Life and health

Explantation

Explantation is the surgical removal of an implanted device, prosthesis, or transplanted tissue from the body, most often to treat infected cardiac device leads or remove breast implants.

Exploding head syndrome (EHS), also called episodic cranial sensory shock, is a benign parasomnia of sudden painless loud noises at sleep-wake transitions, first described in 1876, with variable prevalence and reassurance-based management.

Exploding whale

Exploding whale: a decomposing whale carcass that bursts from trapped decomposition gases, or is deliberately detonated. Famous cases: Florence, Oregon 1970 half-ton dynamite blast and the 2004 Tainan, Taiwan sperm whale street explosion.

Exploratory laparotomy

Exploratory laparotomy is an open surgical exploration of the abdomen through a midline incision, both diagnostic and therapeutic, most often performed as an emergency for bleeding, perforation, or trauma.

Exploratory surgery

Exploratory surgery is a diagnostic operation in which a surgeon opens a body cavity, usually the abdomen, to inspect organs directly when imaging has not produced a diagnosis.

EXPLORER-HCM trial

EXPLORER-HCM: phase 3 randomized double-blind placebo-controlled trial of mavacamten (Camzyos) in 251 adults with symptomatic obstructive hypertrophic cardiomyopathy; 37% vs 17% met the pVO2/NYHA composite endpoint at 30 weeks.

Export of non-coding RNAs

Export of non-coding RNAs is the transport of snRNAs, snoRNAs, and tRNAs between the nucleus and cytoplasm, using dedicated export receptors such as CRM1 and Exportin-t.

Exposure and response prevention

Exposure and response prevention (ERP) is a cognitive-behavioral therapy in which patients deliberately confront feared stimuli while refraining from compulsions, the first-line psychological treatment for obsessive-compulsive disorder, typically over 12 to 20 sessions.

Exposure keratitis

Exposure keratitis (exposure keratopathy, EK): corneal damage from dryness due to incomplete eyelid closure or poor blinking. Common in ICU patients (pooled prevalence 34%); treated with lubricants, moisture chambers, taping, tarsorrhaphy.

Exposure therapy

Exposure therapy, also called in vivo, imaginal, or interoceptive exposure and including flooding and ERP, is a behavior therapy for anxiety disorders, OCD, and PTSD that uses repeated confrontation with feared stimuli; mechanisms debated between habituation and inhibitory learning models.

EXPRED trial

EXPRED (Exercise and Prediabetes After Renal Transplantation, NCT04489043), a Spanish Hospital Universitario de Canarias program: exercise training reversed prediabetes in 60% of kidney transplant recipients in EXPRED-I, with randomized EXPRED-II ongoing.

Expression cloning

Expression cloning is a molecular biology method that introduces a cDNA library into host cells and screens expressed proteins for binding or function to recover the gene.

Expression vector

Expression vector: DNA vehicle, usually a plasmid or virus, carrying a foreign gene plus promoter, replication origin, and selection marker to produce protein in bacterial, yeast, insect, mammalian, or plant host cells.

Expressive aphasia

Expressive aphasia, also called Broca's aphasia or motor aphasia, is a nonfluent aphasia from left frontal lobe damage, with effortful telegraphic speech, relatively spared comprehension, and treatment by speech-language therapy.

Exsanguination

Exsanguination, also called exsanguinating hemorrhage or total blood loss, is rapid extreme blood loss leading to hemorrhagic shock; it causes nearly half of early trauma deaths and is treated with damage-control resuscitation.

Exstrophy-epispadias complex

Exstrophy-epispadias complex (EEC, BEEC), also called bladder exstrophy-epispadias complex: rare congenital malformation spectrum from epispadias to classic bladder exstrophy and cloacal exstrophy (OEIS), incidence about 1/30,000, treated by staged or primary surgical repair.

Exsufflation

Exsufflation is an airway-clearance technique in which a device applies negative pressure to the airway to simulate a cough and mobilize mucus, used mainly in neuromuscular disease.

EXT2 (gene)

EXT2 (exostosin glycosyltransferase 2, HGNC:3513) is a human gene at 11p11.2 encoding exostosin-2, which with EXT1 forms the Golgi heparan sulfate co-polymerase; heterozygous variants cause multiple exostoses type 2, biallelic variants cause AREXT2 syndrome.

Extended evolutionary synthesis

The extended evolutionary synthesis (EES) is a proposed framework for evolutionary biology that would add development, non-genetic inheritance, and niche construction to the modern synthesis.

Oct 20, 2026

Extended Radical Mastectomy

Extended radical mastectomy is a breast cancer operation adding chest wall and internal mammary node removal to the radical mastectomy, introduced by Jerome Urban in 1951.

Extended spectrum beta-lactamase producing Escherichia coli

ESBL-producing Escherichia coli (ESBL-Ec): E. coli strains making extended-spectrum beta-lactamases, mainly CTX-M-15 in pandemic clone ST131, resistant to penicillins and cephalosporins, often carbapenem-treated; global intestinal carriage about 17.6 to 25.4%.

Extended thymectomy

Extended thymectomy is an operation that removes the thymus gland together with the surrounding anterior mediastinal fat, from diaphragm to thyroid, used mainly to treat myasthenia gravis.

Extended-spectrum beta-lactamase PER-1

PER-1 (Pseudomonas extended resistant) is a class A extended-spectrum beta-lactamase first found in 1993 in a Turkish patient's Pseudomonas aeruginosa isolate in France; it hydrolyzes ceftazidime, is clavulanate-inhibited, and is widespread in Turkey.