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Article: False-negative biopsy urease test in bleeding ulcers caused by the buffering effects of blood

TitleFalse-negative biopsy urease test in bleeding ulcers caused by the buffering effects of blood
Authors
Issue Date1998
PublisherNature Publishing Group. The Journal's web site is located at http://www.nature.com/ajg/index.html
Citation
American Journal Of Gastroenterology, 1998, v. 93 n. 10, p. 1914-1918 How to Cite?
AbstractObjectives: A false-negative biopsy urease test (BUT) is common in Helicobacter pylori-associated bleeding peptic ulcers. Although blood in the stomach is thought to interfere with the biopsy urease test, the underlying mechanism remains unknown. This in vitro experiment sought to identify the blood component(s) that interfere with the biopsy urease test, and delineate the mechanism of inhibition. Methods: The modified Hazell's microtiter test was used to detect the urease activity of H. pylori. A positive result was indicated by a color change of the pH indicator, bromothymol blue, at 630 μm. Human whole blood, sera with and without anti-H. pylori antibody, electrolytes, and enzymes were incubated with H. pylori to identify the blood component(s) causing the inhibition of urease activity. In addition, any interference of the pH color indicator was tested by adding different concentrations of serum albumin to the urease reagent that contained a fixed quantity of ammonia in the absence of H. pylori. Results: The color change of the microtiter urease test was significantly reduced by blood (p < 0.0001), regardless of the presence of anti-H. pylori antibody. Electrolytes and serum enzymes did not interfere with the urease test. The color change of the pH indicator was progressively suppressed by higher concentrations of serum albumin. Conclusions: Blood adversely affects the performance of the BUT. This is mediated by the buffering effect of serum albumin on the pH indicator, rather than by a direct inhibition on the urease activity.
Persistent Identifierhttp://hdl.handle.net/10722/162258
ISSN
2015 Impact Factor: 10.383
2015 SCImago Journal Rankings: 3.946
References

 

DC FieldValueLanguage
dc.contributor.authorLeung, WKen_US
dc.contributor.authorSung, JJYen_US
dc.contributor.authorSiu, KLKen_US
dc.contributor.authorChan, FKLen_US
dc.contributor.authorLing, TKWen_US
dc.contributor.authorCheng, AFBen_US
dc.date.accessioned2012-09-05T05:18:27Z-
dc.date.available2012-09-05T05:18:27Z-
dc.date.issued1998en_US
dc.identifier.citationAmerican Journal Of Gastroenterology, 1998, v. 93 n. 10, p. 1914-1918en_US
dc.identifier.issn0002-9270en_US
dc.identifier.urihttp://hdl.handle.net/10722/162258-
dc.description.abstractObjectives: A false-negative biopsy urease test (BUT) is common in Helicobacter pylori-associated bleeding peptic ulcers. Although blood in the stomach is thought to interfere with the biopsy urease test, the underlying mechanism remains unknown. This in vitro experiment sought to identify the blood component(s) that interfere with the biopsy urease test, and delineate the mechanism of inhibition. Methods: The modified Hazell's microtiter test was used to detect the urease activity of H. pylori. A positive result was indicated by a color change of the pH indicator, bromothymol blue, at 630 μm. Human whole blood, sera with and without anti-H. pylori antibody, electrolytes, and enzymes were incubated with H. pylori to identify the blood component(s) causing the inhibition of urease activity. In addition, any interference of the pH color indicator was tested by adding different concentrations of serum albumin to the urease reagent that contained a fixed quantity of ammonia in the absence of H. pylori. Results: The color change of the microtiter urease test was significantly reduced by blood (p < 0.0001), regardless of the presence of anti-H. pylori antibody. Electrolytes and serum enzymes did not interfere with the urease test. The color change of the pH indicator was progressively suppressed by higher concentrations of serum albumin. Conclusions: Blood adversely affects the performance of the BUT. This is mediated by the buffering effect of serum albumin on the pH indicator, rather than by a direct inhibition on the urease activity.en_US
dc.languageengen_US
dc.publisherNature Publishing Group. The Journal's web site is located at http://www.nature.com/ajg/index.htmlen_US
dc.relation.ispartofAmerican Journal of Gastroenterologyen_US
dc.subject.meshBiopsyen_US
dc.subject.meshBuffersen_US
dc.subject.meshFalse Negative Reactionsen_US
dc.subject.meshHelicobacter Infections - Diagnosisen_US
dc.subject.meshHelicobacter Pylori - Isolation & Purificationen_US
dc.subject.meshHumansen_US
dc.subject.meshHydrogen-Ion Concentrationen_US
dc.subject.meshPeptic Ulcer Hemorrhage - Microbiologyen_US
dc.subject.meshSensitivity And Specificityen_US
dc.subject.meshSerum Albumin - Pharmacologyen_US
dc.subject.meshUrease - Analysisen_US
dc.titleFalse-negative biopsy urease test in bleeding ulcers caused by the buffering effects of blooden_US
dc.typeArticleen_US
dc.identifier.emailLeung, WK:waikleung@hku.hken_US
dc.identifier.authorityLeung, WK=rp01479en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1111/j.1572-0241.1998.00457.xen_US
dc.identifier.pmid9772055-
dc.identifier.scopuseid_2-s2.0-0032419067en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-0032419067&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume93en_US
dc.identifier.issue10en_US
dc.identifier.spage1914en_US
dc.identifier.epage1918en_US
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLeung, WK=7201504523en_US
dc.identifier.scopusauthoridSung, JJY=35405352400en_US
dc.identifier.scopusauthoridSiu, KLK=7102312059en_US
dc.identifier.scopusauthoridChan, FKL=7202586434en_US
dc.identifier.scopusauthoridLing, TKW=13310253900en_US
dc.identifier.scopusauthoridCheng, AFB=7402075035en_US

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