Ulcerative jejunitis See Ulcerative coeliac disease
Ulcerative Jejunoileitis A rare condition causing chronic idiopathic ulcerations in the small bowel. This disease is usually considered to be a complication of coeliac disease, but the disease does not always respond to glutenfree diet, and the prognosis is often serious. This disease is also called Refractory Coeliac Disease, and it is considered to be premalignant, or malignant in the form of a T-cell lymphoma. See also Ulcerative coeliac disease.
Ulcus simplex See Dielafoy´s syndrome
Ultrasound A sound with a frequency higher than the audible sound, that is above 20 KHz. Ultrasound used in imaging of the abdominal region has a frequency of 3.5 to 5 MHz. Ultrasound with this frequency is not transmitted in air but well transmitted in fluid and in solid tissues, however not is bones, and bones cannot be examined by ultrasound.
Unblinded trial A medical trial where all the participants are aware of which treatment is given. See also Blinded trial
Unconjugated familial hyperbilirubinemia See Gilbert´s syndrome
Unconjugated hyperbilirubinemia See bilirubin.
Unilateral Concerning one side of the body
United European Gastroenterology Week (UEGW) The premier European meeting in gastroenterology, arranged yearly, usually in the autumn. In 1999 this meeting was arranged in Rome.
Unresectable For example a lesion or tumour, which could not be surgically removed.
Upper GI series X-ray examination of the upper digestive system, oesophagus, stomach and duodenum. The patient drink a barium solution and x-ray-pictures are taken wher the outline of these organs are seen. Upper endoscopy is nowadays used primarily, and x-ray-examination is done only under special circumstansies, for example if the patient cannot swallow the endoscope.
UDCA (Abbr) Ursodeoxycholic acid
Ureter A tube which carries urine from the kidney to the urine bladder
URL (Abbr) Universal Resource Locator, the exact address of a site in the Internet address system.
UrolithiasisA stone (calculus) in the urinary tract
U.S. Gallon A liquid measure, measuring capacity. 1 U.S. gallon is 3.786 litre, and one litre is 0.264 U.S. gallons. 1 English gallon is 4.546 litre and 1 litre is 0.220 English gallons.