A mitochondrial cytochrome P450 enzyme that catalyzes the 1-alpha-hydroxylation of 25-hydroxyvitamin D3 (also known as 25-hydroxycholecalciferol) in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP27B1 gene, converts 25-hydroxyvitamin D3 to 1-alpha,25-dihydroxyvitamin D3 which is the active form of VITAMIN D in regulating bone growth and calcium metabolism. This enzyme is also active on plant 25-hydroxyvitamin D2 (ergocalciferol).
Food BEVERAGES that are used as nutritional substitutes for MILK.
A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS.
9,10-Secoergosta-5,7,10(19),22-tetraene-3,25-diol. Biologically active metabolite of vitamin D2 which is more active in curing rickets than its parent. The compound is believed to attach to the same receptor as vitamin D2 and 25-hydroxyvitamin D3.
The major circulating metabolite of VITAMIN D3. It is produced in the LIVER and is the best indicator of the body's vitamin D stores. It is effective in the treatment of RICKETS and OSTEOMALACIA, both in azotemic and non-azotemic patients. Calcifediol also has mineralizing properties.
A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.
A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)
Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.
Hydroxy analogs of vitamin D 3; (CHOLECALCIFEROL); including CALCIFEDIOL; CALCITRIOL; and 24,25-DIHYDROXYVITAMIN D 3.
Cytochrome P-450 monooxygenases (MIXED FUNCTION OXYGENASES) that are important in steroid biosynthesis and metabolism.
Cholecalciferols substituted with two hydroxy groups in any position.
Derivatives of ERGOSTEROL formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. They differ from CHOLECALCIFEROL in having a double bond between C22 and C23 and a methyl group at C24.
A physiologically active metabolite of VITAMIN D. The compound is involved in the regulation of calcium metabolism, alkaline phosphatase activity, and enhances the calcemic effect of CALCITRIOL.
A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
An NAPH-dependent cytochrome P450 enzyme that catalyzes the oxidation of the side chain of sterol intermediates such as the 27-hydroxylation of 5-beta-cholestane-3-alpha,7-alpha,12-alpha-triol.
The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.
An alpha-globulin found in the plasma of man and other vertebrates. It is apparently synthesized in the liver and carries vitamin D and its metabolites through the circulation and mediates the response of tissue. It is also known as group-specific component (Gc). Gc subtypes are used to determine specific phenotypes and gene frequencies. These data are employed in the classification of population groups, paternity investigations, and in forensic medicine.
An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.
Disorders caused by interruption of BONE MINERALIZATION manifesting as OSTEOMALACIA in adults and characteristic deformities in infancy and childhood due to disturbances in normal BONE FORMATION. The mineralization process may be interrupted by disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis, resulting from dietary deficiencies, or acquired, or inherited metabolic, or hormonal disturbances.
Irradiation directly from the sun.
An adrenal microsomal cytochrome P450 enzyme that catalyzes the 21-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP21 gene, converts progesterones to precursors of adrenal steroid hormones (CORTICOSTERONE; HYDROCORTISONE). Defects in CYP21 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).
Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA with the participation of D receptor interacting proteins (called DRIP). Vitamin D is converted in the liver and kidney to calcitriol and ultimately acts through these receptors.
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
An enzyme that catalyzes the hydroxylation of TRYPTOPHAN to 5-HYDROXYTRYPTOPHAN in the presence of NADPH and molecular oxygen. It is important in the biosynthesis of SEROTONIN.
Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)
Products in capsule, tablet or liquid form that provide dietary ingredients, and that are intended to be taken by mouth to increase the intake of nutrients. Dietary supplements can include macronutrients, such as proteins, carbohydrates, and fats; and/or MICRONUTRIENTS, such as VITAMINS; MINERALS; and PHYTOCHEMICALS.
Organic substances that are required in small amounts for maintenance and growth, but which cannot be manufactured by the human body.
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.
Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.
A mixed-function oxygenase that catalyzes the hydroxylation of a prolyl-glycyl containing peptide, usually in PROTOCOLLAGEN, to a hydroxyprolylglycyl-containing-peptide. The enzyme utilizes molecular OXYGEN with a concomitant oxidative decarboxylation of 2-oxoglutarate to SUCCINATE. The enzyme occurs as a tetramer of two alpha and two beta subunits. The beta subunit of procollagen-proline dioxygenase is identical to the enzyme PROTEIN DISULFIDE-ISOMERASES.
A non-metal element that has the atomic symbol P, atomic number 15, and atomic weight 31. It is an essential element that takes part in a broad variety of biochemical reactions.
Calcium compounds used as food supplements or in food to supply the body with calcium. Dietary calcium is needed during growth for bone development and for maintenance of skeletal integrity later in life to prevent osteoporosis.
Disorder caused by an interruption of the mineralization of organic bone matrix leading to bone softening, bone pain, and weakness. It is the adult form of rickets resulting from disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.
Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.
State of the body in relation to the consumption and utilization of nutrients.
Coloration of the skin.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
Agents that inhibit BONE RESORPTION and/or favor BONE MINERALIZATION and BONE REGENERATION. They are used to heal BONE FRACTURES and to treat METABOLIC BONE DISEASES such as OSTEOPOROSIS.
A drug-metabolizing, cytochrome P-448 (P-450) enzyme which catalyzes the hydroxylation of benzopyrene to 3-hydroxybenzopyrene in the presence of reduced flavoprotein and molecular oxygen. Also acts on certain anthracene derivatives. An aspect of EC 1.14.14.1.
Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.
The rate dynamics in chemical or physical systems.
A group of inherited disorders of the ADRENAL GLANDS, caused by enzyme defects in the synthesis of cortisol (HYDROCORTISONE) and/or ALDOSTERONE leading to accumulation of precursors for ANDROGENS. Depending on the hormone imbalance, congenital adrenal hyperplasia can be classified as salt-wasting, hypertensive, virilizing, or feminizing. Defects in STEROID 21-HYDROXYLASE; STEROID 11-BETA-HYDROXYLASE; STEROID 17-ALPHA-HYDROXYLASE; 3-beta-hydroxysteroid dehydrogenase (3-HYDROXYSTEROID DEHYDROGENASES); TESTOSTERONE 5-ALPHA-REDUCTASE; or steroidogenic acute regulatory protein; among others, underlie these disorders.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
A flavoprotein that catalyzes the synthesis of protocatechuic acid from 4-hydroxybenzoate in the presence of molecular oxygen. EC 1.14.13.2.
Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.
Regular course of eating and drinking adopted by a person or animal.
Individuals whose ancestral origins are in the continent of Europe.
Any food that has been supplemented with essential nutrients either in quantities that are greater than those present normally, or which are not present in the food normally. Fortified food includes also food to which various nutrients have been added to compensate for those removed by refinement or processing. (From Segen, Dictionary of Modern Medicine, 1992)
Steroids with methyl groups at C-10 and C-13 and a branched 8-carbon chain at C-17. Members include compounds with any degree of unsaturation; however, CHOLESTADIENES is available for derivatives containing two double bonds.
Cholesterol derivatives having an additional double bond in any position. 24-Dehydrocholesterol is DESMOSTEROL. The other most prevalent dehydrocholesterol is the 7-isomer. This compound is a precursor of cholesterol and of vitamin D3.
Inorganic salts of phosphoric acid.
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
A condition caused by a deficiency of PARATHYROID HORMONE (or PTH). It is characterized by HYPOCALCEMIA and hyperphosphatemia. Hypocalcemia leads to TETANY. The acquired form is due to removal or injuries to the PARATHYROID GLANDS. The congenital form is due to mutations of genes, such as TBX1; (see DIGEORGE SYNDROME); CASR encoding CALCIUM-SENSING RECEPTOR; or PTH encoding parathyroid hormone.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.
The amounts of various substances in food needed by an organism to sustain healthy life.
A systematic collection of factual data pertaining to the nutritional status of a human population within a given geographic area. Data from these surveys are used in preparing NUTRITION ASSESSMENTS.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
Elements of limited time intervals, contributing to particular results or situations.
Persons living in the United States having origins in any of the black groups of Africa.
Chromatographic techniques in which the mobile phase is a liquid.
The relationship between the dose of an administered drug and the response of the organism to the drug.
An iron-sulfur protein which serves as an electron carrier in enzymatic steroid hydroxylation reactions in adrenal cortex mitochondria. The electron transport system which catalyzes this reaction consists of adrenodoxin reductase, NADP, adrenodoxin, and cytochrome P-450.
An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A noninvasive method for assessing BODY COMPOSITION. It is based on the differential absorption of X-RAYS (or GAMMA RAYS) by different tissues such as bone, fat and other soft tissues. The source of (X-ray or gamma-ray) photon beam is generated either from radioisotopes such as GADOLINIUM 153, IODINE 125, or Americanium 241 which emit GAMMA RAYS in the appropriate range; or from an X-ray tube which produces X-RAYS in the desired range. It is primarily used for quantitating BONE MINERAL CONTENT, especially for the diagnosis of OSTEOPOROSIS, and also in measuring BONE MINERALIZATION.
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An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
Abnormally high level of calcium in the blood.
Guidelines and objectives pertaining to food supply and nutrition including recommendations for healthy diet.
Reduction of bone mass without alteration in the composition of bone, leading to fractures. Primary osteoporosis can be of two major types: postmenopausal osteoporosis (OSTEOPOROSIS, POSTMENOPAUSAL) and age-related or senile osteoporosis.
Uptake of substances through the lining of the INTESTINES.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Breaks in bones.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
The physiological period following the MENOPAUSE, the permanent cessation of the menstrual life.
Dioxygenase enzymes that specifically hydroxylate a PROLINE residue on the HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. They are OXYGEN-dependent enzymes that play an important role in mediating cellular adaptive responses to HYPOXIA.
A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.
The term "United States" in a medical context often refers to the country where a patient or study participant resides, and is not a medical term per se, but relevant for epidemiological studies, healthcare policies, and understanding differences in disease prevalence, treatment patterns, and health outcomes across various geographic locations.
A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).
I'm sorry for any confusion, but "Nebraska" is a state located in the central United States and does not have a medical definition. If you have any medical terms or concepts you would like defined, I would be happy to help!
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
Proteins prepared by recombinant DNA technology.
Abnormally elevated PARATHYROID HORMONE secretion as a response to HYPOCALCEMIA. It is caused by chronic KIDNEY FAILURE or other abnormalities in the controls of bone and mineral metabolism, leading to various BONE DISEASES, such as RENAL OSTEODYSTROPHY.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.
A condition of abnormally elevated output of PARATHYROID HORMONE (or PTH) triggering responses that increase blood CALCIUM. It is characterized by HYPERCALCEMIA and BONE RESORPTION, eventually leading to bone diseases. PRIMARY HYPERPARATHYROIDISM is caused by parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. SECONDARY HYPERPARATHYROIDISM is increased PTH secretion in response to HYPOCALCEMIA, usually caused by chronic KIDNEY DISEASES.
Reduction of the blood calcium below normal. Manifestations include hyperactive deep tendon reflexes, Chvostek's sign, muscle and abdominal cramps, and carpopedal spasm. (Dorland, 27th ed)
A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.
The white liquid secreted by the mammary glands. It contains proteins, sugar, lipids, vitamins, and minerals.
An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.
Vitamin K-dependent calcium-binding protein synthesized by OSTEOBLASTS and found primarily in BONES. Serum osteocalcin measurements provide a noninvasive specific marker of bone metabolism. The protein contains three residues of the amino acid gamma-carboxyglutamic acid (Gla), which, in the presence of CALCIUM, promotes binding to HYDROXYAPATITE and subsequent accumulation in BONE MATRIX.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The country is bordered by RUSSIA on the north and CHINA on the west, south, and east. The capita is Ulaanbaatar.
A drug-metabolizing, cytochrome P-450 enzyme which catalyzes the hydroxylation of aniline to hydroxyaniline in the presence of reduced flavoprotein and molecular oxygen. EC 1.14.14.-.
The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.
A mitochondrial cytochrome P450 enzyme that catalyzes the side-chain cleavage of C27 cholesterol to C21 pregnenolone in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11A1 gene, catalyzes the breakage between C20 and C22 which is the initial and rate-limiting step in the biosynthesis of various gonadal and adrenal steroid hormones.
A member of the NICOTINIC ACETYLCHOLINE RECEPTOR subfamily of the LIGAND-GATED ION CHANNEL family. It consists entirely of pentameric a7 subunits expressed in the CNS, autonomic nervous system, vascular system, lymphocytes and spleen.
A condition of abnormally elevated output of PARATHYROID HORMONE due to parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. It is characterized by the combination of HYPERCALCEMIA, phosphaturia, elevated renal 1,25-DIHYDROXYVITAMIN D3 synthesis, and increased BONE RESORPTION.
Fractures of the FEMUR HEAD; the FEMUR NECK; (FEMORAL NECK FRACTURES); the trochanters; or the inter- or subtrochanteric region. Excludes fractures of the acetabulum and fractures of the femoral shaft below the subtrochanteric region (FEMORAL FRACTURES).
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

Enzymatic properties of mouse 25-hydroxyvitamin D3 1 alpha-hydroxylase expressed in Escherichia coli. (1/296)

Renal 25-hydroxyvitamin D3 1 alpha-hydroxylase cDNA cloned from the kidneys of mice lacking the vitamin D receptor was expressed in Escherichia coli JM109. As expected, the bacterially-expressed enzyme catalyzes the 1 alpha-hydroxylation of 25-hydroxyvitamin D3 with a Michaelis constant, K(m), value of 2.7 microM. Unexpectedly, the enzyme also hydroxylates the 1 alpha-position of 24,25-dihydroxyvitamin D3 with a K(m) of 1.3 microM, and a fourfold higher Vmax/K(m) compared with the 25-hydroxyvitamin D3 hydroxylase activity, suggesting that 24,25-dihydroxyvitamin D3 is a better substrate than 25-hydroxyvitamin D3 for 1 alpha-hydroxylase. In addition, the enzyme showed 1 alpha-hydroxylase activity toward 24-oxo-25-hydroxyvitamin D3. However, it showed only slight activity towards 23,25-dihydroxyvitamin D3 and 24-oxo-23,25-dihydroxyvitamin D3, and no detectable activity towards vitamin D3 and 24,25,26,27-tetranor-23-hydroxyvitamin D3. These results suggest that the 25-hydroxyl group of vitamin D3 is essential for the 1 alpha-hydroxylase activity and the 24-hydroxyl group enhances the activity, but the 23-hydroxyl group greatly reduced the activity. Another remarkable finding is that living recombinant E. coli cells can convert the substrates into the 1 alpha-hydroxylated products, suggesting the presence of a redox partner of 1 alpha-hydroxylase in E. coli cells.  (+info)

Cloning of porcine 25-hydroxyvitamin D3 1alpha-hydroxylase and its regulation by cAMP in LLC-PK1 cells. (2/296)

The 25-hydroxyvitamin D3 1alpha-hydroxylase, also referred to as CYP27B1, is a mitochondrial cytochrome P450 enzyme that catalyzes the biosynthesis of 1alpha, 25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) from 25-hydroxyvitamin D3 in renal proximal tubular cells. Recently, human, mouse, and rat CYP27B1 cDNA have been cloned, however the gene regulation has not been fully elucidated. In the present study, porcine CYP27B cDNA was cloned, and the effects of cAMP and vitamin D3 on the regulation of CYP27B1 mRNA expression in LLC-PK1 cells were examined. PCR cloning revealed that porcine CYP27B1 cDNA consisted of 2316 bp, encoding a protein of 504 amino acids. The deduced amino acid sequence showed over 80% identity to the human, mouse, and rat enzyme. LLC-PK1 cells were incubated with humoral factors, and expression of CYP27B1 mRNA was measured by a quantitative reverse transcription-PCR. At the completion of 3-, 6-, 12-, and 24-h incubations, 500 micromol/L 8-bromo-cAMP had significantly increased CYP27B1 mRNA expression (260 to 340%). The adenylate cyclase activator forskolin at 50 micromol/L also had a stimulatory effect at 6 h (190%). Moreover, the protein kinase A inhibitor H-89 reduced the cAMP effect. On the other hand, 1alpha,25(OH)2D3 had no effect on CYP27B1 mRNA expression at 10 and 100 nmol/L, whereas expression of 25-hydroxyvitamin D3 24-hydroxylase (CYP24) mRNA was markedly increased by 1alpha,25(OH)2D3. These findings suggest that LLC-PK1 cells express CYP27B1 mRNA, and that cAMP is an upregulating factor of the CYP27B1 gene in vitro.  (+info)

Calcitonin is a major regulator for the expression of renal 25-hydroxyvitamin D3-1alpha-hydroxylase gene in normocalcemic rats. (3/296)

Regulation of vitamin D metabolism has long been examined by using vitamin D-deficient hypocalcemic animals. We previously reported that, in a rat model of chronic hyperparathyroidism, expression of 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27B1) mRNA was markedly increased in renal proximal convoluted tubules. It is believed that the major regulator for the expression of renal CYP27B1 is parathyroid hormone (PTH). However, in the normocalcemic state, the mechanism to regulate the renal CYP27B1 gene could be different, since plasma levels of PTH are very low. In the present study, the effect of PTH and calcitonin (CT) on the expression of renal CYP27B1 mRNA was investigated in normocalcemic sham-operated rats and normocalcemic thyroparathyroidectomized (TPTX) rats generated by either PTH or CaCl2 infusion. A single injection of CT dose-dependently decreased the expression of vitamin D receptor mRNA in the kidney of normocalcemic sham-TPTX rats. Concomitantly, CT greatly increased the expression of CYP27B1 mRNA in the kidney of normocalcemic sham-TPTX rats. CT also increased the expression of CYP27B1 mRNA in the kidney of normocalcemic TPTX rats. Conversion of serum [3H]1alpha,25(OH)2D3 from 25-hydroxy[3H]vitamin D3 in vivo was also greatly increased by the injection of CT into sham-TPTX rats and normocalcemic TPTX rats, but not into hypocalcemic TPTX rats. In contrast, administration of PTH did not induce the expression of CYP27B1 mRNA in the kidney of vitamin D-replete sham-TPTX rats and hypocalcemic TPTX rats. PTH increased the expression of renal CYP27B1 mRNA only in vitamin D-deficient hypocalcemic TPTX rats. These results suggest that CT plays an important role in the maintenance of serum 1alpha,25(OH)2D3 under normocalcemic physiological conditions, at least in rats.  (+info)

Enzymatic properties of human 25-hydroxyvitamin D3 1alpha-hydroxylase coexpression with adrenodoxin and NADPH-adrenodoxin reductase in Escherichia coli. (4/296)

We have cloned human 25-hydroxyvitamin D3 1alpha-hydroxylase cDNAs from normal subjects and patients with pseudovitamin D-deficient rickets (PDDR), and expressed the cDNAs in Escherichia coli JM109 cells. Kinetic analysis of normal 1alpha-hydroxylase in the reconstituted system revealed that Km values for 25(OH)D3 and (24R), 25(OH)2D3 were 2.7 and 1.1 microM, respectively. The lower Km value and higher Vmax/Km value for (24R),25(OH)2D3 indicated that it is a better substrate than 25(OH)D3 for 1alpha-hydroxylase. These results are quite similar to those of mouse 1alpha-hydroxylase. To establish a highly sensitive in vivo system, 1alpha-hydroxylase, adrenodoxin and NADPH-adrenodoxin reductase were coexpressed in E. coli cells. The recombinant E. coli cells showed remarkably high 1alpha-hydroxylase activity, suggesting that the electrons were efficiently transferred from NADPH-adrenodoxin reductase through adrenodoxin to 1alpha-hydroxylase in E. coli cells. Using this system, the activities of four mutants of 1alpha-hydroxylase, R107H, G125E, R335P and P382S, derived from patients with PDDR were examined. Although no significant reduction in expression of these mutants was observed, none showed detectable activity. These results strongly suggest that the mutations found in the patients with PDDR completely abolished 1alpha-hydroxylase activity by replacement of one amino acid residue.  (+info)

Expression of 25-hydroxyvitamin D3-1alpha-hydroxylase in the human kidney. (5/296)

The secosteroid hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plays a vital role in calcium metabolism, tissue differentiation, and normal bone growth. Biosynthesis of 1,25(OH)2D3 is catalyzed by the mitochondrial cytochrome P450 enzyme 25-hydroxyvitamin D3 1alpha-hydroxylase (1alpha-hydroxylase). Although activity of this enzyme has been described in several tissues, the kidneys are recognized to be the principal site of 1,25(OH)2D3 production. To date, enzyme activity studies using vitamin D-deficient animals have suggested that 1alpha-hydroxylase is expressed exclusively in proximal convoluted tubules. With the recent cloning of 1alpha-hydroxylase, specific cRNA probes and in-house polyclonal antiserum have been used to determine the distribution of 1alpha-hydroxylase along the human nephron. Immunohistochemistry and in situ hybridization studies indicated strong expression of 1alpha-hydroxylase protein and mRNA in the distal convoluted tubule, the cortical and medullary part of the collecting ducts, and the papillary epithelia. Lower expression was observed along the thick ascending limb of the loop of Henle and Bowman's capsule. Weaker and more variable expression of 1alpha-hydroxylase protein and mRNA was seen in proximal convoluted tubules, and no expression was observed in glomeruli or vascular structures. These data show for the first time the distribution of alpha1-hydroxylase expression in normal human kidney. In contrast to earlier enzyme activity studies conducted in vitamin D-deficient animals, our data indicate that the distal nephron is the predominant site of 1alpha-hydroxylase expression under conditions of vitamin D sufficiency.  (+info)

Calcitonin induces 25-hydroxyvitamin D3 1alpha-hydroxylase mRNA expression via protein kinase C pathway in LLC-PK1 cells. (6/296)

The biosynthesis of 1alpha, 25-dihydroxyvitamin D3 from 25-hydroxyvitamin D3 is catalyzed by 25-hydroxyvitamin D3 1alpha-hydroxylase (CYP27B1) in renal proximal tubules. It was recently demonstrated that LLC-PK1 cells express CYP27B1 mRNA, which is regulated by intracellular cAMP but not vitamin D3. To clarify the effect of calcitonin on vitamin D3 metabolism in vitro, LLC-PK1 cells were incubated with hormonal factors, and expression of CYP27B1 mRNA was measured by quantitative reverse transcription-PCR. Calcitonin at 100 nmol/L significantly increased CYP27B1 mRNA expression by 24 h (271 +/- 21% of control). Incubation with calcitonin over a range of 1 micromol/L to 1 pmol/L resulted in a concentration-dependent increase in CYP27B1 mRNA levels. It is known that the calcitonin receptor has dual intracellular signaling pathways, via protein kinases A and C. Both 500 micromol/L 8-bromo-cAMP, a protein kinase A activator, and 100 nmol/L phorbol 12-myristate 13-acetate, a protein kinase C activator, increased CYP27B1 mRNA levels at 24 h (207 +/- 54 and 246 +/- 58% of control, respectively). However, calcitonin-induced CYP27B1 mRNA expression was only inhibited by the protein kinase C inhibitors staurosporine and calphostin C. The protein kinase A inhibitors Rp-cAMPS at 10 and 100 micromol/L and H-89 at 10 micromol/L had no effect on the action of calcitonin, in spite of cAMP-activation by calcitonin. The present data suggest that calcitonin upregulates CYP27B1 mRNA expression via the protein kinase C pathway in LLC-PK1 cells.  (+info)

Control of renal vitamin D hydroxylases in birds by sex hormones. (7/296)

Kidney homogenates from adult male Japanese quail or chickens demonstrate hydroxylase activity predominantly for the 24 rather than the 1 position of 25-hydroxyvitamin D3 (25-hydroxycholecalciferol). A single injection of 5 mg of estradiol-17beta into a male bird completely suppresses the 24-hydroxylase and greatly increases the 1-hydroxylase activity. Immature males do not respond well to estrogen alone, but they do respond well to estradiol plus testosterone. Testosterone alone has little or no effect on the hydroxylases of either species. Castrated male chickens show an estradiol response only when testosterone is also given. Optimal 24 hr responses to 5 mg of estradiol per kg in the castrate male were obtained with about 12 mg of testosterone per kg. These optimal amounts of estradiol and testosterone increased the activity of 25-hydroxyvitamin D3-1-hydroxylase approximately 225-fold (this enzyme is also known as 25-hydroxycholecalciferol 1-monooxygenase; 25-hydroxycholecalciferol, NADPH: oxygen oxidoreductase (hydroxylating), EC 1.14.13.13). These results demonstrate a strong regulation by the sex hormones of the renal vitamin D hydroxylases in birds.  (+info)

The function of vitamin D receptor in vitamin D action. (8/296)

Vitamin D has roles in a variety of biological actions such as calcium homeostasis, cell proliferation and cell differentiation to many target tissues. Most of these biological actions of vitamin D are now considered to be exerted through the nuclear vitamin D receptor (VDR)-mediated control of target genes. VDR belongs to the nuclear hormone receptor superfamily and acts as a ligand-inducible transcription factor. For the ligand-induced transactivation of VDR, coactivator complexes have recently been shown to be essential. The function of VDR as a ligand-induced transcription factor is overviewed, and the phenotype of VDR gene knock-out mice and the VDR-mediated transcriptional and negative regulation of the key enzyme in vitamin D biosynthesis are also described, based mainly on our recent findings, to gain a better understanding of the function of VDR in the transcriptional control of vitamin D target genes.  (+info)

25-Hydroxyvitamin D3 1-alpha-Hydroxylase is an enzyme that is responsible for converting 25-hydroxyvitamin D3 (a precursor form of vitamin D) to its active form, 1,25-dihydroxyvitamin D3. This activation process occurs primarily in the kidneys and is tightly regulated by various factors such as calcium levels, parathyroid hormone, and vitamin D status.

The activated form of vitamin D, 1,25-dihydroxyvitamin D3, plays a crucial role in maintaining calcium homeostasis by increasing the absorption of calcium from the gut and promoting bone health. It also has various other functions, including modulation of immune function, cell growth regulation, and protection against cancer.

Deficiencies in 25-Hydroxyvitamin D3 1-alpha-Hydroxylase can lead to vitamin D deficiency and its associated symptoms, such as osteomalacia (softening of the bones) and osteoporosis (brittle bones). Conversely, overactivity of this enzyme can result in hypercalcemia (elevated levels of calcium in the blood), which can cause a range of symptoms including kidney stones, abdominal pain, nausea, and vomiting.

Medical definitions of "milk substitutes" refer to products that are designed to replace or serve as an alternative to traditional cow's milk for individuals who cannot consume it or choose not to. These can include a wide variety of products, such as:

1. Plant-based milks: These are made from plants such as soy, almonds, coconuts, oats, rice, hemp, flaxseed, and cashews. They are often fortified with calcium, vitamin D, and other nutrients to make them more similar in nutrition to cow's milk.
2. Animal-based milks: These include goat's milk, sheep's milk, and buffalo milk, which can be suitable alternatives for those who are allergic or intolerant to cow's milk.
3. Formula milks: These are designed for infants and young children who cannot be breastfed or need additional nutrition. They can be based on cow's milk, soy, or other proteins and are fortified with vitamins, minerals, and other nutrients to support growth and development.
4. Specialized milks: These are formulated for individuals with specific dietary needs, such as lactose-free milk for those with lactose intolerance, or hypoallergenic formulas for people with milk protein allergies.

It is important to note that not all milk substitutes are created equal in terms of nutrition and should be chosen based on individual dietary needs and preferences. Always consult a healthcare professional or registered dietitian for personalized advice on selecting the most appropriate milk substitute.

Cholesterol 7-alpha-hydroxylase (CYP7A1) is an enzyme that plays a crucial role in the regulation of cholesterol homeostasis in the body. It is located in the endoplasmic reticulum of hepatic cells and is responsible for the rate-limiting step in the synthesis of bile acids from cholesterol.

The enzyme catalyzes the conversion of cholesterol to 7α-hydroxycholesterol, which is then further metabolized to form primary bile acids, including cholic acid and chenodeoxycholic acid. These bile acids are essential for the digestion and absorption of fats and fat-soluble vitamins in the small intestine.

Additionally, CYP7A1 is also involved in the regulation of cholesterol levels in the body by providing negative feedback to the synthesis of cholesterol in the liver. When cholesterol levels are high, the activity of CYP7A1 increases, leading to an increase in bile acid synthesis and a decrease in cholesterol levels. Conversely, when cholesterol levels are low, the activity of CYP7A1 decreases, reducing bile acid synthesis and allowing cholesterol levels to rise.

Abnormalities in CYP7A1 function have been implicated in several diseases, including gallstones, liver disease, and cardiovascular disease.

25-Hydroxyvitamin D 2 (25(OH)D2) is a form of vitamin D that is produced in the body as a result of the metabolism of ergocalciferol, also known as vitamin D2. Vitamin D2 is found in some plant-based foods and is sometimes used as a dietary supplement.

When vitamin D2 is ingested or absorbed through the skin after exposure to sunlight, it is converted in the liver to 25(OH)D2. This form of vitamin D is then further metabolized in the kidneys to the active form of vitamin D, calcitriol (1,25-dihydroxyvitamin D).

Like other forms of vitamin D, 25(OH)D2 is important for maintaining healthy bones and muscles by regulating the absorption of calcium and phosphorus from the diet. It may also have other health benefits, such as reducing the risk of certain cancers and autoimmune disorders.

It's worth noting that 25-Hydroxyvitamin D2 is not usually measured in clinical settings, as it is converted to 25-Hydroxyvitamin D3 (25(OH)D3) in the body, and total 25(OH)D (which includes both 25(OH)D2 and 25(OH)D3) is typically measured to assess vitamin D status.

Calcifediol is the medical term for 25-hydroxyvitamin D, which is a form of vitamin D that is produced in the liver when it processes vitamin D from sunlight or from dietary sources. It is an important precursor to the active form of vitamin D, calcitriol, and is often used as a supplement for people who have low levels of vitamin D. Calcifediol is converted to calcitriol in the kidneys, where it plays a role in regulating calcium and phosphate levels in the body, which are important for maintaining healthy bones and teeth.

Vitamin D is a fat-soluble secosteroid that is crucial for the regulation of calcium and phosphate levels in the body, which are essential for maintaining healthy bones and teeth. It can be synthesized by the human body when skin is exposed to ultraviolet-B (UVB) rays from sunlight, or it can be obtained through dietary sources such as fatty fish, fortified dairy products, and supplements. There are two major forms of vitamin D: vitamin D2 (ergocalciferol), which is found in some plants and fungi, and vitamin D3 (cholecalciferol), which is produced in the skin or obtained from animal-derived foods. Both forms need to undergo two hydroxylations in the body to become biologically active as calcitriol (1,25-dihydroxyvitamin D3), the hormonally active form of vitamin D. This activated form exerts its effects by binding to the vitamin D receptor (VDR) found in various tissues, including the small intestine, bone, kidney, and immune cells, thereby influencing numerous physiological processes such as calcium homeostasis, bone metabolism, cell growth, and immune function.

Vitamin D deficiency is a condition characterized by insufficient levels of vitamin D in the body, typically defined as a serum 25-hydroxyvitamin D level below 20 nanograms per milliliter (ng/mL) or 50 nanomoles per liter (nmol/L). Vitamin D is an essential fat-soluble vitamin that plays a crucial role in maintaining healthy bones and teeth by regulating the absorption of calcium and phosphorus. It also has various other functions in the body, including modulation of cell growth, immune function, and neuromuscular activity.

Vitamin D can be obtained through dietary sources such as fatty fish, fortified dairy products, and supplements, but the majority of vitamin D is produced in the skin upon exposure to sunlight. Deficiency can occur due to inadequate dietary intake, insufficient sun exposure, or impaired absorption or metabolism of vitamin D.

Risk factors for vitamin D deficiency include older age, darker skin tone, obesity, malabsorption syndromes, liver or kidney disease, and certain medications. Symptoms of vitamin D deficiency can be subtle and nonspecific, such as fatigue, bone pain, muscle weakness, and mood changes. However, prolonged deficiency can lead to more severe health consequences, including osteoporosis, osteomalacia, and increased risk of fractures.

Cholecalciferol is the chemical name for Vitamin D3. It is a fat-soluble vitamin that is essential for the regulation of calcium and phosphate levels in the body, which helps to maintain healthy bones and teeth. Cholecalciferol can be synthesized by the skin upon exposure to sunlight or obtained through dietary sources such as fatty fish, liver, and fortified foods. It is also available as a dietary supplement.

Hydroxycholecalciferols are metabolites of vitamin D that are formed in the liver and kidneys. They are important for maintaining calcium homeostasis in the body by promoting the absorption of calcium from the gut and reabsorption of calcium from the kidneys.

The two main forms of hydroxycholecalciferols are 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D). 25-hydroxyvitamin D is the major circulating form of vitamin D in the body and is used as a clinical measure of vitamin D status. It is converted to 1,25-dihydroxyvitamin D in the kidneys by the enzyme 1α-hydroxylase, which is activated in response to low serum calcium or high phosphate levels.

1,25-dihydroxyvitamin D is the biologically active form of vitamin D and plays a critical role in regulating calcium homeostasis by increasing intestinal calcium absorption and promoting bone health. Deficiency in hydroxycholecalciferols can lead to rickets in children and osteomalacia or osteoporosis in adults, characterized by weakened bones and increased risk of fractures.

Steroid hydroxylases are enzymes that catalyze the addition of a hydroxyl group (-OH) to a steroid molecule. These enzymes are located in the endoplasmic reticulum and play a crucial role in the biosynthesis of various steroid hormones, such as cortisol, aldosterone, and sex hormones. The hydroxylation reaction catalyzed by these enzymes increases the polarity and solubility of steroids, allowing them to be further metabolized and excreted from the body.

The most well-known steroid hydroxylases are part of the cytochrome P450 family, specifically CYP11A1, CYP11B1, CYP11B2, CYP17A1, CYP19A1, and CYP21A2. Each enzyme has a specific function in steroid biosynthesis, such as converting cholesterol to pregnenolone (CYP11A1), hydroxylating the 11-beta position of steroids (CYP11B1 and CYP11B2), or performing multiple hydroxylation reactions in the synthesis of sex hormones (CYP17A1, CYP19A1, and CYP21A2).

Defects in these enzymes can lead to various genetic disorders, such as congenital adrenal hyperplasia, which is characterized by impaired steroid hormone biosynthesis.

Dihydroxycholecalciferols are a form of calcifediol, which is a type of secosteroid hormone that is produced in the body as a result of the exposure to sunlight and the dietary intake of vitamin D. The term "dihydroxycholecalciferols" specifically refers to the compounds 1,25-dihydroxycholecalciferol (calcitriol) and 24,25-dihydroxycholecalciferol. These compounds are produced in the body through a series of chemical reactions involving enzymes that convert vitamin D into its active forms.

Calcitriol is the biologically active form of vitamin D and plays an important role in regulating the levels of calcium and phosphorus in the blood, as well as promoting the absorption of these minerals from the gut. It also has other functions, such as modulating cell growth and immune function.

24,25-dihydroxycholecalciferol is a less active form of vitamin D that is produced in larger quantities than calcitriol. Its exact role in the body is not well understood, but it is thought to have some effects on calcium metabolism and may play a role in regulating the levels of other hormones in the body.

Dihydroxycholecalciferols are typically measured in the blood as part of an evaluation for vitamin D deficiency or to monitor treatment with vitamin D supplements. Low levels of these compounds can indicate a deficiency, while high levels may indicate excessive intake or impaired metabolism.

Ergocalciferols are a form of vitamin D, specifically vitamin D2, that is found in some plants. They are not produced by the human body and must be obtained through diet or supplementation. Ergocalciferols can be converted into an active form of vitamin D in the body, which is important for maintaining healthy bones and calcium levels. However, vitamin D3 (cholecalciferol), which is produced by the body in response to sunlight exposure, is generally considered to be more effective at raising and maintaining vitamin D levels in the body than ergocalciferols.

24,25-Dihydroxyvitamin D3 is a metabolite of vitamin D3, also known as calcitriol. It is formed in the body through the hydroxylation of vitamin D3 by the enzyme 25-hydroxyvitamin D3 1-alpha-hydroxylase, which is primarily found in the kidneys.

24,25-Dihydroxyvitamin D3 plays a role in regulating calcium and phosphate metabolism, but its functions are not as well understood as those of other vitamin D metabolites. Some studies have suggested that it may have anti-inflammatory effects and may be involved in the regulation of cell growth and differentiation. However, more research is needed to fully understand the physiological role of this compound.

It's important to note that 24,25-Dihydroxyvitamin D3 is not typically used as a therapeutic agent, and its levels in the body are not routinely measured in clinical practice.

Parathyroid hormone (PTH) is a polypeptide hormone that plays a crucial role in the regulation of calcium and phosphate levels in the body. It is produced and secreted by the parathyroid glands, which are four small endocrine glands located on the back surface of the thyroid gland.

The primary function of PTH is to maintain normal calcium levels in the blood by increasing calcium absorption from the gut, mobilizing calcium from bones, and decreasing calcium excretion by the kidneys. PTH also increases phosphate excretion by the kidneys, which helps to lower serum phosphate levels.

In addition to its role in calcium and phosphate homeostasis, PTH has been shown to have anabolic effects on bone tissue, stimulating bone formation and preventing bone loss. However, chronic elevations in PTH levels can lead to excessive bone resorption and osteoporosis.

Overall, Parathyroid Hormone is a critical hormone that helps maintain mineral homeostasis and supports healthy bone metabolism.

Cholestanetriol 26-monooxygenase is an enzyme that is involved in the metabolism of bile acids and steroids in the body. This enzyme is responsible for adding a hydroxyl group (-OH) to the cholestanetriol molecule at position 26, which is a critical step in the conversion of cholestanetriol to bile acids.

The gene that encodes this enzyme is called CYP3A4, which is located on chromosome 7 in humans. Mutations in this gene can lead to various metabolic disorders, including impaired bile acid synthesis and altered steroid hormone metabolism.

Deficiency or dysfunction of cholestanetriol 26-monooxygenase has been associated with several diseases, such as liver disease, cerebrotendinous xanthomatosis, and some forms of cancer. Therefore, understanding the function and regulation of this enzyme is essential for developing new therapies and treatments for these conditions.

Calcitriol is the active form of vitamin D, also known as 1,25-dihydroxyvitamin D. It is a steroid hormone that plays a crucial role in regulating calcium and phosphate levels in the body to maintain healthy bones. Calcitriol is produced in the kidneys from its precursor, calcidiol (25-hydroxyvitamin D), which is derived from dietary sources or synthesized in the skin upon exposure to sunlight.

Calcitriol promotes calcium absorption in the intestines, helps regulate calcium and phosphate levels in the kidneys, and stimulates bone cells (osteoblasts) to form new bone tissue while inhibiting the activity of osteoclasts, which resorb bone. This hormone is essential for normal bone mineralization and growth, as well as for preventing hypocalcemia (low calcium levels).

In addition to its role in bone health, calcitriol has various other physiological functions, including modulating immune responses, cell proliferation, differentiation, and apoptosis. Calcitriol deficiency or resistance can lead to conditions such as rickets in children and osteomalacia or osteoporosis in adults.

Vitamin D-Binding Protein (DBP), also known as Group-specific Component (Gc-globulin), is a protein that binds and transports vitamin D and its metabolites in the bloodstream. It plays a crucial role in maintaining the homeostasis of vitamin D by regulating the amount of free, active vitamin D available to cells. DBP also has other functions, including acting as an actin scavenger to prevent the formation of harmful actin aggregates in circulation and participating in immune responses.

Phenylalanine Hydroxylase (PAH) is an enzyme that plays a crucial role in the metabolism of the essential amino acid phenylalanine. This enzyme is primarily found in the liver and is responsible for converting phenylalanine into tyrosine, another amino acid. PAH requires a cofactor called tetrahydrobiopterin (BH4) to function properly.

Defects or mutations in the gene that encodes PAH can lead to a genetic disorder known as Phenylketonuria (PKU). In PKU, the activity of PAH is significantly reduced or absent, causing an accumulation of phenylalanine in the body. If left untreated, this condition can result in severe neurological damage and intellectual disability due to the toxic effects of high phenylalanine levels on the developing brain. A strict low-phenylalanine diet and regular monitoring of blood phenylalanine levels are essential for managing PKU and preventing associated complications.

Rickets is a medical condition characterized by the softening and weakening of bones in children, primarily caused by deficiency of vitamin D, calcium, or phosphate. It leads to skeletal deformities, bone pain, and growth retardation. Prolonged lack of sunlight exposure, inadequate intake of vitamin D-rich foods, or impaired absorption or utilization of vitamin D can contribute to the development of rickets.

I'm sorry for any confusion, but "sunlight" is not a term with a specific medical definition. However, sunlight does have various implications in the field of medicine. It is the light that comes from the sun, which is a star at the center of our solar system. Sunlight is essential for the production of vitamin D in humans, and it can also have effects on mood and sleep patterns due to its influence on circadian rhythms.

In a medical context, sunlight is often discussed in relation to its potential health benefits and risks. For instance, moderate sun exposure can help increase vitamin D levels, which are important for bone health, immune function, and other bodily processes. However, excessive sun exposure can lead to harmful effects, such as sunburn, premature skin aging, and an increased risk of skin cancer.

It's essential to balance the benefits and risks of sunlight exposure by practicing safe sun habits, such as wearing protective clothing, using a broad-spectrum sunscreen with an SPF of at least 30, seeking shade during peak sunlight hours, and avoiding intentional tanning.

Steroid 21-hydroxylase, also known as CYP21A2, is a crucial enzyme involved in the synthesis of steroid hormones in the adrenal gland. Specifically, it catalyzes the conversion of 17-hydroxyprogesterone to 11-deoxycortisol and progesterone to deoxycorticosterone in the glucocorticoid and mineralocorticoid pathways, respectively.

Deficiency or mutations in this enzyme can lead to a group of genetic disorders called congenital adrenal hyperplasia (CAH), which is characterized by impaired cortisol production and disrupted hormonal balance. Depending on the severity of the deficiency, CAH can result in various symptoms such as ambiguous genitalia, precocious puberty, sexual infantilism, infertility, and increased risk of adrenal crisis.

Calcitriol receptors, also known as Vitamin D receptors (VDR), are nuclear receptor proteins that bind to calcitriol (1,25-dihydroxyvitamin D3), the active form of vitamin D. These receptors are found in various tissues and cells throughout the body, including the small intestine, bone, kidney, and parathyroid gland.

When calcitriol binds to its receptor, it forms a complex that regulates the expression of genes involved in calcium and phosphate homeostasis, cell growth, differentiation, and immune function. Calcitriol receptors play a critical role in maintaining normal levels of calcium and phosphate in the blood by increasing the absorption of these minerals from the gut, promoting bone mineralization, and regulating the production of parathyroid hormone (PTH).

Calcitriol receptors have also been implicated in various disease processes, including cancer, autoimmune disorders, and infectious diseases. Modulation of calcitriol receptor activity has emerged as a potential therapeutic strategy for the treatment of these conditions.

I'm sorry for any confusion, but "seasons" is not a term that has a medical definition. Seasons refer to the four divisions of the year (spring, summer, autumn or fall, and winter) based on the position of the earth in its orbit around the sun. If you have any questions related to health or medicine, I'd be happy to try to help answer those!

Tryptophan hydroxylase is an enzyme that plays a crucial role in the synthesis of neurotransmitters and hormones, including serotonin and melatonin. It catalyzes the conversion of the essential amino acid tryptophan to 5-hydroxytryptophan (5-HTP), which is then further converted to serotonin. This enzyme exists in two isoforms, TPH1 and TPH2, with TPH1 primarily located in peripheral tissues and TPH2 mainly found in the brain. The regulation of tryptophan hydroxylase activity has significant implications for mood, appetite, sleep, and pain perception.

Hydroxylation is a biochemical process that involves the addition of a hydroxyl group (-OH) to a molecule, typically a steroid or xenobiotic compound. This process is primarily catalyzed by enzymes called hydroxylases, which are found in various tissues throughout the body.

In the context of medicine and biochemistry, hydroxylation can have several important functions:

1. Drug metabolism: Hydroxylation is a common way that the liver metabolizes drugs and other xenobiotic compounds. By adding a hydroxyl group to a drug molecule, it becomes more polar and water-soluble, which facilitates its excretion from the body.
2. Steroid hormone biosynthesis: Hydroxylation is an essential step in the biosynthesis of many steroid hormones, including cortisol, aldosterone, and the sex hormones estrogen and testosterone. These hormones are synthesized from cholesterol through a series of enzymatic reactions that involve hydroxylation at various steps.
3. Vitamin D activation: Hydroxylation is also necessary for the activation of vitamin D in the body. In order to become biologically active, vitamin D must undergo two successive hydroxylations, first in the liver and then in the kidneys.
4. Toxin degradation: Some toxic compounds can be rendered less harmful through hydroxylation. For example, phenol, a toxic compound found in cigarette smoke and some industrial chemicals, can be converted to a less toxic form through hydroxylation by enzymes in the liver.

Overall, hydroxylation is an important biochemical process that plays a critical role in various physiological functions, including drug metabolism, hormone biosynthesis, and toxin degradation.

A dietary supplement is a product that contains nutrients, such as vitamins, minerals, amino acids, herbs or other botanicals, and is intended to be taken by mouth, to supplement the diet. Dietary supplements can include a wide range of products, such as vitamin and mineral supplements, herbal supplements, and sports nutrition products.

Dietary supplements are not intended to treat, diagnose, cure, or alleviate the effects of diseases. They are intended to be used as a way to add extra nutrients to the diet or to support specific health functions. It is important to note that dietary supplements are not subject to the same rigorous testing and regulations as drugs, so it is important to choose products carefully and consult with a healthcare provider if you have any questions or concerns about using them.

Vitamins are organic substances that are essential in small quantities for the normal growth, development, and maintenance of life in humans. They are required for various biochemical functions in the body such as energy production, blood clotting, immune function, and making DNA.

Unlike macronutrients (carbohydrates, proteins, and fats), vitamins do not provide energy but they play a crucial role in energy metabolism. Humans require 13 essential vitamins, which can be divided into two categories: fat-soluble and water-soluble.

Fat-soluble vitamins (A, D, E, and K) are stored in the body's fat tissues and liver, and can stay in the body for a longer period of time. Water-soluble vitamins (B-complex vitamins and vitamin C) are not stored in the body and need to be replenished regularly through diet or supplementation.

Deficiency of vitamins can lead to various health problems, while excessive intake of certain fat-soluble vitamins can also be harmful due to toxicity. Therefore, it is important to maintain a balanced diet that provides all the essential vitamins in adequate amounts.

Tyrosine 3-Monooxygenase (also known as Tyrosinase or Tyrosine hydroxylase) is an enzyme that plays a crucial role in the synthesis of catecholamines, which are neurotransmitters and hormones in the body. This enzyme catalyzes the conversion of the amino acid L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by adding a hydroxyl group to the 3rd carbon atom of the tyrosine molecule.

The reaction is as follows:

L-Tyrosine + O2 + pterin (co-factor) -> L-DOPA + pterin (oxidized) + H2O

This enzyme requires molecular oxygen and a co-factor such as tetrahydrobiopterin to carry out the reaction. Tyrosine 3-Monooxygenase is found in various tissues, including the brain and adrenal glands, where it helps regulate the production of catecholamines like dopamine, norepinephrine, and epinephrine. Dysregulation of this enzyme has been implicated in several neurological disorders, such as Parkinson's disease.

The Cytochrome P-450 (CYP450) enzyme system is a group of enzymes found primarily in the liver, but also in other organs such as the intestines, lungs, and skin. These enzymes play a crucial role in the metabolism and biotransformation of various substances, including drugs, environmental toxins, and endogenous compounds like hormones and fatty acids.

The name "Cytochrome P-450" refers to the unique property of these enzymes to bind to carbon monoxide (CO) and form a complex that absorbs light at a wavelength of 450 nm, which can be detected spectrophotometrically.

The CYP450 enzyme system is involved in Phase I metabolism of xenobiotics, where it catalyzes oxidation reactions such as hydroxylation, dealkylation, and epoxidation. These reactions introduce functional groups into the substrate molecule, which can then undergo further modifications by other enzymes during Phase II metabolism.

There are several families and subfamilies of CYP450 enzymes, each with distinct substrate specificities and functions. Some of the most important CYP450 enzymes include:

1. CYP3A4: This is the most abundant CYP450 enzyme in the human liver and is involved in the metabolism of approximately 50% of all drugs. It also metabolizes various endogenous compounds like steroids, bile acids, and vitamin D.
2. CYP2D6: This enzyme is responsible for the metabolism of many psychotropic drugs, including antidepressants, antipsychotics, and beta-blockers. It also metabolizes some endogenous compounds like dopamine and serotonin.
3. CYP2C9: This enzyme plays a significant role in the metabolism of warfarin, phenytoin, and nonsteroidal anti-inflammatory drugs (NSAIDs).
4. CYP2C19: This enzyme is involved in the metabolism of proton pump inhibitors, antidepressants, and clopidogrel.
5. CYP2E1: This enzyme metabolizes various xenobiotics like alcohol, acetaminophen, and carbon tetrachloride, as well as some endogenous compounds like fatty acids and prostaglandins.

Genetic polymorphisms in CYP450 enzymes can significantly affect drug metabolism and response, leading to interindividual variability in drug efficacy and toxicity. Understanding the role of CYP450 enzymes in drug metabolism is crucial for optimizing pharmacotherapy and minimizing adverse effects.

Mixed Function Oxygenases (MFOs) are a type of enzyme that catalyze the addition of one atom each from molecular oxygen (O2) to a substrate, while reducing the other oxygen atom to water. These enzymes play a crucial role in the metabolism of various endogenous and exogenous compounds, including drugs, carcinogens, and environmental pollutants.

MFOs are primarily located in the endoplasmic reticulum of cells and consist of two subunits: a flavoprotein component that contains FAD or FMN as a cofactor, and an iron-containing heme protein. The most well-known example of MFO is cytochrome P450, which is involved in the oxidation of xenobiotics and endogenous compounds such as steroids, fatty acids, and vitamins.

MFOs can catalyze a variety of reactions, including hydroxylation, epoxidation, dealkylation, and deamination, among others. These reactions often lead to the activation or detoxification of xenobiotics, making MFOs an important component of the body's defense system against foreign substances. However, in some cases, these reactions can also produce reactive intermediates that may cause toxicity or contribute to the development of diseases such as cancer.

Procollagen-proline dioxygenase is an enzyme that belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with oxygen as an acceptor. This enzyme is involved in the post-translational modification of procollagens, which are the precursors of collagen, a crucial protein found in connective tissues such as tendons, ligaments, and skin.

Procollagen-proline dioxygenase catalyzes the reaction that adds two hydroxyl groups to specific proline residues in the procollagen molecule, converting them into hydroxyprolines. This modification is essential for the proper folding and stabilization of the collagen triple helix structure, which provides strength and resilience to connective tissues.

The enzyme requires iron as a cofactor and molecular oxygen as a substrate, with vitamin C (ascorbic acid) acting as an essential cofactor in the reaction cycle. The proper functioning of procollagen-proline dioxygenase is critical for maintaining the integrity and health of connective tissues, and deficiencies or mutations in this enzyme can lead to various connective tissue disorders, such as scurvy (caused by vitamin C deficiency) or certain forms of osteogenesis imperfecta (a genetic disorder characterized by fragile bones).

Phosphorus is an essential mineral that is required by every cell in the body for normal functioning. It is a key component of several important biomolecules, including adenosine triphosphate (ATP), which is the primary source of energy for cells, and deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), which are the genetic materials in cells.

Phosphorus is also a major constituent of bones and teeth, where it combines with calcium to provide strength and structure. In addition, phosphorus plays a critical role in various metabolic processes, including energy production, nerve impulse transmission, and pH regulation.

The medical definition of phosphorus refers to the chemical element with the atomic number 15 and the symbol P. It is a highly reactive non-metal that exists in several forms, including white phosphorus, red phosphorus, and black phosphorus. In the body, phosphorus is primarily found in the form of organic compounds, such as phospholipids, phosphoproteins, and nucleic acids.

Abnormal levels of phosphorus in the body can lead to various health problems. For example, high levels of phosphorus (hyperphosphatemia) can occur in patients with kidney disease or those who consume large amounts of phosphorus-rich foods, and can contribute to the development of calcification of soft tissues and cardiovascular disease. On the other hand, low levels of phosphorus (hypophosphatemia) can occur in patients with malnutrition, vitamin D deficiency, or alcoholism, and can lead to muscle weakness, bone pain, and an increased risk of infection.

Dietary calcium is a type of calcium that is obtained through food sources. Calcium is an essential mineral that is necessary for many bodily functions, including bone formation and maintenance, muscle contraction, nerve impulse transmission, and blood clotting.

The recommended daily intake of dietary calcium varies depending on age, sex, and other factors. For example, the recommended daily intake for adults aged 19-50 is 1000 mg, while women over 50 and men over 70 require 1200 mg per day.

Good dietary sources of calcium include dairy products such as milk, cheese, and yogurt; leafy green vegetables like broccoli and kale; fortified cereals and juices; and certain types of fish, such as salmon and sardines. It is important to note that some foods can inhibit the absorption of calcium, including oxalates found in spinach and rhubarb, and phytates found in whole grains and legumes.

If a person is unable to get enough calcium through their diet, they may need to take calcium supplements. However, it is important to talk to a healthcare provider before starting any new supplement regimen, as excessive intake of calcium can lead to negative health effects.

Osteomalacia is a medical condition characterized by the softening of bones due to defective bone mineralization, resulting from inadequate vitamin D, phosphate, or calcium. It mainly affects adults and is different from rickets, which occurs in children. The primary symptom is bone pain, but muscle weakness can also occur. Prolonged osteomalacia may lead to skeletal deformities and an increased risk of fractures. Treatment typically involves supplementation with vitamin D, calcium, and sometimes phosphate.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Bone density refers to the amount of bone mineral content (usually measured in grams) in a given volume of bone (usually measured in cubic centimeters). It is often used as an indicator of bone strength and fracture risk. Bone density is typically measured using dual-energy X-ray absorptiometry (DXA) scans, which provide a T-score that compares the patient's bone density to that of a young adult reference population. A T-score of -1 or above is considered normal, while a T-score between -1 and -2.5 indicates osteopenia (low bone mass), and a T-score below -2.5 indicates osteoporosis (porous bones). Regular exercise, adequate calcium and vitamin D intake, and medication (if necessary) can help maintain or improve bone density and prevent fractures.

A cross-sectional study is a type of observational research design that examines the relationship between variables at one point in time. It provides a snapshot or a "cross-section" of the population at a particular moment, allowing researchers to estimate the prevalence of a disease or condition and identify potential risk factors or associations.

In a cross-sectional study, data is collected from a sample of participants at a single time point, and the variables of interest are measured simultaneously. This design can be used to investigate the association between exposure and outcome, but it cannot establish causality because it does not follow changes over time.

Cross-sectional studies can be conducted using various data collection methods, such as surveys, interviews, or medical examinations. They are often used in epidemiology to estimate the prevalence of a disease or condition in a population and to identify potential risk factors that may contribute to its development. However, because cross-sectional studies only provide a snapshot of the population at one point in time, they cannot account for changes over time or determine whether exposure preceded the outcome.

Therefore, while cross-sectional studies can be useful for generating hypotheses and identifying potential associations between variables, further research using other study designs, such as cohort or case-control studies, is necessary to establish causality and confirm any findings.

Nutritional status is a concept that refers to the condition of an individual in relation to their nutrient intake, absorption, metabolism, and excretion. It encompasses various aspects such as body weight, muscle mass, fat distribution, presence of any deficiencies or excesses of specific nutrients, and overall health status.

A comprehensive assessment of nutritional status typically includes a review of dietary intake, anthropometric measurements (such as height, weight, waist circumference, blood pressure), laboratory tests (such as serum albumin, total protein, cholesterol levels, vitamin and mineral levels), and clinical evaluation for signs of malnutrition or overnutrition.

Malnutrition can result from inadequate intake or absorption of nutrients, increased nutrient requirements due to illness or injury, or excessive loss of nutrients due to medical conditions. On the other hand, overnutrition can lead to obesity and related health problems such as diabetes, cardiovascular disease, and certain types of cancer.

Therefore, maintaining a good nutritional status is essential for overall health and well-being, and it is an important consideration in the prevention, diagnosis, and treatment of various medical conditions.

Skin pigmentation is the coloration of the skin that is primarily determined by two types of melanin pigments, eumelanin and pheomelanin. These pigments are produced by melanocytes, which are specialized cells located in the epidermis. Eumelanin is responsible for brown or black coloration, while pheomelanin produces a red or yellow hue.

The amount and distribution of melanin in the skin can vary depending on genetic factors, age, sun exposure, and various other influences. Increased production of melanin in response to UV radiation from the sun helps protect the skin from damage, leading to darkening or tanning of the skin. However, excessive sun exposure can also cause irregular pigmentation, such as sunspots or freckles.

Abnormalities in skin pigmentation can result from various medical conditions, including albinism (lack of melanin production), vitiligo (loss of melanocytes leading to white patches), and melasma (excessive pigmentation often caused by hormonal changes). These conditions may require medical treatment to manage or improve the pigmentation issues.

A kidney, in medical terms, is one of two bean-shaped organs located in the lower back region of the body. They are essential for maintaining homeostasis within the body by performing several crucial functions such as:

1. Regulation of water and electrolyte balance: Kidneys help regulate the amount of water and various electrolytes like sodium, potassium, and calcium in the bloodstream to maintain a stable internal environment.

2. Excretion of waste products: They filter waste products from the blood, including urea (a byproduct of protein metabolism), creatinine (a breakdown product of muscle tissue), and other harmful substances that result from normal cellular functions or external sources like medications and toxins.

3. Endocrine function: Kidneys produce several hormones with important roles in the body, such as erythropoietin (stimulates red blood cell production), renin (regulates blood pressure), and calcitriol (activated form of vitamin D that helps regulate calcium homeostasis).

4. pH balance regulation: Kidneys maintain the proper acid-base balance in the body by excreting either hydrogen ions or bicarbonate ions, depending on whether the blood is too acidic or too alkaline.

5. Blood pressure control: The kidneys play a significant role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS), which constricts blood vessels and promotes sodium and water retention to increase blood volume and, consequently, blood pressure.

Anatomically, each kidney is approximately 10-12 cm long, 5-7 cm wide, and 3 cm thick, with a weight of about 120-170 grams. They are surrounded by a protective layer of fat and connected to the urinary system through the renal pelvis, ureters, bladder, and urethra.

"Bone" is the hard, dense connective tissue that makes up the skeleton of vertebrate animals. It provides support and protection for the body's internal organs, and serves as a attachment site for muscles, tendons, and ligaments. Bone is composed of cells called osteoblasts and osteoclasts, which are responsible for bone formation and resorption, respectively, and an extracellular matrix made up of collagen fibers and mineral crystals.

Bones can be classified into two main types: compact bone and spongy bone. Compact bone is dense and hard, and makes up the outer layer of all bones and the shafts of long bones. Spongy bone is less dense and contains large spaces, and makes up the ends of long bones and the interior of flat and irregular bones.

The human body has 206 bones in total. They can be further classified into five categories based on their shape: long bones, short bones, flat bones, irregular bones, and sesamoid bones.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

Medical Definition:

"Risk factors" are any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury. They can be divided into modifiable and non-modifiable risk factors. Modifiable risk factors are those that can be changed through lifestyle choices or medical treatment, while non-modifiable risk factors are inherent traits such as age, gender, or genetic predisposition. Examples of modifiable risk factors include smoking, alcohol consumption, physical inactivity, and unhealthy diet, while non-modifiable risk factors include age, sex, and family history. It is important to note that having a risk factor does not guarantee that a person will develop the disease, but rather indicates an increased susceptibility.

A biological marker, often referred to as a biomarker, is a measurable indicator that reflects the presence or severity of a disease state, or a response to a therapeutic intervention. Biomarkers can be found in various materials such as blood, tissues, or bodily fluids, and they can take many forms, including molecular, histologic, radiographic, or physiological measurements.

In the context of medical research and clinical practice, biomarkers are used for a variety of purposes, such as:

1. Diagnosis: Biomarkers can help diagnose a disease by indicating the presence or absence of a particular condition. For example, prostate-specific antigen (PSA) is a biomarker used to detect prostate cancer.
2. Monitoring: Biomarkers can be used to monitor the progression or regression of a disease over time. For instance, hemoglobin A1c (HbA1c) levels are monitored in diabetes patients to assess long-term blood glucose control.
3. Predicting: Biomarkers can help predict the likelihood of developing a particular disease or the risk of a negative outcome. For example, the presence of certain genetic mutations can indicate an increased risk for breast cancer.
4. Response to treatment: Biomarkers can be used to evaluate the effectiveness of a specific treatment by measuring changes in the biomarker levels before and after the intervention. This is particularly useful in personalized medicine, where treatments are tailored to individual patients based on their unique biomarker profiles.

It's important to note that for a biomarker to be considered clinically valid and useful, it must undergo rigorous validation through well-designed studies, including demonstrating sensitivity, specificity, reproducibility, and clinical relevance.

I'm sorry for any confusion, but "Linear Models" is actually a term from the field of statistics and machine learning, rather than medicine. A linear model is a type of statistical model that is used to analyze the relationship between two or more variables. In a linear model, the relationship between the dependent variable (the outcome or result) and the independent variable(s) (the factors being studied) is assumed to be linear, meaning that it can be described by a straight line on a graph.

The equation for a simple linear model with one independent variable (x) and one dependent variable (y) looks like this:

y = β0 + β1*x + ε

In this equation, β0 is the y-intercept or the value of y when x equals zero, β1 is the slope or the change in y for each unit increase in x, and ε is the error term or the difference between the actual values of y and the predicted values of y based on the linear model.

Linear models are widely used in medical research to study the relationship between various factors (such as exposure to a risk factor or treatment) and health outcomes (such as disease incidence or mortality). They can also be used to adjust for confounding variables, which are factors that may influence both the independent variable and the dependent variable, and thus affect the observed relationship between them.

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

Bone density conservation agents, also known as anti-resorptive agents or bone-sparing drugs, are a class of medications that help to prevent the loss of bone mass and reduce the risk of fractures. They work by inhibiting the activity of osteoclasts, the cells responsible for breaking down and reabsorbing bone tissue during the natural remodeling process.

Examples of bone density conservation agents include:

1. Bisphosphonates (e.g., alendronate, risedronate, ibandronate, zoledronic acid) - These are the most commonly prescribed class of bone density conservation agents. They bind to hydroxyapatite crystals in bone tissue and inhibit osteoclast activity, thereby reducing bone resorption.
2. Denosumab (Prolia) - This is a monoclonal antibody that targets RANKL (Receptor Activator of Nuclear Factor-κB Ligand), a key signaling molecule involved in osteoclast differentiation and activation. By inhibiting RANKL, denosumab reduces osteoclast activity and bone resorption.
3. Selective estrogen receptor modulators (SERMs) (e.g., raloxifene) - These medications act as estrogen agonists or antagonists in different tissues. In bone tissue, SERMs mimic the bone-preserving effects of estrogen by inhibiting osteoclast activity and reducing bone resorption.
4. Hormone replacement therapy (HRT) - Estrogen hormone replacement therapy has been shown to preserve bone density in postmenopausal women; however, its use is limited due to increased risks of breast cancer, cardiovascular disease, and thromboembolic events.
5. Calcitonin - This hormone, secreted by the thyroid gland, inhibits osteoclast activity and reduces bone resorption. However, it has largely been replaced by other more effective bone density conservation agents.

These medications are often prescribed for individuals at high risk of fractures due to conditions such as osteoporosis or metabolic disorders that affect bone health. It is essential to follow the recommended dosage and administration guidelines to maximize their benefits while minimizing potential side effects. Regular monitoring of bone density, blood calcium levels, and other relevant parameters is also necessary during treatment with these medications.

Benzopyrene hydroxylase is an enzyme that is involved in the metabolism and detoxification of polycyclic aromatic hydrocarbons (PAHs), which are a group of environmental pollutants found in cigarette smoke, air pollution, and charred or overcooked foods. Benzopyrene hydroxylase is primarily found in the liver and is responsible for adding a hydroxyl group to benzopyrene, a type of PAH, making it more water-soluble and easier to excrete from the body. This enzyme plays an important role in the body's defense against the harmful effects of PAHs.

Alpha 1-antitrypsin (AAT, or α1-antiproteinase, A1AP) is a protein that is primarily produced by the liver and released into the bloodstream. It belongs to a group of proteins called serine protease inhibitors, which help regulate inflammation and protect tissues from damage caused by enzymes involved in the immune response.

Alpha 1-antitrypsin is particularly important for protecting the lungs from damage caused by neutrophil elastase, an enzyme released by white blood cells called neutrophils during inflammation. In the lungs, AAT binds to and inhibits neutrophil elastase, preventing it from degrading the extracellular matrix and damaging lung tissue.

Deficiency in alpha 1-antitrypsin can lead to chronic obstructive pulmonary disease (COPD) and liver disease. The most common cause of AAT deficiency is a genetic mutation that results in abnormal folding and accumulation of the protein within liver cells, leading to reduced levels of functional AAT in the bloodstream. This condition is called alpha 1-antitrypsin deficiency (AATD) and can be inherited in an autosomal codominant manner. Individuals with severe AATD may require augmentation therapy with intravenous infusions of purified human AAT to help prevent lung damage.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Congenital Adrenal Hyperplasia (CAH) is a group of inherited genetic disorders that affect the adrenal glands, which are triangular-shaped glands located on top of the kidneys. The adrenal glands are responsible for producing several essential hormones, including cortisol, aldosterone, and androgens.

CAH is caused by mutations in genes that code for enzymes involved in the synthesis of these hormones. The most common form of CAH is 21-hydroxylase deficiency, which affects approximately 90% to 95% of all cases. Other less common forms of CAH include 11-beta-hydroxylase deficiency and 3-beta-hydroxysteroid dehydrogenase deficiency.

The severity of the disorder can vary widely, depending on the degree of enzyme deficiency. In severe cases, the lack of cortisol production can lead to life-threatening salt wasting and electrolyte imbalances in newborns. The excess androgens produced due to the enzyme deficiency can also cause virilization, or masculinization, of female fetuses, leading to ambiguous genitalia at birth.

In milder forms of CAH, symptoms may not appear until later in childhood or even adulthood. These may include early puberty, rapid growth followed by premature fusion of the growth plates and short stature, acne, excessive hair growth, irregular menstrual periods, and infertility.

Treatment for CAH typically involves replacing the missing hormones with medications such as hydrocortisone, fludrocortisone, and/or sex hormones. Regular monitoring of hormone levels and careful management of medication doses is essential to prevent complications such as adrenal crisis, growth suppression, and osteoporosis.

In severe cases of CAH, early diagnosis and treatment can help prevent or minimize the risk of serious health problems and improve quality of life. Genetic counseling may also be recommended for affected individuals and their families to discuss the risks of passing on the disorder to future generations.

A case-control study is an observational research design used to identify risk factors or causes of a disease or health outcome. In this type of study, individuals with the disease or condition (cases) are compared with similar individuals who do not have the disease or condition (controls). The exposure history or other characteristics of interest are then compared between the two groups to determine if there is an association between the exposure and the disease.

Case-control studies are often used when it is not feasible or ethical to conduct a randomized controlled trial, as they can provide valuable insights into potential causes of diseases or health outcomes in a relatively short period of time and at a lower cost than other study designs. However, because case-control studies rely on retrospective data collection, they are subject to biases such as recall bias and selection bias, which can affect the validity of the results. Therefore, it is important to carefully design and conduct case-control studies to minimize these potential sources of bias.

4-Hydroxybenzoate-3-Monooxygenase is a type of enzyme that catalyzes the conversion of 4-hydroxybenzoate to 3,4-dihydroxybenzoate using NADPH and oxygen as cofactors. This enzyme plays a role in the degradation of aromatic compounds in some bacteria. The systematic name for this enzyme is 4-hydroxybenzoate,NAD(P)H:oxygen oxidoreductase (3-hydroxylating).

Hypoxia-Inducible Factor 1 (HIF-1) is a transcription factor that plays a crucial role in the body's response to low oxygen levels, also known as hypoxia. HIF-1 is a heterodimeric protein composed of two subunits: an alpha subunit (HIF-1α) and a beta subunit (HIF-1β).

The alpha subunit, HIF-1α, is the regulatory subunit that is subject to oxygen-dependent degradation. Under normal oxygen conditions (normoxia), HIF-1α is constantly produced in the cell but is rapidly degraded by proteasomes due to hydroxylation of specific proline residues by prolyl hydroxylase domain-containing proteins (PHDs). This hydroxylation reaction requires oxygen as a substrate, and under hypoxic conditions, the activity of PHDs is inhibited, leading to the stabilization and accumulation of HIF-1α.

Once stabilized, HIF-1α translocates to the nucleus, where it heterodimerizes with HIF-1β and binds to hypoxia-responsive elements (HREs) in the promoter regions of target genes. This binding results in the activation of gene transcription programs that promote cellular adaptation to low oxygen levels. These adaptive responses include increased erythropoiesis, angiogenesis, glucose metabolism, and pH regulation, among others.

Therefore, HIF-1α is a critical regulator of the body's response to hypoxia, and its dysregulation has been implicated in various pathological conditions, including cancer, cardiovascular disease, and neurodegenerative disorders.

A diet, in medical terms, refers to the planned and regular consumption of food and drinks. It is a balanced selection of nutrient-rich foods that an individual eats on a daily or periodic basis to meet their energy needs and maintain good health. A well-balanced diet typically includes a variety of fruits, vegetables, whole grains, lean proteins, and low-fat dairy products.

A diet may also be prescribed for therapeutic purposes, such as in the management of certain medical conditions like diabetes, hypertension, or obesity. In these cases, a healthcare professional may recommend specific restrictions or modifications to an individual's regular diet to help manage their condition and improve their overall health.

It is important to note that a healthy and balanced diet should be tailored to an individual's age, gender, body size, activity level, and any underlying medical conditions. Consulting with a healthcare professional, such as a registered dietitian or nutritionist, can help ensure that an individual's dietary needs are being met in a safe and effective way.

The term "European Continental Ancestry Group" is a medical/ethnic classification that refers to individuals who trace their genetic ancestry to the continent of Europe. This group includes people from various ethnic backgrounds and nationalities, such as Northern, Southern, Eastern, and Western European descent. It is often used in research and medical settings for population studies or to identify genetic patterns and predispositions to certain diseases that may be more common in specific ancestral groups. However, it's important to note that this classification can oversimplify the complex genetic diversity within and between populations, and should be used with caution.

"Fortified food" is a term used in the context of nutrition and dietary guidelines. It refers to a food product that has had nutrients added to it during manufacturing to enhance its nutritional value. These added nutrients can include vitamins, minerals, proteins, or other beneficial components. The goal of fortifying foods is often to address specific nutrient deficiencies in populations or to improve the overall nutritional quality of a food product. Examples of fortified foods include certain breakfast cereals that have added vitamins and minerals, as well as plant-based milk alternatives that are fortified with calcium and vitamin D to mimic the nutritional profile of cow's milk. It is important to note that while fortified foods can be a valuable source of essential nutrients, they should not replace whole, unprocessed foods in a balanced diet.

Cholestenes are a type of steroid that is characterized by having a double bond between the second and third carbon atoms in the steroid nucleus. They are precursors to cholesterol, which is an essential component of cell membranes and a precursor to various hormones and bile acids. Cholestenes can be found in some foods, but they are also synthesized in the body from other steroids.

Cholestenes are not typically referred to in medical terminology, as the term is more commonly used in biochemistry and organic chemistry. However, abnormal levels of cholestenes or related compounds may be detected in certain medical tests, such as those used to diagnose liver or gallbladder disorders.

Dehydrocholesterols are a type of sterol that is derived from cholesterol through the process of oxidation and the removal of hydrogen atoms. These compounds are important intermediates in the biosynthesis of vitamin D and other steroid hormones in the body.

The most well-known dehydrocholesterol is 7-dehydrocholesterol, which is converted to vitamin D3 (cholecalciferol) through a reaction that involves exposure to ultraviolet B (UVB) radiation from sunlight. This conversion occurs in the skin and is an essential step in the production of vitamin D, which plays a critical role in maintaining healthy bones, teeth, and immune function.

Other dehydrocholesterols include 4-en-3-oxo-5α-cholest-8(14)-en-3β-ol (also known as Δ4-dehydrocholesterol) and 5,7,22,24-tetrahydroxycholesterol, which are also important intermediates in the biosynthesis of steroid hormones.

It is worth noting that dehydrocholesterols can be oxidized further to form other compounds known as oxysterols, which have been implicated in various disease processes such as atherosclerosis and neurodegeneration.

Phosphates, in a medical context, refer to the salts or esters of phosphoric acid. Phosphates play crucial roles in various biological processes within the human body. They are essential components of bones and teeth, where they combine with calcium to form hydroxyapatite crystals. Phosphates also participate in energy transfer reactions as phosphate groups attached to adenosine diphosphate (ADP) and adenosine triphosphate (ATP). Additionally, they contribute to buffer systems that help maintain normal pH levels in the body.

Abnormal levels of phosphates in the blood can indicate certain medical conditions. High phosphate levels (hyperphosphatemia) may be associated with kidney dysfunction, hyperparathyroidism, or excessive intake of phosphate-containing products. Low phosphate levels (hypophosphatemia) might result from malnutrition, vitamin D deficiency, or certain diseases affecting the small intestine or kidneys. Both hypophosphatemia and hyperphosphatemia can have significant impacts on various organ systems and may require medical intervention.

A cohort study is a type of observational study in which a group of individuals who share a common characteristic or exposure are followed up over time to determine the incidence of a specific outcome or outcomes. The cohort, or group, is defined based on the exposure status (e.g., exposed vs. unexposed) and then monitored prospectively to assess for the development of new health events or conditions.

Cohort studies can be either prospective or retrospective in design. In a prospective cohort study, participants are enrolled and followed forward in time from the beginning of the study. In contrast, in a retrospective cohort study, researchers identify a cohort that has already been assembled through medical records, insurance claims, or other sources and then look back in time to assess exposure status and health outcomes.

Cohort studies are useful for establishing causality between an exposure and an outcome because they allow researchers to observe the temporal relationship between the two. They can also provide information on the incidence of a disease or condition in different populations, which can be used to inform public health policy and interventions. However, cohort studies can be expensive and time-consuming to conduct, and they may be subject to bias if participants are not representative of the population or if there is loss to follow-up.

Prevalence, in medical terms, refers to the total number of people in a given population who have a particular disease or condition at a specific point in time, or over a specified period. It is typically expressed as a percentage or a ratio of the number of cases to the size of the population. Prevalence differs from incidence, which measures the number of new cases that develop during a certain period.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Hypoparathyroidism is a medical condition characterized by decreased levels or insufficient function of parathyroid hormone (PTH), which is produced and released by the parathyroid glands. These glands are located in the neck, near the thyroid gland, and play a crucial role in regulating calcium and phosphorus levels in the body.

In hypoparathyroidism, low PTH levels result in decreased absorption of calcium from the gut, increased excretion of calcium through the kidneys, and impaired regulation of bone metabolism. This leads to low serum calcium levels (hypocalcemia) and high serum phosphorus levels (hyperphosphatemia).

Symptoms of hypoparathyroidism can include muscle cramps, spasms, or tetany (involuntary muscle contractions), numbness or tingling sensations in the fingers, toes, and around the mouth, fatigue, weakness, anxiety, cognitive impairment, and in severe cases, seizures. Hypoparathyroidism can be caused by various factors, including surgical removal or damage to the parathyroid glands, autoimmune disorders, radiation therapy, genetic defects, or low magnesium levels. Treatment typically involves calcium and vitamin D supplementation to maintain normal serum calcium levels and alleviate symptoms. In some cases, recombinant PTH (Natpara) may be prescribed as well.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Radioimmunoassay (RIA) is a highly sensitive analytical technique used in clinical and research laboratories to measure concentrations of various substances, such as hormones, vitamins, drugs, or tumor markers, in biological samples like blood, urine, or tissues. The method relies on the specific interaction between an antibody and its corresponding antigen, combined with the use of radioisotopes to quantify the amount of bound antigen.

In a typical RIA procedure, a known quantity of a radiolabeled antigen (also called tracer) is added to a sample containing an unknown concentration of the same unlabeled antigen. The mixture is then incubated with a specific antibody that binds to the antigen. During the incubation period, the antibody forms complexes with both the radiolabeled and unlabeled antigens.

After the incubation, the unbound (free) radiolabeled antigen is separated from the antibody-antigen complexes, usually through a precipitation or separation step involving centrifugation, filtration, or chromatography. The amount of radioactivity in the pellet (containing the antibody-antigen complexes) is then measured using a gamma counter or other suitable radiation detection device.

The concentration of the unlabeled antigen in the sample can be determined by comparing the ratio of bound to free radiolabeled antigen in the sample to a standard curve generated from known concentrations of unlabeled antigen and their corresponding bound/free ratios. The higher the concentration of unlabeled antigen in the sample, the lower the amount of radiolabeled antigen that will bind to the antibody, resulting in a lower bound/free ratio.

Radioimmunoassays offer high sensitivity, specificity, and accuracy, making them valuable tools for detecting and quantifying low levels of various substances in biological samples. However, due to concerns about radiation safety and waste disposal, alternative non-isotopic immunoassay techniques like enzyme-linked immunosorbent assays (ELISAs) have become more popular in recent years.

Adrenergic receptors are a type of G protein-coupled receptor that bind and respond to catecholamines, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). Alpha adrenergic receptors (α-ARs) are a subtype of adrenergic receptors that are classified into two main categories: α1-ARs and α2-ARs.

The activation of α1-ARs leads to the activation of phospholipase C, which results in an increase in intracellular calcium levels and the activation of various signaling pathways that mediate diverse physiological responses such as vasoconstriction, smooth muscle contraction, and cell proliferation.

On the other hand, α2-ARs are primarily located on presynaptic nerve terminals where they function to inhibit the release of neurotransmitters, including norepinephrine. The activation of α2-ARs also leads to the inhibition of adenylyl cyclase and a decrease in intracellular cAMP levels, which can mediate various physiological responses such as sedation, analgesia, and hypotension.

Overall, α-ARs play important roles in regulating various physiological functions, including cardiovascular function, mood, and cognition, and are also involved in the pathophysiology of several diseases, such as hypertension, heart failure, and neurodegenerative disorders.

Nutritional requirements refer to the necessary amount of nutrients, including macronutrients (carbohydrates, proteins, and fats) and micronutrients (vitamins and minerals), that an individual requires to maintain good health, support normal growth and development, and promote optimal bodily functions. These requirements vary based on factors such as age, sex, body size, pregnancy status, and physical activity level. Meeting one's nutritional requirements typically involves consuming a balanced and varied diet, with additional consideration given to any specific dietary restrictions or medical conditions that may influence nutrient needs.

A nutrition survey is not a medical term per se, but it is a research method used in the field of nutrition and public health. Here's a definition:

A nutrition survey is a study design that systematically collects and analyzes data on dietary intake, nutritional status, and related factors from a defined population or sample. It aims to describe the nutritional situation, identify nutritional problems, and monitor trends in a population over time. Nutrition surveys can be cross-sectional, longitudinal, or community-based and may involve various data collection methods such as interviews, questionnaires, observations, physical measurements, and biological samples. The results of nutrition surveys are used to inform nutrition policies, programs, and interventions aimed at improving the nutritional status and health outcomes of populations.

Tandem mass spectrometry (MS/MS) is a technique used to identify and quantify specific molecules, such as proteins or metabolites, within complex mixtures. This method uses two or more sequential mass analyzers to first separate ions based on their mass-to-charge ratio and then further fragment the selected ions into smaller pieces for additional analysis. The fragmentation patterns generated in MS/MS experiments can be used to determine the structure and identity of the original molecule, making it a powerful tool in various fields such as proteomics, metabolomics, and forensic science.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

African Americans are defined as individuals who have ancestry from any of the black racial groups of Africa. This term is often used to describe people living in the United States who have total or partial descent from enslaved African peoples. The term does not refer to a single ethnicity but is a broad term that includes various ethnic groups with diverse cultures, languages, and traditions. It's important to note that some individuals may prefer to identify as Black or of African descent rather than African American, depending on their personal identity and background.

Liquid chromatography (LC) is a type of chromatography technique used to separate, identify, and quantify the components in a mixture. In this method, the sample mixture is dissolved in a liquid solvent (the mobile phase) and then passed through a stationary phase, which can be a solid or a liquid that is held in place by a solid support.

The components of the mixture interact differently with the stationary phase and the mobile phase, causing them to separate as they move through the system. The separated components are then detected and measured using various detection techniques, such as ultraviolet (UV) absorbance or mass spectrometry.

Liquid chromatography is widely used in many areas of science and medicine, including drug development, environmental analysis, food safety testing, and clinical diagnostics. It can be used to separate and analyze a wide range of compounds, from small molecules like drugs and metabolites to large biomolecules like proteins and nucleic acids.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Adrenodoxin is a small iron-sulfur protein that plays a crucial role in the steroidogenesis process within the mitochondria of cells. It functions as an electron carrier in the final steps of steroid hormone biosynthesis, specifically during the conversion of cholesterol to pregnenolone. This conversion is catalyzed by the cytochrome P450 side-chain cleavage enzyme (P450scc), which requires adrenodoxin to donate electrons for its activity. Adrenodoxin itself receives electrons from another protein, adrenodoxin reductase, in a series of redox reactions. Proper adrenodoxin function is essential for the production of various steroid hormones, including cortisol, aldosterone, and sex hormones.

Body Mass Index (BMI) is a measure used to assess whether a person has a healthy weight for their height. It's calculated by dividing a person's weight in kilograms by the square of their height in meters. Here is the medical definition:

Body Mass Index (BMI) = weight(kg) / [height(m)]^2

According to the World Health Organization, BMI categories are defined as follows:

* Less than 18.5: Underweight
* 18.5-24.9: Normal or healthy weight
* 25.0-29.9: Overweight
* 30.0 and above: Obese

It is important to note that while BMI can be a useful tool for identifying weight issues in populations, it does have limitations when applied to individuals. For example, it may not accurately reflect body fat distribution or muscle mass, which can affect health risks associated with excess weight. Therefore, BMI should be used as one of several factors when evaluating an individual's health status and risk for chronic diseases.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Spectrophotometry, Ultraviolet (UV-Vis) is a type of spectrophotometry that measures how much ultraviolet (UV) and visible light is absorbed or transmitted by a sample. It uses a device called a spectrophotometer to measure the intensity of light at different wavelengths as it passes through a sample. The resulting data can be used to determine the concentration of specific components within the sample, identify unknown substances, or evaluate the physical and chemical properties of materials.

UV-Vis spectroscopy is widely used in various fields such as chemistry, biology, pharmaceuticals, and environmental science. It can detect a wide range of substances including organic compounds, metal ions, proteins, nucleic acids, and dyes. The technique is non-destructive, meaning that the sample remains unchanged after the measurement.

In UV-Vis spectroscopy, the sample is placed in a cuvette or other container, and light from a source is directed through it. The light then passes through a monochromator, which separates it into its component wavelengths. The monochromatic light is then directed through the sample, and the intensity of the transmitted or absorbed light is measured by a detector.

The resulting absorption spectrum can provide information about the concentration and identity of the components in the sample. For example, if a compound has a known absorption maximum at a specific wavelength, its concentration can be determined by measuring the absorbance at that wavelength and comparing it to a standard curve.

Overall, UV-Vis spectrophotometry is a versatile and powerful analytical technique for quantitative and qualitative analysis of various samples in different fields.

Photon Absorptiometry is a medical technique used to measure the absorption of photons (light particles) by tissues or materials. In clinical practice, it is often used as a non-invasive method for measuring bone mineral density (BMD). This technique uses a low-energy X-ray beam or gamma ray to penetrate the tissue and then measures the amount of radiation absorbed by the bone. The amount of absorption is related to the density and thickness of the bone, allowing for an assessment of BMD. It can be used to diagnose osteoporosis and monitor treatment response in patients with bone diseases. There are two types of photon absorptiometry: single-photon absorptiometry (SPA) and dual-photon absorptiometry (DPA). SPA uses one energy level, while DPA uses two different energy levels to measure BMD, providing more precise measurements.

I'm not aware of any medical definition for the term "Boston." It is a city in the state of Massachusetts, USA, and is widely known for its cultural institutions, such as Boston Symphony Orchestra, Boston Ballet, and The Museum of Fine Arts. Additionally, it is home to many renowned medical institutions, including Massachusetts General Hospital, Brigham and Women's Hospital, and Dana-Farber Cancer Institute. However, "Boston" does not have a specific meaning or definition in the medical field.

Alkaline phosphatase (ALP) is an enzyme found in various body tissues, including the liver, bile ducts, digestive system, bones, and kidneys. It plays a role in breaking down proteins and minerals, such as phosphate, in the body.

The medical definition of alkaline phosphatase refers to its function as a hydrolase enzyme that removes phosphate groups from molecules at an alkaline pH level. In clinical settings, ALP is often measured through blood tests as a biomarker for various health conditions.

Elevated levels of ALP in the blood may indicate liver or bone diseases, such as hepatitis, cirrhosis, bone fractures, or cancer. Therefore, physicians may order an alkaline phosphatase test to help diagnose and monitor these conditions. However, it is essential to interpret ALP results in conjunction with other diagnostic tests and clinical findings for accurate diagnosis and treatment.

Hypercalcemia is a medical condition characterized by an excess of calcium ( Ca2+ ) in the blood. While the normal range for serum calcium levels is typically between 8.5 to 10.2 mg/dL (milligrams per deciliter) or 2.14 to 2.55 mmol/L (millimoles per liter), hypercalcemia is generally defined as a serum calcium level greater than 10.5 mg/dL or 2.6 mmol/L.

Hypercalcemia can result from various underlying medical disorders, including primary hyperparathyroidism, malignancy (cancer), certain medications, granulomatous diseases, and excessive vitamin D intake or production. Symptoms of hypercalcemia may include fatigue, weakness, confusion, memory loss, depression, constipation, nausea, vomiting, increased thirst, frequent urination, bone pain, and kidney stones. Severe or prolonged hypercalcemia can lead to serious complications such as kidney failure, cardiac arrhythmias, and calcification of soft tissues. Treatment depends on the underlying cause and severity of the condition.

Nutrition policy refers to a set of guidelines, regulations, or laws established by governmental or organizational bodies to promote healthy eating habits and reduce the risk of diet-related chronic diseases. These policies aim to create an environment that supports and encourages individuals to make healthier food choices. Nutrition policies can cover various aspects such as food labeling, nutrition education, food safety, agricultural practices, and access to affordable and nutritious foods. They may also address issues related to marketing and advertising of unhealthy food products, particularly to children. The ultimate goal of nutrition policy is to improve public health by creating a food environment that supports optimal nutrition and well-being.

Osteoporosis is a systemic skeletal disease characterized by low bone mass, deterioration of bone tissue, and disruption of bone architecture, leading to increased risk of fractures, particularly in the spine, wrist, and hip. It mainly affects older people, especially postmenopausal women, due to hormonal changes that reduce bone density. Osteoporosis can also be caused by certain medications, medical conditions, or lifestyle factors such as smoking, alcohol abuse, and a lack of calcium and vitamin D in the diet. The diagnosis is often made using bone mineral density testing, and treatment may include medication to slow bone loss, promote bone formation, and prevent fractures.

Intestinal absorption refers to the process by which the small intestine absorbs water, nutrients, and electrolytes from food into the bloodstream. This is a critical part of the digestive process, allowing the body to utilize the nutrients it needs and eliminate waste products. The inner wall of the small intestine contains tiny finger-like projections called villi, which increase the surface area for absorption. Nutrients are absorbed into the bloodstream through the walls of the capillaries in these villi, and then transported to other parts of the body for use or storage.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

A bone fracture is a medical condition in which there is a partial or complete break in the continuity of a bone due to external or internal forces. Fractures can occur in any bone in the body and can vary in severity from a small crack to a shattered bone. The symptoms of a bone fracture typically include pain, swelling, bruising, deformity, and difficulty moving the affected limb. Treatment for a bone fracture may involve immobilization with a cast or splint, surgery to realign and stabilize the bone, or medication to manage pain and prevent infection. The specific treatment approach will depend on the location, type, and severity of the fracture.

"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.

Postmenopause is a stage in a woman's life that follows 12 months after her last menstrual period (menopause) has occurred. During this stage, the ovaries no longer release eggs and produce lower levels of estrogen and progesterone hormones. The reduced levels of these hormones can lead to various physical changes and symptoms, such as hot flashes, vaginal dryness, and mood changes. Postmenopause is also associated with an increased risk of certain health conditions, including osteoporosis and heart disease. It's important for women in postmenopause to maintain a healthy lifestyle, including regular exercise, a balanced diet, and routine medical check-ups to monitor their overall health and manage any potential risks.

Hypoxia-Inducible Factor (HIF) is a transcription factor that plays a crucial role in the body's response to low oxygen levels (hypoxia). HIF is composed of two subunits: an alpha subunit and a beta subunit. Under normal oxygen conditions, the alpha subunit is constantly being broken down by prolyl hydroxylase domain-containing proteins, which are a type of enzyme known as HIF-Proline Dioxygenases (HIF-PDOs).

HIF-PDOs post-translationally modify the HIF alpha subunit by adding a hydroxyl group to specific proline residues. This modification marks the HIF alpha subunit for degradation by the proteasome, a complex that breaks down unneeded or damaged proteins in the cell. However, under hypoxic conditions, the activity of HIF-PDOs is inhibited, leading to the stabilization and accumulation of HIF alpha subunits.

Once stabilized, HIF alpha subunits dimerize with HIF beta subunits and translocate to the nucleus where they bind to hypoxia response elements (HREs) in the DNA. This binding induces the expression of genes involved in various cellular responses to hypoxia, such as angiogenesis, metabolic reprogramming, and erythropoiesis. Therefore, HIF-PDOs play a critical role in regulating the body's response to low oxygen levels by controlling the stability and activity of HIF.

The double-blind method is a study design commonly used in research, including clinical trials, to minimize bias and ensure the objectivity of results. In this approach, both the participants and the researchers are unaware of which group the participants are assigned to, whether it be the experimental group or the control group. This means that neither the participants nor the researchers know who is receiving a particular treatment or placebo, thus reducing the potential for bias in the evaluation of outcomes. The assignment of participants to groups is typically done by a third party not involved in the study, and the codes are only revealed after all data have been collected and analyzed.

I'm sorry for any confusion, but "United States" is a geopolitical entity, specifically the name of the country consisting of 50 states, and it is not a medical term or concept. Therefore, I can't provide a medical definition for it. If you have any questions related to health, medicine, or biology, I would be happy to try to help answer those!

Phenylketonurias (PKU) is a genetic disorder characterized by the body's inability to properly metabolize the amino acid phenylalanine, due to a deficiency of the enzyme phenylalanine hydroxylase. This results in a buildup of phenylalanine in the blood and other tissues, which can cause serious neurological problems if left untreated.

The condition is typically detected through newborn screening and can be managed through a strict diet that limits the intake of phenylalanine. If left untreated, PKU can lead to intellectual disability, seizures, behavioral problems, and other serious health issues. In some cases, medication or a liver transplant may also be necessary to manage the condition.

I'm sorry for any confusion, but "Nebraska" is a state in the central United States and not a medical term. If you have any medical questions or terms you would like defined, I'd be happy to help with those!

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

Secondary hyperparathyroidism is a condition characterized by an overproduction of parathyroid hormone (PTH) from the parathyroid glands due to hypocalcemia (low levels of calcium in the blood). This condition is usually a result of chronic kidney disease, where the kidneys fail to convert vitamin D into its active form, leading to decreased absorption of calcium in the intestines. The body responds by increasing PTH production to maintain normal calcium levels, but over time, this results in high PTH levels and associated complications such as bone disease, kidney stones, and cardiovascular calcification.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

Gene expression regulation, enzymologic refers to the biochemical processes and mechanisms that control the transcription and translation of specific genes into functional proteins or enzymes. This regulation is achieved through various enzymatic activities that can either activate or repress gene expression at different levels, such as chromatin remodeling, transcription factor activation, mRNA processing, and protein degradation.

Enzymologic regulation of gene expression involves the action of specific enzymes that catalyze chemical reactions involved in these processes. For example, histone-modifying enzymes can alter the structure of chromatin to make genes more or less accessible for transcription, while RNA polymerase and its associated factors are responsible for transcribing DNA into mRNA. Additionally, various enzymes are involved in post-transcriptional modifications of mRNA, such as splicing, capping, and tailing, which can affect the stability and translation of the transcript.

Overall, the enzymologic regulation of gene expression is a complex and dynamic process that allows cells to respond to changes in their environment and maintain proper physiological function.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Logistic models, specifically logistic regression models, are a type of statistical analysis used in medical and epidemiological research to identify the relationship between the risk of a certain health outcome or disease (dependent variable) and one or more independent variables, such as demographic factors, exposure variables, or other clinical measurements.

In contrast to linear regression models, logistic regression models are used when the dependent variable is binary or dichotomous in nature, meaning it can only take on two values, such as "disease present" or "disease absent." The model uses a logistic function to estimate the probability of the outcome based on the independent variables.

Logistic regression models are useful for identifying risk factors and estimating the strength of associations between exposures and health outcomes, adjusting for potential confounders, and predicting the probability of an outcome given certain values of the independent variables. They can also be used to develop clinical prediction rules or scores that can aid in decision-making and patient care.

Hyperparathyroidism is a condition in which the parathyroid glands produce excessive amounts of parathyroid hormone (PTH). There are four small parathyroid glands located in the neck, near or within the thyroid gland. They release PTH into the bloodstream to help regulate the levels of calcium and phosphorus in the body.

In hyperparathyroidism, overproduction of PTH can lead to an imbalance in these minerals, causing high blood calcium levels (hypercalcemia) and low phosphate levels (hypophosphatemia). This can result in various symptoms such as fatigue, weakness, bone pain, kidney stones, and cognitive issues.

There are two types of hyperparathyroidism: primary and secondary. Primary hyperparathyroidism occurs when there is a problem with one or more of the parathyroid glands, causing them to become overactive and produce too much PTH. Secondary hyperparathyroidism develops as a response to low calcium levels in the body due to conditions like vitamin D deficiency, chronic kidney disease, or malabsorption syndromes.

Treatment for hyperparathyroidism depends on the underlying cause and severity of symptoms. In primary hyperparathyroidism, surgery to remove the overactive parathyroid gland(s) is often recommended. For secondary hyperparathyroidism, treating the underlying condition and managing calcium levels with medications or dietary changes may be sufficient.

Hypocalcemia is a medical condition characterized by an abnormally low level of calcium in the blood. Calcium is a vital mineral that plays a crucial role in various bodily functions, including muscle contraction, nerve impulse transmission, and bone formation. Normal calcium levels in the blood usually range from 8.5 to 10.2 milligrams per deciliter (mg/dL). Hypocalcemia is typically defined as a serum calcium level below 8.5 mg/dL or, when adjusted for albumin (a protein that binds to calcium), below 8.4 mg/dL (ionized calcium).

Hypocalcemia can result from several factors, such as vitamin D deficiency, hypoparathyroidism (underactive parathyroid glands), kidney dysfunction, certain medications, and severe magnesium deficiency. Symptoms of hypocalcemia may include numbness or tingling in the fingers, toes, or lips; muscle cramps or spasms; seizures; and, in severe cases, cognitive impairment or cardiac arrhythmias. Treatment typically involves correcting the underlying cause and administering calcium and vitamin D supplements to restore normal calcium levels in the blood.

Multivariate analysis is a statistical method used to examine the relationship between multiple independent variables and a dependent variable. It allows for the simultaneous examination of the effects of two or more independent variables on an outcome, while controlling for the effects of other variables in the model. This technique can be used to identify patterns, associations, and interactions among multiple variables, and is commonly used in medical research to understand complex health outcomes and disease processes. Examples of multivariate analysis methods include multiple regression, factor analysis, cluster analysis, and discriminant analysis.

Medically, "milk" is not defined. However, it is important to note that human babies are fed with breast milk, which is the secretion from the mammary glands of humans. It is rich in nutrients like proteins, fats, carbohydrates (lactose), vitamins and minerals that are essential for growth and development.

Other mammals also produce milk to feed their young. These include cows, goats, and sheep, among others. Their milk is often consumed by humans as a source of nutrition, especially in dairy products. However, the composition of these milks can vary significantly from human breast milk.

Ferredoxin-NADP Reductase (FDNR) is an enzyme that catalyzes the electron transfer from ferredoxin to NADP+, reducing it to NADPH. This reaction plays a crucial role in several metabolic pathways, including photosynthesis and nitrogen fixation.

In photosynthesis, FDNR is located in the stroma of chloroplasts and receives electrons from ferredoxin, which is reduced by photosystem I. The enzyme then transfers these electrons to NADP+, generating NADPH, which is used in the Calvin cycle for carbon fixation.

In nitrogen fixation, FDNR is found in the nitrogen-fixing bacteria and receives electrons from ferredoxin, which is reduced by nitrogenase. The enzyme then transfers these electrons to NADP+, generating NADPH, which is used in the reduction of nitrogen gas (N2) to ammonia (NH3).

FDNR is a flavoprotein that contains a FAD cofactor and an iron-sulfur cluster. The enzyme catalyzes the electron transfer through a series of conformational changes that bring ferredoxin and NADP+ in close proximity, allowing for efficient electron transfer.

Osteocalcin is a protein that is produced by osteoblasts, which are the cells responsible for bone formation. It is one of the most abundant non-collagenous proteins found in bones and plays a crucial role in the regulation of bone metabolism. Osteocalcin contains a high affinity for calcium ions, making it essential for the mineralization of the bone matrix.

Once synthesized, osteocalcin is secreted into the extracellular matrix, where it binds to hydroxyapatite crystals, helping to regulate their growth and contributing to the overall strength and integrity of the bones. Osteocalcin also has been found to play a role in other physiological processes outside of bone metabolism, such as modulating insulin sensitivity, energy metabolism, and male fertility.

In summary, osteocalcin is a protein produced by osteoblasts that plays a critical role in bone formation, mineralization, and turnover, and has been implicated in various other physiological processes.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

I'm sorry for any confusion, but "Mongolia" is not a medical term. It is the name of a country located in Central Asia. If you have any questions about medical conditions or terminology, I would be happy to help clarify those for you.

Aniline hydroxylase is an enzyme that is involved in the metabolism of aromatic compounds, including aniline and other related substances. The enzyme catalyzes the addition of a hydroxyl group (-OH) to the aromatic ring of these compounds, which helps to make them more water-soluble and facilitates their excretion from the body.

Aniline hydroxylase is found in various tissues throughout the body, including the liver, lung, and kidney. It is a member of the cytochrome P450 family of enzymes, which are known for their role in drug metabolism and other xenobiotic-metabolizing reactions.

It's important to note that exposure to aniline and its derivatives can be harmful and may cause various health effects, including damage to the liver and other organs. Therefore, it is essential to handle these substances with care and follow appropriate safety precautions.

The odds ratio (OR) is a statistical measure used in epidemiology and research to estimate the association between an exposure and an outcome. It represents the odds that an event will occur in one group versus the odds that it will occur in another group, assuming that all other factors are held constant.

In medical research, the odds ratio is often used to quantify the strength of the relationship between a risk factor (exposure) and a disease outcome. An OR of 1 indicates no association between the exposure and the outcome, while an OR greater than 1 suggests that there is a positive association between the two. Conversely, an OR less than 1 implies a negative association.

It's important to note that the odds ratio is not the same as the relative risk (RR), which compares the incidence rates of an outcome in two groups. While the OR can approximate the RR when the outcome is rare, they are not interchangeable and can lead to different conclusions about the association between an exposure and an outcome.

The Cholesterol Side-Chain Cleavage Enzyme, also known as Steroidogenic Acute Regulatory (StAR) protein or P450scc, is a complex enzymatic system that plays a crucial role in the production of steroid hormones. It is located in the inner mitochondrial membrane of steroid-producing cells, such as those found in the adrenal glands, gonads, and placenta.

The Cholesterol Side-Chain Cleavage Enzyme is responsible for converting cholesterol into pregnenolone, which is the first step in the biosynthesis of all steroid hormones, including cortisol, aldosterone, sex hormones, and vitamin D. This enzymatic complex consists of two components: a flavoprotein called NADPH-cytochrome P450 oxidoreductase, which provides electrons for the reaction, and a cytochrome P450 protein called CYP11A1, which catalyzes the actual cleavage of the cholesterol side chain.

Defects in the Cholesterol Side-Chain Cleavage Enzyme can lead to various genetic disorders, such as congenital lipoid adrenal hyperplasia (CLAH), a rare autosomal recessive disorder characterized by impaired steroidogenesis and accumulation of cholesteryl esters in the adrenal glands and gonads.

The alpha7 nicotinic acetylcholine receptor (α7nAChR) is a type of cholinergic receptor found in the nervous system that is activated by the neurotransmitter acetylcholine. It is a ligand-gated ion channel that is widely distributed throughout the central and peripheral nervous systems, including in the hippocampus, cortex, thalamus, and autonomic ganglia.

The α7nAChR is composed of five subunits arranged around a central pore, and it has a high permeability to calcium ions (Ca2+). When acetylcholine binds to the receptor, it triggers a conformational change that opens the ion channel, allowing Ca2+ to flow into the cell. This influx of Ca2+ can activate various intracellular signaling pathways and have excitatory or inhibitory effects on neuronal activity, depending on the location and function of the receptor.

The α7nAChR has been implicated in a variety of physiological processes, including learning and memory, attention, sensory perception, and motor control. It has also been studied as a potential therapeutic target for various neurological and psychiatric disorders, such as Alzheimer's disease, schizophrenia, and pain.

Primary hyperparathyroidism is a medical condition characterized by excessive secretion of parathyroid hormone (PTH) from one or more of the parathyroid glands in the neck. These glands are normally responsible for regulating calcium levels in the body by releasing PTH, which helps to maintain an appropriate balance of calcium and phosphate in the bloodstream.

In primary hyperparathyroidism, the parathyroid gland(s) become overactive and produce too much PTH, leading to elevated calcium levels (hypercalcemia) in the blood. This can result in a variety of symptoms, such as fatigue, weakness, bone pain, kidney stones, and cognitive impairment, although some individuals may not experience any symptoms at all.

The most common cause of primary hyperparathyroidism is a benign tumor called an adenoma that develops in one or more of the parathyroid glands. In rare cases, primary hyperparathyroidism can be caused by cancer of the parathyroid gland(s) or by enlargement of all four glands (four-gland hyperplasia). Treatment typically involves surgical removal of the affected parathyroid gland(s), which is usually curative.

A hip fracture is a medical condition referring to a break in the upper part of the femur (thigh) bone, which forms the hip joint. The majority of hip fractures occur due to falls or direct trauma to the area. They are more common in older adults, particularly those with osteoporosis, a condition that weakens bones and makes them more prone to breaking. Hip fractures can significantly impact mobility and quality of life, often requiring surgical intervention and rehabilitation.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

D3+1-alpha-Hydroxylase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Human CYP27B1 genome location ... VD 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes ... Lagishetty V, Chun RF, Liu NQ, Lisse TS, Adams JS, Hewison M (Jul 2010). "1alpha-hydroxylase and innate immune responses to 25- ... VD 1A hydroxylase) also known as calcidiol 1-monooxygenase or cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a ...
Vitamin D3 Story. Archived 22 January 2012 at the Wayback Machine Retrieved 8 April 2012. "Vitashine Vegan Vitamin D3 ... sigmatropic shift of previtamin D3 to vitamin D3: synthesis and study of pentadeuterio derivatives". Journal of Organic ... Cholecalciferol, also known as vitamin D3 and colecalciferol, is a type of vitamin D that is made by the skin when exposed to ... Incidence of vitamin D3 toxicosis in animals is relatively less than that of anticoagulant and bromethalin toxicosis. Relay ...
It has also been identified as vitamin D3 24-hydroxylase.(EC 1.14.15.16) CYP24A1 is an enzyme expressed in the mitochondrion of ... "Calcitriol regulates the expression of the genes encoding the three key vitamin D3 hydroxylases and the drug-metabolizing ... Hahn CN, Baker E, Laslo P, May BK, Omdahl JL, Sutherland GR (1993). "Localization of the human vitamin D 24-hydroxylase gene ( ... the vitamin D 24-hydroxylase gene, in a patient with severe infantile hypercalcemia". The Journal of Clinical Endocrinology and ...
... 1 receptors, activated by the 34 N-terminal amino acids of PTH, are present at high levels on the cells of ... 128 (1): 9-13. doi:10.1016/j.cell.2006.12.018. PMID 17218247. S2CID 18872015. White JK, Gerdin AK, Karp NA, Ryder E, Buljan M, ... hPTH-(1-84) crystallizes as a slightly bent, long, helical dimer. The extended helical conformation of hPTH-(1-84) is the ... ISBN 1-4160-2328-3. Guyton A (1976). ''Medical Physiology''. p.1062; New York, Saunders and Co. Barrett KE, Barman SM, Boitano ...
... vitamin D3) into calcifediol (25-hydroxyvitamin D3, also known as calcidiol), the major circulatory form of the vitamin. CYP2R1 ... the active form of vitamin D3 which binds to the vitamin D receptor (VDR) and mediates most of the physiological hormonal ... These conditions are known to be linked to low blood levels of 25(OH)D, where even large doses of vitamin D may not produce an ... 409 (1): 18-24. doi:10.1016/S0003-9861(02)00553-2. PMID 12464240. "Office of Dietary Supplements - Vitamin D". ods.od.nih.gov. ...
This occurs through the action of the CYP24A1 24-hydroxylase. Calcitroic acid is more soluble in water and is excreted in bile ... a form of vitamin D3 metabolically active in the intestine". Proceedings of the National Academy of Sciences of the United ... vitamin D3), rather than the product of hydroxylations of ergocalciferol (vitamin D2). 1α,25-Dihydroxyergocalciferol ( ... 1alpha hydroxylase gene by prolactin". Endocrinology. 151 (7): 2974-2984. doi:10.1210/en.2010-0033. PMC 2903940. PMID 20463051 ...
Vitamin D3 (cholecalciferol) is the preferred form since it is more readily absorbed than vitamin D2. Most dermatologists ... Rickets is often a result of vitamin D3 deficiency. The correlation between human skin color and latitude is thought to be the ... 111 (4 Pt 1): 908-910. doi:10.1542/peds.111.4.908. PMID 12671133. Chibuzor MT, Graham-Kalio D, Osaji JO, Meremikwu MM, et al. ( ... 1 (2): 25. doi:10.4103/jmsr.jmsr_28_17. S2CID 79825711. Keller KA, Barnes PD (November 2008). "Rickets vs. abuse: a national ...
Vitamin D3 can alternatively be hydroxylated to calcifediol by sterol 27-hydroxylase (CYP27A1), but vitamin D2 cannot. ... the product is previtamin D3. Second, previtamin D3 spontaneously isomerizes to vitamin D3 (cholecalciferol) in an antarafacial ... The activity of calcifediol and calcitriol can be reduced by hydroxylation at position 24 by vitamin D3 24-hydroxylase, forming ... The conversion of previtamin D3 to vitamin D3 in the skin is about 10 times faster than in an organic solvent. The conversion ...
... steroid 11-beta-hydroxylase MeSH D08.244.453.915.730 - steroid 12-alpha-hydroxylase MeSH D08.244.453.915.737 - steroid 16-alpha ... steroid 12-alpha-hydroxylase MeSH D08.811.682.690.708.170.915.737 - steroid 16-alpha-hydroxylase MeSH D08.811.682.690.708.170. ... steroid 12-alpha-hydroxylase MeSH D08.811.682.690.708.783.737 - steroid 16-alpha-hydroxylase MeSH D08.811.682.690.708.783.745 ... hydroxylase MeSH D08.244.453.915.748 - steroid 17-alpha-hydroxylase MeSH D08.244.453.915.760 - steroid 21-hydroxylase MeSH ...
... steroid 12-alpha-hydroxylase MeSH D12.776.422.220.453.915.737 - steroid 16-alpha-hydroxylase MeSH D12.776.422.220.453.915.748 ... steroid 17-alpha-hydroxylase MeSH D12.776.422.220.453.915.760 - steroid 21-hydroxylase MeSH D12.776.422.512.380.440 - ... cholesterol 7 alpha-hydroxylase MeSH D12.776.422.220.453.915.212 - cholesterol side-chain cleavage enzyme MeSH D12.776.422.220. ... alpha-crystallin a chain MeSH D12.776.306.366.100.300 - alpha-crystallin b chain MeSH D12.776.306.366.300.100 - beta-crystallin ...
D3), is a form of vitamin D produced in the liver by hydroxylation of vitamin D3 (cholecalciferol) by the enzyme vitamin D 25- ... hydroxylase. Calcifediol can be further hydroxylated by the enzyme 25(OH)D-1α-hydroxylase, primarily in the kidney, to form ... Kimball SM, Ursell MR, O'Connor P, Vieth R (September 2007). "Safety of vitamin D3 in adults with multiple sclerosis". The ... PMID 22645788., which cites Arya SC, Agarwal N (May 2012). "The measurement of vitamin D3 requires maintaining quality control ...
"Evidence for the activation of 1alpha-hydroxyvitamin D2 by 25-hydroxyvitamin D-24-hydroxylase: delineation of pathways ... Vitamin+D3+24-hydroxylase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology (Articles ... Vitamin D3 24-hydroxylase (EC 1.14.15.16, CYP24A1) is an enzyme with systematic name calcitriol,NADPH:oxygen oxidoreductase (24 ... H2O Vitamin D3 24-hydroxylase is a heme-thiolate enzyme (P-450). Masuda S, Strugnell SA, Knutson JC, St-Arnaud R, Jones G ( ...
Transforming growth factor alpha. Cholera toxin. Within the epidermis keratinocytes are associated with other cell types such ... Vitamin D3 (cholecalciferol) regulates keratinocyte proliferation and differentiation mostly by modulating calcium ... Hydroxylase and Mutations Causing Vitamin D-Dependent Rickets Type 1". Molecular Endocrinology. 11 (13): 1961-70. CiteSeerX ... The roles of transforming growth factor-alpha and epidermal growth factor". Cell. 50 (7): 1131-7. doi:10.1016/0092-8674(87) ...
Hanukoglu I (2015). "Proteopedia: Rossmann fold: A beta-alpha-beta fold at dinucleotide binding sites". Biochem Mol Biol Educ. ... 157 (1): 27-31. doi:10.1111/j.1432-1033.1986.tb09633.x. PMID 3011431. Hanukoglu I, Suh BS, Himmelhoch S, Amsterdam A (October ... 200 (1-2): 149-56. doi:10.1016/S0378-1119(97)00411-3. PMID 9373149. Müller JJ, Lapko A, Bourenkov G, Ruckpaul K, Heinemann U ( ... 138 (1-2): 171-4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298. Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano ...
89 (1): 7-14. doi:10.1038/labinvest.2008.114. PMC 4292907. PMID 19029978. Silve C, Beck L (June 2002). "Is FGF23 the long ... 285 (1): E1-9. doi:10.1152/ajpendo.00016.2003. PMID 12791601. Fukagawa M, Nii-Kono T, Kazama JJ (July 2005). "Role of ... 82 (1): 485-506. doi:10.1146/annurev-physiol-021119-034332. PMC 8274561. PMID 32040934. Cha SK, Ortega B, Kurosu H, Rosenblatt ... 373 (Pt 1): 271-9. doi:10.1042/BJ20030287. PMC 1223479. PMID 12678920. This article incorporates text from the United States ...
D3+1-alpha-Hydroxylase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Human CYP27B1 genome location ... VD 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes ... Lagishetty V, Chun RF, Liu NQ, Lisse TS, Adams JS, Hewison M (Jul 2010). "1alpha-hydroxylase and innate immune responses to 25- ... VD 1A hydroxylase) also known as calcidiol 1-monooxygenase or cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a ...
Cytochrome P450C1 alpha. *Cytochrome P450VD1-alpha. *EC 1.14.13.13. *EC 1.14.15.18 ... cytochrome P450, family 27, subfamily B, polypeptide 1. *cytochrome P450, subfamily XXVIIB (25-hydroxyvitamin D-1-alpha- ... hydroxylase). * ... Review with an image -- $25/€18/£15/$25 CAD/¥150 Yuan/¥2500 Yen ...
Callejas-Rubio JL, Lopez-Perez L, Ortego-Centeno N. Tumor necrosis factor-alpha inhibitor treatment for sarcoidosis. Ther Clin ... Correlation of CD4:CD8 ratio and tumour necrosis factor (TNF)alpha levels in induced sputum with bronchoalveolar lavage fluid ... Treatment of complicated sarcoidosis with infliximab anti-tumor necrosis factor-alpha therapy. Ann Intern Med. 2001 Jul 3. 135( ... 1, 52] Considering its prognostic significance, the heart rate recovery index may have clinical use in identifying patients ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
CHOLESTEROL 7 ALPHA-MONOOXYGENASE. Cholesterol 7-alpha-Hydroxylase. CHOLESTEROL MONOOXYGENASE (SIDE-CHAIN-CLEAVING). ... 25-HYDROXYCHOLECALCIFEROL 1-HYDROXYLASE. 25-Hydroxyvitamin D3 1-alpha-Hydroxylase. CYTOCHROME P-450 CYP11B2. Aldosterone ... Steroid 12-alpha-Hydroxylase. STEROID 17 ALPHA-MONOOXYGENASE. Steroid 17-alpha-Hydroxylase. ...
Rynecki, N. D., Coban, D., Gantz, O., Gupta, R., Ayyaswami, V., Prabhu, A. V., Ruskin, J., Lin, S. S. & Beebe, K. S., Sep 1 ... Streit, A., Watson, B. C., Granata, J. D., Philbin, T. M., Lin, H. N., OConnor, J. P. & Lin, S., Sep 1 2016, In: Foot and ... Lin, S. S., Solan, M., Cooper, M. T. & Cooper, M. T., Feb 1 2017, In: Foot & ankle specialist. 10, 1, p. 43-45 3 p.. Research ... Schussler, S. D., Uske, K., Marwah, P., Kemp, F. W., Bogden, J. D., Lin, S. S. & Livingston Arinzeh, T., Jul 1 2017, In: AAPS ...
Callejas-Rubio JL, Lopez-Perez L, Ortego-Centeno N. Tumor necrosis factor-alpha inhibitor treatment for sarcoidosis. Ther Clin ... Correlation of CD4:CD8 ratio and tumour necrosis factor (TNF)alpha levels in induced sputum with bronchoalveolar lavage fluid ... Treatment of complicated sarcoidosis with infliximab anti-tumor necrosis factor-alpha therapy. Ann Intern Med. 2001 Jul 3. 135( ... Table 1. Results of Multicenter Trial Sponsored by the British Thoracic Society (Open Table in a new window) ...
The biologically active form of vitamin D is 1,25-dihydroxyvitamin D (1,25(OH)2 D). Measuring serum levels of 1,25(OH)2 D ... should be considered upon suspicion of deficiency or excess of 1,25(OH)2 D. ... alpha Hydroxylase in Human Monocytic THP1 Cells: Mechanisms of Interferon-Mediated Induction. J Clin Endocrinol Metab. 2006 Sep ... Vitamin D3 1,25-Dihydroxyvitamin D Updated: Feb 07, 2014 * Author: Ha Cam Thuy Nguyen, MD; Chief Editor: Eric B Staros, MD more ...
2015 Oct 1;196:108-14.. 9. Zhang X, Li Y, Del Gobbo LC, Rosanoff A, Wang J, Zhang W, Song Y. Effects of magnesium ... 2018 Mar 1;118(3):181-89.. 19. Jahnen-Dechent W, Ketteler M. Magnesium basics. Clin Kidney J. 2012 Feb;5(Suppl 1):i3-i14.. 20. ... 1992 Mar;5(1):5-14.. 16. Touyz RM. Magnesium in clinical medicine. Front Biosci. 2004;9:1278-1293.. 17. Tam M, Gómez S, ... 25. Welsh J. Function of the vitamin D endocrine system in mammary gland and breast cancer. Mol Cell Endocrinol. 2017;453:88-95 ...
Steroid 12-alpha-Hydroxylase D8.244.453.900.500 D8.811.682.690.708.170.900.500 D12.776.422.220.453.900.500 Steroid 17-alpha- ... Vitamin D3 24-Hydroxylase D8.244.453.978 D8.244.453.496.500 D8.811.682.690.708.170.957 D8.811.682.690.708.170.469.500 D12.776. ... Cholesterol 7-alpha-Hydroxylase D8.244.453.890.500 D8.811.682.690.708.170.890.500 D12.776.422.220.453.890.500 Cholesterol ... alpha-Defensins D12.644.276.87.44 D12.776.467.87.125 D23.529.87.48 alpha-Endorphin D12.776.641.650.405.935.119 D12.776.631.650. ...
Peter MC DeBlieux, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine ... FGF23 additionally increases the expression of 24-hydroxylase, leading to inactivation of active 1,25 dihydroxyvitamin D3. The ... FGF23 additionally increases the expression of 24-hydroxylase, leading to inactivation of active 1,25 dihydroxyvitamin D3. The ... As levels of 1,25 vitamin D fall during the development of progressive chronic kidney disease, levels of FGF23 rise inversely. ...
Vitamin D3 can be made by exposure of the skin to UV, or by exposing milk directly to UV (one commercial method). Vitamin D3 is ... Vitamin D increases expression of the tyrosine hydroxylase gene in adrenal medullary cells. It also is involved in the ... the product is previtamin D3. Second, previtamin D3 spontaneously isomerizes to vitamin D3 (cholecalciferol) in an antarafacial ... Vitamin D3 (cholecalciferol) is produced photochemically in the skin from 7-dehydrocholesterol. The precursor of vitamin D3, 7- ...
Addition of 1 alpha 25(OH)(2)D(3) to moDC cultures at different time points indicates that its inhibitory effects are greater ... Addition of 1 alpha 25(OH)(2)D(3) to moDC cultures at different time points indicates that its inhibitory effects are greater ... Addition of 1 alpha 25(OH)(2)D(3) to moDC cultures at different time points indicates that its inhibitory effects are greater ... Addition of 1 alpha 25(OH)(2)D(3) to moDC cultures at different time points indicates that its inhibitory effects are greater ...
The CYP27B1 gene provides instructions for making an enzyme called 1-alpha-hydroxylase (1α-hydroxylase). Learn about this gene ... cytochrome P450VD1-alpha. *P450c1. *VD3 1A hydroxylase. Additional Information & Resources. Tests Listed in the Genetic Testing ... Vitamin D 1alpha-hydroxylase gene mutations in patients with 1alpha-hydroxylase deficiency. J Clin Endocrinol Metab. 2007 Aug; ... 2015 Jul 1;10(7):e0131376. doi: 10.1371/journal.pone.0131376. eCollection 2015. Citation on PubMed or Free article on PubMed ...
"Cholesterol 7-alpha-Hydroxylase" by people in UAMS Profiles by year, and whether "Cholesterol 7-alpha-Hydroxylase" was a major ... "Cholesterol 7-alpha-Hydroxylase" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ( ... Below are the most recent publications written about "Cholesterol 7-alpha-Hydroxylase" by people in Profiles over the past ten ... Below are MeSH descriptors whose meaning is more general than "Cholesterol 7-alpha-Hydroxylase". ...
Steroid 12-alpha-Hydroxylase. *Steroid 16-alpha-Hydroxylase. *Steroid 17-alpha-Hydroxylase ...
Steroid 12-alpha-Hydroxylase. *Steroid 16-alpha-Hydroxylase. *Steroid 17-alpha-Hydroxylase ... "Steroid 11-beta-Hydroxylase" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ( ... This graph shows the total number of publications written about "Steroid 11-beta-Hydroxylase" by people in this website by year ... Below are the most recent publications written about "Steroid 11-beta-Hydroxylase" by people in Profiles. ...
Vitamin D3 24-Hydroxylase Medicine & Life Sciences 79% * 25-Hydroxyvitamin D3 1-alpha-Hydroxylase Medicine & Life Sciences 79% ... Given that 25(OH)D is hydroxylated by CYP27B1 to the bioactive 1,25(OH)2D form, and CYP24A1 catabolizes both 25(OH)D and 1,25( ... Given that 25(OH)D is hydroxylated by CYP27B1 to the bioactive 1,25(OH)2D form, and CYP24A1 catabolizes both 25(OH)D and 1,25( ... Given that 25(OH)D is hydroxylated by CYP27B1 to the bioactive 1,25(OH)2D form, and CYP24A1 catabolizes both 25(OH)D and 1,25( ...
Ultraviolet-B (UVB) light breaks the B ring of 7-dehydrocholesterols chemical structure to form what is called pre-D3. Pre-D3 ... From here, vitamin D3 is transported to your liver, where it is combined with the 25-hydroxylase enzyme to form calcidiol (25- ... Between the ages of 20 and 70, your skin loses about 75% of its ability to produce vitamin D3-the necessary precursor to ... Between the ages of 20 and 70, your skin loses about 75% of its ability to produce vitamin D3-the metabolic precursor to ...
Ovalbumin specific IgE antibody and inflammatory cytokines: IL-4, IL-5, IL-13 and TNF-alpha were measured in serum. Lung and ... 1. Atypical response to bacterial coinfection and persistent neutrophilic bronchoalveolar inflammation distinguish critical ... To assess the upper respiratory tract in response to exercise, we collected nasal lavage fluid (NALF) from human subjects (1) ... The molecular mechanisms governing orderly shutdown and retraction of CD4+ type 1 helper T (TH1) cell responses remain poorly ...
  • 25-Hydroxyvitamin D 1-alpha-hydroxylase (VD 1A hydroxylase) also known as calcidiol 1-monooxygenase or cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the CYP27B1 gene. (wikipedia.org)
  • The CYP27B1 gene provides instructions for making an enzyme called 1-alpha-hydroxylase (1α-hydroxylase). (medlineplus.gov)
  • At least 70 mutations in the CYP27B1 gene have been found to cause vitamin D-dependent rickets type 1A (VDDR1A), also known as vitamin D 1α-hydroxylase deficiency. (medlineplus.gov)
  • The CYP27B1 gene mutations that cause this condition reduce or eliminate the function of 1α-hydroxylase. (medlineplus.gov)
  • Given that 25(OH)D is hydroxylated by CYP27B1 to the bioactive 1,25(OH) 2 D form, and CYP24A1 catabolizes both 25(OH)D and 1,25(OH) 2 D to the inactive metabolites, respectively, our data indicate that the elevated activity of CYP24A1 in the placenta may play a key role in the development of vitamin D deficiency in GDM. (korea.ac.kr)
  • The enzyme catalyzes the hydroxylation of calcifediol to calcitriol (the bioactive form of Vitamin D): calcidiol + 2 reduced adrenodoxin + 2 H+ + O2 ⇌ calcitriol + 2 oxidized adrenodoxin + H2O The enzyme is also able to oxidize ercalcidiol (25-OH D2) to ercalcitriol, secalciferol to calcitetrol, and 25-hydroxy-24-oxocalciol to (1S)-1,25-dihydroxy-24-oxocalciol. (wikipedia.org)
  • This enzyme carries out the second of two reactions to convert vitamin D to its active form, 1,25-dihydroxyvitamin D 3 , also known as calcitriol. (medlineplus.gov)
  • It travels to the kidney where it's converted into calcitriol ( 1,25-(OH)2 vitamin D3 ), the bioactive form, by an enzyme called 1-alpha-hydroxylase and under the influence of parathyroid hormone. (set-db.com)
  • Plasma 1,25-dihydroxyvitamin D (1,25(OH) 2 D) is tightly controlled by plasma parathyroid hormone (PTH), serum calcium, serum phosphate, and fibroblast-like growth factor 23 (FGF-23). (medscape.com)
  • In this follow up case control study, BMD as well as serum levels of FGF23, calcium, phosphorus, alkaline phosphatase, creatinine, parathyroid hormone, 25 hydroxy vitamin D 3 and 1, 25 dihydroxy vitamin D 3 were measured in 47 children with IBD during flare and reassessed in the next remission. (biomedcentral.com)
  • Depression is associated with decreased 25-hydroxyvitamin D and increased parathyroid hormone levels in older adults. (ijbcp.com)
  • There has been some debate concerning the optimal range of 25(OH)D. Serum levels of 25(OH) D below 50 nmol/L are associated with an increase in serum parathyroid hormone (PTH) levels [ 9 ] and a decrease in physical performance in older individuals [ 10 ]. (biomedcentral.com)
  • In the liver, cholecalciferol (vitamin D3) is converted to calcidiol, which is also known as calcifediol (INN), 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 - abbreviated 25(OH)D3. (truthwiki.org)
  • in the liver, vitamin D3 is hydroxylated at the 25' position to produce 25-hydroxycholecalciferol (calcidiol). (gpnotebook.com)
  • Treatment with 25(OH)D can normalize 1,25(OH) 2 D concentrations in patients with vitamin D deficiency. (medscape.com)
  • Consistent with this finding is the observation that the development and function of moDCs is inhibited at physiological concentrations of the inactive metabolite 25(OH)D(3). (birmingham.ac.uk)
  • Evidence supports wider beneficial effects of vitamin D but to achieve such, maintaining serum 25 dihydroxyvitamin D [25(OH)2D] concentrations of more than 30 ng/mL is necessary. (vitamindwiki.com)
  • The individual and the population health can be markedly improved by maintaining serum 25(OH)D concentrations of greater than 30 ng /mL (75 nmol/L). This would also improves the quality of life and reduces all-cause mortality. (vitamindwiki.com)
  • However, for prevention of certain other diseases and to reduce all-cause mortality, serum 25(OH)D concentrations need to be maintained between 40 and 60 ng/mL. (vitamindwiki.com)
  • Elevated 1, 25-dihydroxyvitamin D levels are associated with protracted treatment in sarcoidosis. (medscape.com)
  • In one study, serum 1, 25-dihydroxyvitamin D levels were associated with patients requiring repeated regimens of systemic immunosuppressive therapy or longer than 1 year of therapy. (medscape.com)
  • The biologically active form of vitamin D is 1,25-dihydroxyvitamin D (1,25(OH) 2 D). Measuring serum levels of 1,25(OH) 2 D should be considered upon suspicion of deficiency or excess of 1,25(OH) 2 D. (medscape.com)
  • 1 alpha 25-dihydroxyvitamin D(3) (1 alpha 25(OH)(2)D(3)) has been identified as a major factor that inhibits the differentiation and maturation of DCs, an effect dependent upon its binding to the nuclear vitamin D receptor (VDR). (birmingham.ac.uk)
  • Macrophages and dendritic cells can produce 1,25-dihydroxyvitamin D within the microenvironment. (springer.com)
  • Immunomodulatory role of 1,25-dihydroxyvitamin D3. (springer.com)
  • Finally, XLH patients demonstrate a normal or low serum concentration of 1,25-dihydroxyvitamin D3, suggestive of inadequate formation of this vitamin D metabolite. (medscape.com)
  • Even the serum concentration of 1,25 dihydroxyvitamin D is inappropriately normal or low in XLH patients. (medscape.com)
  • Role of 1,25 dihydroxyvitamin D3 (soltriol) in etiology and therapy of seasonal affective disorder and other mental processes. (ijbcp.com)
  • Biologically active vitamin D (1,25-dihydroxyvitamin D) is involved in the regulation of gastrointestinal calcium absorption and bone homeostasis [ 1 ]. (biomedcentral.com)
  • This is one of the mechanisms by which 1,25-dihydroxyvitamin D regulates the genome, but it has also been shown to affect the epigenome through chromatin modifiers and methylation changes [ 11 ]. (biomedcentral.com)
  • Two lymphoblastoid cell lines stimulated with 1,25-dihydroxyvitamin D were used to generate a ChIP-Seq genome-wide map, which identified 229 genomic regions differentially bound with VDR before and after treatment with active vitamin D [ 13 ]. (biomedcentral.com)
  • Significant changes in gene expression after stimulation with 1,25-dihydroxyvitamin D were observed for gene loci such as IRF8 and PTPN2 which were not previously associated with vitamin D regulation [ 13 ]. (biomedcentral.com)
  • Vitamin D3 is then hydroxylated in the liver to 25(OH)D and further hydroxylated in the kidneys to its active form, 1,25 dihydroxyvitamin D (1,25(OH) 2 D) [ 6 ]. (biomedcentral.com)
  • Vitamin D has to be metabolically activated in the kidney, and patients with CKD including diabetic kidney disease (DKD) are not able to produce enough of the active form of vitamin D (1,25(OH) 2 D). Vice versa, the kidneys are assumed to be a classical 1,25(OH) 2 D target. (karger.com)
  • In humans, the most important compounds in this group are vitamin D3 (also known as cholecalciferol) and vitamin D2 (ergocalciferol). (truthwiki.org)
  • 1] Cholecalciferol and ergocalciferol can be ingested from the diet and from supplements. (truthwiki.org)
  • Recent NICE guidelines recommend that pregnant and breastfeeding women, children ages 6 months to 5 years, adults over 65 years or anyone who is not regularly exposed to the sun should take a daily vitamin D3 (cholecalciferol) supplement up to 10,000 IU [ 3 , 4 ]. (biomedcentral.com)
  • Vitamin D is a fat soluble vitamin and exists in two main forms as cholecalciferol(vitamin D3) which is synthesized in skin from 7-dehydrocholesterol in response to sunlight exposure & Ergocalciferol(vitamin D2) present mainly in dietary sources.Both cholecalciferol & Ergocalciferol are converted to 25(OH)vitamin D in liver. (meditest.in)
  • Ergocalciferol (vitamin D2) is converted in the liver to 25-hydroxyergocalciferol, also known as 25-hydroxyvitamin D2 - abbreviated 25(OH)D2. (truthwiki.org)
  • Alfacaldisol is activated by the enzyme 25-hydroxylase in the liver to mediate its effects in the body, or most importantly, the kidneys and bones. (drugbank.com)
  • An alpha-globulin, vitamin D transport protein, binds to the gut- and skin-derived vitamin D3 and transports it to the liver. (gpnotebook.com)
  • In granulomatous disease such as lymphoproliferative disorders, sarcoidosis, tuberculosis, and inflammatory bowel disease, 1α-hydroxylase enzyme activity was found in macrophages as the extrarenal source of 1,25(OH) 2 D. When 1α-hydroxylase is activated, it converts 25(OH)D to 1,25(OH) 2 D, just as what occurs under physiologic conditions in the kidneys. (medscape.com)
  • This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS. (uams.edu)
  • UVB radiation in the 290-315 nm wavelength converts 7-dehydrocholesterol in the skin to previtamin D3, which, in turn, is converted into vitamin D3. (biomedcentral.com)
  • Vitamin D 1alpha-hydroxylase gene mutations in patients with 1alpha-hydroxylase deficiency. (medlineplus.gov)
  • Human 25-hydroxyvitamin D-1alpha-hydroxylase: cloning, mutations, and gene expression. (medlineplus.gov)
  • 1, 25 dihydroxy vitamin D 3 , FGF23, serum calcium and urinary phosphorus were significant determinants of BMD in IBD patients. (biomedcentral.com)
  • Despite the significant effort in the last century to eradicate or minimize vitamin D deficiency among the population, especially children, there is still a high prevalence for vitamin D insufficiency/deficiency worldwide [ 1, 2 ]. (karger.com)
  • In distinction to the high prevalence of 25-OH-VitD deficiency, hypervitaminosis D is rare, and is only seen after prolonged exposure to extremely high doses of vitamin D. (meditest.in)
  • For diagnosis of vitamin D deficiency it is recommended to have clinical correlation with serum 25(OH)vitamin D, serum calcium, serum PTH & serum alkaline phosphatase. (meditest.in)
  • Physiological control of 1 alpha 25(OH)(2)D(3) levels is critically dependent upon 25-hydroxyvitamin D(3)-1 alpha-hydroxylase (1 alpha OHase), a mitochondrial cytochrome P450 enzyme that catalyzes the conversion of inactive precursor 25-hydroxyvitamin D(3) (25(OH)D(3)) to the active metabolite 1 alpha 25(OH)(2)D(3). (birmingham.ac.uk)
  • A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. (uams.edu)
  • VD 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes), immune cells, and bone (osteoblasts). (wikipedia.org)
  • Decreased levels of 1,25(OH) 2 D can result from chronic kidney disease , various heritable disorders, tumor-induced osteomalacia, the use of HIV protease inhibitors, or severe vitamin D deficiency . (medscape.com)
  • Chronic kidney disease: Low 1,25(OH) 2 D levels have been shown to present even in early stages of kidney failure. (medscape.com)
  • The decrease of 1,25(OH) 2 D level is more prominent when kidney failure progresses. (medscape.com)
  • [ 3 ] Impaired production of the enzyme 1α-hydroxylase in kidney failure was thought to be the main mechanism. (medscape.com)
  • [ 12 ] However, unlike the kidney, the 1α-hydroxylase in the macrophages in granulomatous diseases is not controlled by the usual physiologic regulators. (medscape.com)
  • Severe vitamin D deficiency: 25(OH)D is the main substrate of 1,25(OH) 2 D. Vitamin D deficiency can affect the production of 1,25(OH) 2 D owing to the lack of substrate. (medscape.com)
  • Deficiency in either nutrient is associated with various disorders, including skeletal deformities, cardiovascular diseases, and metabolic syndrome [25-30]. (milkgenomics.org)
  • However, despite the presence of abundant sunlight, the incidence of vitamin D deficiency is high even among those who live within 1,000 km of the equator, such as the populations of India, Sri Lanka, and Far Eastern, Middle Eastern, and Persian Gulf countries [1-4]. (vitamindwiki.com)
  • Vitamin D deficiency also contributes to many extraskeletal outcomes, including higher risk of type 1 or type 2 diabetes mellitus, allergy, autoimmunity, pregnancy complications, and many other pathologies. (karger.com)
  • The patients' mean level of 25-hydroxyvitamin D (25(OH)D) and the prevalence of vitamin D deficiency were compared with those of a control group, and a comparison of vitamin D deficiency across different diagnostic groups was also made. (biomedcentral.com)
  • This test is used to determine the levels of 25-hydroxy-vitamin D and is used to determine if bone weakness, bone malformation, or abnormal metabolism of calcium is occurring as a result of a deficiency or more than D. (meditest.in)
  • Despite some short-term consequences in the newborns, maternal vitamin D deficiency also have long-term effects as rickets, increased susceptibility to respiratory illness, autoimmune diseases and type 1 diabetes [ 9 , 10 ]. (biomedcentral.com)
  • Alfacalcidol, or 1-alpha-hydroxycholecalciferol or 1-alpha-hydroxyvitamin D3, is a non-endogenous analogue of vitamin D. It plays an essential function in calcium homeostasis and bone metabolism. (drugbank.com)
  • and enzyme-inducing drugs, in particular many antiepileptic drugs, that increase 25-OH-VitD metabolism. (meditest.in)
  • Vitamin D, with a vital role in calcium absorption and bone metabolism, also functioned in cell proliferation and differentiation, affecting the immune system as well [ 1 ]. (biomedcentral.com)
  • Cholesterol 7-alpha-Hydroxylase" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (uams.edu)
  • This graph shows the total number of publications written about "Cholesterol 7-alpha-Hydroxylase" by people in UAMS Profiles by year, and whether "Cholesterol 7-alpha-Hydroxylase" was a major or minor topic of these publications. (uams.edu)
  • Below are the most recent publications written about "Cholesterol 7-alpha-Hydroxylase" by people in Profiles over the past ten years. (uams.edu)
  • Following terminal differentiation induced by a diverse set of maturation stimuli, there is marked transcriptional up-regulation of 1 alpha OHase leading to increased 1 alpha OHase enzyme activity. (birmingham.ac.uk)
  • The enzyme CYP24A1 plays a key role in this process, and is activated by 1α,25(OH) 2 D 3 whenever there is an increase in the levels of this hormone. (biomedcentral.com)
  • However, phosphate retention and FGF-23 also contribute to the decreased synthesis of 1,25(OH) 2 D. (medscape.com)
  • In tumor-induced osteomalacia, tumor-secreted FGF-23 inhibits enzyme 1α-hydroxylase and subsequently results in decreased 1,25(OH) 2 D synthesis. (medscape.com)
  • HIV protease inhibitors have been reported to markedly suppress the activities of 25- and 1α-hydroxylase and thus affect 1,25(OH) 2 D synthesis. (medscape.com)
  • It has been suggested that serum 25(OH)D levels above 50 nmol/L are sufficient to sustain bone density and calcium absorption and to prevent osteomalacia [ 11 ]. (biomedcentral.com)
  • Low levels of Vitamin D3 can cause loss of bone density which can further trigger fractures. (meditest.in)
  • Calcifediol is what's measured in the blood to determine a patient's vitamin D status and is the sum of what was produced in the skin as well as any ingested D2 or D3. (set-db.com)
  • After a typical daily intake of vitamin D3, it takes about seven days to convert it to calcifediol. (set-db.com)
  • Despite its availability in a wide variety of foods, magnesium is often reported as being consumed at inadequate levels [1]. (milkgenomics.org)
  • Despite the crucial physiological roles played by magnesium, more than half of the US population may be consuming inadequate amounts of this mineral [1]. (milkgenomics.org)
  • In a study by Levin et al (2007), 13% of patients with an estimated glomerular filtration rate (eGFR) greater than 80 mL/min and more than 60% of patients with an eGFR of less than 30 mL/min had low serum levels of 1,25(OH) 2 D. (medscape.com)
  • A positive correlation between serum levels of 25(OH)D and 1,25(OH) 2 D was observed during seasonal changes. (medscape.com)
  • Increased 1,25(OH) 2 D levels can result from extrarenal 1α-hydroxylation or hereditary vitamin D-resistant rickets. (medscape.com)
  • Serum levels of 25-hydroxyvitamin D (25[OH]D) were measured with enzyme-linked immunosorbent assay. (korea.ac.kr)
  • In contrast, α-1 antitrypsin levels and net proteolytic activity were comparable in COVID-19 and influenza BAL fluids. (bvsalud.org)
  • these women also have high serum levels of anti-angiogenic soluble Fms-like tyrosine kinase-1 (sFlt-1), which is known to be located on the chromosome13 and 3 (15). (ac.ir)
  • 75 nmol/L), 3.07% were sufficient (25(OH)D ≥ 75 nmol/L). The maternal 25(OH)D levels varied with age, pre-pregnancy BMI, season when blood sample was collected, number of previous-pregnancy. (biomedcentral.com)
  • Vitamin D3 Test / Vitamin D25 OH Test also known as sunshine Vitamin is essential for strong Bones as it helps the body to use calcium from the food. (meditest.in)
  • It has additionally been proven that peripheral bloodstream Compact disc8+ T cells from four Compact disc3 antibody-treated sufferers with type 1 diabetes portrayed a lot more than threefold higher degrees of FoxP3 after medications, instead of nondrug treated sufferers, where FoxP3 expression transformed little as time passes. (ipa2014.org)
  • Hence, many effects of nutrition on the development and progression of cancer lack 'specificity' in their association, and such alimentary cues also affect the risk of developing metabolic syndrome, a prelude to arteriosclerosis and neurodegeneration ( Fig. 1 ). (nature.com)
  • Worldwide, 25 percent of maternal deaths are related to preeclampsia (4). (ac.ir)
  • Jain SK, Micinski D. Vitamin D upregulates glutamate cysteine ligase and glutathione reductase, and GSH formation, and decreases ROS and MCP-1 and IL-8 secretion in high-glucose exposed U937 monocytes. (springer.com)
  • In this review, for simplicity purposes, whenever we state vitamin D, we are referring to the biologically active form (1α,25(OH) 2 D 3 ) unless stated otherwise. (biomedcentral.com)
  • The level of 25-hydroxyvitamin D (25(OH)D) is used to evaluate subjects' vitamin D status. (biomedcentral.com)
  • In vitro studies of monocytes/macrophages indicate that gamma interferon is an important regulator of 1α-hydroxylase but only when other key signaling pathways are also activated (eg, JAK-STAT and MAP-Kinase). (medscape.com)
  • We show for the first time that moDCs are able to synthesize 1 alpha 25(OH)(2)D(3) in vitro as a consequence of increased 1 alpha OHase expression. (birmingham.ac.uk)
  • Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. (frontiersin.org)
  • The global burden has risen with the near tripling in the last half-century of multiple sclerosis (MS) ( 2 , 3 ), type 1 diabetes (T1D) ( 4 ), and other autoimmune diseases. (frontiersin.org)
  • It had been reported from the original research in type 1 diabetes that the full total circulating lymphocyte count number after huOKT31ala-ala therapy reached a nadir of 26.5 9.0% from the baseline depend on time 5, recovering by time 30 to attain 123 52% from the pre-treatment amounts (16). (ipa2014.org)
  • With these total outcomes at hand, the ITN shifted forward using its have randomized, managed, open-label stage IIb trial of huOKT31ala-ala in brand-new onset type 1 diabetes, where subjects had been to receive another and third span of medication (20). (ipa2014.org)
  • Two proteins have been implicated in expression-independent vitamin D action: membrane VDR and the membrane-associated rapid response steroid binding (1,25D 3 -MARRS) protein. (biomedcentral.com)
  • The recognition of fibroblast growth factor 23 (FGF23), a phosphaturic hormone related to tumor necrosis factor alpha (TNF-α) makes it plausible to hypothesize its possible relation to this pathology. (biomedcentral.com)
  • Preclinical evaluation of melanin-concentrating hormone receptor 1 antagonism for the treatment of obesity and depression. (ijbcp.com)
  • DKD - by itself and mostly during haemodialysis - also highly increases the risk of cardiovascular diseases such as heart attack, stroke, and others [ 1, 6 ]. (karger.com)
  • Although we measure 25-(OH)D in the blood, it's not the active form of the vitamin. (set-db.com)
  • Latitude and season affect the quantity and quality (wavelength) of solar radiation and thus influence the ability of sunlight to synthesize vitamin D3 in the skin [ 7 ]. (biomedcentral.com)

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