Richard A. Mountford

The roles of enteric bacterial sialidase, sialate O-acetyl esterase and glycosulfatase in the degradation of human colonic mucin

Sialidase activity in normal faecal extracts showed a preference for mucin-related glycoprotein and oligosaccharide substrates, but the presence of two or moreO-acetyl esters at positions C7–C9 on the sialic acids retarded the rate of hydrolysis. A specific sialateO-acetyl esterase was detected with a lower total activity relative to sialidase with mucin substrates and having a pH optimum of 7.8 and aKM of approximately 1mm sialateO-acetyl ester. A specific glycosulfatase activity was found in faecal extracts using the substrate lactit-[3H]ol 6-O-sulfate with a pH optimum of pH 5.0 and aKM of approximately 1mm.Faecal extracts from ulcerative colitis (UC) patients had higher sialateO-acetyl esterase and glycosulfatase activity, while mucin sialidase activity was unchanged.Metabolically labelled mucin isolated from UC patients contained less sulfate and had lower sialic acidO-acetylation compared with normal mucin. Colonic mucin was degraded more efficiently by faecal extracts from UC patients compared with normal extracts. The UC mucin was degraded more rapidly than the normal mucin by faecal enzyme extracts from both normal and UC subjects.

Prevalence of Helicobacter pylori in respiratory physicians performing bronchoscopy : a comparison with gastroenterologists using the carbon 13 urea breath test

The mode of transmission of Helicobacter pylori is unclear, but it has been shown that gastroenterologists are at a greater risk of acquiring the infection when performing endoscopy. The current study was designed to assess the risk H. pylori infection in respiratory physicians performing bronchoscopy compared to an at‐risk group of gastroenterologists. We were interested in identifying whether the oral cavity is important in the transmission of H. pylori.