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Multiple Carboxylase Deficiency
Multiple carboxylase deficiency is a form of metabolic disorder involving failures of carboxylation enzymes. The deficiency can be in biotinidase or holocarboxylase synthetase. These conditions respond to biotin. Forms include: * Holocarboxylase synthetase deficiency - neonatal; * Biotinidase deficiency - late onset; If left untreated, the symptoms can include feeding problems, decreased body tone, generalized red rash with skin exfoliation and baldness, failure to thrive, seizure, coma, developmental delay, foul smelling urine, lactic acidosis, and high levels of ketones and ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ... in the blood. References External links * http://www.pmh.health.wa.gov.au/services/newborn/health_professionals/disorders/mcd_prof.htm Vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylation
Carboxylation is a chemical reaction in which a carboxylic acid is produced by treating a substrate with carbon dioxide. The opposite reaction is decarboxylation. In chemistry, the term carbonation is sometimes used synonymously with carboxylation, especially when applied to the reaction of carbanionic reagents with CO2. More generally, carbonation usually describes the production of carbonates. Organic chemistry Carboxylation is a standard conversion in organic chemistry. Specifically carbonation (i.e. carboxylation) of Grignard reagents and organolithium compounds is a classic way to convert organic halides into carboxylic acids. Sodium salicylate, precursor to aspirin, is commercially prepared by treating sodium phenolate (the sodium salt of phenol) with carbon dioxide at high pressure (100 atm) and high temperature (390 K) – a method known as the Kolbe-Schmitt reaction. Acidification of the resulting salicylate salt gives salicylic acid. : Many detailed procedures are des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotinidase
Biotinidase (, ''amidohydrolase biotinidase'', ''BTD''), also known as biotinase, is an enzyme that in humans is encoded by the ''BTD'' gene. The enzyme breaks down biotin amides, releasing free biotin and the amine. The main substrate is biocytin, or biotin linked to lysine. It is also capable of breaking apart biotin esters. Function This enzyme allows the body to use and to recycle the B vitamin biotin, sometimes called vitamin H. Biotinidase extracts biotin from food because the body needs biotin in its free, unattached form. This enzyme also recycles biotin from enzymes in the body that use it as a helper component in order to function. These enzymes, known as carboxylases, are important in the processing of fats, carbohydrates, and proteins. Biotin is attached to these carboxylase enzymes through an amino acid (the building material of proteins) called lysine, forming a complex called biocytin. Biotinidase removes biotin from biocytin and makes it available to be reused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocarboxylase Synthetase
Holocarboxylase synthetase (biotin—(propionyl-Coenzyme A-carboxylase (ATP-hydrolysing)) ligase)), also known as protein—biotin ligase, is a family of enzymes ({{{EnzExplorer, 6.3.4.10). This enzyme is important for the effective use of biotin, a B vitamin found in foods such as liver, egg yolks, and milk. In many of the body's tissues, holocarboxylase synthetase activates other specific enzymes (called biotin-dependent carboxylases) by attaching biotin to them. These carboxylases are involved in many critical cellular functions, including the production and breakdown of proteins, fats, and carbohydrates. The catalyzed reaction: :ATP + biotin + apo- propionyl-CoA:carbon-dioxide ligase (ADP-forming) \rightleftharpoons AMP + diphosphate + propionyl-CoA:carbon-dioxide ligase (ADP-forming) The 3 substrates of this enzyme are ATP, biotin, and products_are_adenosine_monophosphate.html" "title="product_(chemistry).html" "title="ropionyl-CoA:carbon-dioxide ligase (ADP-for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotin
Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', borrowed from the German , derives from the Ancient Greek word (; 'life') and the suffix "-in" (a suffix used in chemistry usually to indicate 'forming'). Chemical description Biotin is classified as a heterocyclic compound, with a sulfur-containing ring fused ureido and tetrahydrothiophene group. A C5-carboxylic acid side chain is appended to one of the rings. The ureido ring, containing the −N−CO−N− group, serves as the carbon dioxide carrier in carboxylation reactions. Biotin is a coenzyme for five carboxylase enzymes, which are involved in the catabolism of amino acids and fatty acids, synthesis of fatty acids, and gluconeogenesis. Biotinylation of histone proteins in nuclear chromatin plays a role in chromatin stability and g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocarboxylase Synthetase Deficiency
Holocarboxylase synthetase deficiency is an inherited metabolic disorder in which the body is unable to use the vitamin biotin effectively. This disorder is classified as a multiple carboxylase deficiency, a group of disorders characterized by impaired activity of certain enzymes that depend on biotin. Symptoms are very similar to biotinidase deficiency and treatment – large doses of biotin – is also the same. Symptoms and signs Genetics Mutations in the ''HLCS'' gene cause holocarboxylase synthetase deficiency. The ''HLCS'' gene makes an enzyme, holocarboxylase synthetase, that attaches biotin to other molecules. Biotin, a B vitamin, is found in foods such as liver, egg yolks, and milk. It is essential for the normal production and breakdown of proteins, fats, and carbohydrates in the body. Mutations in the ''HLCS'' gene reduce the activity of holocarboxylase synthetase, preventing cells from using biotin effectively and disrupting many cellular functions. This conditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotinidase Deficiency
Biotinidase deficiency is an autosomal recessive metabolic disorder in which biotin is not released from proteins in the diet during digestion or from normal protein turnover in the cell. This situation results in biotin deficiency. Biotin is an important water-soluble nutrient that aids in the metabolism of fats, carbohydrates, and proteins. Biotin deficiency can result in behavioral disorders, lack of coordination, learning disabilities and seizures. Biotin supplementation can alleviate and sometimes totally stop such symptoms. Signs and symptoms Signs and symptoms of a biotinidase deficiency can appear several days after birth. These include seizures, hypotonia and muscle/limb weakness, ataxia, paresis, hearing loss, optic atrophy, skin rashes (including seborrheic dermatitis and psoriasis), and alopecia. If left untreated, the disorder can rapidly lead to coma and death. Biotinidase deficiency can also appear later in life. This is referred to as "late-onset" biotinidase def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotonia
Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but a potential manifestation of many different diseases and disorders that affect motor nerve control by the brain or muscle strength. Hypotonia is a lack of resistance to passive movement, whereas muscle weakness results in impaired active movement. Central hypotonia originates from the central nervous system, while peripheral hypotonia is related to problems within the spinal cord, peripheral nerves and/or skeletal muscles. Severe hypotonia in infancy is commonly known as floppy baby syndrome. Recognizing hypotonia, even in early infancy, is usually relatively straightforward, but diagnosing the underlying cause can be difficult and often unsuccessful. The long-term effects of hypotonia on a child's development and later life depend primarily on the severity of the muscle weakness and the na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythema
Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not associated with pathology include nervous blushes. Types * Erythema ab igne * Erythema chronicum migrans * Erythema induratum * Erythema infectiosum (or fifth disease) * Erythema marginatum * Erythema migrans * Erythema multiforme (EM) * Erythema nodosum * Erythema toxicum * Erythema elevatum diutinum * Erythema gyratum repens * Keratolytic winter erythema * Palmar erythema Causes It can be caused by infection, massage, electrical treatment, acne medication, allergies, exercise, solar radiation (sunburn), photosensitization, acute radiation syndrome, mercury toxicity, blister agents, niacin administration, or waxing and tweezing of the hairs—any of which can cause the capillaries to dilate, resulting in redness. Erythema is a common sid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alopecia
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring is not usually present. Hair loss in some people causes psychological distress. Common types include male- or female-pattern hair loss, alopecia areata, and a thinning of hair known as telogen effluvium. The cause of male-pattern hair loss is a combination of genetics and male hormones; the cause of female pattern hair loss is unclear; the cause of alopecia areata is autoimmune; and the cause of telogen effluvium is typically a physically or psychologically stressful event. Telogen effluvium is very common following pregnancy. Less common causes of hair loss without inflammation or scarring include the pulling out of hair, certain medications including chemotherapy, HIV/AIDS, hypothyroidism, and malnutrition including iron defici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failure To Thrive
Failure to thrive (FTT), also known as weight faltering or faltering growth, indicates insufficient weight gain or absence of appropriate physical growth in children. FTT is usually defined in terms of weight, and can be evaluated either by a low weight for the child's age, or by a low rate of increase in the weight. The term "failure to thrive" has been used in different ways, as there is no objective standard or universally accepted definition for when to diagnose FTT. One definition describes FTT as a fall in one or more weight centile spaces on a World Health Organization (WHO) growth chart depending on birth weight or when weight is below the 2nd percentile of weight for age irrespective of birth weight. Another definition of FTT is a weight for age that is consistently below the 5th percentile or weight for age that falls by at least two major percentile lines on a growth chart. While weight loss after birth is normal and most babies return to their birth weight by three wee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness ( tonic-clonic seizure), to shaking movements involving only part of the body with variable levels of consciousness (focal seizure), to a subtle momentary loss of awareness ( absence seizure). Most of the time these episodes last less than two minutes and it takes some time to return to normal. Loss of bladder control may occur. Seizures may be provoked and unprovoked. Provoked seizures are due to a temporary event such as low blood sugar, alcohol withdrawal, abusing alcohol together with prescription medication, low blood sodium, fever, brain infection, or concussion. Unprovoked seizures occur without a known or fixable cause such that ongoing seizures are likely. Unprovoked seizures may be exacerbated by stress or sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coma
A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. Coma patients exhibit a complete absence of wakefulness and are unable to consciously feel, speak or move. Comas can be derived by natural causes, or can be medically induced. Clinically, a coma can be defined as the inability consistently to follow a one-step command. It can also be defined as a score of ≤ 8 on the Glasgow Coma Scale (GCS) lasting ≥ 6 hours. For a patient to maintain consciousness, the components of ''wakefulness'' and ''awareness'' must be maintained. Wakefulness describes the quantitative degree of consciousness, whereas awareness relates to the qualitative aspects of the functions mediated by the cortex, including cognitive abilities such as attention, sensory perception, explicit memory, language, the execution of tasks, temporal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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