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BCNU
Carmustine, sold under the brand name BiCNU among others, is a medication used mainly for chemotherapy. It is a nitrogen mustard β-chloro- nitrosourea compound used as an alkylating agent. Description Carmustine is an orange-yellow solid medication used mainly for chemotherapy. It is a nitrogen mustard β-chloro- nitrosourea compound. Mechanism of action As an alkylating agent, carmustine can form interstrand crosslinks in DNA, which prevents DNA replication and DNA transcription. Uses Carmustine is used as an alkylating agent to treat several types of brain cancer including glioma, glioblastoma multiforme, medulloblastoma and astrocytoma), multiple myeloma, and lymphoma (Hodgkin's and non-Hodgkin). Carmustine is sometimes used in conjunction with alkyl guanine transferase (AGT) inhibitors, such as ''O''6-benzylguanine. The AGT-inhibitors increase the efficacy of carmustine by inhibiting the direct reversal pathway of DNA repair, which will prevent formation of the inters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O6-Benzylguanine
''O''6-Benzylguanine (O6-BG) is a synthetic derivative of guanine. It is an antineoplastic agent. It exerts its effect by acting as a suicide inhibitor of the enzyme O6-alkylguanine-DNA alkyltransferase which leads to interruption of DNA repair. O6-BG was used clinically in combination with the alkylating agent temozolomide for glioblastoma Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality ..., however the combination was found to be overly toxic without adding significant benefit. O6-BG is also used as a biochemical tool in the study of DNA repair mechanisms. References External links * {{DEFAULTSORT:Benzylguanine, O6- Purines Antineoplastic drugs Experimental cancer drugs Benzyl compounds ... [...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] |
Nitrosourea Compounds
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:Nimus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glioblastoma Multiforme
Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Symptoms often worsen rapidly and may progress to unconsciousness. The cause of most cases of glioblastoma is not known. Uncommon risk factors include genetic disorders, such as neurofibromatosis and Li–Fraumeni syndrome, and previous radiation therapy. Glioblastomas represent 15% of all brain tumors. They can either start from normal brain cells or develop from an existing low-grade astrocytoma. The diagnosis typically is made by a combination of a CT scan, MRI scan, and tissue biopsy. There is no known method of preventing the cancer. Treatment usually involves surgery, after which chemotherapy and radiation therapy are used. The medication temozolomide is frequently used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crosslinking Of DNA
In genetics, crosslinking of DNA occurs when various exogenous or endogenous agents react with two nucleotides of DNA, forming a covalent linkage between them. This crosslink can occur within the same strand (intrastrand) or between opposite strands of double-stranded DNA (interstrand). These adducts interfere with cellular metabolism, such as DNA replication and transcription, triggering cell death. These crosslinks can, however, be repaired through excision or recombination pathways. DNA crosslinking also has useful merit in chemotherapy and targeting cancerous cells for apoptosis, as well as in understanding how proteins interact with DNA. Crosslinking agents Many characterized crosslinking agents have two independently reactive groups within the same molecule, each of which is able to bind with a nucleotide residue of DNA. These agents are separated based upon their source of origin and labeled either as exogenous or endogenous. Exogenous crosslinking agents are chemicals an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethylurea
Dimethylurea (DMU) (IUPAC systematic name: 1,3-Dimethylurea ) is a urea derivative and used as an intermediate in organic synthesis. It is a colorless crystalline powder with little toxicity. Uses 1,3-Dimethylurea is used for synthesis of caffeine, theophylline, pharmachemicals, textile aids, herbicides and others.http://www.inchem.org/documents/sids/sids/96311.pdf SIDS Initial Assessment Report In the textile manufacturing, textile processing industry 1,3-dimethylurea is used as intermediate for the production of formaldehyde-free easy-care textile finishing, finishing agents for textiles. The estimated world production of DMU is estimated to be less than 25,000 tons. References {{Authority control Ureas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hodgkin's Lymphoma
Hodgkin lymphoma (HL) is a type of lymphoma, in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells (RS cells) are present in the patient's lymph nodes. The condition was named after the English physician Thomas Hodgkin, who first described it in 1832. Symptoms may include fever, night sweats, and weight loss. Often, nonpainful enlarged lymph nodes occur in the neck, under the arm, or in the groin. Those affected may feel tired or be itchy. The two major types of Hodgkin lymphoma are classic Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. About half of cases of Hodgkin lymphoma are due to Epstein–Barr virus (EBV) and these are generally the classic form. Other risk factors include a family history of the condition and having HIV/AIDS. Diagnosis is conducted by confirming the presence of cancer and identifying RS cells in lymph node biopsies. The virus-positive cases are classified ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-Hodgkin Lymphoma
Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredness. Other symptoms may include bone pain, chest pain, or itchiness. Some forms are slow-growing while others are fast-growing. Lymphomas are types of cancer that develop from lymphocytes, a type of white blood cell. Risk factors include poor immune function, autoimmune diseases, ''Helicobacter pylori'' infection, hepatitis C, obesity, and Epstein–Barr virus infection. The World Health Organization classifies lymphomas into five major groups, including one for Hodgkin lymphoma. Within the four groups for NHL are over 60 specific types of lymphoma. Diagnosis is by examination of a bone marrow or lymph node biopsy. Medical imaging is done to help with cancer staging. Treatment depends on whether the lymphoma is slow- or fast-growing an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Repair
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs). This can eventually lead to malignant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanine
Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called guanosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. This unsaturated arrangement means the bicyclic molecule is planar. Properties Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA, and uracil only in RNA. Guanine has two tautomeric forms, the major keto form (see figures) and rare enol form. It binds to cytosine through three hydrogen bonds. In cytosine, the amino group acts as the hydrogen bond donor and the C-2 carbonyl and the N-3 amine as the hydrogen-bond acceptors. Guanine has the C-6 carbonyl group that acts as the hydrogen bond acceptor, while a group at N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Myeloma
Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, anemia, kidney dysfunction, and infections may occur. Complications may include amyloidosis. The cause of multiple myeloma is unknown. Risk factors include obesity, radiation exposure, family history, and certain chemicals. There is an increased risk of multiple myeloma in certain occupations. This is due to the occupational exposure to aromatic hydrocarbon solvents having a role in causation of multiple myeloma. Multiple myeloma may develop from monoclonal gammopathy of undetermined significance that progresses to smoldering myeloma. The abnormal plasma cells produce abnormal antibodies, which can cause kidney problems and overly thick blood. The plasma cells can also form a mass in the bone marrow or soft tissue. When one tumor i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosine
Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). The nucleoside of cytosine is cytidine. In Watson-Crick base pairing, it forms three hydrogen bonds with guanine. History Cytosine was discovered and named by Albrecht Kossel and Albert Neumann in 1894 when it was hydrolyzed from calf thymus tissues. A structure was proposed in 1903, and was synthesized (and thus confirmed) in the laboratory in the same year. In 1998, cytosine was used in an early demonstration of quantum information processing when Oxford University researchers implemented the Deutsch-Jozsa algorithm on a two qubit nuclear magnetic resonance quantum computer (NMRQC). In March 2015, NASA scientists reported the formation of cytosine, along with uracil and thym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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