25,729 articles
Cyclofenil
Cyclofenil (Ondogyne, Fertodur, F-6066) is a non-steroidal ovulation inducer related to clomiphene, once used for female infertility and amenorrhea, now a WADA-prohibited anti-estrogen.
Cyclooxygenase-2 inhibitor
Cyclooxygenase-2 (COX-2) inhibitors, or coxibs (celecoxib, rofecoxib, etoricoxib), are NSAIDs selectively blocking the COX-2 enzyme to treat arthritis pain with less gastrointestinal toxicity, but carry cardiovascular, renal, and blood pressure risks; rofecoxib and valdecoxib were withdrawn in 2004–2005.
Cyclopentolate
Cyclopentolate (Cyclogyl) is a synthetic antimuscarinic eye drop producing mydriasis and cycloplegia for diagnostic refraction; onset 15-60 min, recovery within 24 h, WHO essential medicine, first approved 1974.
Cyclophosphamide
Cyclophosphamide (Endoxan, Cytoxan) is a nitrogen mustard-derived alkylating chemotherapy prodrug, FDA-approved in 1959, used for leukemias, lymphomas, breast and ovarian cancer, autoimmune disease, and transplant conditioning.
Cyclophosphamide/dexamethasone regimen
The cyclophosphamide/dexamethasone (Cy-Dex) regimen is a chemotherapy combination pairing the alkylating agent cyclophosphamide with the corticosteroid dexamethasone, formerly used as induction therapy for multiple myeloma before stem cell transplantation.
Cyclophosphamide/doxorubicin regimen (chemotherapy)
The cyclophosphamide/doxorubicin regimen, usually abbreviated AC or CA, is a two-drug chemotherapy combination pairing the alkylator cyclophosphamide with the anthracycline doxorubicin, used mainly to treat operable breast cancer.
Cyclopia
Cyclopia (synophthalmia) is the most severe facial form of holoprosencephaly: a single central eye with absent nose or proboscis, caused by failed forebrain division; prevalence 1 in 100,000 births, lethal within days, linked to SHH mutations, trisomy 13, and cyclopamine.
Cyclosporiasis
Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora cayetanensis, which causes watery diarrhea lasting weeks if untreated and spreads through contaminated food, especially fresh produce.
Cyclothiazide
Cyclothiazide (Anhydron, Fluidil), a thiazide diuretic first approved in 1963, treats hypertension and edema via distal tubule Na-Cl transport inhibition, and is widely used in neuroscience as an AMPA receptor desensitization blocker.
Cyclothymia
Cyclothymia (cyclothymic disorder) is a chronic bipolar-spectrum mood disorder with recurrent hypomanic and depressive symptoms below full episode thresholds for at least 2 years, with no more than 2 symptom-free months.
Cycrimine
Cycrimine (Pagitane) is a discontinued synthetic piperidine central anticholinergic, a muscarinic M1 antagonist once marketed by Eli Lilly as 1.25 and 2.5 mg tablets for Parkinson's disease.
CYDS IV trial
The CYDS IV trial is the fourth phase of the Community Youth Development Study, a University of Washington trial testing the Communities That Care prevention system's long-term effects.
Cynophobia
Cynophobia, fear of dogs, is a DSM-5-TR specific phobia of the animal type. It arises through conditioning, observational learning, and poor extinction, and is treated mainly with exposure therapy.
Cyproheptadine
Cyproheptadine (Periactin, glutodine), a first-generation H1-antihistamine approved 1961, also blocks 5-HT2A and muscarinic receptors; used for allergy, appetite stimulation, serotonin syndrome, and pediatric cyclic vomiting.
Cyproterone acetate
Cyproterone acetate, sold under trade names including Androcur, is a synthetic steroidal antiandrogen and progestogen used for androgen-dependent conditions such as hirsutism, acne, and prostate cancer, with a known meningioma risk at higher doses.
Cyril Chantler
Sir Cyril Chantler, born 1939, is a British pediatric nephrologist who led Guy's and Great Ormond Street hospitals, chaired UCL Partners, and reviewed tobacco packaging.
Cyril Wecht
Cyril H. Wecht (1931–2024), American forensic pathologist, attorney, and Allegheny County coroner 1970–1980 and 1996–2006; leading critic of the Warren Commission's single-bullet theory and commentator on JFK, Elvis Presley, and JonBenét Ramsey deaths.
Cyrus S. Poonawalla
Cyrus S. Poonawalla, Indian billionaire founder-chairman of Serum Institute of India (founded Pune, 1966), the world's largest vaccine maker by doses; Padma Bhushan 2022, Oxford honorary DSc 2019.
Cyst
Cyst: a closed tissue sac filled with fluid, pus, air, or keratin, forming in skin, ovaries, breasts, kidneys, and other organs; true cysts have epithelial linings, unlike pseudocysts, and most are benign.
Cyst in the anterior chamber of the eye
Cyst in the anterior chamber of the eye (ICD-11 9A82), usually an iris cyst; primary pigment epithelial cysts are typically stationary, while secondary implantation cysts after trauma or surgery enlarge and cause glaucoma, requiring aspiration, laser, or excision.
Cyst of pancreas
Cyst of pancreas (pancreatic cyst): a fluid-filled lesion in the pancreas, found in 2–20% of CT/MRI scans. Types range from benign pseudocysts and serous cystadenomas to mucinous IPMNs and MCNs with malignant potential; managed by MRI surveillance or surgery.
Cystectomy
Cystectomy, also called radical cystectomy, is the surgical removal of all or part of the urinary bladder, typically for muscle-invasive bladder cancer, with urinary tract reconstruction by diversion or neobladder.
Cystic diseases of the pancreas
Cystic diseases of the pancreas (ICD-11 DC30) cover pancreatic pseudocysts and cystic neoplasms, chiefly serous cystadenoma, mucinous cystic neoplasm, and IPMN, found incidentally in up to 45% of imaging series and managed by Fukuoka, AGA, European, and 2024 Kyoto guidelines.
Cystic echinococcosis
Cystic echinococcosis (hydatid disease, hydatidosis), zoonotic disease from Echinococcus granulosus larvae; dog-sheep cycle; hydatid cysts mainly liver (~80%) and lung (~15%); ~207,000 new cases in 2019.
Cystic hygroma
Cystic hygroma, also called cystic lymphangioma or macrocystic lymphatic malformation, is a benign congenital lymphatic malformation forming large fluid-filled cysts, usually in the neck, treated by surgery or sclerotherapy.
Cystic leukoencephalopathy without megalencephaly
Cystic leukoencephalopathy without megalencephaly (CLWM) is a rare inherited brain disorder, described in 2005, with temporal lobe cysts, normal head size, and severe psychomotor impairment.
Cystic meniscus
Cystic meniscus (meniscal or parameniscal cyst): fluid collection at the knee meniscus margin, usually with a horizontal tear; prevalence 1–8%, mostly lateral, treated by arthroscopic decompression, excision, or percutaneous drainage.
Cysticercosis
Cysticercosis, tissue infection by Taenia solium larvae (neurocysticercosis when in the brain), acquired from tapeworm eggs not pork; causes about 30% of endemic epilepsy, 2.8 million DALYs.
Cysticercosis of central nervous system
Neurocysticercosis, or cysticercosis of the central nervous system (ICD-11 1F70.0), is Taenia solium larval cyst infection of the brain acquired from fecal-oral tapeworm eggs, causing seizures, hydrocephalus, and stroke; treated with albendazole, praziquantel, steroids, and surgery.
Cystitis
Cystitis, bladder inflammation (ICD-11 GC00), usually bacterial with E. coli causing 80-90% of UTIs; classified by EAU as localised UTI, treated with antibiotics or non-antibiotic strategies, and distinct from interstitial, radiation, and chemical cystitis.