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FUT2
Galactoside 2-alpha-L-fucosyltransferase 2 is an enzyme that in humans is encoded by the ''FUT2'' (fucosyltransferase 2) gene. FUT2 is a key enzyme that catalyzes the transfer of L-fucose from guanosine diphosphate-beta-L-fucose to the terminal galactose on both O- and N-linked glycans of cell surface glycoproteins and glycolipids. This enzymatic activity is essential for the synthesis of the H antigen, a precursor required for the formation of ABO blood group antigens, and determines "secretor status"—the presence of blood group antigens in bodily fluids such as saliva. Beyond its role in blood group antigen synthesis, FUT2 influences cell-cell interactions, modulates the composition of the gut microbiome, and impacts susceptibility to infections and autoimmune diseases, highlighting its broad significance in human health and disease. Approximately 20% of Caucasians are non-secretors due to the G428A (rs601338) and C571T (rs492602?) nonsense mutations in FUT2 and therefore hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norovirus
Norovirus, also known as Norwalk virus and sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually develop 12 to 48 hours after being exposed, and recovery typically occurs within one to three days. Complications are uncommon, but may include dehydration, especially in the young, the old, and those with other health problems. The virus is usually spread by the fecal–oral route. This may be through contaminated food or water or person-to-person contact. It may also spread via contaminated surfaces or through air from the vomit of an infected person. Risk factors include unsanitary food preparation and sharing close quarters. Diagnosis is generally based on symptoms. Confirmatory testing is not usually available but may be performed by public health agencies during outbreaks. Prevention involves proper han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABO Blood Group
The ABO blood group system is used to denote the presence of one, both, or neither of the A and B antigens on erythrocytes (red blood cells). For human blood transfusions, it is the most important of the 47 different blood type (or group) classification systems currently recognized by the International Society of Blood Transfusions (ISBT) as of December 2022. A mismatch in this serotype (or in various others) can cause a potentially fatal adverse reaction after a transfusion, or an unwanted immune response to an organ transplant. Such mismatches are rare in modern medicine. The associated anti-A and anti-B antibodies are usually IgM antibodies, produced in the first years of life by sensitization to environmental substances such as food, bacteria, and viruses. The ABO blood types were discovered by Karl Landsteiner in 1901; he received the Nobel Prize in Physiology or Medicine in 1930 for this discovery. ABO blood types are also present in other primates such as apes, mon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-secretor
Secretor status refers to the presence or absence of water-soluble ABO blood group antigens in a person's bodily fluids, such as saliva, tears, breast milk, urine, and semen. People who secrete these antigens in their bodily fluids are referred to as secretors, while people who do not are termed non-secretors. Secretor status is controlled by the ''FUT2'' gene (also called the ''Se'' gene), and the secretor Phenotypic trait, phenotype is inherited in an Autosome, autosomal Dominance (genetics), dominant manner, being expressed by individuals who have at least one functioning copy of the gene. The non-secretor phenotype (''se'') is a recessive trait. Approximately 80% of White people are secretors, while 20% are non-secretors. Non-secretors have reduced susceptibility to the most common strains of norovirus. Expression of the antigens in the Lewis blood group is also affected by secretor status: non-secretors cannot produce the Le(b) antigen. Genetics The expression of ABO blood gro ... [...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] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L-fucose
Fucose is a hexose deoxy sugar with the chemical formula C6H12O5. It is found on ''N''-linked glycans on the mammalian, insect and plant cell surface. Fucose is the fundamental sub-unit of the seaweed polysaccharide fucoidan. The α(1→3) linked core of fucoidan is a suspected carbohydrate antigen for IgE-mediated allergy. Two structural features distinguish fucose from other six-carbon sugars present in mammals: the lack of a hydroxyl group on the carbon at the 6-position (C-6) (thereby making it a deoxy sugar) and the L -configuration. It is equivalent to 6-deoxy--galactose. In the fucose-containing glycan structures, fucosylated glycans, fucose can exist as a terminal modification or serve as an attachment point for adding other sugars. In human ''N''-linked glycans, fucose is most commonly linked α-1,6 to the reducing terminal β-''N''-acetylglucosamine. However, fucose at the non-reducing termini linked α-1,2 to galactose forms the H antigen, the substructure of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactose
Galactose (, ''wikt:galacto-, galacto-'' + ''wikt:-ose#Suffix 2, -ose'', ), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweetness, sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecule linked with a glucose molecule forms a lactose molecule. Galactan is a polymeric form of galactose found in hemicellulose, and forming the core of the galactans, a class of natural polymeric carbohydrates. D-Galactose is also known as brain sugar since it is a component of glycoproteins (oligosaccharide-protein compounds) found in Nerve tissue, nerve tissue. Etymology The word ''galactose'' was coined by Charles Weissman in the mid-19th century and is derived from Greek language, Greek , , and the generic chemical suffix for sugars ''-ose''. The etymology is comparable to that of the word ''lactose'' in that both contain roots meaning "milk sugar". Lactose is a disaccharide of galactose plus glucose. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycan
The terms glycans and polysaccharides are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, or a proteoglycan, even if the carbohydrate is only an oligosaccharide. Glycans usually consist solely of O-glycosidic linkages of monosaccharides. For example, cellulose is a glycan (or, to be more specific, a glucan) composed of β-1,4-linked D-glucose, and chitin is a glycan composed of β-1,4-linked ''N''-acetyl-D-glucosamine. Glycans can be homo- or heteropolymers of monosaccharide residues, and can be linear or branched. Interactions with proteins Glycans can be found attached to proteins as in glycoproteins and proteoglycans. In general, they are found on the exterior surface of cells. ''O''- and ''N''-linked glycans are very common in eukaryotes but may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H Antigen
H antigen can refer to one of the various types of antigens having diverse biological functions: * Also known as substance H, H antigen is a precursor to each of the ABO blood group antigens, apparently present in all people except those with the Bombay Blood phenotype (see hh blood group). The gene responsible for making H antigen is FUT1, located on the 19th chromosome in humans. * Histocompatibility antigen, a major factor in graft rejection. Even when Major Histocompatibility Complex genotype is perfectly matched, can cause slow rejection of a graft. ** major H antigens "encode molecules that present foreign peptides to T cells" ** minor H antigens "present polymorphic self peptides to T cells". Includes, e.g. the H-Y antigen H-Y antigen is a male tissue specific antigen. Originally thought to trigger the formation of testes (via Locus (genetics), loci, an Autosome, autosomal gene that Gene expression, generates the antigen and one that generates the Receptor (bioche ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crohn’s Disease
Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea, fever, abdominal distension, and weight loss. Complications outside of the gastrointestinal tract may include anemia, skin rashes, arthritis, inflammation of the eye, and fatigue. The skin rashes may be due to infections, as well as pyoderma gangrenosum or erythema nodosum. Bowel obstruction may occur as a complication of chronic inflammation, and those with the disease are at greater risk of colon cancer and small bowel cancer. Although the precise causes of Crohn's disease (CD) are unknown, it is believed to be caused by a combination of environmental, immune, and bacterial factors in genetically susceptible individuals. It results in a chronic inflammatory disorder, in which the body's immune system defends the gastrointestinal tract, possibly targeting microbial antigens. Although Crohn's is an immune-rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type 1 Diabetes
Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that occurs when the body's immune system destroys pancreatic cells (beta cells). In healthy persons, beta cells produce insulin. Insulin is a hormone required by the body to store and convert blood sugar into energy. T1D results in high blood sugar levels in the body prior to treatment. Common symptoms include frequent urination, increased thirst, increased hunger, weight loss, and other complications. Additional symptoms may include blurry vision, tiredness, and slow wound healing (owing to impaired blood flow). While some cases take longer, symptoms usually appear within weeks or a few months. The cause of type 1 diabetes is not completely understood, but it is believed to involve a combination of genetic and environmental factors. The underlying mechanism involves an autoimmune destruction of the insulin-producing beta cells in the pancreas. Diabetes is diagnosed by testing the leve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
