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Abetalipoproteinemia
Abetalipoproteinemia (also known as: Bassen–Kornzweig syndrome, microsomal triglyceride transfer protein deficiency disease, MTP deficiency, and betalipoprotein deficiency syndrome) is a disorder characterized by abnormal absorption of fat and fat-soluble vitamins from food. It is caused by a mutation in microsomal triglyceride transfer protein resulting in deficiencies in the apolipoproteins B-48 and B-100, which are used in the synthesis and exportation of chylomicrons and VLDL respectively. It is not to be confused with familial dysbetalipoproteinemia. It is a rare autosomal recessive disorder. Presentation Symptoms Initial symptoms usually appear in infancy, including: * Failure to thrive (i.e. failure to grow in infancy) * Steatorrhea (i.e. fatty, pale stools) * Frothy stools * Foul smelling stools * Protruding abdomen The rate of occurrence of additional symptoms later in life varies and increases with age. These may include: * Intellectual disability/developmenta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthocytosis
Acanthocyte (from the Greek word ἄκανθα ''acantha'', meaning 'thorn'), in biology and medicine, refers to an abnormal form of red blood cell that has a spiked cell membrane, due to thorny projections. A similar term is spur cells. Often they may be confused with echinocytes or schistocytes. Acanthocytes have coarse, irregularly spaced, variably sized crenations, resembling many-pointed stars. They are seen on blood films in abetalipoproteinemia, liver disease, chorea acanthocytosis, McLeod syndrome, and several inherited neurological and other disorders such as neuroacanthocytosis, anorexia nervosa, infantile pyknocytosis, hypothyroidism, idiopathic neonatal hepatitis, alcoholism, congestive splenomegaly, Zieve syndrome, and chronic granulomatous disease. Usage Spur cells may refer synonymously to acanthocytes, or may refer in some sources to a specific subset of 'extreme acanthocytes' that have undergone spleen, splenic modification whereby additional cell membrane loss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsomal Triglyceride Transfer Protein
Microsomal triglyceride transfer protein large subunit is a protein that in humans is encoded by the ''MTTP'', also known as ''MTP'', gene. ''MTTP'' encodes the large subunit of the heterodimeric microsomal triglyceride transfer protein (MTP). Protein disulfide isomerase (PDI) completes the heterodimeric MTP, which has been shown to play a central role in lipoprotein assembly. Mutations in ''MTTP'' can cause abetalipoproteinemia. Apolipoprotein B48 on chylomicra and Apolipoprotein B100 on LDL, IDL, and VLDL are important for MTP binding. MTP adds triglycerides to nascent chylomicrons in the intestine, and to VLDL in the liver. Structure The large subunit of MTP, also known as the alpha subunit, contains an N-terminal half beta barrel, an alpha helix and a C-terminal lipid binding site that lies between two beta pleated sheets. It is a member of the large lipid transfer protein family, like apolipoprotein B (apo B), with which it interacts, but unlike apo B, it is not secr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypocholesterolemia
Hypocholesterolemia is the presence of abnormally low (''hypo-'') levels of cholesterol in the blood (''-emia''). A defect in the body's production of cholesterol can lead to adverse consequences as well. Cholesterol is an essential component of mammalian cell membranes and is required to establish proper membrane permeability and fluidity. It is not clear if a lower than average cholesterol level is directly harmful; however, it is often encountered in particular illnesses. Presentation Role in disease With the increased use of medication to suppress cholesterol, some have expressed concern that lowering cholesterol levels excessively will itself cause disease. Specific disease entities Demographic studies suggest that cholesterol levels form a U-shape curve when plotted against mortality; this suggests that low cholesterol is associated with increased mortality, mainly due to depression, cancer, hemorrhagic stroke, aortic dissection and respiratory diseases. It is possible tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ataxia
Ataxia (from Greek α- negative prefix+ -τάξις rder= "lack of order") is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements, that indicates dysfunction of parts of the nervous system that coordinate movement, such as the cerebellum. These nervous system dysfunctions occur in several different patterns, with different results and different possible causes. Ataxia can be limited to one side of the body, which is referred to as hemiataxia. Friedreich's ataxia has gait abnormality as the most commonly presented symptom. Dystaxia is a mild degree of ataxia. Types Cerebellar The term cerebellar ataxia is used to indicate ataxia due to dysfunction of the cerebellum. The cerebellum is responsible for integrating a significant amount of neural information that is used to coordinate smoothly ongoing movements and to participate in motor planning. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steatorrhea
Steatorrhea (or steatorrhoea) is the presence of excess fat in Human feces, feces. Stools may be bulky and difficult to flush, have a pale and oily appearance, and can be especially foul-smelling. An oily anal leakage or some level of fecal incontinence may occur. There is increased fat excretion, which can be measured by determining the fecal fat level. Causes Impaired digestion or absorption can result in fatty stools. Possible causes include exocrine pancreatic insufficiency, with poor digestion from lack of lipases, loss of bile salts, which reduces micelle formation, and small intestinal disease-producing malabsorption. Various other causes include certain medicines that block fat absorption or indigestible or excess oil/fat in diet. The absence of bile secretion can cause the feces to turn gray or pale. Bile is responsible for the brownish color of feces. In addition to this, bile also plays a role in fat absorption, where dietary lipids are combined so that pancreatic lipa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipoprotein
A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid (also known as fat) molecules in water, as in blood plasma or other extracellular fluids. They consist of a triglyceride and cholesterol center, surrounded by a phospholipid outer shell, with the hydrophilic portions oriented outward toward the surrounding water and lipophilic portions oriented inward toward the lipid center. A special kind of protein, called apolipoprotein, is embedded in the outer shell, both stabilising the complex and giving it a functional identity that determines its role. Plasma lipoprotein particles are commonly divided into five main classes, based on size, lipid composition, and apolipoprotein content. They are, in increasing size order: HDL, LDL, IDL, VLDL and chylomicrons. Subgroups of these plasma particles are primary drivers or modulators of atherosclerosis. Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinitis Pigmentosa
Retinitis pigmentosa (RP) is a member of a group of genetic disorders called inherited retinal dystrophy (IRD) that cause loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may experience " tunnel vision". Complete blindness is uncommon. Onset of symptoms is generally gradual and often begins in childhood. Retinitis pigmentosa is generally inherited from one or both parents. It is caused by genetic variants in nearly 100 genes. The underlying mechanism involves the progressive loss of rod photoreceptor cells that line the retina of the eyeball. The rod cells secrete a neuroprotective substance (rod-derived cone viability factor, RdCVF) that protects the cone cells from apoptosis. When these rod cells die, this substance is no longer provided. This is generally followed by the loss of cone photoreceptor cells. Diagnosis is through eye examination of the retina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triglyceride
A triglyceride (from '' tri-'' and '' glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver and are a major component of human skin oils. Many types of triglycerides exist. One specific classification focuses on saturated and unsaturated types. Saturated fats have ''no'' C=C groups; unsaturated fats feature one or more C=C groups. Unsaturated fats tend to have a lower melting point than saturated analogues; as a result, they are often liquid at room temperature. Chemical structure The three fatty acids substituents can be the same, but they are usually different. The positions of the three fatty acids are specified using stereospecific numbering as sn-1, sn-2, and sn- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecule
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (molecule), water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinol
Retinol, also called vitamin A1, is a fat-soluble vitamin in the vitamin A family that is found in food and used as a dietary supplement. Retinol or other forms of vitamin A are needed for vision, cellular development, maintenance of skin and mucous membranes, immune function and reproductive development. Dietary sources include fish, dairy products, and meat. As a supplement it is used to treat and prevent vitamin A deficiency, especially that which results in xerophthalmia. It is taken by mouth or by intramuscular injection, injection into a muscle. As an ingredient in skin-care products, it is used to reduce wrinkles and other effects of skin aging. Retinol at normal doses is well tolerated. High doses may cause hepatomegaly, enlargement of the liver, dry skin, and hypervitaminosis A. High doses during pregnancy may harm the fetus. The body converts retinol to retinal and retinoic acid, through which it acts. Retinol was discovered in 1909, isolated in 1931, and first m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin
Vitamins are Organic compound, organic molecules (or a set of closely related molecules called vitamer, vitamers) that are essential to an organism in small quantities for proper metabolism, metabolic function. Nutrient#Essential nutrients, Essential nutrients cannot be biosynthesis, synthesized in the organism in sufficient quantities for survival, and therefore must be obtained through the Diet (nutrition), diet. For example, vitamin C can be synthesized by some species but not by others; it is not considered a vitamin in the first instance but is in the second. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, there are eight vitamers of vitamin E: four tocopherols and four tocotrienols. The term ''vitamin'' does not include the three other groups of essential nutrients: mineral (nutrient), minerals, essential fatty acids, and essential amino acids. Major health organizations list thirteen vitamins: * Vitamin A (all-' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
