The short chain fatty acids, acetate, propionate, and butyrate are produced by colonic bacterial fermentation of non-starch polysaccharides. Butyrate is the major fuel source for the colonic epithelium and there is evidence to suggest that its oxidation is impaired in ulcerative colitis. Triplicate biopsy specimens were taken at colonoscopy from five regions of the large bowel in 15 sufferers of ulcerative colitis. These patients ali had mild or quiescent colitis as assessed by clinical condition, mucosal endoscopic and histological appearance. The rate of oxidation of glucose, glutamine, and butyrate through to carbon dioxide was compared with that in biopsy specimens from 28 patients who had no mucosal abnormality. ) was the preferred fuel source for the colitic mucosa followed by glutamine (33 (24-62)) then glucose (7.2 (5-3-15)) pmol/tg/hour; medians and 95% confidence intervals, p< 001. There was no regional difference in the rate of utilisation of these metabolites. In the group with colitis the rate of butyrate oxidation to carbon dioxide was significantly impaired compared with that in normal mucosa decreasing from 472 (351-637) pmol/tg/hour to 272 pmol/4tgfhour; median and 95% confidence intervals, p=0016. The rate of glucose and glutamine utilisation were not significantly different between normal and colitic mucosa. These data confirm that in quiescent ulcerative colitis there is an impairment of butyrate oxidation. (Gut 1994; 35: 73-76) exhibited an impaired ability to metabolise butyrate.7 This led to the hypothesis that ulcerative colitis is characterised by an energy deficiency, its predilection for the distal colon reflecting its greater dependence on butyrate as a fuel source.Roediger's work can be criticised as there was doubt about the viability of the cell suspensions, 15-30% of the cells exhibited damaged membranes and their oxygen consumption was linear for only one hour. Also, all the patients from whom the colonocytes were isolated had severe colitis needing resection and hence the changes seen in butyrate oxidation may have been secondary to the inflammatory response.We have developed and validated a radiotracer technique to study the rate of fuel substrate oxidation in endoscopically obtained biopsy samples. We have shown that in normal large bowel mucosa there is no regional variation in the rate of substrate oxidation.8 Using this technique we have investigated the regional variation in the rate of substrate oxidation in colonoscopically obtained mucosal biopsy specimens from 15 sufferers of quiescent colitis and we have compared this with substrate oxidation in biopsy specimens of healthy mucosa from 28 patients. The fuel substrates used were butyrate, glutamine, and glucose. Glutamine was chosen, as it is the preferred fuel substrate for the small intestinal enterocyte and may play a part in the nutrition of the large bowel, especially if there was an inability to utilise butyrate.9 Glucose metabolism was measured as it is the ubiquitous fuel source for mammalian cells. ...

Two outbreaks of gastroenteritis in the UK which occurred nine days apart at Lymington and Southampton hospitals were investigated. The clinical and epidemiological features of both outbreaks were characteristic of small round-structured virus (SRSV) infection with rapid onset of diarrhoea and/or nausea and vomiting and propagation of the outbreaks by secondary spread. SRSV particles were observed by immune electron microscopy (EM) in 60% of faecal samples from both outbreaks and no other pathogens were detected. The index case for the second outbreak was a patient who was admitted with diarrhoea and vomiting after being discharged from Lymington hospital during the first outbreak. The possibility that the two outbreaks were caused by the same strain of SRSV was investigated by the polymerase chain reaction (PCR). New inosine-containing PCR primers were designed to amplify the RNA polymerase region of SRSV cDNA from genetic groups I and II. The PCR using the group II primers achieved a higher detection rate for SRSVs in faecal samples (68% of samples positive from both outbreaks) than immune EM. SRSVs were not detected using the group I primers or using conventional degenerate PCR primers. The nucleotide sequences of PCR amplicons from both outbreaks were identical providing molecular epidemiological evidence for the involvement of a single SRSV strain. Comparison of the RNA polymerase region of this virus with the equivalent regions of genetic group I (69.4-75.0% amino acid identify) and genetic group II (88.9-100% amino acid and 77.1-88.1% nucleotide identity) SRSVs revealed that the causative SRSV was a distinct member of genetic group II.

Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72°C was investigated. Anaerobic sediment slurries prepared from local freshwater pond sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. Reductive 2,4-DCP dechlorination occurred only in the temperature range between 5 and 50°C, although methane was formed up to 60°C. In sediment samples from two sites and at all tested temperatures from 5 to 50°C, 2,4-DCP was transformed to 4-chlorophenol (4-CP). The 4-CP intermediate was subsequently degraded after an extended lag period in the temperature range from 15 to 40°C. Adaptation periods for 2,4-DCP transformation decreased between 5 and 25°C, were essentially constant between 25 and 35°C, and increased in the tubes incubated at temperatures between 35 and 40°C. The degradation rates increased exponentially between 15 and 30°C, had a second peak at 35°C, and decreased to about 5% of the peak activity by 40°C. In tubes from one sediment sample, incubated at temperatures above 40°C, an increase in the degradation rate was observed following the minimum at 40°C. This suggests that at least two different organisms were involved in the transformation of 2,4-DCP to 4-CP. Storage of the original sediment slurries for 2 months at 12°C resulted in increased adaptation times, but did not affect the degradation rates.

SUMMARY Intraluminal pressure activity has been recorded in the unprepared true sigmoid colon of seven normal controls (mean age 37 years, range 22-55, three men) and seven patients with irritable bowel syndrome (IBS) (45 years, 24-75, four men) for 30 minutes before and 100 minutes after a standard 1000 kcal meal. Results differ from previously published data'3' by showing much higher indices of pressure activity with amplitudes up to 490 mmHg in IBS, and 450 mmHg in controls. Study segment activity index and mean pressure wave amplitudes were significantly (p<0O015 and p

SUMMARY Twenty one patients with diabetic peripheral neuropathy, 18 with idiopathic faecal incontinence and 11 normal controls were studied with techniques of mucosal electrosensitivity, rectal distension for the quantitative assessment of anorectal sensation, and manometric and electromyographic tests for the assessment of anorectal motor function. An asymptomatic sensorimotor deficit was found in the anal canal of patients with diabetic peripheral neuropathy. Mucosal electrosensitivity thresholds in the anal canal were significantly higher (p<001 v controls) and fibre density of the external anal sphincter significantly raised (p<0-0001 v controls). Anal manometry and pudendal nerve terminal motor latencies were similar to controls. In patients with idiopathic faecal incontinence the tests of sensory and motor function also showed a sensorimotor neuropathy; compared with controls, mucosal electrosensitivity thresholds were significantly higher (p<0002), anal canal resting and maximum squeeze pressures were significantly lower (p<005 and p<0002 respectively), and pudendal nerve terminal motor latencies and fibre density of the external anal sphincter were significantly raised (both p<0-05). Sensory thresholds to rectal distension were similar in all groups. Pelvic floor sensorimotor neuropathy in diabetic patients has several features in common with that of patients with idiopathic faecal incontinence but its functional significance remains uncertain.