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Frontonasal dysplasia-alopecia-genital anomalies syndrome
Frontonasal dysplasia-alopecia-genital anomalies syndrome (FND type 2, ALX4-related, OMIM 613451): autosomal recessive disorder with coronal craniosynostosis, skull defects, hypertelorism, bifid nose, total alopecia, hypogonadism, and mild-moderate intellectual disability.
Frontonasal dysplasia-severe microphthalmia-severe facial clefting syndrome
A rare genetic disorder, also called frontonasal dysplasia type 3, caused by ALX1 gene variants and marked by severe facial clefts, small eyes, and hypertelorism.
Frontorhiny
Frontorhiny, also called ALX3-related frontonasal dysplasia or frontonasal dysplasia type 1, is a rare autosomal recessive midline facial malformation caused by homozygous ALX3 mutations, marked by hypertelorism, broad columella, widened philtrum, and bifid nasal tip.
Frontotemporal dementia
Frontotemporal dementia (FTD), also called Pick's disease historically, is a group of early-onset dementias with frontal and temporal lobe atrophy, behavioral or language decline, tau/TDP-43/FUS pathology, MAPT/GRN/C9orf72 genes, and no cure.
Frontotemporal dementia with motor neuron disease
Frontotemporal dementia with motor neuron disease (FTD-MND, FTD-ALS): combined frontotemporal dementia and ALS within the ALS-FTD spectrum, onset 38-78 years, TDP-43 pathology, C9orf72 expansion, death 2-5 years after onset.
Frontotemporal lobar degeneration
Frontotemporal lobar degeneration (FTLD), also called frontotemporal dementia (FTD), is a group of neurodegenerative diseases causing frontal and temporal lobe atrophy; leading early-onset dementia under 60, with tau, TDP-43, or FUS protein inclusions and C9orf72, GRN, MAPT mutations.
FROST trial
FROST trial refers to several unrelated studies, chiefly UK FROST, a 503-patient three-arm UK randomized trial comparing manipulation under anaesthesia, arthroscopic capsular release, and physiotherapy for frozen shoulder.
Frostbite
Frostbite, a freezing cold injury (FCI), is tissue damage from exposure below 0°C, classified by depth (1st–4th degree) or Cauchy grades; treated with rapid rewarming at 38–42°C, thrombolytics, and iloprost.
Frostbite with tissue necrosis
Frostbite with tissue necrosis (ICD-11 NE41), also called third or fourth degree frostbite, is deep freezing injury killing skin, muscle, and bone; treated with rapid rewarming, thrombolysis, iloprost, and delayed amputation.
Frovatriptan
Frovatriptan (frovatriptan succinate, brand FROVA), a 5-HT1B/1D agonist triptan, treats acute migraine with or without aura in adults as 2.5 mg tablets; its ~26-hour half-life lowers headache recurrence versus other triptans.
Frozen elephant trunk technique
The frozen elephant trunk technique is a one-stage cardiac operation that replaces the aortic arch and stents the descending thoracic aorta, introduced in 2003 by Matthias Karck.
Frozen section diagnosis
Frozen section diagnosis is a pathology technique in which fresh, unfixed tissue is rapidly frozen, cut, stained, and examined microscopically during surgery, giving the surgeon a preliminary diagnosis within minutes.
Frozen Sections
Frozen sections: rapid intraoperative histopathology of fresh frozen tissue cut on a cryostat, also called frozen section biopsy or intraoperative consultation; accuracy 92-98% versus permanent sections, used for margins, diagnosis, and lymph nodes.
FRS2
FRS2 (FGF receptor substrate 2, SNT/SNT-1), with family member FRS2β (SNT-2/FRS3), is a membrane docking protein relaying FGFR, Trk, RET, and ALK signals to Ras/ERK and PI3K pathways, amplified in cancers.
FRTL-5
FRTL-5 (FRTL5, Fischer rat thyroid line 5) is a clonal rat thyroid follicular cell line from Fischer 344 rats, TSH-dependent, iodide-concentrating, used in TSH and Graves' autoantibody bioassays; ATCC CRL-8305.
Fructolysis
Fructolysis is the metabolic pathway that converts fructose into the glycolytic intermediates DHAP and glyceraldehyde 3-phosphate, via fructokinase and aldolase B, mainly in the liver.
Fructooligosaccharide
Fructooligosaccharide (FOS), also known as oligofructose, is a prebiotic fiber and low-calorie sweetener found in chicory, onion, and banana, fermented in the colon to boost beneficial Bifidobacterium.
Fructosamine
Fructosamine is a ketoamine formed when glucose reacts nonenzymatically with proteins; clinically it denotes glycated serum proteins, mostly albumin, measured as a shorter-term alternative to HbA1c for monitoring diabetes.
Fructose
Fructose (levulose, fruit sugar) is a six-carbon ketohexose monosaccharide, C6H12O6, discovered 1847 by Dubrunfaut. Metabolized via ketohexokinase to fructose 1-phosphate, faster and less regulated than glucose; linked to metabolic disease at high intakes.
Fructose 1,6-bisphosphate
Fructose 1,6-bisphosphate is a phosphorylated six-carbon sugar, D-fructose with phosphate groups at positions 1 and 6, discovered in yeast extracts by Harden and Young in 1908 and central to glycolysis.
Fructose malabsorption
Fructose malabsorption: incomplete small-intestinal absorption of free fructose via GLUT5, affecting up to half of people at 25 g loads; causes IBS-like symptoms, diagnosed by hydrogen breath test, managed with low-FODMAP diet; distinct from hereditary fructose intolerance.
Fructose metabolism
Fructose metabolism: how the monosaccharide fructose (in sucrose, HFCS, fruit) is absorbed via GLUT5/GLUT2, phosphorylated by fructokinase (KHK) to fructose 1-phosphate, cleared mainly by liver and intestine, and linked to uric acid, lipogenesis, and metabolic disease.
Fructose-1,6-bisphosphatase
Fructose-1,6-bisphosphatase (FBPase, EC 3.1.3.11), encoded in vertebrates by FBP1 (liver) and FBP2 (muscle), hydrolyzes fructose-1,6-bisphosphate to fructose-6-phosphate as the rate-limiting gluconeogenesis enzyme, inhibited by AMP and fructose-2,6-bisphosphate; FBP1 deficiency causes hypoglycemia with lactic acidosis.
Fructose-1,6-bisphosphatase deficiency
Fructose-1,6-bisphosphatase deficiency (FBPase deficiency, Baker-Winegrad disease, OMIM 229700) is a rare autosomal recessive FBP1 gluconeogenesis disorder causing fasting hypoglycemia and lactic acidosis episodes in infants, treatable with glucose and fasting avoidance.
Fructose-2,6-bisphosphatase
Fructose-2,6-bisphosphatase (FBPase-2, EC 3.1.3.46) is the C-terminal phosphohydrolase domain of the bifunctional PFK-2/FBPase-2 (PFKFB) enzyme that degrades fructose-2,6-bisphosphate, the allosteric activator of glycolysis, via a phospho-histidine intermediate.
Fructose-bisphosphate aldolase
Fructose-bisphosphate aldolase, commonly called aldolase, is a lyase enzyme (EC 4.1.2.13) that splits fructose 1,6-bisphosphate into two triose phosphates in glycolysis, gluconeogenesis, and the Calvin cycle.
Fructose-bisphosphate aldolase, class-II
Class-II fructose-bisphosphate aldolase (EC 4.1.2.13, F_bP_aldolase, PF01116) is the zinc-dependent, mainly bacterial and fungal form of aldolase, a homodimeric TIM-barrel enzyme cleaving fructose 1,6-bisphosphate via a metal-stabilized enolate, distinct from the Schiff-base class I enzyme.
Frugivore
Frugivore: an animal feeding primarily on fruit, including frugivorous birds, primates, bats, fish, and reptiles. Key facts: frugivory evolved independently many times; frugivores disperse seeds for roughly 60–80% of plant species; interactions span a mutualism–antagonism continuum.
Fruit salad
Fruit salad: a dish of mixed cut or whole fruits, served plain or dressed. Known in American recipe books since the 1850s; related to fruit cocktail; regulated as fresh-cut produce; includes rujak and ananas chaat variants.
Fruit tree
Fruit tree: woody perennial grown for edible fruit (apple, olive, citrus, mango, banana). Domesticated after grain agriculture in the fourth millennium BC; propagated by grafting scion onto rootstock; key crops in orchards and agroforestry.