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Pseudoexfoliation
Pseudoexfoliation syndrome, often abbreviated as PEX and sometimes as PES or PXS, is an aging-related systemic disease manifesting itself primarily in the eyes which is characterized by the accumulation of microscopic granular amyloid-like protein fibers. Its cause is unknown, although there is speculation that there may be a genetic basis. It is more prevalent in women than men, and in persons past the age of seventy. Its prevalence in different human populations varies; for example, it is prevalent in Scandinavia. The buildup of protein clumps can block normal drainage of the eye fluid called the aqueous humor and can cause, in turn, a buildup of pressure leading to glaucoma and loss of vision (pseudoexfoliation glaucoma, exfoliation glaucoma). As worldwide populations become older because of shifts in demography, PEX may become a matter of greater concern. Signs and symptoms Patients may have no specific symptoms. In some cases, patients may complain of lessened visual acuity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LOXL1
Lysyl oxidase homolog 1, also known as LOXL1, is an enzyme which in humans is encoded by the ''LOXL1'' gene. Function This gene encodes a member of the lysyl oxidase gene family. The prototypic member of the family is essential to the biogenesis of connective tissue, encoding an extracellular copper-dependent amine oxidase that catalyses the first step in the formation of crosslinks in collagens and elastin. A highly conserved amino acid sequence at the C-terminus end appears to be sufficient for amine oxidase activity, suggesting that each family member may retain this function. The N-terminus is poorly conserved and may impart additional roles in developmental regulation, senescence, tumor suppression, cell growth control, and chemotaxis to each member of the family. Clinical significance Polymorphisms of the LOXL1 gene are associated with pseudoexfoliation syndrome, a disease where the extracellular matrix contains abnormal amounts of cross-linked, amyloid-like fibrillar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Disease
A systemic disease is one that affects a number of Organ (anatomy), organs and Tissue (biology), tissues, or affects the Human body, body as a whole. It differs from a localized disease, which is a disease affecting only part of the body (e.g., a mouth ulcer). Examples * Mastocytosis, including mast cell activation syndrome and eosinophilic esophagitis * Chronic fatigue syndrome * vasculitis, Systemic vasculitis e.g. Lupus erythematosus, SLE, Polyarteritis nodosa, PAN * Sarcoidosis – a disease that mainly affects the lungs, brain, joints and eyes, found most often in young African-American women. * Hypothyroidism – where the thyroid gland produces too little thyroid hormones. * Diabetes mellitus – an imbalance in blood glucose (sugar) levels. * Fibromyalgia * Ehlers-Danlos syndromes - an inherited connective tissue disorder with multiple subcategories * Adrenal insufficiency – where the adrenal glands don't produce enough steroid hormones * Coeliac disease – an autoimmu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraocular Pressure
Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg). Physiology Intraocular pressure is determined by the production and drainage of aqueous humour by the ciliary body and its drainage via the trabecular meshwork and uveoscleral outflow. The reason for this is because the vitreous humour in the posterior segment has a relatively fixed volume and thus does not affect intraocular pressure regulation. An important quantitative relationship (Goldmann's equation) is as follows: :P_o = \frac + P_v Where: * P_o is the IOP in millimeters of mercury (mmHg) * F the rate of aqueous humour formation in microliters per minute (μL/min) * U the resorption of aqueous humour through the uveoscleral route (μL/min) * C is the facility of outflow in mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative '' phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic country by both area and population, and is the List of European countries by area, fifth-largest country in Europe. Its capital and largest city is Stockholm. Sweden has a population of 10.6 million, and a low population density of ; 88% of Swedes reside in urban areas. They are mostly in the central and southern half of the country. Sweden's urban areas together cover 1.5% of its land area. Sweden has a diverse Climate of Sweden, climate owing to the length of the country, which ranges from 55th parallel north, 55°N to 69th parallel north, 69°N. Sweden has been inhabited since Prehistoric Sweden, prehistoric times around 12,000 BC. The inhabitants emerged as the Geats () and Swedes (tribe), Swedes (), who formed part of the sea-faring peopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iceland
Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the region's westernmost and most list of countries and dependencies by population density, sparsely populated country. Its Capital city, capital and largest city is Reykjavík, which is home to about 36% of the country's roughly 380,000 residents (excluding nearby towns/suburbs, which are separate municipalities). The official language of the country is Icelandic language, Icelandic. Iceland is on a rift between Plate tectonics, tectonic plates, and its geologic activity includes geysers and frequent Types of volcanic eruptions, volcanic eruptions. The interior consists of a volcanic plateau with sand and lava fields, mountains and glaciers, and many Glacial stream, glacial rivers flow to the sea through the Upland and lowland, lowlands. Iceland i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malondialdehyde
Malondialdehyde belong to the class of β-dicarbonyls. A colorless solid, malondialdehyde is a highly reactive compound that occurs as the enol. It is a physiological metabolite, and a marker for oxidative stress. Structure and synthesis Malondialdehyde mainly exists as its enol, hydroxyacrolein:V. Nair, C. L. O'Neil, P. G. Wang "Malondialdehyde", ''Encyclopedia of Reagents for Organic Synthesis'', 2008, John Wiley & Sons, New York. Article Online Posting Date: March 14, 2008 :CH2(CHO)2 → HOC(H)=CH-CHO In organic solvents, the ''cis''-isomer is favored, whereas in water the ''trans''-isomer predominates. The equilibrium is rapid and is inconsequential for many purposes. In the laboratory it can be generated in situ by hydrolysis of its acetal 1,1,3,3-tetramethoxypropane, which is commercially available and shelf-stable, unlike malondialdehyde. Malondialdehyde is easily deprotonated to give the sodium salt of the enolate (m.p. 245 °C). Biosynthesis and reactivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascorbic Acid
Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Ascorbic acid exists as two enantiomers (mirror-image isomers), commonly denoted "" (for "levo") and "" (for "dextro"). The isomer is the one most often encountered: it occurs naturally in many foods, and is one form (" vitamer") of vitamin C, an essential nutrient for humans and many animals. Deficiency of vitamin C causes scurvy, formerly a major disease of sailors in long sea voyages. It is used as a food additive and a dietary supplement for its antioxidant properties. The "" form ( erythorbic acid) can be made by chemical synthesis, but has no significant biological role. Etymology The term ''ascorbic'' means antiscruvy and denotes the ability to fight off scurvy. It is related to combating Vitamin C deficiency. History The antiscor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homocysteine
Homocysteine (; symbol Hcy) is a non-proteinogenic α-amino acid. It is a homologous series, homologue of the amino acid cysteine, differing by an additional methylene bridge (). It is biosynthesized from methionine by the removal of its terminal Cε methyl group. In the body, homocysteine can be recycled into methionine or converted into cysteine with the aid of Vitamin B6, vitamin B6, Folate, B9, and Vitamin B12, B12. High levels of homocysteine in the blood (hyperhomocysteinemia) is regarded as a marker of cardiovascular disease, likely working through atherogenesis, which can result in Ischemia, ischemic injury. Therefore, hyperhomocysteinemia is a possible risk factor for coronary artery disease. Coronary artery disease occurs when an atherosclerotic plaque blocks blood flow to the Coronary artery, coronary arteries, which supply the heart with oxygenated blood. Hyperhomocysteinemia has been correlated with the occurrence of blood clots, heart attacks, and strokes, although ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiovascular Disease
Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases (e.g. angina, heart attack), heart failure, hypertensive heart disease, rheumatic heart disease, cardiomyopathy, arrhythmia, 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 approximately 13% of CVD deaths, while tobacco accounts for 9%, di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample Cell (biology), cells or Biological tissue, tissues for examination to determine the presence or extent of a disease. The tissue is then Histopathology, fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
