Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-ulcer dyspepsia (NUD) means the presence of upper abdominal pain and discomfort and also nausea, vomiting, flatulence, heartburn and belching. It is estimated, that about 20-30% of all patients refer to a doctor because of dyspeptic symptoms. Helicobacter pylori (Hp) infections are diagnosed in about 60% of persons with NUD and in 80-100% of patients with clinical, endoscopic and histological diagnosis of gastritis. The authors decided to investigate a correlation between gastritis and Hp infection and a relationship between the influence of antibacterial therapy and Hp eradication from gastric mucus and to observe gastric mucosa condition. We examined 73 patients (range age 16-73): 40 females and 33 males. We employed the Sydney System for evaluation of gastric mucosa condition. The patients were divided into two groups: Hp-positive 50 persons and Hp-negative-23 persons. Hp infected subjects were treated with antibacterial drugs (bismuth + metronidazol + amoxycillin or bismuth + metronidazol + tetracycline) and Hp-negative only with bismuth. Hp eradication was obtained in 72.7% of patients treated with bismuth + metronidazol + amoxycillin and 76.4% of persons treated with bismuth + metronidazol + tetracycline. A statistically significant difference between these two kinds of antibacterial therapy was not noted. Both methods are equally effective. We observed also and improvement of the histological state of antrum and corpus gastric mucosa after therapy in comparison to changes before treatment. We noticed a decrease of dyspeptic complaint in 89.2% of Hp infected persons in whom Hp had been eradicated. Among Hp-negative 23 patients gastric mucosa was normal in 30% and chronic gastritis was found in 70% of subjects. Based upon the present results it seems very important and suitable to detect Hp organisms in gastric mucus of all dyspeptic patients who are endoscopically examined and biopsied at the same time. We would suggest to do an urease test and to take histological samples together with full endoscopic examination according to the Sydney System guidelines.
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PMID:Non-ulcer dyspepsia and Helicobacter pylori infection--morphological analysis according to the Sydney system--changes before and after treatment. 885 27

Most current non-invasive tests for Helicobacter pylori depend on the conversion of labelled (13C or 14C) urea to labelled carbon dioxide (13CO2 or 14CO2) and ammonium (NH4+) by the enzyme urease, with the labelled CO2 detected in exhaled air. Despite suggestions going back over a number of years, the alternative possibility of using NH4+ (in the form of gaseous ammonia [NH3]) as the test parameter has received little or no attention. However, this approach is now being explored using a chemiresistive sensor detecting sub-parts per million concentrations of NH3. An in vitro 'glass stomach' (containing various volumes of hydrochloric acid [HCl] and ammonium chloride [NH4Cl]) was used to evaluate the means of increasing 'gastric' pH to that of the NH4+-->NH3 transition that occurs significantly at pH 9.24. This 'stomach' also was used to study mechanisms by which NH3 may be expelled in a pulse (as a surrogate belch), either by the in situ production of CO2 or through an exogenous source. On the basis of the protocols developed, H. pylori-negative subjects were tested before and after ingestion of 10 mg NH4Cl (as a surrogate for bacteria-produced NH4,), and H. pylori-positive subjects were tested without taking urea or NH4Cl. 'Intragastric' pH in the in vitro 'glass stomach' could be increased above pH 9.24 by adding a mixture of 15-30 mL magnesium hydroxide mixture (or the proprietary equivalent) and 50 mL water, and the resulting NH3 expelled by adding 100 mL CO2-saturated cold water (sparkling water). In vivo, NH3 levels in the oral cavity of H. pylori-negative subjects were increased after ingestion of 10 mg NH4Cl; however, levels in the oral cavity of a small number of H. pylori-positive subjects were two- to threefold higher after magnesium hydroxide and sparkling water. On the basis of in vitro studies, an in vivo protocol was developed to increase gastric pH above that required for the NH4+-->NH3 transition, and a mechanism established to release the NH3 into the oral cavity. Preliminary in vivo data confirm the chemiresistive sensor is sufficiently sensitive to NH3 to distinguish H. pylori-negative subjects who have taken 10 mg NH4Cl from those who have not, and clearly distinguish H. pylori-negative subjects from H. pylori-positive subjects. Ingestion of urea or other labelled tracers is not required, nor is belching; and the sensor takes less than two minutes to reach a maximum response. The data provide good evidence that the chemiresistive detection of NH3 has considerable potential as a rapid, point-of-care diagnostic test for H. pylori infection.
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PMID:Ammonia vapour in the mouth as a diagnostic marker for Helicobacter pylori infection: preliminary 'proof of principle' pharmacological investigations. 1144 Feb 9