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Catamenia
Catamenia (Bonaparte, 1850) is a genus of three Andean seedeater birds in the tanager family Thraupidae, formerly placed in Emberizidae: Band-tailed, Paramo, and Plain-colored Seedeaters, sister to Diglossa.
Catamenial pneumothorax
Catamenial pneumothorax is recurrent lung collapse in reproductive-age women within 72 hours before or after menstruation, the most common form of thoracic endometriosis syndrome, usually right-sided, treated with VATS, pleurodesis, diaphragm repair, and hormonal therapy.
Catanduanes
Catanduanes: island province in the Bicol Region, Philippines, east of Camarines Sur; capital Virac, 11 municipalities, abaca capital, typhoon-prone, site of the Philippines' first described Cretaceous ammonites.
Cataplexy
Cataplexy: sudden, brief, emotion-triggered bilateral loss of muscle tone with preserved consciousness, the hallmark of narcolepsy type 1; diagnosed clinically, treated with sodium oxybate or pitolisant.
Cataract
Cataract: clouding of the eye's lens, mainly age-related; leading cause of curable blindness (94 million affected). Treated only by surgery, phacoemulsification or manual small incision cataract surgery, with comparable outcomes.
Cataract surgery
Cataract surgery removes the eye's clouded lens and implants an intraocular lens; standard technique is Kelman's 1967 phacoemulsification through sub-3 mm incisions, evolved from couching and Daviel's 1750 extraction.
Cataract-growth hormone deficiency-sensory neuropathy-sensorineural hearing loss-skeletal dysplasia syndrome
CAGSSS (OMIM 616007, ORPHA:436174) is an ultra-rare autosomal recessive mitochondrial disease caused by IARS2 mutations, combining cataract, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and spondyloepimetaphyseal dysplasia with normal cognition.
Cataract-intellectual disability-hypogonadism syndrome
Cataract-intellectual disability-hypogonadism syndrome, also called Martsolf syndrome, is a rare autosomal recessive genetic disorder featuring congenital cataract, mild-to-moderate intellectual disability, hypogonadism, and characteristic facial features.
Cataract-microcornea syndrome
Cataract-microcornea syndrome (CCMC, ORPHA:1377) is a rare genetic disorder combining congenital cataract with microcornea under 10 mm, without systemic anomalies; autosomal dominant or recessive, linked to crystallin, GJA8, MAF, ABCA3, and SOX2 genes.
Catarrh
Catarrh, also called postnasal drip, is a build-up of mucus in the nose, sinuses, and throat from infection, allergy, smoke, or nasal polyps; usually self-limiting, but chronic forms last months or years.
Catarrhal gingivitis
Catarrhal gingivitis, also called simple gingivitis (カタル性歯肉炎), is the common red, swollen, easily bleeding form of gum inflammation without attachment loss; ICD-11 code DA0B.1, mapped to ICD-10 K05X/K05.00.
Catarrhini
Catarrhini, the down-nosed primates or Old World anthropoids, is a parvorder comprising Old World monkeys (Cercopithecidae), gibbons (Hylobatidae), and great apes including humans (Hominidae), defined by narrow downward nostrils and a 2:1:2:3 dental formula.
Catasetum
Catasetum (catasetum orchids) is a Neotropical orchid genus, tribe Cymbidieae, native from Mexico to Tropical America, with about 170-206 species of unisexual, sexually dimorphic flowers pollinated by euglossine bees via a catapult-like pollinarium ejection mechanism.
Catastrophic antiphospholipid syndrome
Catastrophic antiphospholipid syndrome (CAPS, Asherson's syndrome): rare, life-threatening variant of antiphospholipid syndrome with multiorgan small-vessel thrombosis within days, ~1% of APS cases, 37% mortality, treated with heparin, steroids, plasma exchange or IVIG.
Catatonia
Catatonia: neuropsychiatric syndrome of abnormal motor behavior, volition, and behavior, first named by Kahlbaum in 1874. Diagnosed by DSM-5-TR (3 of 12 features) or ICD-11; treated with lorazepam and ECT.
Catatonia associated with another mental disorder
Catatonia associated with another mental disorder (ICD-11 6A40) is a catatonia diagnosis occurring with mood disorders, schizophrenia, or autism; diagnosis needs three psychomotor features, treatment is benzodiazepines or ECT.
Catatonic depression
Catatonic depression: major depressive disorder with catatonic features (DSM-5-TR specifier; ICD-11 catatonia associated with another mental disorder). Mutism, stupor, posturing; treated with lorazepam and ECT.
Catch per unit effort
Catch per unit effort (CPUE) is a fishery and ecology abundance index recording catch per unit of fishing effort, widely used in stock assessments to track relative population size.
Catechin
Catechin, a flavan-3-ol plant polyphenol, and its relatives EGCG, EGC, ECG, and epicatechin are the major catechins of green tea; EGCG is 50-80% of tea catechins, intake is 18-50 mg/day, and EFSA flags liver risk at 800 mg EGCG/day supplements.
Catechol-O-methyltransferase
Catechol-O-methyltransferase (COMT, EC 2.1.1.6) is a magnesium-dependent, SAM-using enzyme that O-methylates catecholamines like dopamine; the Val158Met polymorphism halves brain activity, and its inhibitors entacapone, tolcapone, and opicapone treat Parkinson's disease.
Catecholaminergic polymorphic ventricular tachycardia
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited cardiac arrhythmia syndrome in which exercise or emotional stress triggers ventricular tachycardia in a structurally normal heart.
Catequentinib
Catequentinib, also called anlotinib hydrochloride or AL3818, is an oral multi-target tyrosine kinase inhibitor targeting VEGFR2/3, FGFR1-4, and PDGFR; NMPA-approved in 2018 for advanced NSCLC after two chemotherapy lines.
Caterpillar
Caterpillar: the larval stage of butterflies and moths (Lepidoptera), the feeding stage of complete metamorphosis; molts three to nine times, defends against predators with venom, eyespots, camouflage, and behavior, and is key food for birds.
Catfish
Catfish (order Siluriformes) are barbelled ray-finned fishes, about 4,000 valid species on every continent except Antarctica, named for whisker-like barbels and known for taste buds covering their entire body.
Catgut
Catgut: absorbable surgical suture and string material made from sheep, cattle, or goat intestine collagen, not cats. Plain gut lasts 1–2 weeks, chromic gut 3–4 weeks; superseded by synthetic sutures and banned in Europe after BSE.
Catharanthus roseus
Catharanthus roseus (Madagascar periwinkle, formerly Vinca rosea), Apocynaceae ornamental native to Madagascar and sole natural source of anticancer alkaloids vinblastine and vincristine, made via strictosidine from tryptamine and secologanin.
Catharina Svanborg
Catharina Svanborg is a Swedish physician-scientist, professor of clinical immunology at Lund University, known for discovering HAMLET, a protein-lipid complex from human milk that kills tumor cells.
Cathartes
Cathartes is a genus of three New World vultures (Turkey, Lesser and Greater Yellow-headed) in Cathartidae, unique among vultures for locating carrion by smell, detecting ethyl mercaptan from decaying flesh.
Catharus
Catharus, the nightingale-thrushes and migratory New World thrushes (Turdidae), a genus of about 12 forest songbirds; known for four independent origins of migration, speciation with gene flow, and the 2023 seven-species split of Catharus fuscater.
Cathepsin
Cathepsins are lysosomal proteases active at acidic pH; humans have 15 (11 cysteine, 2 serine, 2 aspartate). Named in 1929, they drive bone resorption, immunity, and cancer, but no inhibitor has been approved.