72,234 articles
Ex-vacuo hydrocephalus
Ex-vacuo hydrocephalus (hydrocephalus ex vacuo, ICD-11 8D64.2) is ventricular enlargement from brain tissue loss, not raised CSF pressure; causes include stroke, injury, and atrophy, and it must be distinguished from treatable normal pressure hydrocephalus.
Exagamglogene autotemcel
Exagamglogene autotemcel (Casgevy, exa-cel) is Vertex Pharmaceuticals' CRISPR/Cas9-edited autologous stem cell gene therapy for sickle cell disease and beta-thalassemia, first authorized by the UK MHRA in November 2023.
Exametazime
Exametazime (HMPAO, hexamethylpropylene amine oxime) is a ketoxime chelator for technetium-99m, marketed as the Ceretec kit (US approval 1988), used for Tc-99m brain perfusion SPECT in stroke and for labeling autologous leukocytes to image infection.
Examination Tables
Examination tables, also called exam or clinical couches, are medical furniture for patient physical examinations. Key facts: FDA Class I device (21 CFR 878.4960), fixed-height models about 32 inches, MDE Standards requiring 17-inch low transfer height, and 2024 ADA Title II acquisition rules.
Examination under anesthesia
Examination under anesthesia (EUA) is a clinical examination performed while a patient is sedated, used when pain or muscle guarding prevents an adequate awake assessment.
EXAMINE trial
EXAMINE (Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care), NCT00968708, was Takeda's 5,380-patient noninferiority trial showing the DPP-4 inhibitor alogliptin did not increase cardiovascular events in type 2 diabetes after acute coronary syndrome.
Exanthem
Exanthem: a widespread skin rash accompanying systemic illness, usually viral; counterpart of enanthem. Includes the numbered childhood exanthems, with roseola infantum (HHV-6, sixth disease) as the classic example.
EXCEL trial (NCT01205776)
EXCEL (NCT01205776), Evaluation of XIENCE Versus CABG for Effectiveness of Left Main Revascularization: 1,905-patient randomized trial showing everolimus-eluting stent PCI noninferior to bypass surgery at 3 years for low/intermediate SYNTAX left main disease, later controversial over its MI definition.
Excessive attrition of teeth
Excessive attrition of teeth (ICD-11 DA08.10, ICD-10 K03.0) is pathological tooth wear from tooth-to-tooth contact, usually linked to bruxism, appearing as shiny matching wear facets and managed with splints and minimal intervention.
Excessive daytime sleepiness
Excessive daytime sleepiness, also called excessive daytime somnolence, is the inability to stay awake and alert during the day's main waking hours, most often caused by obstructive sleep apnea.
Excessive startle reflex
Excessive startle reflex (hyperekplexia, startle disease, ICD-11 8A07.2): exaggerated startle reactions to unexpected stimuli, mainly from glycine receptor defects (GLRA1), treated with clonazepam.
Excessive weight gain
Excessive weight gain, or abnormal weight gain, is an unhealthy rise in body mass from fluid, fat, or muscle, classified in ICD-11 as symptom code MG43.6.
Excessive weight gain in pregnancy
Excessive weight gain in pregnancy, or excessive gestational weight gain (GWG), is gain above IOM 2009 BMI-based ranges; it affects 20-40% of women in Europe and the US and raises risks of macrosomia, gestational diabetes, and cesarean delivery.
Excessive weight loss
Excessive weight loss, ICD-11 code MG43.5, also called unintentional or unexplained weight loss: loss of fluid, fat, or muscle mass great enough to risk health, typically 5% of body weight over 6-12 months, with causes including cancer, depression, and gastrointestinal disease.
Exchange arthroplasty
Exchange arthroplasty is a surgical procedure that removes an infected or failed joint prosthesis and implants a new one, in one stage or two with an antibiotic spacer.
Exchange transfusion
Exchange transfusion is a procedure in which a patient's blood is gradually withdrawn and replaced with donor blood, used for severe neonatal jaundice and sickle cell disease.
Exchange Transfusion, Whole Blood
Exchange transfusion, whole blood: replacing a patient's blood aliquot by aliquot with donor whole blood or reconstituted red cells plus plasma. Used for neonatal hyperbilirubinemia, hemolytic disease, and sickle cell disease; double-volume exchange is 160 mL/kg.
Excinuclease Cho, C-terminal domain
Excinuclease Cho, C-terminal domain: the C-terminal region of Cho (UvrC homolog, gene ydjQ), a bacterial NER endonuclease making only 3′ incisions 4 nt beyond UvrC's site; in Mycobacterium it carries an epsilon 3′ exonuclease-like domain.
Excipient
Excipient: inactive ingredient added to drug products alongside the active pharmaceutical ingredient; from Latin excipere; aids manufacture, stability, bioavailability; 80-90% of product; regulated via FDA IID and EMA guidelines.
Excision Repair
Excision repair: DNA repair mechanisms (base-excision, nucleotide-excision, mismatch repair) that cut damaged DNA from one strand and resynthesize it using the complementary strand as template.
Excitatory amino acid transporter 2
EAAT2 (SLC1A2, GLT-1) is the main astrocytic glutamate transporter of the brain, clearing over 90% of extracellular glutamate; its loss is linked to ALS, Alzheimer's, epilepsy, and excitotoxicity.
Excitatory postsynaptic potential
Excitatory postsynaptic potential (EPSP), a depolarizing postsynaptic potential that increases action potential likelihood; distinguished from IPSP by a reversal potential above spike threshold; mediated by glutamate receptors such as AMPA.
Excited delirium
Excited delirium (ExD/ExDS) is a disputed agitation syndrome coined in 1980s Miami by Wetli and Fishbain, long used to explain restraint deaths; unrecognized in DSM-5/ICD and abandoned by major medical bodies since 2023.
Excoriation disorder
Excoriation disorder, also called skin-picking disorder or dermatillomania, is a DSM-5 obsessive-compulsive and related disorder involving recurrent skin picking causing lesions; prevalence about 3.45%, treated with habit reversal therapy, SSRIs, and N-acetyl cysteine.
Excretion
Excretion: removal of metabolic wastes, toxins, and excess substances from organisms. Main animal nitrogenous wastes are ammonia, urea, uric acid; aquatic animals excrete ammonia, terrestrial ones urea or uric acid; kidneys, nephridia, Malpighian tubules, and plant stomata serve the process.
Excretory cell
An excretory cell is a specialized cell type that performs excretion or osmoregulation, removing toxic wastes and keeping the balance between cells and their surroundings.
Excretory system
Excretory system: animal organs (nephridia, Malpighian tubules, vertebrate kidneys) that remove nitrogenous wastes (ammonia, urea, uric acid) and regulate water and ion balance; human GFR averages 180 L/day.
Excretory system of gastropods
The excretory system of gastropods removes nitrogenous waste in snails and slugs through a metanephridial renopericardial complex, where the pericardium produces urine by ultrafiltration and kidneys modify it.
Exebacase
Exebacase (CF-301, PlySs2) is ContraFect's first-in-class antistaphylococcal phage lysin for S. aureus bacteremia; phase 2 showed MRSA benefit, but the phase 3 DISRUPT trial stopped for futility in 2022.
Executive dysfunction
Executive dysfunction is impaired ability to manage thoughts, emotions, and actions, seen in ADHD, addictions, depression, brain injury, and dementia. Core deficits involve inhibition, working memory, and cognitive flexibility; treated via the underlying condition.