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Phosphoryl-choline
:''Phosphorylcholine refers to the functional group derived from phosphocholine. Also not to be confused with phosphatidylcholine.'' Phosphorylcholine (abbreviated ChoP) is the hydrophilic polar head group of some phospholipids, which is composed of a negatively charged phosphate bonded to a small, positively charged choline group. Phosphorylcholine is part of the platelet-activating factor; the phospholipid phosphatidylcholine and sphingomyelin, the only phospholipid of the membrane that is not built with a glycerol backbone. Treatment of cell membranes, like those of RBCs, by certain enzymes, like some phospholipase A2 renders the phosphorylcholine moiety exposed to the external aqueous phase, and thus accessible for recognition by the immune system. Antibodies against phosphorylcholine are naturally occurring autoantibodies that are created by CD5+/ B-1 B cells and are referred to as non-pathogenic autoantibodies. Thrombus-resistant stents In interventional cardiology, ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphocholine
Phosphocholine is an intermediate in the synthesis of phosphatidylcholine in tissues. Phosphocholine is made in a reaction, catalyzed by choline kinase, that converts ATP and choline into phosphocholine and ADP. Phosphocholine is a molecule found, for example, in lecithin. In nematodes and human placentas, phosphocholine is selectively attached to other proteins as a posttranslational modification to suppress an immune response by their hosts. It is also one of the binding targets of C-reactive protein (CRP). Thus, when a cell is damaged, CRP binds to phosphocholine, beginning the recognition and phagocytotic immunologic response. Phosphocholine is a natural constituent of hens' eggs (and many other eggs) often used in biomimetic membrane studies. See also * Alkylphosphocholines * Choline * Phosphoethanolamine Phosphorylethanolamine or phosphoethanolamine is an ethanolamine derivative that is used to construct two different categories of phospholipids. One category ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug-eluting Stents
A drug-eluting stent (DES) is a peripheral or coronary stent (a scaffold) placed into narrowed, diseased peripheral or coronary arteries that slowly release a drug to block cell proliferation. This prevents fibrosis that, together with clots ( thrombi), could otherwise block the stented artery, a process called restenosis. The stent is usually placed within the peripheral or coronary artery by an interventional cardiologist or interventional radiologist during an angioplasty procedure. Drug-eluting stents in current clinical use were approved by the FDA after clinical trials showed they were statistically superior to bare-metal stents for the treatment of native coronary artery narrowings, having lower rates of major adverse cardiac events (usually defined as a composite clinical endpoint of death + myocardial infarction + repeat intervention because of restenosis). The first drug-eluting stents to be approved in Europe and the U.S. were coated with paclitaxel or an m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choline
Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but require additional choline in the diet to maintain health. Dietary requirements can be met by choline per se or in the form of choline phospholipids, such as phosphatidylcholine. Choline is not formally classified as a vitamin despite being an essential nutrient with an amino acid–like structure and metabolism. In most animals, choline phospholipids are necessary components in cell membranes, in the membranes of cell organelles, and in very low-density lipoproteins. Choline is required to produce acetylcholine – a neurotransmitter – and ''S''-adenosylmethionine (SAM), a universal methyl donor. Upon methylation SAM is transformed into homocysteine. Symptomatic choline deficiency causes non-alcoholic fatty liver disease and muscl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterilization (microbiology)
Sterilization refers to any process that removes, kills, or deactivates all forms of life (particularly microorganisms such as fungi, bacteria, spores, and unicellular eukaryotic organisms) and other biological agents such as prions present in or on a specific surface, object, or fluid. Sterilization can be achieved through various means, including heat, chemicals, irradiation, high pressure, and filtration. Sterilization is distinct from disinfection, sanitization, and pasteurization, in that those methods reduce rather than eliminate all forms of life and biological agents present. After sterilization, an object is referred to as being sterile or aseptic. Applications Foods One of the first steps toward modernized sterilization was made by Nicolas Appert, who discovered that application of heat over a suitable period slowed the decay of foods and various liquids, preserving them for safe consumption for a longer time than was typical. Canning of foods is an extension ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zotarolimus
Zotarolimus (INN, codenamed ABT-578) is an immunosuppressant. It is a semi-synthetic derivative of sirolimus (rapamycin). It was designed for use in stents with phosphorylcholine as a carrier. Zotarolimus, or ABT-578, was originally used on Abbott's coronary stent platforms to reduce early inflammation and restenosis; however, Zotarolimus failed Abbott's primary endpoint to bring their stent/drug delivery system to market. The drug was sold/distributed to Medtronic for use on their stent platforms, which is the same drug they use today. Coronary stents reduce early complications and improve late clinical outcomes in patients needing interventional cardiology. The first human coronary stent implantation was first performed in 1986 by Puel et al. However, there are complications associated with stent use, development of thrombosis which impedes the efficiency of coronary stents, haemorrhagic and restenosis complications are problems associated with stents. These complications have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrombosis
Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thrombocytes) and fibrin to form a blood clot to prevent blood loss. Even when a blood vessel is not injured, blood clots may form in the body under certain conditions. A clot, or a piece of the clot, that breaks free and begins to travel around the body is known as an embolus. Thrombosis may occur in veins ( venous thrombosis) or in arteries ( arterial thrombosis). Venous thrombosis (sometimes called DVT, deep vein thrombosis) leads to a blood clot in the affected part of the body, while arterial thrombosis (and, rarely, severe venous thrombosis) affects the blood supply and leads to damage of the tissue supplied by that artery (ischemia and necrosis). A piece of either an arterial or a venous thrombus can break off as an embolus, which c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. When severe, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. The exact cause is not known and is proposed to be multifactorial. Risk factors include abnormal cholesterol levels, elevated levels of inflammatory markers, high blood pressure, diabetes, smoking, obesity, family history, genetic, and an unhealthy diet. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, electrocardiogram, and exercise str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balloon Angioplasty
Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter (a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A stent may be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn. Angioplasty has come to include all manner of vascular interventions that are typically performed percutaneously. The word is composed of the combining forms of the Greek words ἀνγεῖον ' "vessel" or "cavity" (of the human body) and πλάσσω ' "form" or "mould". Uses and indications Coronary angioplasty A coronar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery Disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves Ischemia, the reduction of blood flow to the myocardium, heart muscle due to build-up of atherosclerotic plaque in the Coronary arteries, arteries of the heart. It is the most common of the cardiovascular diseases. Types include stable angina, unstable angina, myocardial infarction, and sudden cardiac death. A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw. Occasionally it may feel like heartburn. Usually symptoms occur with exercise or emotional Stress (psychological), stress, last less than a few minutes, and improve with rest. Shortness of breath may also occur and sometimes no symptoms are present. In many cases, the first sign is a Myocardial infarction, heart attack. Other complications include heart failure or an Heart arrhythmia, abnormal heartbeat. Risk factors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restenosis
Restenosis is the recurrence of stenosis, a narrowing of a blood vessel, leading to restricted blood flow. Restenosis usually pertains to an artery or other large blood vessel that has become narrowed, received treatment to clear the blockage and subsequently become renarrowed. This is usually restenosis of an artery, or other blood vessel, or possibly a vessel within an organ. Restenosis is a common adverse event of endovascular procedures. Procedures frequently used to treat the vascular damage from atherosclerosis and related narrowing and renarrowing (restenosis) of blood vessels include vascular surgery, cardiac surgery, and angioplasty. When a stent is used and restenosis occurs, this is called in-stent restenosis or ISR. If it occurs following balloon angioplasty, this is called post-angioplasty restenosis or PARS. The diagnostic threshold for restenosis in both ISR or PARS is ≥50% stenosis. If restenosis occurs after a procedure, follow-up imaging is not the only way t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interventional Cardiology
Interventional cardiology is a branch of cardiology that deals specifically with the catheter based treatment of structural heart diseases. Andreas Gruentzig is considered the father of interventional cardiology after the development of angioplasty by interventional radiologist Charles Dotter. Many procedures can be performed on the heart by catheterization. This most commonly involves the insertion of a sheath into the femoral artery (but, in practice, any large peripheral artery or vein) and cannulating the heart under X-ray visualization (most commonly fluoroscopy). The radial artery may also be used for cannulation; this approach offers several advantages, including the accessibility of the artery in most patients, the easy control of bleeding even in anticoagulated patients, the enhancement of comfort because patients are capable of sitting up and walking immediately following the procedure, and the near absence of clinically significant sequelae in patients with a norma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatidylcholine
Phosphatidylcholines (PC) are a class of phospholipids that incorporate choline as a headgroup. They are a major component of biological membranes and can be easily obtained from a variety of readily available sources, such as egg yolk or soybeans, from which they are mechanically or chemically extracted using hexane. They are also a member of the lecithin group of yellow-brownish fatty substances occurring in animal and plant tissues. Dipalmitoyl phosphatidylcholine (a.k.a. lecithin) is a major component of pulmonary surfactant and is often used in the L/S ratio to calculate fetal lung maturity. While phosphatidylcholines are found in all plant and animal cells, they are absent in the membranes of most bacteria, including ''Escherichia coli''. Purified phosphatidylcholine is produced commercially. The name ''lecithin'' was derived from Greek λέκιθος, ''lekithos'' 'egg yolk' by Theodore Nicolas Gobley, a French chemist and pharmacist of the mid-19th century, who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
