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Arbekacin
Arbekacin (INN) is a semisynthetic aminoglycoside antibiotic which was derived from kanamycin. It is primarily used for the treatment of infections caused by multi-resistant bacteria including methicillin-resistant ''Staphylococcus aureus'' (MRSA). Arbekacin was originally synthesized from dibekacin in 1973 by Hamao Umezawa and collaborators. It has been registered and marketed in Japan since 1990 under the trade name Habekacin. Arbekacin is no longer covered by patent and generic versions of the drug are also available under such trade names as Decontasin and Blubatosine. Pharmacology Arbekacin is approved for the treatment of pneumonia and sepsis caused by methicillin-resistant ''Staphylococcus aureus'' (MRSA). Because of its synergistic effect with beta-lactams, arbekacin also holds promise as a treatment for multidrug-resistant Gram-negative bacterial infections such as multidrug-resistant ''Pseudomonas aeruginosa'' and '' Acinetobacter baumannii''. Pharmacodynamics Ami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aminoglycoside Antibiotic
Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). The term can also refer more generally to any organic molecule that contains amino sugar substructures. Aminoglycoside antibiotics display bactericidal activity against Gram-negative aerobes and some anaerobic bacilli where resistance has not yet arisen but generally not against Gram-positive and anaerobic Gram-negative bacteria.ME Levison, MD, 2012, Aminoglycosides, The Merck Manua accessed 22 February 2014. Streptomycin is the first-in-class aminoglycoside antibiotic. It is derived from ''Streptomyces griseus'' and is the earliest modern agent used against tuberculosis. Streptomycin lacks the common 2-deoxystreptamine moiety (image right, below) present in most other members of this class. Other examples of aminoglycosides include the deoxystreptamine-containin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acinetobacter Baumannii
''Acinetobacter baumannii'' is a typically short, almost round, rod-shaped ( coccobacillus) Gram-negative bacterium. It is named after the bacteriologist Paul Baumann. It can be an opportunistic pathogen in humans, affecting people with compromised immune systems, and is becoming increasingly important as a hospital-derived (nosocomial) infection. While other species of the genus '' Acinetobacter'' are often found in soil samples (leading to the common misconception that ''A. baumannii'' is a soil organism, too), it is almost exclusively isolated from hospital environments. Although occasionally it has been found in environmental soil and water samples, its natural habitat is still not known. Bacteria of this genus lack flagella, whip-like structures many bacteria use for locomotion, but exhibit twitching or swarming motility. This may be due to the activity of type IV pili, pole-like structures that can be extended and retracted. Motility in ''A. baumannii'' may also be due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intramuscular Injection
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles have larger and more numerous blood vessels than subcutaneous tissue, leading to faster absorption than subcutaneous or intradermal injections. Medication administered via intramuscular injection is not subject to the first-pass metabolism effect which affects oral medications. Common sites for intramuscular injections include the deltoid muscle of the upper arm and the gluteal muscle of the buttock. In infants, the vastus lateralis muscle of the thigh is commonly used. The injection site must be cleaned before administering the injection, and the injection is then administered in a fast, darting motion to decrease the discomfort to the individual. The volume to be injected in the muscle is usually limited to 2–5 milliliters, depending on in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adverse Drug Reaction
An adverse drug reaction (ADR) is a harmful, unintended result caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs. The meaning of this term differs from the term "side effect" because side effects can be beneficial as well as detrimental. The study of ADRs is the concern of the field known as ''pharmacovigilance''. An adverse drug event (ADE) refers to any unexpected and inappropriate occurrence at the time a drug is used, whether or not associated with the administration of the drug. An ADR is a special type of ADE in which a causative relationship can be shown. ADRs are only one type of medication-related harm, as harm can also be caused by omitting to take indicated medications. Classification ADRs may be classified by e.g. cause and severity. Cause *Type A: Augmented pharmacologic effects - dose dependent and predictable :Type A reactions, which constitute approximate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephrotoxicity
Nephrotoxicity is toxicity in the kidneys. It is a poisonous effect of some substances, both toxic chemicals and medications, on kidney function. There are various forms, and some drugs may affect kidney function in more than one way. Nephrotoxins are substances displaying nephrotoxicity. Nephrotoxicity should not be confused with some medications predominantly excreted by the kidneys needing their dose adjusted for the decreased kidney function (e.g., heparin, lithium). Types of toxicity Cardiovascular * General: diuretics, β-blockers, vasodilator agents * Local: ACE inhibitors, ciclosporin, tacrolimus. Direct tubular effect * Proximal convoluted tubule: Aminoglycoside antibiotics (e.g., gentamicin), amphotericin B, cisplatin, radiocontrast media, immunoglobulins, mannitol * Distal tubule: NSAIDs (e.g. aspirin, ibuprofen, diclofenac), ACE inhibitors, ciclosporin, lithium salts, cyclophosphamide, amphotericin B * Tubular obstruction: sulphonamides, methotrexate, acicl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ototoxicity
Ototoxicity is the property of being toxic to the ear (''oto-''), specifically the cochlea or auditory nerve and sometimes the vestibular system, for example, as a side effect of a drug. The effects of ototoxicity can be reversible and temporary, or irreversible and permanent. It has been recognized since the 19th century. There are many well-known ototoxic drugs used in clinical situations, and they are prescribed, despite the risk of hearing disorders, for very serious health conditions. Ototoxic drugs include antibiotics (such as gentamicin, streptomycin, tobramycin), loop diuretics (such as furosemide), and platinum-based chemotherapy agents (such as cisplatin and carboplatin). A number of nonsteroidal anti-inflammatory drugs (NSAIDS) have also been shown to be ototoxic. This can result in sensorineural hearing loss, dysequilibrium, or both. Some environmental and occupational chemicals have also been shown to affect the auditory system and interact with noise. Signs and sym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parenteral
A route of administration in pharmacology and toxicology is the way by which a drug, fluid, poison, or other substance is taken into the body. Routes of administration are generally classified by the location at which the substance is applied. Common examples include oral and intravenous administration. Routes can also be classified based on where the target of action is. Action may be topical (local), enteral (system-wide effect, but delivered through the gastrointestinal tract), or parenteral (systemic action, but delivered by routes other than the GI tract). Route of administration and dosage form are aspects of drug delivery. Classification Routes of administration are usually classified by application location (or exposition). The route or course the active substance takes from application location to the location where it has its target effect is usually rather a matter of pharmacokinetics (concerning the processes of uptake, distribution, and elimination of drugs). Exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysomes
A polyribosome (or polysome or ergosome) is a group of ribosomes bound to an Messenger RNA, mRNA molecule like “beads” on a “thread”. It consists of a complex of an mRNA molecule and two or more ribosomes that act to translation (biology), translate mRNA instructions into polypeptides. Originally coined "ergosomes" in 1963, they were further characterized by Jonathan Warner, Paul M. Knopf, and Alex Rich. Polysomes are formed during the Eukaryotic_transcription#Elongation, elongation phase when ribosomes and elongation factors synthesize the encoded polypeptide. Multiple ribosomes move along the coding region of mRNA, creating a polysome. The ability of multiple ribosomes to function on an mRNA molecule explains the limited abundance of mRNA in the cell. Polyribosome structure differs between prokaryotic polysomes, eukaryotic polysomes, and membrane bound polysomes. Polysome activity can be used to measure the level of gene expression through a technique called polysomal pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and, utilising amino acids carried by transfer RNA (tRNA), the ribosome creates the protein. This process is known as translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, genetic inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticodon
Transfer RNA (abbreviated tRNA and formerly referred to as sRNA, for soluble RNA) is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes), that serves as the physical link between the mRNA and the amino acid sequence of proteins. tRNAs genes from Bacteria are typically shorter (mean = 77.6 bp) than tRNAs from Archaea (mean = 83.1 bp) and eukaryotes (mean = 84.7 bp). The mature tRNA follows an opposite pattern with tRNAs from Bacteria being usually longer (median = 77.6 nt) than tRNAs from Archaea (median = 76.8 nt), with eukaryotes exhibiting the shortest mature tRNAs (median = 74.5 nt). Transfer RNA (tRNA) does this by carrying an amino acid to the protein synthesizing machinery of a cell called the ribosome. Complementation of a 3-nucleotide codon in a messenger RNA (mRNA) by a 3-nucleotide anticodon of the tRNA results in protein synthesis based on the mRNA code. As such, tRNAs are a necessary component of translation, the biological syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16S Ribosomal RNA
16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome (SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as 16S rRNA gene and are used in reconstructing phylogenies, due to the slow rates of evolution of this region of the gene. Carl Woese and George E. Fox were two of the people who pioneered the use of 16S rRNA in phylogenetics in 1977. Multiple sequences of the 16S rRNA gene can exist within a single bacterium. Functions * Like the large (23S) ribosomal RNA, it has a structural role, acting as a scaffold defining the positions of the ribosomal proteins. * The 3-end contains the anti- Shine-Dalgarno sequence, which binds upstream to the AUG start codon on the mRNA. The 3-end of 16S RNA binds to the proteins S1 and S21 which are known to be involved in initiation of protein synthesis * Interacts with 23S, aiding in the binding of the two ribosomal s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Anaerobe
Obligate anaerobes are microorganisms killed by normal atmospheric concentrations of oxygen (20.95% O2). Oxygen tolerance varies between species, with some species capable of surviving in up to 8% oxygen, while others lose viability in environments with an oxygen concentration greater than 0.5%. Oxygen sensitivity The oxygen sensitivity of obligate anaerobes has been attributed to a combination of factors including oxidative stress and enzyme production. Oxygen can also damage obligate anaerobes in ways not involving oxidative stress. Because molecular oxygen contains two unpaired electrons in the highest occupied molecular orbital, it is readily reduced to superoxide () and hydrogen peroxide () within cells. A reaction between these two products results in the formation of a free hydroxyl radical (OH.). Superoxide, hydrogen peroxide, and hydroxyl radicals are a class of compounds known as reactive oxygen species (ROS), highly reactant products that are damaging to microbes, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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