Lomustine has a long time to nadir (the time when white blood cells reach their lowest number). Unlike carmustine, lomustine is administered orally. It is a bifunctional alkylating agent, alkylates both DNA and RNA, has the ability to created interstrand cross-links (ICLs) in DNA. As with other nitrosoureas, it may also inhibit several key enzymatic processes by carbamoylation of amino acids in proteins. Lomustine is cell-cycle nonspecific. It has also been used in veterinary practice as a treatment for mast cell tum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Withdrawn Drugs
Withdrawal means "an act of taking out" and may refer to: * Anchoresis (withdrawal from the world for religious or ethical reasons) * ''Coitus interruptus'' (the withdrawal method) * Drug withdrawal * Social withdrawal * Taking of money from a bank * Water withdrawal * Withdrawal (military) * Withdrawal reflex * ''Withdrawal'', Twista Carl Terrell Mitchell (born November 27, 1973), better known by his stage name Twista (formerly Tung Twista), is an American rapper and record producer. He is best known for his Chopper (rap), chopper style of rapping and for once holding the t .../ Do or Die EP * "Withdrawals" (Tyler Farr song) See also * * {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organochlorides
An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlorine) provides common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with TCDD being one of the most notorious. Physical and chemical properties Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. Aliphatic organochlorides are often alkylating agents as chlorine can act as a leaving group, which can result in cellular damage. Natural occurrence Many organochlorine compounds have been isolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosoureas
Nitrosourea is both the name of a molecule, and a class of compounds that include a nitroso (R-NO) group and a urea. Examples Examples include: * Arabinopyranosyl-''N''-methyl-''N''-nitrosourea (Aranose) * Carmustine (BCNU, BiCNU) * Chlorozotocin * Ethylnitrosourea (ENU) * Fotemustine * Lomustine (CCNU) * Nimustine * ''N''-Nitroso-''N''-methylurea (NMU) * Ranimustine (MCNU) * Semustine * Streptozocin (Streptozotocin) Nitrosourea compounds are DNA alkylating agents and are often used in chemotherapy. They are lipophilic and thus can cross the blood–brain barrier, making them useful in the treatment of brain tumors such as glioblastoma multiforme. File:Aranose (Haworth).svg, Arabinopyranosyl-''N''-methyl-''N''-nitrosourea File:Carmustine.svg, Carmustine File:Chlorozotocin (Haworth).svg, Chlorozotocin File:ENU.svg, Ethylnitrosourea File:Fotemustine.svg, Fotemustine File:Lomustine.svg, Lomustine File:N-Nitroso-N-methylurea.svg, ''N''-Nitroso-''N''-methylurea File:Nimust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosamines
In organic chemistry, nitrosamines (or more formally ''N''-Nitrosamines) are organic compounds with the chemical structure , where R is usually an alkyl group. They feature a nitroso group () bonded to a deprotonated amine. Most nitrosamines are carcinogenic in nonhuman animals. A 2006 systematic review supports a "positive association between nitrite and nitrosamine intake and gastric cancer, between meat and processed meat intake and gastric cancer and oesophageal cancer, and between preserved fish, vegetable and smoked food intake and gastric cancer, but is not conclusive". Chemistry The organic chemistry of nitrosamines is well developed with regard to their syntheses, their structures, and their reactions. They usually are produced by the reaction of nitrous acid () and secondary amines. :HONO + R2NH -> R2N-NO + H2O The nitrous acid usually arises from protonation of a nitrite. This synthesis method is relevant to the generation of nitrosamines under some biological cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IARC Group 1 Carcinogens
IARC may refer to: * International Aerial Robotics Competition * International Age Rating Coalition * International Agency for Research on Cancer * International Arctic Research Center * Israel Amateur Radio Club * iArc, South Korean architecture firm {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkylating Antineoplastic Agents
Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents. Nucleophilic alkylating agents Nucleophilic alkylating agents deliver the equivalent of an alkyl anion (carbanion). The formal "alkyl anion" attacks an electrophile, forming a new covalent bond ... [...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] |
Connecticut
Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its capital is Hartford and its most populous city is Bridgeport. Historically the state is part of New England as well as the tri-state area with New York and New Jersey. The state is named for the Connecticut River which approximately bisects the state. The word "Connecticut" is derived from various anglicized spellings of "Quinnetuket”, a Mohegan-Pequot word for "long tidal river". Connecticut's first European settlers were Dutchmen who established a small, short-lived settlement called House of Hope in Hartford at the confluence of the Park and Connecticut Rivers. Half of Connecticut was initially claimed by the Dutch colony New Netherland, which included much of the land between the Connecticut and Delaware Rivers, although the firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Fibrosis
Pulmonary fibrosis is a condition in which the lungs become scarred over time. Symptoms include shortness of breath, a dry cough, feeling tired, weight loss, and nail clubbing. Complications may include pulmonary hypertension, respiratory failure, pneumothorax, and lung cancer. Causes include environmental pollution, certain medications, connective tissue diseases, infections, and interstitial lung diseases. Idiopathic pulmonary fibrosis (IPF), an interstitial lung disease of unknown cause, is most common. Diagnosis may be based on symptoms, medical imaging, lung biopsy, and lung function tests. There is no cure and there are limited treatment options available. Treatment is directed towards efforts to improve symptoms and may include oxygen therapy and pulmonary rehabilitation. Certain medications may be used to try to slow the worsening of scarring. Lung transplantation may occasionally be an option. At least 5 million people are affected globally. Life expectancy is gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
