Linked Life Data

9508511

Source:http://linkedlifedata.com/resource/pubmed/id/9508511

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-3-13
pubmed:abstractText
The therapeutic potential of urease inhibition of Helicobacter pylori has been studied by examining the effect of the potent urease inhibitor, fluorofamide (N-(diaminophosphinyl)-4-fluorobenzenamide), on urease activity and bacterial survival in vivo and in vitro. In culture, acid protection in H. pylori was shown to be due to changes in the pH of the medium brought about by the release of ammonia. Both the acid protection and the ammonia release were completely blocked by fluorofamide at low doses (ED50 = approximately 100 nM). However, fluorofamide was unstable under acidic conditions (T1/2 = 5.7 min at pH 2). Despite this, fluorofamide was the best available compound to test in vivo. In ferrets naturally infected with H. mustelae, a single dose (50 mg/kg, per os) of fluorofamide completely inhibited bacterial urease. In repeat dosing studies, fluorofamide (50 mg/kg per os, three times a day) was compared with the Helicobacter triple therapy regime (amoxycillin, metronidazole, and bismuth subcitrate). Fluorofamide failed to eradicate the H. mustelae infection, compared to 80% eradication with triple therapy. However, histological samples showed a profound reduction in bacterial numbers following fluorofamide treatment. A combination of fluorofamide and amoxycillin was dosed to ferrets (seven days of treatment with 50 mg/kg fluorofamide plus 10 mg/kg amoxycillin per os twice a day); however, this failed to eradicate the infection, despite there being a reduction in bacterial numbers in 3/5 ferrets after 21 days after dosing stopped. It was concluded that urease inhibitors (either alone or in combination with antibiotics) are unlikely to have therapeutic potential for Helicobacter pylori infections. This is probably because, in vivo, some bacteria (perhaps dormant forms) are not entirely dependent upon urease for survival. However, given the acid instability of fluorofamide, the possibility that more stable urease inhibitors might have therapeutic potential, cannot be excluded.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0163-2116
pubmed:author
pubmed:issnType
Print
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
109-19
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Effect of potent urease inhibitor, fluorofamide, on Helicobacter sp. in vivo and in vitro.
pubmed:affiliation
SmithKline Beecham, The Frythe, Welwyn, Herts, UK.
pubmed:publicationType
Journal Article