Abstract Using native fluorescence detection, 5‐hydroxytryptamine (5‐HT), 5‐hydroxyindoleacetic acid (5‐HIAA) and tryptophan were resoved from themselves and other naturally occurring compounds using reversed‐Phase HPLC within 5 min. Deproteinated platelet‐poor plasma (ppp) and crude diluted urine were injected directly into the chromatograph. Careful selection of the HPLC column is important and various octadecyl silica (ODS) and base deactivated silic (BDS) columns were evaluated. Pre‐treatment of an ODS column with tetrabutylammonium ions gave good selectivity. Between pH5 and 6 the compounds were well resolved from each other. The limit of quantitatiave detection of 5‐HT and 5‐HIAA was 3.5 nmol/L. The overal chromatogram obtained using native fluorescence is cleaner than that obtained with the more commonly employed electrochemical (EC) systems although the chromatography is effectively the same. For analysis of 5‐HT in plasma, collection in EDTA was more efficient than lithium heparin. Plasma 5‐HT in healthy volunteers was mean 61 (SD=±73) nmol/L, n=20; urine 5‐HIAA gave mean 28.95 (SD=±0.98)μmol/L, ( n =12). Whole blood 5‐HT analysis is unreliable in comparison with platelet‐poor plasma.
Thirty-six healthy men aged 20-31 years took part in a randomized, double-blind, double-dummy, parallel-group study to compare the effects of repeated doses of piroxicam-beta-cyclodextrin, piroxicam and placebo on faecal blood loss and the endoscopic appearances of gastric and duodenal mucosa. After an initial endoscopy, subjects received on day 0 autologous erythrocytes labelled with 51Cr. Complete daily faecal collections were then made from days 6 to 12. From days 13 to 40, subjects received daily by mouth either piroxicam-beta-cyclodextrin (containing 20 mg piroxicam), piroxicam 20 mg, or placebo. Complete faecal collections were made daily from days 13 to 41; blood samples for red-cell 51Cr activity were taken weekly. Endoscopy was repeated 16-20 h after the last dose of medication. Faecal blood loss was calculated from 51Cr activity of blood and faeces. Compliance with medication was confirmed by blood sampling on days 20, 27 and 34. General tolerability of the medication was good, although 1 subject was withdrawn from piroxicam-beta-cyclodextrin and 1 from piroxicam treatment because of abdominal pain. There were no clinically significant changes in haematology, biochemistry or urinalysis results in any subject. Endoscopic appearances deteriorated moderately in 3 subjects receiving piroxicam and 3 receiving piroxicam-beta-cyclodextrin, but did not deteriorate in any subject receiving placebo. There was a trend for cumulative blood loss to be higher for piroxicam than for the other treatments in the last 12 days of dosing.(ABSTRACT TRUNCATED AT 250 WORDS)
Lichen planus is a recognized complication of sulfasalazine therapy. Two patients developed typical oral and cutaneous lichen planus on sulfasalazine and their skin lesions recurred when they were subsequently changed to mesalazine. Lichen planus only resolved on withdrawal of both drugs. It seems likely that the aminosalicylic acid moiety is responsible for this reaction and that lichen planus is a true complication of mesalazine therapy.
Summary: Increasing numbers of cases of Vero cytotoxin producing Escherichia coli (VTEC) O157 infection, well publicised incidents, and new scientific evidence make it appropriate to produce new guidelines for their control. This document reviews the clinical and epidemiological features of VTEC O157 infection, describes the principles of microbiological investigation and laboratory safety, and presents recommendations for the prevention of spread of VTEC) O157. The recommendations consider direct spread of infection from animals, foodborne spread, the institutions in which spread is more likely to occur (nursing homes, schools, and children’s day nurseries), and groups at particular risk of acquiring and transmitting infection (in essence, food handlers, and those unable to maintain high standards of hygiene for themselves and their carers).
1. Unlike standard glucose-electrolyte oral rehydration solutions, solutions containing polymeric glucose as substrate can significantly reduce stool output, duration of diarrhoea and total oral rehydration solution requirements. However, neither the underlying mechanisms nor the optimal size and concentration of glucose polymer has been defined. 2. We have used a model of rotavirus diarrhoea in neonatal rats to compare the effects on water and solute absorption of varying the concentration of a glucose polymer (mean chain length five glucose residues) in experimental oral rehydration solutions. Three polymer (P) solutions were compared with solutions of identical electrolyte content (mmol/l: sodium, 60; potassium, 20; chloride, 60; citrate, 10) containing equivalent amounts of free glucose (G) as substrate by perfusion of the entire small intestine in situ. The polymer (9, 18, 36 mmol/l; 159, 168, 186 mosmol/kg, respectively) and the monomer (45, 90, 180 mmol/l; 195, 240 320 mosmol/kg) solutions were perfused in normal and rotavirus-infected neonatal rats. 3. In normal intestine polymer solutions promoted greater water absorption [P9, mean 291.4 (SEM 16.4); P18, 331.9(13.1); P36, 284.3 (11.8) μl mi−1 g−1] than their equivalent monomer solutions [G45, 220.8 (8.4); G90, 240 (21); G180,79.4 (145) μl min− g−1; P < 0.02]. In rotavirus-infected intestine, water absorption from all solutions declined, but the fall was much less pronounced from the polymer solutions [P9, 232.8 (6); P18, 277.2 (20.5); P36, 166 (18.2) μl min−1 g−1] than from their monomeric counterparts [G45, 116.7 (25.5); G90, 68.7 (12.4); G180, 21 (11.6) μl min−1 g−1; P < 0.005]. 4. In both the normal net absorptive state and the net secretory state induced by rotavirus infection, there was a striking inverse correlation between net water absorption and perfusate osmolality (r = −0.94 and r = −0.88, respectively; P < 0.05). In rotavirus-infected intestine, increasing the polymer concentration from 18 to 36 mmol/l resulted in a relative fall in water absorption (P < 0.01). The hypertonic solution G180 was associated with the lowest water absorption (P < 0.01). None of the solutions was able to reverse rotavirus-induced net secretion of sodium, which was similar from all solutions, whether polymer- or monomer-based. 5. These results (i) emphasize the pre-eminence of hypotonicity among the factors promoting water absorption from polymer-based oral rehydration solutions in acute diarrhoea, (ii) confirm the adverse consequence of raising substrate concentration (whether polymer or monomer) beyond certain limits and (iii) indicate that the concentration of this glucose polymer yielding the optimum compromise between substrate availability and low osmolality may be approximately 9–18 mmol/l.
The bacterial population colonising the large intestine is able to metabolise a variety of ingested or endogenously produced substances to products, some of which possess toxic, mutagenic or carcinogenic properties. Dietary components, resistant to digestion and absorption in the upper alimentary tract, may influence these reactions by altering the environment of the gut or through the provision of nutrients to the flora. Evidence for the involvement of bacterial enzymes in the formation of toxic products in vivo has come largely from animal studies, particularly where fermentable plant cell-wall components are present in the diet. The role of diet in the modification of toxicologically important bacterial biotransformation processes will be discussed. Preliminary data will also be presented from a study demonstrating changes in the enzymic activity of the human faecal flora induced by pectin and bran. The significance of these changes to the disposition of chemicals in the gut will be discussed.
Editor,—We read with great interest the paper by Gorard et al ( Gut 1996; 39: 551–5) on intestinal transit in patients with anxiety and depression. The authors used the lactulose hydrogen breath test to evaluate 21 consecutive outpatients attending a general psychiatry clinic who fulfilled DSM III R criteria for major depression or generalised anxiety disorders, or both. They reported a significantly prolonged orocaecal transit time (OCTT) in depressed patients compared with anxious patients, and a significant correlation between whole gut transit time and the score of the psychometric tests used to assess depression, showing evidence for an association between severity of depression and colon inertia. The authors conclude that depressed patients tend to be constipated and that mood has an effect on intestinal motor function, although mechanisms by which mood can alter colonic motility remain unknown.
Recently, we found a significantly prolonged OCTT in patients with chronic alcoholism without severe liver disease compared with social drinkers and teetotal subjects.1 Thirty one alcoholic patients without diseases which …
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)
