Life and health

Gastroscopes

Gastroscopes, also called upper endoscopes or EGD scopes, are flexible camera tubes for examining the esophagus, stomach, and duodenum; diameters 4.9–12.8 mm, with single-use and reusable variants compared in recent evidence.

Gastroscopy

Gastroscopy, also called esophagogastroduodenoscopy or EGD, is an endoscopic procedure in which a flexible camera passed through the mouth examines the esophagus, stomach, and upper duodenum.

Gastrostomy

Gastrostomy is the creation of an opening through the abdominal wall into the stomach, most often to place a feeding tube for long-term enteral nutrition in patients with swallowing difficulty.

Gastrostomy malfunction

Gastrostomy malfunction (ICD-11 DE12.1) covers feeding tube dislodgement, leakage, obstruction, and buried bumper after gastrostomy; displacement affects about 10.8% of adults, clogging 25-35%.

Gastrotheca

Gastrotheca, marsupial frogs (Hemiphractidae), 79 Neotropical species whose females incubate eggs in a dorsal brood pouch; embryos bear bell gills, and tadpoles re-evolved within the genus.

Gastrotrich

Gastrotricha, hairy-bellied worms, a phylum of about 900 microscopic acoelomate meiofaunal worms in two orders, Chaetonotida and Macrodasyida, sister to Platyhelminthes, feeding via a triradiate pharynx.

Gastrulation

Gastrulation: early embryogenesis stage converting a blastula into a multilayered gastrula with ectoderm, mesoderm, and endoderm via emboly, epiboly, convergence, and extension; in humans it begins around day 14 with the primitive streak.

GATA1

GATA1 (GATA binding protein 1, ERYF1, NF-E1) is an X-linked zinc finger transcription factor binding (A/T)GATA(A/G) motifs that master-regulates erythroid and megakaryocytic differentiation; its GATA1s truncation causes Down syndrome leukemias and dyserythropoietic anemia.

GATA2

GATA2 (GATA binding protein 2) is a zinc-finger transcription factor gene essential for hematopoietic stem cell maintenance; germline mutations cause GATA2 deficiency syndrome (MonoMAC, DCML, Emberger) with MDS/AML and immunodeficiency.

Oct 20, 2026

GATA3

GATA3 (GATA binding protein 3) is a zinc-finger transcription factor at 10p14, master regulator of Th2 differentiation, cause of HDR syndrome when haploinsufficient, and a sensitive immunohistochemical marker of breast and urothelial carcinoma.

GATA4

GATA4 (GATA binding protein 4), gene at 8p23.1, encodes a GATA-family zinc-finger transcription factor regulating cardiac and testicular development; mutations cause congenital heart defects and 46,XY DSD.

GATA6

GATA6 (GATA-binding factor 6) is a zinc-finger transcription factor gene on 18q11.2 regulating heart and pancreas development; mutations cause congenital heart defects, pancreatic agenesis, and neonatal-to-adult diabetes.

Gated Blood-Pool Imaging

Gated blood-pool imaging, also called MUGA, ERNA, or gated radionuclide ventriculography, is an ECG-gated nuclear medicine scan using Tc-99m-labeled red blood cells to measure left ventricular ejection fraction reproducibly, mainly for chemotherapy cardiotoxicity monitoring.

Gated single-photon emission computed tomography

Gated single-photon emission computed tomography (gated SPECT, GSPECT) is a nuclear medicine method, developed in the late 1980s, that synchronizes heart perfusion imaging with the cardiac cycle to measure left ventricular function.

Gatekeeping

Gatekeeping: a health-system arrangement in which a primary care physician or GP controls access to specialist care by referral. Also GP gatekeeping. Used in 31 of 38 OECD countries; reduces specialist use and costs but lowers patient satisfaction.

Gaucher's disease

Gaucher's disease (Gaucher disease) is a rare autosomal recessive lysosomal storage disorder caused by GBA1 variants and glucocerebrosidase deficiency, with types 1, 2, and 3, treated by enzyme replacement or substrate reduction therapy.

Gaudeamus

Gaudeamus is an extinct hystricognathous rodent genus from the late Eocene and early Oligocene of Egypt, Libya, Oman, and Morocco; type species G. aegyptius Wood, 1968, basis of the family Gaudeamuridae, not the student song or conference.

Sep 20, 2026

Gaudenz Danuser

Gaudenz Danuser is a computational biologist who develops computer-vision methods for live-cell imaging of cancer cells; he led bioinformatics at UT Southwestern before joining Roche's Institute of Human Biology in 2025.

Gaultheria

Gaultheria is a genus of heath-family shrubs and subshrubs, named by Linnaeus in 1753, whose berry-like fruits and leaves yield wintergreen oil; it includes wintergreen and salal.

Gaultheria shallon

Gaultheria shallon, salal or shallon, an evergreen Ericaceae shrub native from Alaska to California, forming rhizomatous thickets with urn-shaped flowers and edible purple pseudoberries used for food and floral greenery.

Gaur

Gaur (Bos gaurus, Indian bison, seladang), largest living wild bovine, native to South and Southeast Asia; IUCN Vulnerable since 1986, CITES Appendix I, about 85% of the population in India; ancestor of domestic mithun.

GAUT (galacturonosyltransferase) family

The GAUT (galacturonosyltransferase) family is a group of plant Golgi enzymes of glycosyltransferase family 8 that transfer galacturonic acid onto pectin backbones, building homogalacturonan, which makes up roughly 55–70% of pectin.

Sep 21, 2026

Gautam Dantas

Gautam Dantas is a microbiologist at Washington University in St. Louis known for research on antibiotic resistance genes in soil, animals, and the human gut.

Gauze sponge

Gauze sponge: a folded square of absorbent woven or non-woven cotton gauze (USP Type VII, 4x4 inch, 8-16 ply) used to absorb fluid, dress, clean, or pack wounds; first sterilized in bulk by Johnson & Johnson in 1887; main risk is retention, causing 48-69% of retained surgical items.

Gavage

Gavage is the delivery of liquid nutrition or medication through a tube passed into the stomach, by nose or mouth, used for feeding, gastric decompression, and rodent dosing.