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Biomedical subjects

M A Gassull

Publications and source records attributed to M A Gassull.

At least 109 records · Page 6Linked to original sources

Methane production and colon cancer.

The cause of the high incidence of methane producers in patients with colorectal cancer is not clear. A total of 270 individuals were studied for methane production, using an end-expiratory breath sampling technique. They were divided into eight groups: 156 healthy controls (group 1); 47 patients with colorectal cancer (group 2); 36 patients (34 of them included in the previous group) after resection of the tumor (group 3); 7 (also included in group 2) with nonresectable tumor (group 4); 29 with nonmalignant diseases of the colon (group 5); 12 with extensive ulcerative colitis (group 6); 12 with ulcerative proctosigmoiditis (group 7); and 12 with colonic polyposis (group 8). Significantly more patients (91.4%) with colorectal cancer in group 2 produced methane than either healthy controls (42.9%) (p less than 0.001) or patients with benign diseases of the colon (41.3%) (p less than 0.001). In 36 patients (group 3) in whom the cancer was resected, the incidence of methane producers fell to 47.2%, similar to the control group, but significantly different from group 2 (p less than 0.001). The percentage of methane producers in patients operated on, but with unresectable cancer, remained very high (87.7%). A significantly higher proportion of patients with extensive ulcerative colitis (group 6) and colonic polyposis (group 7) produced methane than patients with ulcerative proctosigmoiditis (group 7), benign diseases of the colon (group 5), and healthy controls (p less than 0.05). The results suggest that the presence of cancer in the large bowel directly influences methane production. In addition, in the group of diseases with a high risk of malignancy, the prevalence of methane-producing individuals was significantly higher than in the healthy population and in patients with benign diseases of the colon.

Adolescent↗

Dietary fibres, fibre analogues, and glucose tolerance: importance of viscosity.

To define the type of dietary fibre of fibre analogue with the greatest potential use in diabetic treatment, groups of four to six volunteers underwent 50-g glucose tolerance tests (GTT) with and without the addition of either guar, pectin, gum tragacanth, methylcellulose, wheat bran, or cholestyramine equivalent to 12 g fibre. The addition of each substance significantly reduced blood glucose concentration at one or more points during the GTT and generally reduced serum insulin concentrations. The greatest flattening of the glucose response was seen with guar, but this effect was abolished when hydrolysed non-viscous guar was used. The reduction in the mean peak rise in blood glucose concentration for each substance correlated positively with its viscosity (r = 0.926; P less than 0.01), as did delay in mouth-to-caecum transit time (r = 0.885; P less than 0.02). Viscous types of dietary fibre are therefore most likely to be therapeutically useful in modifying postprandial hyperglycaemia.

Adult↗

Decrease in postprandial insulin and glucose concentrations by guar and pectin.

Postprandila glycaemia and rise in serum insulin after carbohydrate-containing meals were reduced by the addition of guar flour or pectin, or both. After a liquid test meal (four subjects) the 30-min blood glucose was reduced from 6.33 +/- 0.19 mmol/litre (114 +/- mg/dl), mean +/- SEM, in the control subjects of 4.77 +/- 0.17 mmol/litre (86 +/- 3 mg/dl) by addition of guar gum (P less than 0.05). The mean insulin level was also significantly lower at 15 min. A breakfast test meal (bread, butter, marmalade, and tea) resulted in a mean 15-min blood glucose of 6.18 +/- 0.21 mmol/litre (111 +/- 4 mg/dl) in eight subjects; 10 g of pectin added to the marmalade reduced this level to 5.64 +/- 0.17 mmol/litre (102 +/- 3 mg/dl) (P less than 0.01). The insulin levels were significantly lower at 15, 30, and 45 min. A similar meal in which guar was added to the bread and pectin to the marmalade resulted in significant reductions of blood glucose at 15 min (P less than 0.002) and 30 min (P less than 0.01). The insulin values were also significantly lower throughout the first 90 min of the test. This action of unavailable carbohydrate may prove useful in the dietary control of diabetes.

Adult↗

Effect of dietary fiber on complications of gastric surgery: prevention of postprandial hypoglycemia by pectin.

The dumping syndrome is a very troublesome problem to some patients after gastric surgery. Gel-forming carbohydrates have recently been used to modify glucose absorption. The addition of 14.5 g of pectin to a 50-g oral glucose load prevented the occurrence of hypoglycemic symptoms and maintained the blood glucose levels above control values by 64% at 90 min (P less than 0.002) and 46% at 120 min (P less than 0.01) in postgastric surgery patients whose 120-min values after 50 g of glucose alone had fallen below 50 mg per 100 ml (2.8 mmoles per liter). Breath H2 production, used as an index of bacterial fermentation of glucose, was abolished or reduced by pectin in all 5 cases in which this had previously occurred. A trial of 10 g of pectin per day prevented recurrent postprandial hypoglycemic attacks in the most severely affected individual. Pectin and perhaps other unabsorbable polysaccharides are likely to prove useful in the treatment of abnormal carbohydrate absorption after gastric surgery.

Adult↗

Unabsorbable carbohydrates and diabetes: Decreased post-prandial hyperglycaemia.

Two test meals were taken in random order on separate days by 8 non-insulin-requiring diabetic volunteers after 14-hour overnight fasts. Addition of 16 g guar and 10 g pectin to the control meal containing 106 g carbohydrate decreased markedly and significantly the rise in blood-glucose between 30 and 90 minutes and also resulted in significantly lower insulin levels between 30 and 120 minutes. When these meals were fed to 3 insulin-dependent diabetic subjects, a similar flattening of the post-prandial glucose rise ensued. This addition of certain forms of dietary fibre to the diet of diabetics significantly decreases post-prandial hyperglycaemia and would be expected to improve the control of blood-glucose concentration.

Blood Glucose↗

Breath-hydrogen test for small-intestinal bacterial colonisation.

Breath-hydrogen production after oral glucose administration was examined in patients suspected of having small-intestinal colonisation and compared with the 14C-glycine-cholate breath test (14C-G.C.) and with bacteriological examination of the small intestine. Of 17 patients, 12 had bacteriological evidence of small-intestinal colonisation. Each breath test showed 8 of the 12 patients to be colonised, but only 5 patients gave positive results with both tests. Nevertheless, using both tests only 1 patients out of 12 with small-intestinal colonisation would have been missed. There were no false-positive results in the 5 bacteriologically normal patients when the breath-hydrogen test was used. It is concluded that simultaneous use of these two relatively simple breath tests may improve the indirect diagnosis of small-intestinal colonisation.

Bacteria↗

A simple method of measuring breath hydrogen in carbohydrate malabsorption by end-expiratory sampling.

1. A simple method is described for measuring the hydrogen concentration in alveolar air by end-expiratory sampling, by using a modified Haldane-Priestley tube and gas chromatography. Hydrogen was generated in vivo by ingestion of the non-absorbable sugar lactulose. 2. Alveolar hydrogen concentration showed a highly significant correlation with hydrogen production measured either by a rebreathing technique or by a total collection procedure. 3. The coefficient of variation of the end-expiratory method, assessed by comparing sixty-one paired results, was 11-6%. The coefficient of variation in ten measurements in one subject at 1 min intervals was 17-6%.

Carbohydrate Metabolism↗

The relation of impaired vitamin A and E tolerance to fat absorption in biliary diversion.

Eleven patients have been studied after cholecystectomy with exploration of the common bile duct (CBD) and insertion of a T tube for free biliary drainage. Prior to clamping the T tube no significant rise was seen above fasting serum vitamin A and E, or serum triglyceride levels after 6 of the patients had been given these substances in a liquid test meal. In addition no rise in fasting vitamin E levels was seen after 3 subjects had been loaded for 4 days with 0.5 g DL alpha-tocopherol acetate/day. Faecal fat collections performed on 9 subjects indicated that over 70% of the ingested fat was absorbed. All these findings returned to normal when the T tube was clamped and the intraluminal flow of bile re-established. We conclude that deficiency of bile may allow the absorption of fat in the absence of fat soluble vitamins.

Bile↗