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Biomedical subjects

T Lindberg

Publications and source records attributed to T Lindberg.

At least 73 records · Page 4Linked to original sources
PubMed1983

Small intestinal dipeptidases and disaccharidases in uraemic rats on a low protein diet.

Small intestinal dipeptidases (substrate: glycyl-L-leucine, L-methionyl-L-methionine, and L-alanyl-L-proline) were determined in uraemic and sham-operated rats given normal protein diet (24%), low protein diet (6%), and total parenteral nutrition for 10-14 days. Disaccharidases (substrate: maltose, sucrose, trehalose, and lactose) were measured after normal and low protein diet orally. Glycyl-L-leucine and L-methionyl-L-methionine splitting activities were increased on normal protein diet but decreased after low protein feeding in uraemic rats. Parenteral nutrition further lowered the enzyme activity. L-Alanyl-L-proline dipeptidase activity showed an inverse relation to protein intake with the highest values after parenteral nutrition. Lactase increased in uraemic rats after low protein feeding and was the only disaccharidase to be affected by the nutritional change. It is suggested that the changes of the intestinal dipeptidase activities in uraemia are adaptive to variation in the luminal content of di- and oligopeptides because of the type of nutrition given.

Animals↗
PubMed1983

Opposite effects of carbohydrate and protein on phenytoin absorption in man.

Food intake has been found to enhance the absorption of phenytoin, as judged from single-dose studies in healthy volunteers taking phenytoin (acid) with and without a standardized breakfast of 1,840 kJ. In order to investigate whether this effect was due to food intake as such or to the ingestion of a certain nutrient, the influence of carbohydrate, fat, and protein, respectively, on phenytoin (acid) absorption was examined in ten healthy volunteers. The nutrients were given separately in amounts corresponding to those of the standardized breakfast previously employed. Phenytoin concentrations in plasma were measured by high-pressure liquid chromatography. The results indicate that, while fat had no measurable influence, carbohydrate may enhance, and protein reduce, the absorption of phenytoin.

Adult↗
PubMed1983

Cow's milk proteins cause infantile colic in breast-fed infants: a double-blind crossover study.

Sixty-six mothers of 66 breast-fed infants with infantile colic were put on a diet free from cow's milk. The colic disappeared in 35 infants; it reappeared on at least two challenges (cow's milk to mother) in 23 infants (35%). A double-blind crossover trial with cow's milk whey protein was performed in 16 of these 23 mothers and infants. Six infants had to be taken out of the study for various reasons; of the remaining ten infants, nine reacted with colic after their mothers' intake of whey protein-containing capsules. Sequential analysis showed a high correlation between infantile colic in breast-fed infants and their mothers' consumption of cow's milk protein. A diet free of cow's milk is suggested for the mothers as a first trial of treatment of infantile colic in breast-fed infants.

Animals↗
PubMed1982

In vitro digestion of cow's milk proteins by duodenal juice from infants with various gastrointestinal disorders.

The hydrolysis of bovine alpha-lactalbumin, beta-lactoglobulin, and casein by duodenal juice from 20 infants (18 with normal exocrine pancreatic function, 2 with pancreatic insufficiency), aged 3-19 months was studied in vitro with the aid of electroimmunoassay and sodium dodecyl sulfate-poly-acrylamide gel electrophoresis. The results from the two methods were almost identical. Duodenal juice from infants with cow's milk protein intolerance (7), celiac disease (5), and unclassified gastrointestinal disorder (6) had the same capacity to hydrolyze the milk proteins. No hydrolysis occurred in the two patients with pancreatic insufficiency. The hydrolyzing capacity was not correlated with age in the actual age group. The hydrolysis of the milk proteins occurred at a considerably slower rate when the proteins were crude, as in cow's milk, adapted, or unadapted formula, than when they were in a purified form. About 1 mg of purified alpha-lactalbumin or beta-lactoglobulin, and about 30 mg of purified casein could be hydrolyzed per milliliter duodenal juice per minute. Corresponding figures for the hydrolysis of the various proteins in cow's milk were 0.03, 0.12, and 16.1 mg/ml duodenal juice/min. Preincubation (60 min) with gastric aspirate after adjusting pH to 4-5 did not change the results. In conclusion, the duodenal juice from infants with normal exocrine pancreatic function has a great ability to hydrolyze casein. Corresponding hydrolytic capacity for alpha-lactalbumin or beta-lactoglobulin is considerably lower.

Animals↗
PubMed1982

Immunoreactive trypsin screening for cystic fibrosis.

Immunoreactive cationic trypsin (irCT) was measured in 22 cystic fibrosis (CF) and 132 control infants. IrCT was analysed with radioimmunoassay of dried blood samples collected for PKU screening around the 5th day of life and stored on filter paper. The mean +/- 1 SD level of irCT for the control infants was 42 +/- 19 micrograms/1. Sixteen of the 22 CF children had an irCT level above 100 micrograms/1 (mean + 3 SD) while 6 had a level at or below this cut-off limit. A specificity of 99%, which gives a sensitivity of 73%, and an approximative noise: signal ratio of 30:1, suggests that the irCT test may be unsatisfactory as a neonatal screening method for CF.

Child, Preschool↗
PubMed1982

Immunoactive trypsins in duodenal juice from children with gastrointestinal disorders.

Duodenal juice contains two trypsins, one anionic and one cationic at pH 8.6. To investigate their distribution, we studied fasting specimens of duodenal juice from 89 children with different gastrointestinal problems. The two trypsins were separately determined with electroimmunoassay parallel with determinations of total trypsin esterolytic activity and total protein. In 81 children with normal pancreatic function the ratio immunoactivity: esterolytic activity averaged 3.25:1. Anionic trypsin comprised an average 12% of immunoactivity: the average trypsin contribution to the total protein content was 37% for immunoactivity and 12% for esterolytic activity. These ratios were not influenced by age. Fourteen children with coeliac disease had significantly lower mean values for trypsins and total protein'. Eight children with pancreatic insufficiency had discrepant trypsin distribution, anionic trypsin being the dominant residuum in five of the eight.

Celiac Disease↗
PubMed1982

Protease inhibitors and their relation to protease activity in human milk.

Protease inhibitors and protease (caseinolytic, elastinolytic and esterolytic) activity were analysed in 190 milk samples from 94 mothers from day 1 to day 160 after delivery. The main protease inhibitors in human milk are alpha 1-antichymotrypsin and alpha 1-antitrypsin. As measured by electroimmunoassay, the level of alpha 1-antichymotrypsin in day 1 colostrum was higher than that in normal serum. Trace amounts of inter-alpha-trypsin inhibitor, alpha 2-antiplasmin, alpha 2-macroglobulin, antithrombin III, or antileukoprotease could be demonstrated. According to their protease inhibiting activity, the 53 milk samples from day 1-3 could be divided into two groups. (1) Presence of protease inhibiting activity (n = 35). Both alpha 1-antitrypsin and alpha 1-antichymotrypsin appeared intact and were able to form complexes with added trypsin or chymotrypsin although the major part of alpha 1-antichymotrypsin showed a retarded electrophoretic mobility. The proteolytic inhibiting activity, in spite of the presence of immunoreactive inhibitors (n = 18). alpha 1-antichymotrypsin had a precipitate pattern similar to group 1, whereas alpha 1-antitrypsin had a major fraction with slightly retarded mobility and two minor peaks in the alpha 1-and beta-regions. These precipitate patterns were unchanged on addition of human trypsin or chymotrypsin compatible with the presence of nonreactive inhibitor only. These samples had a caseinolytic and esterolytic activity with an electrophoretic mobility in the beta-region. All samples from day 4 and later had a demonstrable protease inhibiting activity.

Chymotrypsin↗
PubMed1982

Amylase in human milk.

Amylase activity and isoenzyme pattern were determined in human milk from various stages of lactation and were compared with that in duodenal juice. The activity is high in colostrum and somewhat lower in milk from day 15 to day 90 after delivery. In this period of lactation, human milk contains higher amounts of amylase than duodenal juice from infants aged 1 to 6 months. Low activity was found in milk from 90 days or more after delivery. The amylase is of the salivary type. A pH of 5.3 does not inactivate the amylase; there is considerable human milk amylase activity in duodenal juice after a meal of human milk. Human milk amylase could thus contribute to the breast-fed infant's ability to digest starch.

Amylases↗
PubMed1982

Cow's milk formula as a cause of infantile colic: a double-blind study.

The role of cow's milk in infantile colic in formula-fed infants was estimated in a double-blind study. Sixty colicky infants were given a cow's milk-containing formula (Enfamil) and a cow's milk-free formula based on soy (ProSobee). Eleven infants (18%) were free of symptoms while receiving soy formula. Symptoms of 32 infants (53%) were unchanged or worse when they were fed cow's milk formula and soy formula, but symptoms disappeared when they were fed a formula containing hydrolyzed casein (Nutramigen). Symptoms of 17 infants (29%) could not be related to the diet; these infants were permitted to continue on a cow's milk-based formula. A challenge with cow's milk-based formula after one month (at approximately age 3 months) produced symptoms of infantile colic in 22 infants (36%). At age 6 months, a challenge with cow's milk was positive in 11 infants (18%) with epidermal and gastrointestinal symptoms. Eight infants (13%) at 12 months of age and five infants (8%) at 16 months of age were still intolerant to cow's milk. Cow's milk seems to be a major cause of infantile colic in formula-fed infants. A dietary treatment is suggested for moderate or severe forms of the colic. Cow's milk protein intolerance is common later in infancy in these infants.

Animals↗
PubMed1981

Cathodal elastase in duodenal juice from children with gastrointestinal disorders.

Immunoreactive cathodal elastase, elastinolytic activity, and activity on the low-molecular elastase substrate succinyl-trialanine were assayed in duodenal juice from 89 fasting children with different malabsorption problems. Cathodal elastase immunoactivity (mean value, 0.06 g/liter) averaged 1% of the total protein content in duodenal juice and 1/16 of the succinyl-trialanine-splitting activity. A strong influence of age was found for immunoactivity and elastinolytic activity, indicating continuing development of the cathodal elastase during the first 24 months of life. In 81 children with normal pancreatic function, significantly lower levels for all parameters including total protein were found for 14 with coeliac disease than for 34 children with unclassified gastrointestinal disorders and 33 with cow's milk protein intolerance. In eight children with pancreatic insufficiency, seven lacked detectable immunoactive cathodal elastase; low levels of succinyl-trialanine-splitting activity were found in six, and remnants of elastinolytic activity in three.

Age Factors↗