| 61. |
- Bernbäck, S, et al.
(författare)
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Bovine pregastric lipase : a model for the human enzyme with respect to properties relevant to its site of action.
- 1987
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Ingår i: Biochimica et Biophysica Acta. - 0006-3002 .- 1878-2434. ; 922:2, s. 206-13
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Tidskriftsartikel (refereegranskat)abstract
- Preduodenal lipolysis is considered to promote efficient lipid digestion in the neonatal period. The lipase(s) responsible may be of pregastric or gastric origin depending upon the species. We have previously reported on purification and molecular characterization of a pregastric lipase from calf. Antibodies to this bovine enzyme crossreact with a protein of similar size in human gastric contents and also inhibit its lipolytic activity. Since the bovine and human enzymes also have similar kinetic properties, the view is favoured that the bovine enzyme can be used as a model for physiological studies relevant to human neonates. In contrast to the lipases operating in the small intestine pregastric lipase has the unique property of initiating the hydrolysis of human milk fat globule triacylglycerol. In order to do this no cofactor is required. Pregastric lipase was stable at low pH and had an acid-pH optimum. Furthermore, it was extremely resistant to pepsin. In contrast, pancreatic proteinases, i.e. trypsin and chymotrypsin, inactivated the enzyme. The rate of inactivation was increased in the presence of bile salts which by themselves could inhibit enzyme activity. Thus, pregastric lipase is ideally suited for activity in the stomach but will not, under healthy conditions, contribute to lipid digestion in the duodenum.
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| 62. |
- Bernbäck, S, et al.
(författare)
-
Fatty acids generated by gastric lipase promote human milk triacylglycerol digestion by pancreatic colipase-dependent lipase.
- 1989
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Ingår i: Biochimica et Biophysica Acta. - 0006-3002 .- 1878-2434. ; 1001:3, s. 286-93
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Tidskriftsartikel (refereegranskat)abstract
- The concerted action of purified bovine gastric lipase and human pancreatic colipase-dependent lipase and colipase, or crude human pancreatic juice, in the digestion of human milk triacylglycerols was explored in vitro. Gastric lipase hydrolyzed milk triacylglycerol with an initially high rate but became severely inhibited already at low concentration of released fatty acid. In contrast, colipase-dependent lipase could not, by itself, hydrolyze milk triacylglycerol. However, a short preincubation of milk with gastric lipase, resulting in a limited lipolysis, made the milk fat triacylglycerol available for an immediate and rapid hydrolysis by pancreatic juice, and also for purified colipase-dependent lipase, provided colipase and bile salts were present. The same effect was obtained when incubation with gastric lipase was replaced by addition of long-chain fatty acid. Long-chain fatty acid increased the binding of colipase-dependent lipase to the milk fat globule. Binding was efficient only in the presence of both fatty acid and colipase. We conclude that a limited gastric lipolysis of human milk triacylglycerol, resulting in a release of a low concentration of long-chain fatty acids, is of major importance for the subsequent hydrolysis by colipase-dependent lipase in the duodenum.
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| 63. |
- Bernbäck, S, et al.
(författare)
-
The complete digestion of human milk triacylglycerol in vitro requires gastric lipase, pancreatic colipase-dependent lipase, and bile salt-stimulated lipase.
- 1990
-
Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 85:4, s. 1221-6
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Tidskriftsartikel (refereegranskat)abstract
- Gastric lipase, pancreatic colipase-dependent lipase, and bile salt-stimulated lipase all have potential roles in digestion of human milk triacylglycerol. To reveal the function of each lipase, an in vitro study was carried out with purified lipases and cofactors, and with human milk as substrate. Conditions were chosen to resemble those of the physiologic environment in the gastrointestinal tract of breast-fed infants. Gastric lipase was unique in its ability to initiate hydrolysis of milk triacylglycerol. Activated bile salt-stimulated lipase could not on its own hydrolyze native milk fat globule triacylglycerol, whereas a limited hydrolysis by gastric lipase triggered hydrolysis by bile salt-stimulated lipase. Gastric lipase and colipase-dependent lipase, in combination, hydrolyzed about two thirds of total ester bonds, with monoacylglycerol and fatty acids being the end products. Addition of bile salt-stimulated lipase resulted in hydrolysis also of monoacylglycerol. When acting together with colipase-dependent lipase, bile salt-stimulated lipase contributed also to digestion of tri- and diacylglycerol. We conclude that digestion of human milk triacylglycerol depends on three lipases with unique, only partly overlapping, functions. Their concerted action results in complete digestion with free glycerol and fatty acids as final products.
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| 64. |
- Björkstén, B, et al.
(författare)
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Collecting and banking human milk : to heat or not to heat?
- 1980
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Ingår i: British medical journal. - 0007-1447. ; 281:6243, s. 765-9
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Tidskriftsartikel (refereegranskat)abstract
- Data on human breast milk and its handling when fed to babies who cannot be breast-fed were reviewed to determine whether the method of processing and storage affected the properties of the milk. Breast milk is normally contaminated by potential pathogens, which seem to produce no ill effects, but it also contains antimicrobial properties which protect against infection. The evidence suggests that pasteurisation not only eliminates pathogenic bacteria but also damages bacteriostatic mechanisms, so making the milk more susceptible to later contamination. Pasteurisation also affects the nutritional properties of milk. Freezing has little effect on milk proteins, while a study on the effect of refrigeration showed that there was little bacterial growth at temperatures below 8 degrees C. Several years' experience of feeding donated raw milk to newborn infants has confirmed that it produces no ill effects. These findings suggest that pasteurisation of donated breastmilk is unnecessary, and it is not recommended, while the decision whether or not to freeze the milk may be made on practical grounds. Raw breast milk can be safely stored at 4-6 degrees C for 72 hours.
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| 65. |
- Björmsjö, Maria, 1978-
(författare)
-
Clinical effects of reduced iron content and fortification with bovine lactoferrin in infant formula
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Breast milk, with its complex, individual and over time adapting composition, is considered the optimal source of nutrition for infants during the first months of life. Two possible contributing factors to the benefits of breastfeeding compared to infant formula-feeding are the differences in iron and lactoferrin (Lf) concentrations between breast milk and infant formula. The overall purpose of the LIME (a Swedish acronym) study was to add knowledge on how to reduce the gap in health and development between breastfed and formula-fed infants. The aim of this double-blinded controlled trial, and doctoral thesis, was to investigate how added bovine lactoferrin and reduced iron concentration in infant formula affect health and development.Methods: Recruitment took place from June 2014 to June 2018. With equal gender distribution, healthy term Swedish formula-fed infants (n=180) were randomly assigned, from 6 weeks to 6 months of age, to receive a low iron formula (2 mg/L) with bovine Lf (1.0 g/L) (Lf+, n=72), a low iron formula without Lf (Lf-, n=72) or a control standard formula with 8 mg/L iron and no Lf (CF, n=36). Additionally, 72 breastfed infants were recruited as a reference (BF) group. Blood samples were drawn at 4, 6, and 12 months. Primary outcomes were cytokine levels and iron status. Secondary outcomes were growth, gastrointestinal symptoms, infection-related morbidity and treatments, antibody response to vaccines and cognitive development.Findings: All explored outcomes were unaffected by Lf fortification and the two low iron groups (Lf+ and Lf-) were combined and compared to the CF group. At 6 months of age the TGF-β2 levels were lower among the low iron groups and more similar to the BF infants. No other significant differences in cytokine levels were observed. There was a trend of lower geometric mean of ferritin at 4, 6, and 12 months for the combined low iron groups compared to the CF group (67.7 vs 88.7, 39.5 vs 50.9, and 20.5 vs 25.1 μg/L, respectively, p=0.054, p=0.056, and p=0.082). No similar trends or significant differences were found for any of the other iron status indicators, except for hepcidin at 12 months with lower levels in the low iron group compared to CF (37.8 vs 49.4 ng/mL, p=0.027). Overall, infants fed low iron formula had iron status indicators closer to the breastfed reference group and the prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) was generally low with no significant differences among the intervention groups.There were no clinically relevant effects of the interventions on growth, gastrointestinal symptoms, infection-related morbidity, vaccine antibody response or neurocognitive development.In secondary analyses, the present study confirmed previous results of higher cognitive scores among breastfed infants compared to formula-fed and observed an unexpected lower IgG response to vaccines against Hib and Diphtheria.Conclusion: Adding bovine lactoferrin did not affect any of the clinical outcomes explored. Lowering infant formula iron concentration from 8 to 2 mg/L minimally reduced iron stores to levels closer to breastfed infants but did not increase the risk of ID/IDA during the first year of life. Consequently, 2 mg/L is a sufficient level of iron fortification during the first six months of life in a population with low risk of ID. Both adjustments are considered safe with no observed adverse effects.
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| 66. |
- Björmsjö, Maria, et al.
(författare)
-
Immunological Effects of Adding Bovine Lactoferrin and Reducing Iron in Infant Formula : A Randomized Controlled Trial
- 2022
-
Ingår i: Journal of Pediatric Gastroenterology and Nutrition - JPGN. - : Wolters Kluwer. - 0277-2116 .- 1536-4801. ; 74:3, s. e65-e72
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Compared to formula-fed infants, breastfed infants have a lower risk of infections. Two possible reasons for this are the presence of the anti-infective and anti-inflammatory protein lactoferrin and the lower level of iron in breast milk. We explored how adding bovine lactoferrin and reducing the iron concentration in infant formula affect immunology and risk of infections in healthy infants.METHODS: In a double-blind controlled trial, term formula-fed (FF) Swedish infants (n = 180) were randomized to receive, from 6 weeks to 6 months of age, a low-iron formula (2 mg/L) with added bovine lactoferrin (1.0 g/L) (Lf+; n = 72); low-iron formula with no added lactoferrin (Lf-; n = 72); and standard formula at 8 mg/L iron and no added lactoferrin (control formula [CF]; n = 36). Cytokines, infections, and infection related treatments were assessed until 12 months of age.RESULTS: No adverse effects were observed. There were no apparent effects on transforming growth factor beta (TGF-β)1, TGF-β2, tumor necrosis factor alfa (TNF-α) or interleukin2 (IL-2) at 4, 6, or 12 months, except of higher TGF-β2 at 6 months in the CF group in comparison to the low iron groups combined (P = 0.033). No significant differences in otitis, respiratory infections, gastroenteritis, or other monitored infections and treatments were detected for any of the study feeding groups during the first 6 months and only a few and diverging effects were observed between 6 and 12 months.CONCLUSIONS: Adding bovine lactoferrin and reducing iron from 8 to 2 mg/L in infant formula was safe. No clinically relevant effects on cytokines or infection related morbidity were observed in this well-nourished and healthy population.
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| 67. |
- Björmsjö, Maria, et al.
(författare)
-
Reducing Iron Content in Infant Formula from 8 to 2 mg/L Does Not Increase the Risk of Iron Deficiency at 4 or 6 Months of Age : A Randomized Controlled Trial
- 2021
-
Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Many infant formulas are fortified with iron at 8-14 mg/L whereas breast milk contains about 0.3 mg/L. Another major difference between breast milk and infant formula is its high concentration of lactoferrin, a bioactive iron-binding protein. The aim of the present study was to investigate how reducing the iron content and adding bovine lactoferrin to infant formula affects iron status, health and development. Swedish healthy full-term formula-fed infants (n = 180) were randomized in a double-blind controlled trial. From 6 weeks to 6 months of age, 72 infants received low-iron formula (2 mg/L) fortified with bovine lactoferrin (1.0 g/L) (Lf+), 72 received low-iron formula un-fortified with lactoferrin (Lf-) and 36 received standard formula with 8 mg of iron/L and no lactoferrin fortification as controls (CF). Iron status and prevalence of iron deficiency (ID) were assessed at 4 and 6 months. All iron status indicators were unaffected by lactoferrin. At 4 and 6 months, the geometric means of ferritin for the combined low-iron groups compared to the CF-group were 67.7 vs. 88.7 and 39.5 vs. 50.9 mu g/L, respectively (p = 0.054 and p = 0.056). No significant differences were found for other iron status indicators. In the low-iron group only one infant (0.7%) at 4 months and none at 6 months developed ID. Conclusion: Iron fortification of 2 mg/L is an adequate level during the first half of infancy for healthy term infants in a well-nourished population. Adding lactoferrin does not affect iron status.
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| 68. |
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| 69. |
- Björmsjö, Maria, et al.
(författare)
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Vaccine response was higher in formula-fed infants compared to breastfed but not affected by lactoferrin or iron in a randomised controlled trial
- 2024
-
Ingår i: Acta Paediatrica. - : John Wiley & Sons. - 0803-5253 .- 1651-2227.
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To examine how reduced iron content and added bovine lactoferrin in infant formula affect the antibody response following routine immunisation.Methods: In this randomised controlled trial, 180 Swedish formula-fed infants received, from 6 weeks to 6 months of age, a 2 mg/L iron formula with (n = 72) or without (n = 72) bovine lactoferrin, or a control formula with 8 mg/L iron and no lactoferrin (n = 36). Another 72 infants were recruited as a breastfed reference. Serum immunoglobulin G (IgG) levels against Haemophilus influenzae type b (Hib), diphtheria and tetanus were assessed at four, six and 12 months of age.Results: With an equal gender distribution, 180 + 72 term infants were included with a mean age of 7.0 ± 0.7 weeks. At 12 months, infants fed low iron formula showed a significantly higher geometric mean Hib IgG (1.40 μg/mL [1.07–1.83]) compared to the control formula infants (0.67 μg/mL [0.42–1.07]). For all three vaccines, breastfed infants had significantly lower IgG levels at six and 12 months of age.Conclusion: Except for higher Hib IgG levels at 12 months in infants fed low iron formula, the interventions did not affect vaccine IgG response. Unexpectedly, breastfed infants had significantly lower vaccine IgG levels compared to formula-fed infants.
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| 70. |
- Blind, Per Jonas, et al.
(författare)
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Carboxylic ester hydrolase : a serum marker of acute pancreatitis
- 1987
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Ingår i: Pancreas. - 0885-3177 .- 1536-4828. ; 2:5, s. 597-603
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Tidskriftsartikel (refereegranskat)abstract
- By use of an enzyme-linked immunosorbent assay we established serum reference values of carboxylic ester hydrolase, a pancreatic secretory lipolytic enzyme, and explored to see if a raised serum level is indicative of acute pancreatitis. Postoperative elevation of carboxylic ester hydrolase was observed in seven out of ten patients who underwent pancreatic surgery. Serum levels of carboxylic ester hydrolase and amylase were determined in 129 patients admitted due to abdominal emergency conditions. Amylase was elevated in 27 patients, and in 20 of these raised carboxylic ester hydrolase levels affirmed the diagnosis acute pancreatitis. In five out of the seven patients with elevated amylase alone no etiologic factor of acute pancreatitis was found. Another 11 patients had raised carboxylic ester hydrolase levels without concomitant elevation of amylase. In all these patients, a likely cause of pancreatic inflammation was identifiable. Hence, a raised carboxylic ester hydrolase level, even in presence of normal amylase, could be indicative of acute pancreatic inflammation.
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