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Biomedical subjects

N G Asp

Publications and source records attributed to N G Asp.

At least 73 records · Page 4Linked to original sources
PubMed1981

Dietary fibre in type II diabetes.

Recent studies have indicated that diets rich in digestible carbohydrates and dietary fibre might be beneficial in the regulation of type II non insulin dependent diabetes (NIDD). Addition of the gel forming type of dietary fibre such as pectin and guar gum to meals or glucose solutions reduces post-prandial glucose and insulin response. Addition of cereal fibres in the form of bran seems to have long term beneficial effect improving glucose tolerance. Little is known, however, concerning effects of dietary fibre naturally occurring in food on postprandial glucose and hormone response. In the present study we prepared two breakfast meals which were similar regarding digestible carbohydrates but differed in their dietary fibre content. One of the meals, including whole grain bread and whole apples, contained 8.4 g of dietary fibre, and the other one, containing white bread and apple juice, 3.1 g. When given to eight NIDD, the fibre rich breakfast gave significantly lower blood glucose increment during the three hours following ingestion. The results indicate that foods rich in dietary fibre might be useful in the regulation of type II diabetes.

Blood Glucose↗
PubMed1981

Effect of two kinds of pectin and guar gum on 1,2-dimethylhydrazine initiation of colon tumors and on fecal beta-glucuronidase activity in the rat.

The effect of 5% low-methoxylated pectin, high-methoxylated pectin, and guar gum on 1,2-dimethylhydrazine initiation of colon cancer was investigated using groups of 30 rats. The growth of the rats in the different groups was very similar to that of control group fed a fiber-free diet. Both kinds of pectin increased the multiplicity of color tumors, whereas guar gum did not significantly influence carcinogenesis. Bacterial beta-glucuronidase activity in feces and colonic content was the same in pectin-fed rats and controls but significantly lower in the guar gum group. Thus, it was not related to the number of tumors in each group.

Adenocarcinoma↗
PubMed1980

Small intestinal dipeptidases and disaccharidases in experimental uremia in rats.

Rats were made severely uremic with partial nephrectomy (24-hour creatinine clearance 10% of normal). Jejunal dipeptidase activities (substrates: glycyl-L-leucine, L-alanyl-L-proline, and L-methionyl-L-methionine), disaccharidase activities (maltase, sucrase, trehalase, and lactase) and morphology were studied. A highly significant increase in glycyl-L-leucine and L-methionyl-L-methionine dipeptidases was found in uremic rats compared with controls. Proline dipeptidase activities were unaltered. Disaccharidase activities showed a slight increase in sucrase in uremic rats; otherwise no change was found.

Animals↗
PubMed1979

Enzyme activities and morphological appearance in functioning and excluded segments of the small intestine after shunt operation for obesity.

Five patients in whom small-intestinal bypass was performed for severe obesity had a second operation 11-19 months later because of insufficient weight loss. Mucosal enzyme activities and histological appearance were investigated in biopsies from different parts of the functioning and excluded small intestine. These were compared with biopsies form corresponding sites obtained at the first operation. In addition to a prominent increase in length, circumference, and mucosal thickness in the functioning shunt, the disaccharidases and two intracellular beta-galactosidases increased in specific activity,, especially in the distal ileal part of the shunt. In the excluded segment of the small intestine different enzymes showed a different response: trehalase increased and alkaline phosphate decreased significantly. Other enzymes that were measured showed a varied pattern. The results indicated that not only the luminal content but also other, presumably hormonal, factors regulated the enzyme activities, and that different regulating factors influenced the various enzymes differently. The marked adaptive increase in mucosal surface of the functioning shunt could be one factor in explaining the weight stabilisation and, in some cases, weight increase after the initial rapid weight loss after the operation for small-intestinal bypass. The increase in specific enzyme activities would further increase the digestive capacity of the shunt.

Adult↗
PubMed1979

Mucosal enzyme activities in the functioning intestine one and six months after jejuno-ileal by-pass operation for obesity.

Enzyme activity changes in the functioning segment (the shunt) of the small intestine during the first 6 months after by-pass operation for obesity were investigated. At the ligament of Treitz no significant changes in disaccharidase activities occurred, whereas two intracellular beta-galactosidases showed increased activities after 1 month. In the jejunal part of the shunt (studied in patients operated on with a long jejunal functioning segment) there was an in most cases temporary decrease in lactase activity after 1 month. Other enzymes studied showed less pronounced changes. In the ileal part of the shunt (studied in patients operated on with a long ileal functioning segment) the initially low enzyme activities increased especially after 6 months towards the levels normally seen in the jejunal mucosa. The lactase activity, however, remained low also after 6 months. Adaptive changes in the functioning small-intestinal segment is probably an important factor in weight stabilization and, in some cases, in the weight increase that recurs after the initial period of rapid weight loss after by-pass operation for obesity.

Disaccharidases↗
PubMed1979

Effect of dietary fiber on the induction of colorectal tumors and fecal beta-glucuronidase activity in the rat.

The purpose of the present study was to investigate whether three different types of dietary fiber, wheat bran, carrot fiber, and citrus pectin, influenced the induction of colorectal tumors produced by 1,2-dimethylhydrazine in rats. In all groups, the tumor yield was high (87 to 97%). In the wheat bran and carrot fiber groups, the incidence of colorectal tumors was not significantly different from that of the group fed on the fiber-free basic diet. The citrus pectin group, however, had a significantly higher incidence of colorectal tumors (p less than 0.001). An increased number of auditory duct tumors was also noted in this group. In a separate experiment, dietary pectin induced a 10-fold increase in fecal beta-glucuronidase activity but did not alter this activity in the bowel wall. It has been suggested that dietary fiber protects against the induction of colorectal tumors, but this was not the case in the experiment. It is possible that the high tumor yield made the demonstration of a weak protective effect of wheat bran impossible. The reason for the increased occurrence of tumors in the citrus pectin group is obscure and will be subjected to further investigation. Fecal beta-glucuronidase activity might be one factor of importance in the activation of the carcinogen.

Animals↗
PubMed1978

Storage of lactose-hydrolysed dried milk: effect of water activity on the protein nutritional value.

The retention of the protein nutritional value during storage of lactose-hydrolysed dried milk at different water activities (aw) was studied and compared with that of ordinary milk. In the lactose-hydrolysed milk biologically available lysine decreased much more rapidly than in the ordinary milk at all the different aw studied. Thus, at conditions normally accepted for ordinary dried milk (aw approximately 0.2; moisture approximately 4%) there was an available lysine loss in the hydrolysed milk of about 25% after 2 months and about 40% after 6-months storage at room temperature. This occurred without any visible browning. It is concluded that drying to very low aw (less than or equal to 0.11) is necessary to obtain good stability of the protein nutritional value (PNV) in lactose-hydrolysed milk. The drying, however, must be done so that losses in nutritional value are minimal during that process. It should also be noted that fat oxidation might be a problem at such low aw. A chemical method for available lysine assay (guanidination and assay of homoarginine) gave values in good agreement with the biological evaluations with rats.

Animals↗
PubMed1978

Lactose malabsorption after bypass operation for obesity.

After bypass operation for obesity the remaining lactose-hydrolyzing capacity of the functioning shunt is very low, especially if the shunt is constructed from a shorter jejunal and a longer ileal segment. In most cases a temporary decrease in the lactase activity of the jejunal part of the shunt occurs during the first postoperative months. In the present study lactose provoked or aggravated diarrhoea and other symptoms in 20 of 33 shunt-operated patients, and 10 patients reported milk intolerance postoperatively. Oral glucose tolerance tests indicated that the lactase activity was rate limiting for lactose absorption postoperatively.

Diarrhea↗
PubMed1975

Intestinal disaccharidases in Greenland Eskimos.

Jejunal biopsies from 19 adult Greenland Eskimos were studied regarding disaccharidases, two intracellular beta-galactosidases, and morphological appearance. Fifteen of the patients (79%) had low lactase activity, and 3 of these (16%) had sucrase-isomaltase deficiency as well. Two patients had low trehalase activity. Microscopical appearance was essentially normal in all the biopsies, except for a certain stromal plasma cell infiltration. All the patients with low lactase activity had a measurable residual activity of brush border lactase, which was localized in the middle and apical parts of villi, as normally seen for digestive enzymes. Lysosomal acid beta-galactosidase and cytosol hetero beta-galactosidase were not altered. In the patients with sucrase-isomaltase deficiency there was a complete absence of active sucrase-isomaltase complex. The residual maltase, as well as the very weak residual isomaltase, was exerted exclusively by the heat stable maltases (maltase II and III). The material is the first one in which multiple, but not generalized disaccharidase deficiencies are demonstrated.

Adolescent↗
PubMed1975

Distribution of disaccharidases, alkaline phosphatase, and some intracellular enzymes along the human small intestine.

The longitudinal distribution of various enzymes along the human small intestine was studied by analysis of biopsies from different parts of the small intestine, obtained from 13 patients during shunt-operation for severe obesity. Alkaline phosphatase and 3 glycolytic enzyme activities studied were rather uniformly distributed along the small intestine. Acid beta-galactosidase and hetero beta-galactosidase activities were highest in the proximal small intestine with a gradual decline throughout the intestine. The activity in the distal ileum was about half of the maximum activity. Maltase, isomaltase, sucrase, and trehalase activity had a broad maximum in the proximal and middle small intestine with a rather sharp decrease in the distal ileum. Lactase activity had a more pronounced maximum in the middle intestine with a pronounced decrease towards the proximal and distal ends. The disaccharidase activities in surgical biopsies taken 5 cm distal to the ligament of Treitz were about 10% higher than in peroral biopsies taken just at the ligament.

Adult↗
PubMed1975

Disaccharidase activities in intestinal metaplasia - contribution of lysosomal brush border enzymes.

Maltase, sucrase, and lactase were measured at pH 4 and pH 6 in normal and intestinalized gastric mucosa. In the normal mucosa the low activities of maltase and lactase seemed to be entirely due to lysosomal enzymes with acid pH-optimum. In intestinal metaplasia, brush border maltase and sucrase, but not lactase, appeared. On the other hand, there was a significant increase in lysosomal lactase (beta-galactosidase) activity.

Disaccharidases↗