The urea breath test (UBT) is a procedure for diagnosing the presence of a bacterium, Helicobacter pylori (H. pylori) that causes inflammation, ulcers, and atrophy of the stomach. The test also may be used to demonstrate that H. pylori has been eliminated by treatment with antibiotics.
The urea breath test is based on the ability of H. pylori to break down urea, a chemical made of nitrogen and carbon, that normally is produced by the body from excess (“waste”) nitrogen and then eliminated in the urine. For the test, patients swallow a capsule containing urea made from an isotope of carbon. (Isotopes of carbon occur in minuscule amounts in nature, and can be measured with special testing machines.) If H. pylori is present in the stomach, the urea is broken up into nitrogen and carbon (as carbon dioxide). The carbon dioxide is absorbed across the lining of the stomach and into the blood. It then is excreted from the lungs in the breath. Samples of exhaled breath are collected, and the isotopic carbon in the exhaled carbon dioxide is measured.
If the isotope is detected in the breath, it means that H. pylori is present in the stomach. If the isotope is not found, H. pylori is not present. When the H. pylori is effectively treated (eradicated) by antibiotics, the test changes from positive (isotope present) to negative (isotope absent).
A bacterium that commonly infects the urogenital tract and can cause premature birth or spontaneous abortion. During delivery, ureaplasma can infect the newborn and cause meningitis, pneumonia, or septicemia. Ureaplasma is similar to mycoplasma. They are among the smallest free-living organisms known. Ureaplasma lacks several proteins standard in comparable organisms. Its low biosynthetic capacity means […]
The presence of excessive amounts of urea in the blood, which may be a sign of kidney disease or failure. It is also referred to as azotemia. See also urea.
One of the two tubes that carry urine from the kidneys to the bladder. Each ureter arises from a kidney, descends, and ends in the bladder.
The tube that leads from the bladder and transports and discharges urine outside the body. In males, the urethra travels through the penis and carries semen as well as urine. In females, the urethra is shorter than in the male, and it emerges above the vaginal opening.
- Urethral sphincter
the internal and external urinary sphincters. Part of the muscular bladder wall acts as the internal urethral sphincter and prevents urine from leaving the bladder to enter the urethra. This sphincter cannot be willfully controlled but is under involuntary control by the brain. A layer of muscle called the urogenital diaphragm supplies support for the […]