Human health and medicine

Status quo bias

Status quo bias, coined by Samuelson and Zeckhauser (1988), is the non-rational preference for keeping the current state or default option, explained by loss aversion, transition costs, and sunk costs, and documented in health plans, retirement saving, and organ donation.

STAU1

STAU1 is a human gene on chromosome 20 that encodes Staufen1, an RNA-binding protein involved in mRNA transport, translation, and decay, and linked to prostate cancer.

Steady-state free precession imaging

Steady-state free precession (SSFP) is an MRI pulse sequence that uses rapid repeated radiofrequency pulses to maintain steady transverse magnetization, producing high-signal images with bright-fluid contrast.

Oct 15, 2026

Steady-state visually evoked potential

The steady-state visually evoked potential (SSVEP) is the brain's periodic electrical response to a flickering visual stimulus, recorded from the scalp and easy to isolate in the frequency domain.

Steatopygia

Steatopygia: pronounced accumulation of fat on the buttocks and thighs, described among Khoisan peoples, depicted in Paleolithic and Jomon figurines, and causing imaging artifacts in obese patients.

Steatorrhea

Steatorrhea, also called fatty stool, is excess fat in stool (>7 g/day) from fat malabsorption or maldigestion. Causes include exocrine pancreatic insufficiency, celiac disease, and bile acid deficiency; diagnosed by 72-hour fecal fat testing or fecal elastase.

Steatosis

Steatosis, also known as fatty degeneration, is the abnormal retention of fat within cells, most often the buildup of triglycerides in liver cells that marks fatty liver disease.

Steel syndrome

Steel syndrome (STLS, OMIM 615155): rare autosomal recessive skeletal dysplasia from biallelic COL27A1 variants, with short stature, congenital hip and radial head dislocation, carpal coalition, scoliosis; Puerto Rican founder mutation p.Gly697Arg.

Stellate ganglion block

A stellate ganglion block (SGB) is an injection of local anesthetic beside the cervical sympathetic trunk in the neck, used to treat conditions like CRPS and PTSD.

Oct 20, 2026

Stellate multiform amelanotic choroidopathy

Stellate multiform amelanotic choroidopathy (SMACH), formerly serous maculopathy due to aspecific choroidopathy, is a rare choroidal disease with stellate amelanotic lesions, subretinal fluid in about 59% of cases, and stable lesion size.

Stellate neuron

Stellate neuron (Cell Ontology CL:0000122, stellate cell): a neuron with star-shaped radiating dendrites. Distinct populations exist in cerebellar molecular layer (GABAergic), neocortical layer 4 (excitatory spiny stellate), and entorhinal cortex layer II (grid-cell related).

Stellate non-hereditary idiopathic foveomacular retinoschisis

SNIFR (stellate non-hereditary idiopathic foveomacular retinoschisis) is a rare, usually unilateral macular schisis of the Henle fiber layer in middle-aged women, described by Ober et al. in 2014, with preserved vision and diagnosis by exclusion.

Stem Cell Transplantation

Stem cell transplantation (HSCT, bone marrow transplant): infusion of healthy blood-forming stem cells after high-dose chemotherapy; autologous, allogeneic, syngeneic, or cord blood; treats leukemia, lymphoma, myeloma, aplastic anemia, sickle cell disease.

STEM trial

STEM trial (Supportive Text vs Email Messaging trial, NCT04638231): randomized noninferiority pilot trial in Edmonton, Canada comparing daily CBT-based supportive text messages versus email for major depressive disorder; found no significant difference between channels (N=66).

STEMI equivalents and occlusion patterns

STEMI equivalents are ECG patterns indicating acute coronary artery occlusion when standard ST-elevation criteria are absent, including de Winter pattern, posterior MI, Wellens syndrome, and modified Sgarbossa-positive LBBB; missing them delays reperfusion.

Steno-2 trial

Steno-2 trial: Danish randomized trial (1993) of intensified versus conventional multifactorial treatment in 160 patients with type 2 diabetes and microalbuminuria; 53% lower cardiovascular risk, 7.9 years longer median survival.

Oct 20, 2026

Stenosis of larynx

Stenosis of larynx, or laryngotracheal stenosis, is narrowing of the laryngeal airway, usually from intubation injury or idiopathic subglottic stenosis; treated endoscopically or by open resection and reconstruction.

Stenosis of the rectum

Stenosis of the rectum (rectal stenosis, ICD-11 DB30.4) is narrowing of the rectum from malignant or benign, intrinsic or extrinsic causes; anastomotic stricture after rectal resection affects 3-20%, treated first by endoscopic balloon dilation.

Stent

Stent: small mesh tube (bare metal, drug-eluting, stent graft, silicone) holding open arteries, ureters, bile ducts, or airways; evolved from 1977 balloon angioplasty, first FDA-approved 1987; main failures restenosis and thrombosis.

Stent graft implantation

Stent graft implantation is an endovascular procedure in which a fabric-covered metal scaffold is placed inside a blood vessel to exclude aneurysms, first reported by Juan Parodi in 1991.

Stent implantation

Stent implantation is a percutaneous procedure in which a small metal mesh tube is expanded inside a narrowed coronary artery to hold the vessel open and restore blood flow.

Stent retriever thrombectomy

Stent retriever thrombectomy is an endovascular procedure that removes a clot from a cerebral artery by deploying a stent-like mesh across it and withdrawing the device.

Stent-electrode recording array

Stent-electrode recording array (Stentrode, Synchron): a nitinol stent with 16 platinum electrodes implanted via the jugular vein into the superior sagittal sinus to record vascular ECoG for brain-computer interfaces in paralysis; first-in-human SWITCH trial showed no serious adverse events over 12 months.

Stenting

Stenting is a medical procedure that places a small mesh tube, called a stent, into a narrowed artery or passage such as the esophagus to hold it open.

Step nucleic acid amplification test

Step nucleic acid amplification test (sNAAT) is a proposed label for an isothermal nucleic acid amplification test detecting pathogen genomes at one constant temperature, without PCR's thermal cycling.

STEP trial (NCT03015311)

STEP (NCT03015311), Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients: Chinese randomized trial of 8,511 patients aged 60-80 testing intensive systolic target 110-<130 mm Hg versus 130-<150 mm Hg; intensive treatment cut cardiovascular events (HR 0.74; 6-year HR 0.82).

STEP trial (NCT03137368)

STEP (NCT03137368) is a Phase 3 Chinese trial comparing exemestane plus ovarian function suppression/ablation versus tamoxifen plus ovarian suppression in premenopausal ER-positive, HER2-negative breast cancer with CYP2D6*10 T/T genotype; 300 planned participants, primary endpoint disease-free survival.