A hiccup (scientific name singultus, from a Latin word meaning "to catch ones breath while sobbing"; also spelled hiccough) is an involuntary contraction (myoclonic jerk) of the diaphragm that may repeat several times per minute. The hiccup is an involuntary action involving a reflex arc. Once triggered, the reflex causes a strong contraction of the diaphragm followed about a quarter of a second later by closure of the vocal cords, which results in the "hic" sound. Hiccups may occur individually, or they may occur in bouts. The rhythm of the hiccup, or the time between hiccups, tends to be relatively constant. A bout of hiccups generally resolves itself without intervention, although many home remedies are often used to attempt to shorten the duration. Medical treatment is occasionally necessary in cases of chronic hiccups. Incidence
Hiccups affect people of all ages, even being observed in utero. They become less frequent with advancing age. Intractable hiccups, lasting more than a month, are more common in adults. While males and females are affected equally often, men are more likely to develop hiccups lasting more than 48 hours. Dogs may also get hiccups. Signs and symptoms
A hiccup consists of a single or a series of breathing diaphragm spasms, of variable spacing and duration, and a brief (less than one half second), unexpected, shoulder, abdomen, throat, or full body tremor. Hiccups may present as an audible chirp, squeak, "hupp", or if controlled, a quick inhaling gasp, sigh, or sniff.
deoxycholic acid), others such as ursodeoxycholic acid are thought to be chemopreventive, perhaps by inducing cellular differentiation and/or cellular senescence in colon epithelial cells. Chemistry
Ursodeoxycholic acid is an epimer of chenodeoxycholic acid, which has similar choleretic effects and a wider species distribution. However, CDCA is not as well-tolerated in humans and it does not show immunomodulating or chemoprotective effects. Both are 7-hydroxyl derivatives of deoxycholic acid, but UDCA has the group in the beta instead of the alpha orientation. Biosynthesis
Among mammals, only bears (Ursidae; excluding giant pandas) produce UDCA at useful amounts (>30%). It is produced in the bear liver, but the pathway remains unknown.Other vertebrates produce UDCA in much smaller amounts by gut bacteria. CDCA is oxidized into 7-oxo-CDCA then reduced into UDCA. Industrial production
UDCA is most commonly produced from cholic acid (CA) derived from bovine bile, a by-product of the beef industry. The current yield of this semisynthesis is about 30%. Society and culture
Names
The term is from the Latin noun ursus meaning bear, as bear bile contains the substance.Ursodeoxycholic acid can be chemically synthesized and is marketed under multiple trade names, including Ursetor, Udikast, Actibile, Actigall, Biliver, Deursil, Egyurso, Udcasid, Udiliv, Udinorm, Udoxyl, Urso, Urso Forte, Ursocol, Ursoliv, Ursofalk, Ursosan, Ursoserinox, Udimarin, Ursonova, and Stener. History
Bear bile, a natural source of UDCA, is used in traditional Chinese medicine since the seventh century. Japanese scientists successfully synthesized UDCA chemically in 1955.