72,234 articles
Chlozolinate
Chlozolinate (dichlozolinate, CAS 84332-86-5) is an obsolete dicarboximide fungicide first reported in 1980, used against Botrytis and Sclerotinia on grapes and fruit; not EU-approved, classified as a suspected carcinogen (H351).
CHO-K1
CHO-K1 (ATCC CCL-61, ECACC 85051005) is a proline-auxotrophic, adherent subclone of the Chinese hamster ovary cell line established by T.T. Puck in 1957; ancestral to CHO-DXB11 and CHO-DG44 and widely used as a transfection and bioproduction host.
CHO-S
CHO-S is a suspension-adapted Chinese hamster ovary cell line, reported by Thompson and coworkers in 1973, used as a host for recombinant protein production in serum-free suspension culture.
Choanal atresia
Choanal atresia: congenital bony or membranous obstruction of the posterior nasal openings (choanae), incidence 1:5000–8000, female-predominant, linked to CHARGE syndrome; bilateral form is a neonatal airway emergency treated by endoscopic transnasal repair, with stenting increasingly questioned.
Choanoflagellate
Choanoflagellates (Choanoflagellata) are unicellular and colonial collar-flagellate eukaryotes, the closest living relatives of animals. They feed on bacteria with a flagellum plus 30-40 microvilli collar; key models are Monosiga brevicollis and Salpingoeca rosetta.
CHOCO-PAD study
CHOCO-PAD (NCT06933992) is a prospective, multicenter, single-arm observational trial at eight Chinese centres testing the Chocolate PTA balloon catheter, a nitinol-constrained angioplasty balloon, in 171 PAD patients, with 12-month target lesion patency as the primary outcome.
Choe Jae-chun
Choe Jae-chun (최재천) is a South Korean behavioral ecologist who trained under Edward O. Wilson at Harvard and founded Korea's National Institute of Ecology in 2013.
Choffatia
Choffatia (Siemiradzki, 1898; sometimes attributed to Spath 1930) is a quasi-cosmopolitan Middle Jurassic perisphinctid ammonite genus, Bathonian to Callovian, with dimorphic macroconchs and lappeted microconchs, important in Kutch biostratigraphy.
Choh Hao Li
Choh Hao Li (1913–1987) was a Chinese-born American biochemist at the University of California who purified most anterior pituitary hormones, synthesized human growth hormone, discovered β-endorphin, and won the 1962 Lasker Award.
Choice-of-anchor H domain
Choice-of-anchor H domain: a conserved bacterial protein domain defining the choice-of-anchor H family, annotated in Shewanella baltica (SBAL678_RS45380, WP_006084639.1) and Candidatus Thiodiazotropha endolucinida; function not yet established.
Choking
Choking is airway obstruction by a foreign body. Covers partial versus complete obstruction, 2025 AHA and Red Cross first-aid sequences, hypoxia timelines, mortality statistics, complications, and the anti-choking device evidence.
Cholangiocarcinoma
Cholangiocarcinoma (bile duct cancer; iCCA, pCCA/Klatskin, dCCA): adenocarcinoma of biliary epithelium, second most common primary liver cancer. Risk: PSC, liver flukes, cirrhosis; drivers FGFR2 fusions, IDH1/2, KRAS; treated by resection, transplant protocols, chemoimmunotherapy.
Cholangiocyte
Cholangiocytes, or biliary epithelial cells, line the bile ducts of the biliary tree and modify bile through secretin-driven bicarbonate secretion. They are targets of cholangiopathies and can be grown as organoids for disease modeling and bile duct repair.
Cholangiography
Cholangiography is the radiologic or endoscopic imaging of the bile ducts with contrast agents or MRI, performed to diagnose duct obstruction, stones, strictures, and leaks.
Cholangiopancreatography
Cholangiopancreatography visualizes the bile and pancreatic ducts to diagnose ductal disease, in two forms: noninvasive MRI (MRCP) and endoscopic retrograde contrast imaging (ERCP), which is mainly therapeutic.
Cholangioscopy
Cholangioscopy is an endoscopic technique in which a very thin endoscope is advanced into the bile ducts, most often during ERCP, to fragment difficult stones and biopsy indeterminate strictures.
Cholangitis
Cholangitis: inflammation of the bile ducts, intrahepatic or extrahepatic. Covers acute ascending cholangitis (obstruction plus infection, treated with antibiotics and ERCP drainage) and chronic sclerosing forms including PSC and IgG4-related disease.
Cholecalciferol
Cholecalciferol (vitamin D3), the animal form of vitamin D, is made in skin from 7-dehydrocholesterol by UVB, activated by liver and kidney hydroxylations, and raises serum 25(OH)D more effectively than ergocalciferol (D2).
Cholecystectomy
Cholecystectomy is surgical removal of the gallbladder, mainly for symptomatic gallstones. First done openly by Langenbuch in 1882; laparoscopic since Mühe (1985) and Mouret (1987); main risk is bile duct injury (0.04–0.6%).
Cholecystitis
Cholecystitis is gallbladder inflammation, usually from a gallstone blocking the cystic duct; acute or chronic, calculous or acalculous. Diagnosed by ultrasound and HIDA; treated with antibiotics and early laparoscopic cholecystectomy.
Cholecystography
Cholecystography is x-ray imaging of the gallbladder after a contrast medium is swallowed or injected. Introduced in the 1920s, it was the principal test for gallstones until ultrasound displaced it.
Cholecystokinin
Cholecystokinin (CCK), also called pancreozymin, is a gut peptide hormone discovered in 1928 by Ivy and Oldberg, structurally identified in 1968 as sulfated CCK-33, that contracts the gallbladder, stimulates pancreatic enzyme secretion, and signals satiety.
Cholecystokinin receptor
Cholecystokinin receptors (CCK1R/CCKAR, CCK2R/CCKBR): class A GPCRs for CCK and gastrin. CCK1R needs sulfated CCK, couples Gs/Gq; CCK2R is the gastrin receptor, couples Gq; cloned 1992, cryo-EM structures 2022.
Cholecystokinin-like
Cholecystokinin-like (IPR015499) is the InterPro protein family for gastrin/cholecystokinin peptides: human CCK (P06307, 115 aa) processed into CCK-58 to CCK-8, acting via CCK1/CCK2 GPCRs on digestion, satiety, and brain functions.
Cholecystostomy
Cholecystostomy, also known as percutaneous cholecystostomy, drains the gallbladder through a catheter placed through the abdominal wall, mainly to treat acute cholecystitis in patients unfit for surgery.
Choledochal cysts
Choledochal cysts (congenital choledochal malformation) are rare congenital dilatations of the bile ducts, classified by the Todani system into five types, most common in Asian populations and females, premalignant, and treated by complete cyst excision.
Choledochoduodenostomy
Choledochoduodenostomy is a surgical operation creating a direct connection between the common bile duct and the duodenum, most often performed for recurrent bile duct stones or benign strictures.
Choledochojejunostomy
Choledochojejunostomy is a surgical operation that joins the common bile duct to the jejunum, relieving biliary obstruction, most commonly from an obstructing periampullary mass of pancreatic or duodenal origin.
Choledochoscopy
Choledochoscopy is direct endoscopic visualization of the common bile duct, performed intraoperatively or peroral during ERCP to remove stones, evaluate strictures, and assess tumors; first performed in 1923.
Cholera
Cholera, also called Asiatic cholera, is an acute diarrheal infection from Vibrio cholerae spread via contaminated water and food; seventh pandemic since 1961, treatable with oral rehydration solution and preventable with WASH and oral cholera vaccines.