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Alcohol Flush Reaction
Alcohol flush reaction is a condition in which a person develops flushes or blotches associated with erythema on the face, neck, shoulders, ears, and in some cases, the entire body after consuming alcoholic beverages. The reaction is the result of an accumulation of acetaldehyde, a metabolic byproduct of the catabolic metabolism of alcohol, and is caused by an aldehyde dehydrogenase 2 deficiency. This syndrome has been associated with lower than average rates of alcoholism, possibly due to its association with adverse effects after drinking alcohol. However, it has also been associated with an increased risk of esophageal cancer in those who do drink. The reaction is informally termed Asian flush due to its frequent occurrence in East Asians, with approximately 30 to 50% of Chinese, Japanese, and Koreans showing characteristic physiological responses to drinking alcohol that includes facial flushing, nausea, headaches and a fast heart rate. The condition may be also high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALDH2
Aldehyde dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ''ALDH2'' gene located on chromosome 12. ALDH2 belongs to the aldehyde dehydrogenase family of enzymes. Aldehyde dehydrogenase is the second enzyme of the major oxidative pathway of alcohol metabolism. ALDH2 has a low Km for acetaldehyde, and is localized in mitochondrial matrix. The other liver isozyme, ALDH1, localizes to the cytosol. Most White people have both major isozymes, while approximately 36% of East Asians have the cytosolic isozyme but not a functional mitochondrial isozyme. A remarkably higher frequency of acute alcohol intoxication among East Asians than among Whites could be related to this absence of a catalytically active form of ALDH2. The increased exposure to acetaldehyde in individuals with the catalytically inactive form may also confer greater susceptibility to many types of cancer. Gene The ''ALDH2'' gene is about 44 kbp in length and contains at least 13 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhinitis
Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip. The inflammation is caused by viruses, bacteria, irritants or allergens. The most common kind of rhinitis is allergic rhinitis, which is usually triggered by airborne allergens such as pollen and dander. Allergic rhinitis may cause additional symptoms, such as sneezing and nasal itching, coughing, headache, fatigue, malaise, and cognitive impairment. The allergens may also affect the eyes, causing watery, reddened, or itchy eyes and puffiness around the eyes. The inflammation results in the generation of large amounts of mucus, commonly producing a runny nose, as well as a stuffy nose and post-nasal drip. In the case of allergic rhinitis, the inflammation is caused by the degranulation of mast cells in the nose. When mast cells degranulate, they release histamine and other chemicals, starting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homozygote
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Most eukaryotes have two matching sets of chromosomes; that is, they are diploid. Diploid organisms have the same loci on each of their two sets of homologous chromosomes except that the sequences at these loci may differ between the two chromosomes in a matching pair and that a few chromosomes may be mismatched as part of a chromosomal sex-determination system. If both alleles of a diploid organism are the same, the organism is homozygous at that locus. If they are different, the organism is heterozygous at that locus. If one allele is missing, it is hemizygous, and, if both alleles are missing, it is nullizygous. The DNA sequence of a gene often varies from one individual to another. These gene variants are called alleles. While some gen ... [...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] |
Alcohol Dehydrogenase
Alcohol dehydrogenases (ADH) () are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD+) to NADH. In humans and many other animals, they serve to break down alcohols that are otherwise toxic, and they also participate in the generation of useful aldehyde, ketone, or alcohol groups during the biosynthesis of various metabolites. In yeast, plants, and many bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD+. Evolution Genetic evidence from comparisons of multiple organisms showed that a glutathione-dependent formaldehyde dehydrogenase, identical to a class III alcohol dehydrogenase (ADH-3/ADH5), is presumed to be the ancestral enzyme for the entire ADH family. Early on in evolution, an effective method for eliminating both endogenous and exogenous fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADH1B
Alcohol dehydrogenase 1B is an enzyme that in humans is encoded by the ''ADH1B'' gene. The protein encoded by this gene is a member of the alcohol dehydrogenase family. Members of this enzyme family metabolize a wide variety of substrates, including ethanol (beverage alcohol), retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. The encoded protein, known as ADH1B or beta-ADH, can form homodimers and heterodimers with ADH1A and ADH1C subunits, exhibits high activity for ethanol oxidation and plays a major role in ethanol catabolism (oxidizing ethanol into acetaldehyde). The acetaldehyde is further metabolized to acetate by aldehyde dehydrogenase genes. Three genes encoding the closely related alpha, beta and gamma subunits are tandemly organized in a genomic segment as a gene cluster. The human gene is located on chromosome 4 in 4q22. Previously ''ADH1B'' was called ''ADH2''. There are more genes in the family of alcohol dehydrogenase. These gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entamoeba Histolytica
''Entamoeba histolytica'' is an anaerobic organism, anaerobic parasitic amoebozoan, part of the genus ''Entamoeba''. Predominantly infecting humans and other primates causing amoebiasis, ''E. histolytica'' is estimated to infect about 35-50 million people worldwide. ''E. histolytica'' infection is estimated to kill more than 55,000 people each year. Previously, it was thought that 10% of the world population was infected, but these figures predate the recognition that at least 90% of these infections were due to a second species, ''E. dispar''. Mammals such as dogs and cats can become infected transiently, but are not thought to contribute significantly to transmission. The word ''histolysis'' literally means disintegration and dissolution of organic tissues. Transmission The active (trophozoite) stage exists only in the host and in fresh loose feces; Microbial cyst, cysts survive outside the host in water, in soils, and on foods, especially under moist conditions on the lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South China
South China ( zh, s=, p=Huá'nán, j=jyut6 naam4) is a geographical and cultural region that covers the southernmost part of China. Its precise meaning varies with context. A notable feature of South China in comparison to the rest of China is that most of its citizens are not native speakers of Standard Chinese. Cantonese is the most common language in the region while the Hong Kong region contains the largest concentration of China's ethnic minorities. Administrative divisions Cities with urban area over one million in population Provincial capitals in bold. Namesake * South China tiger (southern China) * ''South China Morning Post'' (Hong Kong, South China) * Huanan Seafood Wholesale Market (Wuhan, Central China) * South China Normal University, a university in Guangzhou, Guangdong, China * South China Athletic Association (Hong Kong SR, China) See also * Lingnan * List of regions of China ** Northern and southern China, Southern China *** South Central China — ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Asia
East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Japan, Japan, Economy of South Korea, South Korea, and Economy of Taiwan, Taiwan are among the world's largest and most prosperous. East Asia borders North Asia to the north, Southeast Asia to the south, South Asia to the southwest, and Central Asia to the west. To its east is the Pacific Ocean. East Asia, especially History of China, Chinese civilization, is regarded as one of the earliest Cradle of civilization#China, cradles of civilization. Other ancient civilizations in East Asia that still exist as independent countries in the present day include the History of Japan, Japanese, History of Korea, Korean, and History of Mongolia, Mongolian civilizations. Various other civilizations existed as independent polities in East Asia in the past ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HapMap
The International HapMap Project was an organization that aimed to develop a haplotype map (HapMap) of the human genome, to describe the common patterns of human genetic variation. HapMap is used to find genetic variants affecting health, disease and responses to drugs and environmental factors. The information produced by the project is made freely available for research. The International HapMap Project is a collaboration among researchers at academic centers, non-profit biomedical research groups and private companies in Canada, China (including Hong Kong), Japan, Nigeria, the United Kingdom, and the United States. It officially started with a meeting on October 27 to 29, 2002, and was expected to take about three years. It comprises three phases; the complete data obtained in Phase I were published on 27 October 2005. The analysis of the Phase II dataset was published in October 2007. The Phase III dataset was released in spring 2009 and the publication presenting the final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALDH2 Rs671 Genotype Frequency
Aldehyde dehydrogenases () are a group of enzymes that catalyse the oxidation of aldehydes. They convert aldehydes (R–C(=O)) to carboxylic acids (R–C(=O)). The oxygen comes from a water molecule. To date, nineteen ALDH genes have been identified within the human genome. These genes participate in a wide variety of biological processes including the detoxification of exogenously and endogenously generated aldehydes. Function Aldehyde dehydrogenase is a polymorphic enzyme responsible for the oxidation of aldehydes to carboxylic acids. There are three different classes of these enzymes in mammals: class 1 (low ''K''m, cytosolic), class 2 (low ''K''m, mitochondrial), and class 3 (high ''K''m, such as those expressed in tumors, stomach, and cornea). In all three classes, constitutive and inducible forms exist. ALDH1 and ALDH2 are the most important enzymes for aldehyde oxidation, and both are tetrameric enzymes composed of 54 kDa subunits. These enzymes are found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetaldehyde Dehydrogenase
Acetaldehyde dehydrogenases () are dehydrogenase enzymes which catalyze the conversion of acetaldehyde into acetyl-CoA. This can be summarized as follows: Acetaldehyde + NAD+ + Coenzyme A ↔ Acetyl-CoA + NADH + H+ In humans, there are three known genes which encode this enzymatic activity, ''ALDH1A1'', ''ALDH2'', and the more recently discovered '' ALDH1B1'' (also known as '' ALDH5''). These enzymes are members of the larger class of aldehyde dehydrogenases. The CAS number for this type of the enzyme is 028-91-5 Structure Cysteine-302 is one of three consecutive Cys residues and is crucial to the enzyme's catalytic function. The residue is alkylated by iodoacetamide in both the cytosolic and mitochondrial isozymes, with modifications to Cys-302 indicative of catalytic activity with other residues. Furthermore, the preceding sequence Gln-Gly-Gln-Cys is conserved in both isozymes for both human and horse, which is consistent with Cys-302 being crucial to catalytic function. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
