| 1. |
- Bergström, Erik, et al.
(författare)
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Sex differences in iron stores of adolescents : what is normal?
- 1995
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - JPGN. - 0277-2116 .- 1536-4801. ; 20:2, s. 215-24
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated iron status and its determinants in healthy adolescents. Fasting morning blood samples from a school-based cross-sectional study were analyzed for serum ferritin (SF), serum iron, total iron-binding capacity, and circulating transferrin receptors. Physical development, chronic disease, medication, dietary intake, and physical activity were assessed using clinical examination, questionnaires, and 7-day records. The risk of having low serum ferritin values was estimated using bivariate and multivariate regression. Subjects were 867 healthy Swedish adolescents, 14- and 17-year-olds (472 boys and 395 girls). SF values increased with pubertal stage in boys but not in girls. Five percent of the boys and 15% of the girls had SF values < 12 micrograms/L. Of the 17-year-old boys, 7% compared to 1% of the 17-year-old girls had SF values > 100 micrograms/L. Forty-one percent of cases with SF values > 12 micrograms/L had serum iron values < 15 microM, and 22% had transferrin saturation values < 16%. Mean total iron intakes of the boys were high [1.6 times recommended daily allowance (RDA)] and mean intakes of the girls were adequate (0.9 times RDA). Low heme iron intakes increased the risk of low iron stores (< 12 micrograms/L) in girls but not in boys. Total iron intake or other dietary factors, physical development, or level of physical activity did not influence the risk of low SF. The findings of this study suggest that the differences in iron status between boys and girls in adolescence results primarily from biological differences other than menstrual bleeding or insufficient iron intake. Furthermore, the results question the role of SF as an indicator of iron deficiency in adolescence, in particular if age and sex are not taken into consideration. We suggest that different reference values for SF, including the cut-off limit for low SF, adjusted for age and sex, should be considered. The high iron intakes and corresponding high SF values found in the older boys are noticeable in light of the possible negative health consequences of iron overload.
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| 2. |
- Flygare, Annika, et al.
(författare)
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Ultrasound measurements of subcutaneous adipose tissue in infants are reproducible
- 1999
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - Jpgn. - 1536-4801. ; 28:5, s. 492-494
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The purpose of this study was to evaluate the ultrasound technique for measuring subcutaneous adipose tissue in infants. METHODS: Twenty infants were investigated at 3, 6, and 12 months of age. All measurements were made by the same investigator in triplicate on the left side of the body at the triceps and subscapular anatomic landmarks and at the abdomen and thigh. An ultrasound system equipped with a linear 7.0-MHz transducer was used. RESULTS: The intraclass correlation coefficients were 0.88 to 0.99. Random errors ranged from 0.01 to 0.19 mm. For log-transformed values, the random error ranged from 2.4% to 5.7%. CONCLUSIONS: Measurements of subcutaneous fat in infants using ultrasound are reproducible when performed by the same observer.
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| 3. |
- Karlsland Åkeson, Pia, et al.
(författare)
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Growth and nutrient intake in three- to twelve-month-old infants fed human milk or formulas with varying protein concentrations
- 1998
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - Jpgn. - : Ovid Technologies (Wolters Kluwer Health). - 1536-4801 .- 0277-2116. ; 26:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Results on growth and nutrient intake in infants in the second half of infancy fed human milk or formulas with varying protein concentrations in combination with supplementary foods have not previously been reported. Methods: Seventy-one healthy infants were studied from 3 to 12 months of age. They were exclusively breast-fed until 3 months and were then randomly assigned to one of three feeding groups, F13, F15, or F18, indicating formulas with 13, 15 or 18 g/l of protein, respectively. Formula was gradually introduced when breast-feeding was terminated. Infants fed breast milk only were included in the breast-fed group, and those with breast milk and formula were included in the mixed-fed group. The same supplementary foods were provided to all infants. Results: There were no differences in growth between the feeding groups. Total protein intake exceeded minimum recommendations in all groups at all ages and was higher at 6 months in F18 than in F13 (2.3 vs. 1.9 g/kg per day; p < 0.01), whereas formula protein intake was higher at all ages in F18 compared with F13. Intake of protein from supplementary foods increased, but that from formula decreased between 6 and 12 months in all groups. Conclusions: Intake of breast milk or infant formula with 13 g/l of protein along with high-protein supplementary foods provided enough protein with no adverse effect on growth. Infants fed formulas with higher protein concentrations had similar growth, despite higher intakes of formula protein.
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| 4. |
- Karlsland Åkeson, Pia, et al.
(författare)
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Protein and amino acid metabolism in three- to twelve-month-old infants fed human milk or formulas with varying protein concentrations
- 1998
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - Jpgn. - 1536-4801. ; 26:3, s. 297-304
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Tidskriftsartikel (refereegranskat)abstract
- PermissionsORIGINAL ARTICLESProtein and Amino Acid Metabolism in Three- to Twelve-Month-Old Infants Fed Human Milk or Formulas with Varying Protein ConcentrationsÅkeson, Pia M. Karlsland; Axelsson, Irene E. M.; Räihä, Niels C. R.Author InformationJournal of Pediatric Gastroenterology & Nutrition 26(3):p 297-304, March 1998.FREEAbstractBackground: The metabolic response to different protein intakes from breast milk and/or formulas varying in protein concentrations, in combination with supplementary foods, has not been studied in infants who are in the second half of infancy.Methods: Healthy infants, exclusively breast-fed until 3 months old, were randomly assigned to one of three groups, F13, F15, or F18, and were given formulas with 13, 15, or 18 g/l of protein, respectively. Infants breast-fed (B) and mixedfed (M) (breast milk and formula) at months formed the fourth and fifth groups. All infants received the same supplementary foods and were studied from ages 3 to 12 months.Results: The concentrations of albumin, prealbumin, and transferrin were similar in all groups. At 6 months, serum and urine urea concentrations were lower in B and M, compared with urea levels in the formula-fed groups of infants. At 12 months, urine urea was lower in B + M than it was in F18. At 6 months, plasma concentrations of phenylalanine, tyrosine, and methionine were higher in all formula-fed groups; and those of valine, isoleucine, and threonine were higher in F18 and F15 than they were in B and M. Plasma concentrations of methionine, valine, and threonine were higher in F18 than in F13. At 12 months, plasma levels of tyrosine, methionine, valine, isoleucine, and leucine were higher in F18 than they were in B + M.Conclusion: Many indexes of protein metabolism were similar in groups F13, B, and M, particularly at 6 months. In contrast, the provision of a formula with 18 g/l of protein resulted in a different metabolic pattern, which could indicate unnecessarily high protein intakes.
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| 5. |
- Lindberg, Tor, et al.
(författare)
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Digestion of proteins in human milk, human milk fortifier, and preterm formula in infant rhesus monkeys.
- 1997
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - JPGN. - 0277-2116 .- 1536-4801. ; 24:5, s. 537-43
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is limited information in the literature on the capacity of the preterm infant to digest human and bovine milk proteins. We therefore studied in vivo the luminal phase of the hydrolysis of proteins in human milk, human milk fortifier, and preterm formula in preterm rhesus monkeys and in infant rhesus monkeys at 6 weeks and 7 months of age. METHODS: Protein hydrolysis was followed by polyacrylamide gradient gel electrophoresis and electroimmunoassay. The serum level of absorbed unhydrolyzed human alpha-lactalbumin was measured by a radioimmunoassay method. Trypsin and elastase activities in duodenal contents were measured before and after the meal. RESULTS: In 6-week-old monkeys, the enzyme activities decreased by 50% postprandially, whereas they increased in 7-month-old monkeys. In preterm and in 6-week-old monkeys, hydrolysis of human and bovine whey proteins was slow, and in 6-week-old monkeys, 30-50% of the proteins could still be detected immunochemically in duodenal contents after 60 min. At these ages, serum level of absorbed alpha-lactalbumin were high. At 7 months of age, no or small (lactoferrin and bovine serum albumin) amounts of the proteins could be detected in duodenal contents after 15 min. At this age alpha-lactalbumin was not measurable in serum. CONCLUSIONS: The low capacity to digest whey proteins in suckling monkeys may depend upon an immaturity of the exocrine pancreas to respond to secretogogues.
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| 6. |
- Lindberg, Tor, et al.
(författare)
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In vitro digestion of proteins in human milk fortifiers and in preterm formula.
- 1998
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - JPGN. - 0277-2116 .- 1536-4801. ; 27:1, s. 30-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Knowledge about the digestibility of the proteins in new products designed for feeding preterm infants is limited. The purpose of this study was to observe in vitro the hydrolysis of the bovine and human whey proteins in such products. METHODS: Proteins in human milk, in human milk fortifiers (Presemp [Semper AB, Stockholm, Sweden] and Enfamil [Mead Johnson, Evansville, IN, U.S.A.] human milk fortifiers), in preterm formulas (Similac Special Care [Ross, Columbus, OH, U.S.A.] and Enfalac [Mead Johnson]), and whey protein concentrates with varying degrees of denaturation were digested by duodenal juice from healthy preterm infants, from a 3-year-old child, and from adults. Digestion was studied in vitro using polyacrylamide gradient gel electrophoresis, electroimmunoassay, and nonprotein nitrogen analysis. RESULTS: Casein was the protein most rapidly degraded in all products. Human and bovine whey proteins were more slowly digested; as much as 68% of human lactoferrin was still immunoreactive after 40 minutes of digestion. The corresponding figure for bovine serum albumin was 24-69%; for B-lactoglobulin, 20-40%; for bovine alpha-lactalbumin, 20-51%; and for human alpha-lactalbumin, 41%. Contrary to common belief, digestibility of bovine whey proteins decreased with a high degree of denaturation of the proteins. CONCLUSIONS: Bovine whey proteins in human milk fortifiers and in preterm formulas are relatively slowly digested in vitro by normal duodenal juice. The results may have implications for the design of products for feeding preterm infants.
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| 7. |
- Sundqvist, Tommy, et al.
(författare)
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Significantly increased levels of nitric oxide products in urine of children with celiac disease
- 1998
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - JPGN. - : Ovid Technologies (Wolters Kluwer Health). - 0277-2116 .- 1536-4801. ; 27:2, s. 196-198
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Tidskriftsartikel (refereegranskat)abstract
- Background: Celiac disease is characterized by morphologic and functional aberrations of the small intestinal mucosa, i.e. crypt hyperplasia, villous atrophy, infiltration of intraepithelial lymphocytes, and alteration of permeability. Nitric oxide has been shown to affect mucosal permeability after ischemia-reperfusion, but little is known about the regulatory role of nitric oxide in celiac disease. The purpose of this study was to assess nitric oxide production in children with celiac disease and in control subjects.Methods: The sum of nitrite and nitrate in the urine was measured with a colorimetric method in 137 children with a median age of 3 years, 84 patients and 53 reference children, all of whom underwent a small intestinal biopsy to confirm or overrule suspicion of celiac disease.Results: Median urinary nitrite-nitrate concentration in celiac children was 3323µM (4147 ± 1102; mean ± SEM) at first clinical examination and 2501 µM (2939 ± 386) after gluten challenge, which was significantly higher than concentrations in reference children(1029 µM; 1174 ± 116) and in children with celiac disease on a gluten-free diet (882 µM; 1369 ± 360) (p< 0.0001).Conclusions: A gluten-containing diet is associated with an increased nitrite-nitrate secretion in the urine in children with celiac disease, presumably as a result of nitric oxide synthase activation and nitric oxide production in the diseased small intestinal mucosa.
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