X - Xylyl

X

Symbol for Kienböck unit of x-ray dose; symbol for xanthine; symbol for exsanguinating hemorrhage. Symbol for unable to be assessed or measured.

Xalatan

(zal′ă-tan″) Latanoprost.

Xanax

(zan′aks″) Alprazolam.

xanthelasma

(zan″thĕ-laz′mă) [xantho- + Gr. elasma, (metal) plate] A xanthoma on the eyelids, esp. near the inner canthus. SEE: illus.

XANTHELASMA

xanthene

(zan′thēn″) [xantho- + -ene] O=(C₆H₄)₂=CH₂, a crystalline compound, from which various dyes are formed, including rhodamine and fluorescein.

xanthine oxidase

ABBR: XO. An enzyme of the oxidoreductase class that contains iron and molybdenum and catalyzes hypoxanthine to xanthin.

xantho-, xanth-

[Gr. xanthos, yellow, yellowish] Prefixes meaning yellow.

xanthochromia

(zan″thŏ-krō′mē-ă) [xantho- + chrom- + -ia] Yellowish discoloration resembling jaundice, as of the skin in patches or of the cerebrospinal fluid.

xanthochromic

(zan″thŏ-krō′mik), adj.

xanthogranuloma

(zan″thŏ-gran″yŭ-lō′mă) [xantho- + granuloma] A tumor having characteristics of both an infectious granuloma and a xanthoma.

 juvenile x. A skin disease that may be present at birth or develop in the first months of life. Firm, dome-shaped yellow, pink, or orange papules, ranging from a few millimeters to 4 cm in diameter, are usually present on the scalp, face, and upper trunk. Biopsy of these lesions reveals lipid-filled histiocytes, inflammatory cells, and Touton cells. The lesions regress spontaneously during the first years of life. Juvenile xanthogranuloma of the iris is one of the most common causes of bleeding into the anterior chamber of the eye in childhood.

xanthoma

(zan-thō′mă) [xantho- + -oma] A soft, yellow plaque or nodule on the skin, containing deposits of lipoproteins inside histiocytes. Xanthomas are esp. likely to be found on the skin of patients with hyperlipidemia.

xanthomatosis

(zan″thō″mă-tō′sĭs) [xanthoma + -osis] A deposition of lipid in tissues, usually accompanied by hyperlipemia. Cholesterol may accumulate in tumor nodules (xanthoma) or in individual cells, esp. histiocytes and reticuloendothelial cells.

xanthomatous

(zn-thō′măt-ŭs) [xanthoma + -ous] Pert. to a xanthoma or to xanthomatosis.

xanthophyll

(zan′thŏ-fil″) [xantho- + Gr. phyllon, leaf] A yellow pigment derived from carotene. It is present in some plants and egg yolk.

xanthous

(zan′thŭs) [xantho- + -ous] Yellow or yellowish.