Urease, distribution specificity

An enzyme deposited on the LAPS surface allows one to observe the spatial distribution of a specific substrate. In a urea-selective sensor urease was immobilized on a pH-selective LAPS [75],... 

The diagnosis of HP infection can be made using endoscopic or nonendoscopic tests (Table 33-6). The tests that require upper endoscopy are more expensive, uncomfortable, and require a mucosal biopsy for histology, culture, or detection of urease activity. Recommendations to maximize the diagnostic yield include taking at least three tissue samples from specific areas of the stomach, as patchy distribution of HP infection can lead to false-negative results. Because certain medications may decrease the sensitivity of these tests, antibiotics and bismuth salts should be withheld for 4 weeks and PPIs for 1 to 2 weeks prior to endoscopic testing. 

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