Human health and medicine

X-linked spondyloepimetaphyseal dysplasia

X-linked spondyloepimetaphyseal dysplasia (SEMDX, OMIM 300106) is a rare X-linked recessive bone dysplasia caused by BGN mutations at Xq28, causing short-trunk short stature, leg bowing, platyspondyly, and dysplastic epiphyses and metaphyses in males.

X-Ray Film

X-ray film: silver halide emulsion on a polyester base, used with intensifying screens as the classic radiographic image receptor; 8–12 line pairs/mm resolution, limited dynamic range, now largely replaced by digital detectors.

Oct 20, 2026

X-Ray Intensifying Screens

X-ray intensifying screens are fluorescent phosphor sheets in film cassettes that convert X-rays to visible light, cutting patient dose. Calcium tungstate dominated from 1896 until rare-earth phosphors arrived in the 1970s.

X-ray luminescence computed tomography

X-ray luminescence computed tomography (XLCT) is a hybrid imaging method, reported by Guillem Pratx and colleagues in 2010, that maps x-ray-excited luminescent nanoparticles inside an object from surface optical measurements.

Xaliproden

Xaliproden (SR 57746A) is an orally active, non-peptidic 5-HT1A receptor agonist with neurotrophic activity developed by Sanofi-Aventis for ALS, Alzheimer's disease, and neuropathy; phase III trials failed and development was discontinued.

Xanthelasma

Xanthelasma palpebrarum (XP) is the most common cutaneous xanthoma, a benign yellow lipid plaque on the eyelids, twice as common in women, linked variably to dyslipidemia, and treated by excision, CO2/Er:YAG laser, TCA peel, cryotherapy, or radiofrequency.

Xanthinol

Xanthinol (xanthinol nicotinate, xanthinol niacinate; CAS 2530-97-4 free base, 437-74-1 salt) is a water-soluble niacin-derivative vasodilator used for peripheral vascular insufficiency, causing flushing, gastric discomfort, and hypotension.

Xanthoma

Xanthoma (xanthelasma when on the eyelids) is a benign yellowish skin deposit of cholesterol-filled macrophage foam cells, usually signaling dyslipidemia; subtypes include plane, eruptive, tendinous, tuberous, and verruciform forms.

Xanthoma disseminatum

Xanthoma disseminatum (Montgomery syndrome, xanthoma multiplex) is a rare normolipidemic non-Langerhans cell histiocytosis with yellow-brown coalescing skin and mucosal papules, diabetes insipidus, CD68+/S100- histiocytes, and about 140 reported cases.

Xb&Nin trial

Xb&Nin (NCT06551870), Xbox Kinect Sports versus Nintendo Switch Sports: Chilean three-arm RCT in 45 inactive women aged 60-75 comparing 12 weeks of exergames against a control; Xbox Kinect Sports won on most outcomes.

Xeligekimab (GR1501)

Xeligekimab (GR1501, 赛立奇单抗, brand Jinlixi) is a fully human IgG4 monoclonal antibody neutralizing IL-17A, developed by Chongqing Genrix Biopharmaceutical and approved in China (2024 psoriasis, 2025 ankylosing spondylitis), the first domestic anti-IL-17A drug.

XELOX regimen

XELOX, also called CAPOX or OX, is a chemotherapy regimen combining oral capecitabine with intravenous oxaliplatin, used mainly for colorectal and other gastrointestinal cancers, and is an alternative to FOLFOX.

Xenazoic acid

Xenazoic acid (xenalamine, xenalmine, SKF-8318), CAS 1174-11-4, C23H21NO4, is a synthetic antiviral benzoic acid derivative introduced in the early 1960s and withdrawn in 1965 in France and Belgium for hepatic toxicity.

Xenodiagnosis

Xenodiagnosis is a diagnostic method in which laboratory-reared triatomine bugs feed on a patient's blood and are later examined for Trypanosoma cruzi, mainly to confirm chronic Chagas disease.

Xenotransfusion

Xenotransfusion is the transfusion of blood or blood products from another species into a human patient, investigated to relieve blood shortages, particularly in emergency settings.

Xenotransplantation

Xenotransplantation, also called heterologous transplantation, is the transfer of living cells, tissues, or organs from nonhuman animals, chiefly pigs, into human patients to ease the organ shortage.

Oct 20, 2026

Xeroderma pigmentosum variant

Xeroderma pigmentosum variant (XP-V, XPV) is a milder autosomal recessive subtype of xeroderma pigmentosum in which DNA polymerase eta is defective, causing skin cancers from about age 20–30.

Xeroderma pigmentosum-Cockayne syndrome complex

Xeroderma pigmentosum-Cockayne syndrome complex (XP-CS, XP/CS complex) is a rare autosomal recessive nucleotide excision repair disorder combining XP skin cancer risk with Cockayne syndrome growth failure and neurodegeneration, caused by ERCC3, ERCC2, or ERCC5 mutations.

Xeromammography

Xeromammography is xeroradiography of the breast, a filmless electrostatic X-ray method using selenium plates and dry toner, commercialized by Xerox around 1970-1971, widely used in the 1970s, and replaced by screen-film and digital mammography.

Xerophthalmia

Xerophthalmia, from Greek for dry eye, is the range of eye disorders caused by vitamin A deficiency, from night blindness and Bitot spots to blinding keratomalacia.

Xeroradiography

Xeroradiography is a dry electrostatic method for recording X-ray images using a selenium-coated plate and charged powder toner. It was widely used in mammography in the 1970s.

Xerostomia

Xerostomia (dry mouth) is the subjective sensation of oral dryness, distinct from hyposalivation. Main causes are medications, Sjögren's disease, diabetes, and head and neck radiotherapy; pilocarpine has the best-supported benefit.

Xevinapant

Xevinapant (AT-406, Debio 1143, SM-406) is an oral Smac-mimetic inhibitor of apoptosis proteins (XIAP, cIAP1/2) developed for head and neck cancer; positive phase II results were reversed by the negative phase III TrilynX trial, and development was discontinued in 2024.

Xiangsu Powder

香苏散 (Xiangsu Powder, Xiang Su San; Japanese Kōso-san) is a four-herb classic Chinese medicine formula (cyperus, perilla leaf, licorice, tangerine peel) first recorded in Song dynasty formulary texts, originally for wind-cold colds with qi stagnation, now used mainly for gastrointestinal complaints.

Xiao'er Huangjin Zhike granules

Xiao'er Huangjin Zhike granules (小儿黄金止咳颗粒), also called Pediatric Golden Cough Granules, is a Class 1.1 innovative TCM approved by NMPA on 3 January 2025 for children's mild acute bronchitis cough with phlegm-heat obstructing lung syndrome.

Xiao'er Niuhuang Tuire patch

Xiao'er Niuhuang Tuire patch (小儿牛黄退热贴膏), a class 1.1 TCM gel patch approved by NMPA in April 2025 by Jianmin Group, treats fever ≤38.5°C from wind-heat AURI in children 1–5 via Dazhui and Shenque acupoint application.

Xiaochengqi Tang

小承气汤 (Xiaochengqi Decoction), a mild purgative formula from the Shanghan Lun of rhubarb, magnolia bark, and bitter orange, used for mild yangming fu-excess and modern digestive disorders.

Xiaoer Tongbian granules

Xiaoer Tongbian granules (小儿通便颗粒), known during development as Xiaoer Biantong granules, is a traditional Chinese medicine approved by China's NMPA in August 2026 as the first innovative TCM for pediatric constipation.

Xiaoer Zibei Xuanfei Syrup

Xiaoer Zibei Xuanfei Syrup (小儿紫贝宣肺糖浆), also called Children's Zibei Xuanfei Syrup, is a traditional Chinese medicine syrup approved by China in 2023 for children's cough from acute bronchitis.