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Oxysterols
An oxysterol is a derivative of cholesterol obtained by oxidation involving enzymes and / or pro-oxidants. Such compounds play important roles in various biological processes such as cholesterol homeostasis, lipid metabolism (sphingolipids, fatty acids), apoptosis, autophagy, and prenylation of proteins; the mode of action of oxysterols in these effects is still poorly understood. Several oxysterols are associated with age-related diseases such as cardiovascular disease, eye disease (cataract, age-related macular degeneration), certain neurodegenerative diseases and cancers. The activities of oxysterols in these diseases could be due to their pro-oxidative and pro-inflammatory activities and their ability to act on cellular organelles (mitochondria, peroxisome, lysosome) that can contribute to activate apoptosis and autophagy. There are arguments supporting that oxysterols have important roles in atherosclerosis progression which is involved in several cardiovascular diseases. Ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid. Cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Cholesterol is the principal sterol synthesized by all animals. In vertebrates, hepatic cells typically produce the greatest amounts. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as '' Mycoplasma'', which require cholesterol for growth. François Poulletier de la Salle first identified cholesterol in solid form in gallstones in 1769. However, it was not until 1815 that chemist Michel Eugène Chevreul named the compound "cholesterine". Etymology The word "cholesterol" comes from the Ancient Greek ''chole-'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataract
A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause 51% of all cases of blindness and 33% of visual impairment worldwide. Cataracts are most commonly due to aging but may also occur due to trauma or radiation exposure, be present from birth, or occur following eye surgery for other problems. Risk factors include diabetes, longstanding use of corticosteroid medication, smoking tobacco, prolonged exposure to sunlight, and alcohol. The underlying mechanism involves accumulation of clumps of protein or yellow-brown pigment in the lens that reduces transmission of li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxycholesterol
Oxycholesterol or 5,6-epoxycholesterol is a form of oxidized cholesterol implicated in atherosclerosis. It is commonly formed from the reaction of fats and oxygen during high temperature cooking such as frying. In a study about the effects of oxycholesterol in rabbits with induced hypercholesterolemia, it was shown that compared feeding rabbits cholesterol and unoxidized cholesterol, feeding rabbits oxycholesterol resulted in their developing much higher levels of total cholesterol and low density lipoprotein cholesterol. It is also shown to increase the amount of homocysteine and asymmetric dimethylarginine levels in the rabbits. An abundance of homocysteine leads to an organism with greater chances of endothelial cell injury which can then lead to coronary artery disease. Asymmetric dimethylarginine is shown to cause adverse effects on humans in the form of cardiovascular and metabolic diseases. Therefore it was concluded that adding oxycholesterol into diets of animals with h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioremediation
Bioremediation broadly refers to any process wherein a biological system (typically bacteria, microalgae, fungi, and plants), living or dead, is employed for removing environmental pollutants from air, water, soil, flue gasses, industrial effluents etc., in natural or artificial settings. The natural ability of organisms to adsorb, accumulate, and degrade common and emerging pollutants has attracted the use of biological resources in treatment of contaminated environment. In comparison to conventional physicochemical treatment methods bioremediation may offer considerable advantages as it aims to be sustainable, eco-friendly, cheap, and scalable. Most bioremediation is inadvertent, involving native organisms. Research on bioremediation is heavily focused on stimulating the process by inoculation of a polluted site with organisms or supplying nutrients to promote the growth. In principle, bioremediation could be used to reduce the impact of byproducts created from anthropogenic acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Therapy
Gene therapy is a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material. The first attempt at modifying human DNA was performed in 1980, by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989. The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990. It is thought to be able to cure many genetic disorders or treat them over time. Between 1989 and December 2018, over 2,900 clinical trials were conducted, with more than half of them in phase I.Gene Therapy Cli ... [...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 atheroma, 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 Artery, arteries are affected. The exact cause is not known and is proposed to be multifactorial. Risk factors include dyslipidemia, abnormal cholesterol levels, elevated levels of inflammatory markers, high blood pressure, diabetes, smoking, obesity, family history, genetic, and an unhealthy diet. Atheroma, Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of Artery, arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysosome
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane proteins, and its lumenal proteins. The lumen's pH (~4.5–5.0) is optimal for the enzymes involved in hydrolysis, analogous to the activity of the stomach. Besides degradation of polymers, the lysosome is involved in various cell processes, including secretion, plasma membrane repair, apoptosis, cell signaling, and energy metabolism. Lysosomes act as the waste disposal system of the cell by digesting used materials in the cytoplasm, from both inside and outside the cell. Material from outside the cell is taken up through endocytosis, while material from the inside of the cell is digested through autophagy. The sizes of the organelles vary greatly—the larger ones can be more than 10 times the size of the smaller ones. They were discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome
A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H2O2) is then formed. Peroxisomes owe their name to hydrogen peroxide generating and scavenging activities. They perform key roles in lipid metabolism and the conversion of reactive oxygen species. Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines, the reduction of reactive oxygen species – specifically hydrogen peroxide – and the biosynthesis of plasmalogens, i.e., ether phospholipids critical for the normal function of mammalian brains and lungs. They also contain approximately 10% of the total activity of two enzymes (Glucose-6-phosphate dehydrogenase and 6-Phosphogluconate dehydrogenase) in the pentose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrion
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into other structures. One eukaryote, ''Monocercomonoides'', is known to have completely lost its mitochondria, and one multicellular organism, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurodegenerative Diseases
A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, Alzheimer's disease, Huntington's disease, multiple system atrophy, and prion diseases. Neurodegeneration can be found in the brain at many different levels of neuronal circuitry, ranging from molecular to systemic. Because there is no known way to reverse the progressive degeneration of neurons, these diseases are considered to be incurable; however research has shown that the two major contributing factors to neurodegeneration are oxidative stress and inflammation. Biomedical research has revealed many similarities between these diseases at the subcellular level, including atypical protein assemblies (like proteinopathy) and induced cell death. These similarities suggest that th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macular Degeneration
Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual hallucinations may also occur. Macular degeneration typically occurs in older people. Genetic factors and smoking also play a role. It is due to damage to the macula of the retina. Diagnosis is by a complete eye exam. The severity is divided into early, intermediate, and late types. The late type is additionally divided into "dry" and "wet" forms with the dry form making up 90% of cases. The difference between the two forms is the change of macula. Those with dry form AMD have drusen, ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiovascular Disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, heart failure, hypertensive heart disease, rheumatic heart disease, cardiomyopathy, abnormal heart rhythms, congenital heart disease, valvular heart disease, carditis, aortic aneurysms, peripheral artery disease, thromboembolic disease, and venous thrombosis. The underlying mechanisms vary depending on the disease. It is estimated that dietary risk factors are associated with 53% of CVD deaths. Coronary artery disease, stroke, and peripheral artery disease involve atherosclerosis. This may be caused by high blood pressure, smoking, diabetes mellitus, lack of exercise, obesity, high blood cholesterol, poor diet, excessive alcohol consumption, and poor sleep, among other things. High blood pressure is estimated to account for approximat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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