M. A. Eastwood

Studies on the adsorption of bile salts to non-absorbed components of diet

Abstract Bile salts and acids are strongly adsorbed by a constituent of vegetable fibrous tissue. The more polar the bile acid, the less strong this affinity. The adsorption is maximal when the acidic groupings on the fibre are unionised, either in an acid medium or by methylation. It has been demonstrated that lignin is responsible for this adsorption. The adsorption is abolished in the presence of 6 M urea and it is postulated that the binding has a “hydrophobic” character.

The medicine of nuclear warfare. A clinical dead-end.

hospitals were left unscathed. There were 150 doctors, of whom 65 were killed outright and most of the remainder were wounded. Of the 1780 nurses, 1654 were dead or too badly wounded to work. This casualty rate suggests that receiving stations would be short of fit medical and nursing staff. The most conspicuous deficiency is a lack of training and experience. Medical survivors would be exposed both personally and professionally to a series of deadly hazards. Few, if any, general textbooks have a section devoted to postnuclear-warfare medicine. Yet the whole of their texts are an

An examination of factors which may affect the water holding capacity of dietary fibre

1. Dietary fibre has a water holding capacity (WHC) and this is a function of the fibre source and method of measurement. Water can be associated with fibre either as trapped water or bound water. This makes it difficult to predict the ability of fibre to influence stool weight in humans. 2. Examination of various fibre concentrates for chemical composition, as neutral detergent fibre (NDF), acid detergent fiber (ADF) and lignin; structure, by scanning electron microscopy; WHC, by centrifugation, suggests that WHC is more a function of fibre structure than chemical composition. Cereal fibre and vegetable fibre have a different chemical composition and are structurally very distinct. Structure is also dependent on the method of fibre preparation. 3. Measurement of WHC by centrifugation gives an estimate of the water which can be bound and also trapped by the fibre. The amount of trapped water will depend on the structure of the fibre whereas bound water will depend on the chemical composition.

Degradation of polyphenols (catechin and tannic acid) in the rat intestinal tract. Effect on coloic fermentation and faecal output

Low- and intermediate-molecular-weight polyphenols are usually extracted by using different solvents (e.g. water, methanol, aqueous acetone). The aim of the present work was to study the possible effects of some extractable polyphenols (EPP) on fat and protein digestibilities and on the colonic microflora. Degradability of these compounds through the intestinal tract was also studied. Catechin and tannic acid (TA) were chosen as representatives of the most common basic structures of EPP (flavonoids and gallic acid respectively). Three groups of eight male Wistar rats were given either a control diet free of EPP, or diets containing 20 g/kg dry matter of catechin and TA. Body-weight and food intake were monitored during a 3-week experimental period. Faeces and urine were collected daily during the third experimental week. EPP and fat were determined in faeces, and N in both urine and faeces. Only 3.1 and 4.6% of the ingested catechin and TA respectively were excreted in faeces, indicating that absorption and/or degradation of these EPP had occurred. HPLC analysis of the polyphenolic content of faeces showed qualitative differences between groups. A significant increase of total faecal weight as well as water, fat and N excretion was produced by TA. Catechin only caused an increase in fat excretion. In vitro fermentation assays were also performed to study the effect of EPP on the colonic microflora. Both catechin and TA affected the yield of end-products of fermentation, and were also degraded during the fermentation process.

A method to measure the water-holding properties of dietary fibre using suction pressure

1. Water-holding capacity (WHC) of dietary fibre is usually considered as the amount of water held but the manner in which water is held by the fibre matrix may be more relevant in understanding the role of fibre in nutrition. 2. A method used to determine WHC under physiological conditions has been adapted to determine how strongly water is held by fibre. Solutions of compounds, such as polyethylene glycol, of known osmotic potential are used to generate a suction pressure across a dialysis membrane containing a fibre sample. The WHC at each suction pressure can then be determined. 3. The method can be applied to water-soluble and water-insoluble sources of fibre. Fibre sources studied included potato fibre concentrate, bran and gum arabic. 4. Results are comparable to other similar systems of WHC measurement for gels and suggest that vegetable fibre has water-holding properties more akin to a true gel than bran. Bran has very poor water-holding properties. 5. Differences in WHC between fibre sources are more apparent if WHC is considered as fibre concentration (g fibre/g water). 6. Differences in the water-holding properties could be important in determining fibre activity in the gut.

Measurement of water-holding properties of fibre and their faecal bulking ability in man.

Experiments to measure the effect of a fibre source in the diet on stool bulk are difficult and lack precision. In vitro methods which would identify fibre sources that are effective for clinical and epidemiologic use would be valuable. One important property of fibre which influences the ability of fibre to increase stool weight is its water-holding capacity (WHC). WHC was measured using centrifugation, filtration, suction pressure and water flow-rate techniques using fibre concentrates of potato, cereal bran and gum arabic. Dietary supplementation of three preparations of potato fibre (20 g/d) had no significant effect on stool weight but 16 g bran/d increased stool weight from 107 (SE 44) g/d to 174 (SE 51) g/d. The effects of these fibres on stool weight can be related to the nature of the water-holding properties of fibre rather than absolute WHC.

DIETARY FIBRE AND SERUM-LIPIDS

Abstract The effect of altering the fibre content Summary of the diet on the serum triglycerides and total cholesterol concentration of a community of Cistercian monks has been studied. An enhanced cereal-fibre content of the diet had no effect on serum-cholesterol. In the control group, whose dietary fibre came entirely from non-cereal vegetables, the serum-cholesterol fell, but began to increase after eight weeks. Serum-triglyceride concentrations were only affected in younger men.

Long-Term Results of Subtotal Colectomy and Evidence of Noncolonic Involvement in Patients with Idiopathic Slow-Transit Constipation

BACKGROUND Patients with chronic idiopathic constipation can be difficult to manage either medically or surgically. We report our experience of long-term follow-up of 21 patients who had undergone colectomy with ileorectal anastomosis for difficult chronic idiopathic constipation. METHODS The patients (19 female, 2 male) were aged 26-68 (median = 46) years and had undergone subtotal colectomy 5-12 (median = 8) years before their assessment. They answered a questionnaire about severity of abdominal pain, bloating, urgency, and straining. They also completed the hospital anxiety and depression questionnaire. Fifteen ulcerative colitis patients with panproctocolectomy and 13 colon cancer patients with colonic resection who had a similar follow-up period served as control groups. The following assessments were performed in chronic idiopathic constipation patients with subtotal colectomy: a) oesophageal manometry; b) scintigraphic gastric emptying test; c) review of barium follow-through; d) glucose H2 breath test; e) urodynamic studies; and f) autonomic function tests. RESULTS Twenty-four per cent of patients with chronic idiopathic constipation had a family history of difficult constipation requiring hospital investigations and treatment. At the time of assessment abdominal pain, bloating, urgency, and straining at defecation were all significantly more frequent in patients with chronic idiopathic constipation with colectomy than in the control groups with colectomy. Seventy-one per cent of chronic idiopathic constipation patients had at least one episode of intestinal obstruction after subtotal colectomy, which is significantly higher (P < 0.01) than in the control groups (ulcerative colitis, 13%; colonic carcinoma, 8%). In patients with chronic idiopathic constipation, among those studied, 68% had some oesophageal motor dysfunction: 19% delayed gastric emptying; 10%, prolonged small-bowel transit on barium follow-through; 54%, abnormal urodynamic variables; and 14%, abnormal autonomic function tests. CONCLUSIONS This study shows considerable morbidity in a selected cohort of patients with chronic idiopathic constipation who were sufficiently disabled by their symptoms to undergo subtotal colectomy. They had more abdominal and rectal symptoms and more frequent intestinal obstructive episodes than control groups with colonic resection. Evidence of generalized smooth-muscle dysfunction and familial occurrence of constipation suggests a primary chronic intestinal pseudo-obstruction-like disorder in some of these patients.

Irritable bowel syndrome: The influence of psychological factors on the symptom complex

A 5 yr follow up of Irritable Bowel Syndrome (IBS) is described. With the notable exception of abdominal pain, gastrointestinal symptoms changed little over this period, and were unrelated to the overall improvement in wellbeing reported by 65% of patients. The anxiety ratings of the improved and unimproved groups at initial assessment and 5 yr later are considered. There was a persisting trend towards higher ratings in those who did not improve, and an exaggeration of this trend after 5 yr, which owed more to a reduction in anxiety in those who improved than to an increase in the anxiety ratings of those who did not. There was no evidence that depression ratings behaved similarly. We suggest that anxiety may be more important in the maintenance of the IBS symptom complex, and depression more important in determining intercurrent fluctuations in perceived distress and illness behaviour in response to adverse life events.

Submucosal collagen changes in the normal colon and in diverticular disease

Full thickness specimens of normal colon (n=15), and colon from patients with diverticular disease (n = 5) were obtained at operation or autopsy. In the isolated submucosa the ultrastructure of the constituent collagen fibres was examined by transmission electron microscopy. Collagen fibrils in the left colon become smaller (p < 0.001) and more tightly packed (p< 0.001) than those in the right colon with increasing age. This difference is accentuated in diverticular disease (p<0.01). Factors which contribute to the development of colonic diverticulosis, such as raised intraluminal pressure, may be responsible for premature change in submucosal structure.