| 1. |
- Timby, Niklas, et al.
(författare)
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Effects of age, sex and diet on salivary nitrate and nitrite in infants
- 2020
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Ingår i: Nitric oxide. - : Elsevier. - 1089-8603 .- 1089-8611. ; 94, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- The inorganic anions nitrate and nitrite are oxidation products from endogenous nitric oxide (NO) generation and constituents in our diet. A nitrate-nitrite-NO pathway exists in which nitrate can be serially reduced to bioactive NO. The first step of this pathway occurs in the oral cavity where oral bacteria convert salivary nitrate to nitrite, whereafter nitrite is reduced to NO systemically by several enzymatic and non-enzymatic pathways. Data are scarce regarding salivary levels and oral conversion capacity of these anions in infants. We measured salivary nitrate and nitrate in infants at 4 and 12 months of age and related values to age, sex, dietary pattern and oral microbiome. Saliva was collected from a total of 188 infants at 4 and 12 months of age. Salivary nitrate, nitrite and nitrite/nitrate ratio as a measure of oral nitrate-reducing capacity were analyzed by HPLC and related to age, sex, type of diet (breast milk or formula) and oral microbiome. There was no difference in salivary nitrate, nitrite or nitrite/nitrate ratio between boys and girls at any age. At 4 months levels of these parameters were lower than what has been described in adults but they had all increased significantly at 12 months of age. At 4 months of age salivary nitrite/nitrate ratio was lower in breast-fed compared to formula-fed infants, but these differences disappeared at 12 months. Several bacterial species were associated with oral nitrate reducing capacity including Prevotella, Veillonella, Alloprevotella and Leptotrichia. We conclude that in infants there is an increase in salivary nitrate and nitrite as well as in oral nitrate-reductase capacity during the first year of life. Differences observed at 4 months of age between breast-fed and formula-fed infants disappear at one year of age.
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| 2. |
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| 3. |
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| 4. |
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| 5. |
- Aggett, Peter J, et al.
(författare)
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Feeding preterm infants after hospital discharge : a commentary by the ESPGHAN Committee on Nutrition.
- 2006
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Ingår i: Journal of pediatric gastroenterology and nutrition. - : Ovid Technologies (Wolters Kluwer Health). - 1536-4801 .- 0277-2116. ; 42:5, s. 596-603
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Tidskriftsartikel (refereegranskat)abstract
- Survival of small premature infants has markedly improved during the last few decades. These infants are discharged from hospital care with body weight below the usual birth weight of healthy term infants. Early nutrition support of preterm infants influences long-term health outcomes. Therefore, the ESPGHAN Committee on Nutrition has reviewed available evidence on feeding preterm infants after hospital discharge. Close monitoring of growth during hospital stay and after discharge is recommended to enable the provision of adequate nutrition support. Measurements of length and head circumference, in addition to weight, must be used to identify those preterm infants with poor growth that may need additional nutrition support. Infants with an appropriate weight for postconceptional age at discharge should be breast-fed when possible. When formula-fed, such infants should be fed regular infant formula with provision of long-chain polyunsaturated fatty acids. Infants discharged with a subnormal weight for postconceptional age are at increased risk of long-term growth failure, and the human milk they consume should be supplemented, for example, with a human milk fortifier to provide an adequate nutrient supply. If formula-fed, such infants should receive special postdischarge formula with high contents of protein, minerals and trace elements as well as an long-chain polyunsaturated fatty acid supply, at least until a postconceptional age of 40 weeks, but possibly until about 52 weeks postconceptional age. Continued growth monitoring is required to adapt feeding choices to the needs of individual infants and to avoid underfeeding or overfeeding
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| 6. |
- Ahlsson, Fredrik, 1967-
(författare)
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Being Born Large for Gestational Age : Metabolic and Epidemiological Studies
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Obesity is a major health problem in the Western world. Mean birth weight has increased during the last 25 years. One explanation is that the proportion of large for gestational age (LGA) infants has increased. Such infants risk developing obesity, cardiovascular disease and diabetes later in life. Despite the risk of neonatal hypoglycemia, their postnatal metabolic adaptation has not been investigated. Our data, obtained with stable isotope labeled compounds, demonstrate that newborn LGA infants have increased lipolysis and decreased insulin sensitivity. After administration of glucagon, the plasma levels of glucose and the rate of glucose production increased. The simultaneous increase in insulin correlated with the decrease in lipolysis, indicating an antilipolytic effect of insulin in these infants.We also demonstrated an intergenerational effect of being born LGA, since women born LGA, were at higher risk of giving birth to LGA infants than women not born LGA. Further, the LGA infants formed three subgroups: born long only, born heavy only, and born both long and heavy. Infants born LGA of women with high birth weight or adult obesity were at higher risk of being LGA concerning weight alone, predisposing to overweight and obesity at childbearing age. In addition we found that pregnant women with gestational diabetes were at increased risk of giving birth to infants that were heavy alone. This could explain the risk of both perinatal complications and later metabolic disease in infants of this group of women.To identify determinants of fetal growth, 20 pregnant women with a wide range of fetal weights were investigated at 36 weeks of gestation. Maternal fat mass was strongly associated with insulin resistance. Insulin resistance was related to glucose production, which correlated positively with fetal size. The variation in resting energy expenditure, which was closely related to fetal weight, was largely explained by BMI, insulin resistance, and glucose production. Lipolysis was not rate limiting for fetal growth in this group of women. Consequently, high maternal glucose production due to a high fat mass may result in excessive fetal growth.
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| 7. |
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| 8. |
- Andersson, Eva-Lotta, et al.
(författare)
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Bile salt-stimulated lipase and pancreatic lipase-related protein 2 : key enzymes for lipid digestion in the newborn examined using the Caco-2 cell line
- 2011
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Ingår i: Journal of Lipid Research. - : American Society for Biochemistry and Molecular Biology. - 0022-2275 .- 1539-7262. ; 52:11, s. 1949-1956
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Tidskriftsartikel (refereegranskat)abstract
- In rodents, bile salt-stimulated lipase (BSSL) and pancreatic lipase-related protein 2 (PLRP2) are the dominant lipases expressed in the exocrine pancreas in early life, when milk is the main food. The aim of the present study was to evaluate if BSSL and PLRP2 are also key enzymes in neonatal intestinal fat digestion. Using Caco-2 cells as a model for the small intestinal epithelium, purified human enzymes were incubated in the apical chamber with substrates and bile salt concentrations resembling the milieu of the small intestine of newborn infants. BSSL and PLRP2 hydrolyzed triglycerides (TG) to free fatty acids (FA) and glycerol. The cells took up the FA, which were reesterfied to TG. Together, BSSL and PLRP2 have a synergistic effect, increasing cellular uptake 4-fold compared to the sum of each lipase alone. A synergistic effect was also observed with retinyl ester as a substrate. PLRP2 hydrolyzed cholesteryl ester but not as efficiently as BSSL, and the two had an additive rather than synergistic effect. We conclude the key enzymes in intestinal fat digestion are different in newborns than later in life. Further studies are needed to fully understand this difference and its implication for designing optimal neonatal nutrition.
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| 9. |
- Andersson, Yvonne, et al.
(författare)
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Formula feeding skews immune cell composition toward adaptive immunity compared to breastfeeding
- 2009
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Ingår i: Journal of Immunology. - : The American Association of Immunologists, Inc.. - 0022-1767 .- 1550-6606. ; 183:7, s. 4322-4328
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Tidskriftsartikel (refereegranskat)abstract
- The ontogeny of the immune system and the effect thereon by type of infant feeding is incompletely understood. We analyzed frequencies and composition of immune cells in blood of breastfed (BF) and formula-fed (FF) infants at 1.5, 4, and 6 mo of age. Three formulas with the same protein concentration but with varying levels of alpha-lactalbumin and caseinoglycomacropeptide were compared. Twenty-nine exclusively BF infants served as reference, and 17 infants in each formula group completed the study. Whole blood and PBMCs were analyzed by flow cytometry and immunoflow cytometry, respectively. Leukocyte count of BF infants increased with time due to increased frequency of neutrophils. Lymphocyte count was high at 1.5 mo and was unchanged over time, as were the relative proportions of CD4+ alphabetaT cells, CD8+ alphabetaT cells, B cells, NK cells, and gammadeltaT cells. Most CD45R0+CD3+ cells were HLA-DR- and hence memory cells. Compared with breastfeeding, formula feeding resulted in a significant decrease in proportion of NK cells, but a significant increase in naive CD4+ alphabetaT cells and an elevated CD4-to-CD8 ratio, that is, 3.3 in the combined FF groups compared with 2.6 in the BF group. No significant differences were found between the three groups of FF infants. In conclusion, blood cells of lymphoid lineage did not change significantly in frequencies or composition from 1.5 to 6 mo of age in BF infants. In contrast, FF infants displayed an ongoing maturation of adaptive immunity cells and a delayed recruitment of innate immunity cells as compared with BF infants.
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| 10. |
- Andersson, Yvonne, et al.
(författare)
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Lactoferrin is responsible for the fungistatic effect of human milk.
- 2000
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Ingår i: Early Human Development. - 0378-3782 .- 1872-6232. ; 59:2, s. 95-105
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Tidskriftsartikel (refereegranskat)abstract
- Human milk has recognized anti-microbial effects and it has been repeatedly shown that breast-fed infants have fewer and less severe infections than formula-fed infants. While most studies have focused on anti-bacterial and anti-viral activities few have focused on the anti-fungal effect of human milk. Dermal and other infections caused by fungi are common in very low birth weight (VLBW) infants. Using a liquid culturing method and Candida albicans and Rhodotorula rubra as representative fungi, we studied the anti-fungal effect of human milk and certain human milk proteins. In vitro, human milk showed potent inhibitory effect on fungal growth. Most, if not all of this effect was caused by lactoferrin via its iron-binding capacity; increasing the iron content of the incubation medium abolished the inhibitory effect. In contrast, other human milk proteins with known or suggested anti-microbial effects rather increased fungal growth. Viability test and electron microscopy revealed that the growth inhibitory effect of human milk, i.e. mediated by lactoferrin, is fungistatic rather than fungicidal.
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| 11. |
- Andersson, Yvonne, et al.
(författare)
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Three variants of parathyroid hormone-related protein messenger RNA are expressed in human mammary gland.
- 1997
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Ingår i: Pediatric Research. - 0031-3998 .- 1530-0447. ; 41:3, s. 380-3
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Tidskriftsartikel (refereegranskat)abstract
- PTH-related protein (PTHrP) is found in a variety of tissues; particularly high levels are present in human milk. The structure of the human PTHrP gene is complex, and alternative splicing allows expression of three different variants PTHrP139, PTHrP173, and PTHrP141, respectively. To determine which of the variants are expressed in human mammary gland a reverse transcriptase polymerase chain reaction (RT-PCR) method was elaborated, distinguishing the three variants. mRNA isolated from human milk cells, human mammary epithelial cells (HMEC) and human nonlactating mammary gland cells were analyzed. The RT-PCR experiments resulted in amplification of DNA fragments corresponding to all three variants for all three cell sources tested. The nucleotide sequences of the PCR fragments were determined and verified to be identical to the reported sequences. Hence, it is concluded that human mammary gland epithelial cells express three variants of PTHrP. Whether these have different physiologic effects in the mammary gland or in the breast fed infant remain to be explored.
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| 12. |
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| 13. |
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| 14. |
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| 15. |
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| 16. |
- Bas, A, et al.
(författare)
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Aberrant extrathymic T cell receptor gene rearrangement in the small intestinal mucosa : a risk factor for coeliac disease?
- 2009
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Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 58:2, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Coeliac disease is a small intestine enteropathy caused by permanent intolerance to wheat gluten. Gluten intake by patients with coeliac disease provokes a strong reaction by intestinal intraepithelial lymphocytes (IELs), which normalises on a gluten-free diet. AIM: To investigate whether impaired extrathymic T cell maturation and/or secondary T cell receptor (TCR) gene recombination in IELs are features of coeliac disease which could contribute to the failure of establishing tolerance to gluten.METHODS: Expression levels of the four splice-forms of recombination activating gene-1 (RAG1) mRNA and preT alpha-chain (preTalpha) mRNA were determined in IEL-subsets of children with coeliac disease and controls. Frequencies of RAG1 expressing IELs were determined by immunomorphometry.RESULTS: In controls, the RAG1-1A/2 splice-form selectively expressed outside the thymus, was dominant and expressed in both mature (TCR(+)) and immature (CD2(+)CD7(+)TCR(-)) IELs ( approximately 8 mRNA copies/18S rRNA U). PreTalpha was expressed almost exclusively in CD2(+)CD7(+)TCR(-) IELs ( approximately 40 mRNA copies/18S rRNA U). By contrast, RAG1 and preTalpha mRNA levels were low in patients with coeliac disease compared to controls, both with active disease and with inactive, symptom-free disease on a gluten-free diet (p values <0.01 for mature and <0.05 for immature IELs). Similarly, the frequencies of RAG1+ IELs were significantly lower in patients with coeliac disease compared to controls (p<0.001).CONCLUSIONS: Patients with coeliac disease appear to have an impaired capacity for extrathymic TCR gene rearrangement. This is an inherent feature, which probably plays a pivotal role in the failure to efficiently downregulate the T cell response to gluten.
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| 17. |
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| 18. |
- Berglund, Staffan, 1975-, et al.
(författare)
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Effects of iron supplementation of LBW infants on cognition and behavior at 3 years
- 2013
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Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 0031-4005 .- 1098-4275. ; 131, s. 47-55
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Low birth weight (LBW) infants are at increased risk of cognitive and behavioral problems and at risk for iron deficiency, which is associated with impaired neurodevelopment. We hypothesized that iron supplementation of LBW infants would improve cognitive scores and reduce behavioral problems. METHODS: In a randomized controlled trial, 285 marginally LBW (2000-2500 g) infants received 0, 1, or 2 mg/kg/day of iron supplements from 6 weeks to 6 months of age. At 3.5 years of age, these infants and 95 normal birth weight controls were assessed with a psychometric test (Wechsler Preschool and Primary Scale of Intelligence) and a questionnaire of behavioral problems (Child Behavior Checklist; CBCL). RESULTS: There were no significant differences in IQ between the LBW groups or LBW infants versus controls. Mean (SD) full-scale IQ was 105.2 (14.5), 104.2 (14.7), and 104.5 (12.7) in the placebo, 1 mg, and 2 mg groups, respectively (P = .924). However, for behavioral problems, there was a significant effect of intervention. The prevalence of children with CBCL scores above the US subclinical cutoff was 12.7%, 2.9%, and 2.7% in the placebo, 1-mg, and 2-mg groups, respectively (P = .027), compared with 3.2% in controls. Relative risk (95% confidence interval) for CBCL score above cutoff in placebo-treated children versus supplemented was 4.5 (1.4-14.2). CONCLUSIONS: Early iron supplementation of marginally LBW infants does not affect cognitive functions at 3.5 years of age but significantly reduces the prevalence of behavioral problems. The study suggests a causal relation between infant iron deficiency and later behavioral problems.
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| 19. |
- Berglund, Staffan, 1975-
(författare)
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Effects of iron supplementation on iron status, health and neurological development in marginally low birth weight infants.
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background Due to small iron stores and rapid growth during the first months of life, infants with low birth weight (LBW) are at risk of iron deficiency (ID). ID in infancy is associated with irreversible impaired neurodevelopment. Preventive iron supplementation may reduce the risk of ID and benefit neurodevelopment, but there is also a possible risk of adverse effects. More than 50% of all LBW infants are born with marginally LBW (MLBW, 2000-2500g), and it is not known if they benefit from iron supplementation. Methods We randomized 285 healthy, Swedish, MLBW infants to receive 3 different doses of oral iron supplements; 0 (Placebo), 1, and 2 mg/kg/day from six weeks to six months of age. Iron status, during and after the intervention was assessed and so was the prevalence of ID and ID anemia (IDA), growth, morbidity and the interplay with iron and the erythropoetic hormones hepcidin and erythropoietin (EPO). As a proxy for conduction speed in the developing brain, auditory brainstem response (ABR) was analyzed at six months. In a follow up at 3.5 years of age, the children were assessed with a cognitive test (WPPSI-III) and a validated parental checklist of behavioral problems (CBCL), and compared to a matched reference group of 95 children born with normal birth weight. Results At six months of age, the prevalence of ID and IDA was significantly higher in the placebo group compared to the iron supplemented infants. 36% had ID in the placebo group, compared to 8% and 4 % in the 1 and 2mg/kg/day-groups, respectively. The prevalence of IDA was 10%, 3% and 0%, respectively. ABR-latencies did not correlate with the iron intake and was not increased in infants with ID or IDA. ABR wave V latencies were similar in all three groups. Hepcidin correlated to ferritin and increased in supplemented infants while EPO, which was negatively correlated to iron status indicators, decreased. At follow up there were no differences in cognitive scores between the groups but the prevalence of behavioral problems was significantly higher in the placebo group compared to those supplemented and to controls. The relative risk increase of CBCL-scores above a validated cutoff was 4.5 (1.4 – 14.2) in the placebo-group compared to supplemented children. There was no detected difference in growth or morbidity at any age. Conclusion MLBW infants are at risk of ID in infancy and behavioral problems at 3 years of age. Iron supplementation at a dose of 1-2 mg/kg/day from six weeks to six months of age reduces the risks with no adverse effects, suggesting both short and long term benefit. MLBW infants should be included in general iron supplementation programs during their first six months of life.
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| 20. |
- Bergström, Erik, 1944-
(författare)
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Cardiovascular risk indicators in adolescents : the Umeå youth study
- 1995
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Atherosclerotic cardiovascular diseases (CVD), particularly coronary heart disease (CHD) and cerebrovascular disease, are today major causes of death in the industrialised parts of the world. There are evidence to suggest that the atherosclerotic process starts in childhood, implying that preventive measures should be implemented already in children and adolescents.The aim of this study was to examine CVD risk indicators and their determinants in healthy Swedish adolescents. The study population comprised 14- and 17-year-old boys and girls (n=1032), in the dty and surroundings of Umeå in northern Sweden.Biochemical, anthropometric, and physiological parameters associated to CVD (s- lipoproteins and s-apolipoproteins, s-insulin, s-ferritin, anthropometric measurements, blood pressure, and physical fitness) were evaluated in relation to family history of CVD, weight and length at birth, infant feeding regimen, physical growth during infancy and childhood, current diet, physical activity, smoking, and educational level and occupation of the parents.The main findings of the study were that, on average, total serum cholesterol (TC) values in boys and girls were at the same level as reported from other European countries. A family history of CVD, short duration of breast feeding, low attained height during infancy and childhood, high body mass index (BMI), and low physical fitness were all associated with an unfavourable serum lipid profile. The findings also showed that features typical of the insulin resistance syndrome are present already in adolescents. In boys, iron stores, estimated by serum ferritin, were related to BMI and physical fitness, in a similar way as well established CVD risk indicators. Compared to previous dietary studies in Sweden, mean relative (energy %) fat intake had decreased substantially although the mean relative intake of saturated fat was still rather high. For both boys and girls, reported relative energy intake (energy intake/estimated energy expenditure) decreased with increasing level of BMI. Furthermore, daily smoking was more common among adolescents from families with low socio-economic status (SES) but was most strongly associated to smoking in peers. Tobacco use was considerably higher among adolescents attending vocational programs at secondary high school as compared to theoretical programs. Daily smokers had a more unfavourable serum lipid profile compared to non-smokers. Low socio-economic status of the parents was related to higher BMI and low educational level to higher dietary fat intake in both boys and girls.In conclusion, the findings of the study show that parameters linked to adult CVD when examined in adolescents, are related to family history, infant nutrition, previous physical growth, current body composition, physical fitness, physical activity, smoking, and social status and educational level of the parents.
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| 21. |
- Bergström, Erik, et al.
(författare)
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Dietary changes in Swedish adolescents.
- 1993
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Ingår i: Acta Paediatrica. - 0803-5253 .- 1651-2227. ; 82:5, s. 472-80
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Tidskriftsartikel (refereegranskat)abstract
- A school-based dietary survey, using seven-day records, was performed in two cohorts of Swedish adolescents; 14- and 17-year-olds. The study comprised 366 boys and 365 girls. When compared to previous studies in Sweden, a striking finding was a decrease in dietary fat intake and an increase in carbohydrate intake. However, the relative intake of saturated fat had not changed (15% of total energy). The dietary change was mainly due to an increased consumption of cereal products. There were no major differences in dietary habits or nutrient density of the food between the two age groups, or between boys and girls. The mean intakes of protein, fat and carbohydrate, expressed as a percentage of the total energy intake, were 15, 33 and 52%, respectively. The mean intakes of vitamins and minerals were low only for selenium. The boys had a high iron intake (1.5 and 1.7 times the recommended intake for 14- and 17-year-olds, respectively) while the mean iron intake for girls was 0.9 times the recommended dietary allowances in both age groups. The intake of dietary salt was higher in boys than in girls (7.7 g and 9.0 g per day in 14- and 17-year-old boys, respectively, and 5.8 g per day in both 14- and 17-year-old girls). In a long-term health perspective, this positive change in nutrient intake in adolescents may contribute to a reduction in the incidence of diet-related diseases in Sweden.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 22. |
- Bergström, Erik, et al.
(författare)
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Serum lipid values in adolescents are related to family history, infant feeding, and physical growth.
- 1995
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 117:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Total serum cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-I (apo A-I), apolipoprotein B (apo B), and lipoprotein (a) (Lp(a)) were analysed in 879 14- and 17-year-old healthy adolescents (477 boys and 402 girls), and related to family history of cardiovascular disease, early feeding, weight and length at birth, and physical growth during infancy and childhood. Mean TC was significantly higher in girls than in boys (4.4 and 4.2 mmol/l, respectively, both age-groups together). High TC values ( > 5.2 mmol/l) were more prevalent in girls than in boys: 14% and 17% compared to 6% and 12% in 14- and 17-year-old girls and boys, respectively. Mean TC and LDL-C values were lower during mid-puberty in both boys and girls while, in boys but not in girls, mean HDL-C values decreased and TG values increased successively with increasing pubertal stage. Girls who were taking oral contraceptives had higher mean values of TC (4.91/4.39 mmol/l), TG (1.32/0.83 mmol/l), and apo B (0.89/0.73 g/l). Boys with a family history of early deaths ( < 55 years) from myocardial infarction and girls with a family history of cerebral haemorrhage/thrombosis in fathers had higher mean values of TC (4.55/4.17 and 5.03/4.40 mmol/l, for boys and girls, respectively), LDL-C (2.84/2.47 and 3.08/2.56 mmol/l), and apo B (0.73/0.70 and 0.86/0.73 g/l). Adolescents with short duration of breast feeding ( < 6 months), or early introduction of infant formula, had higher mean values of TC (4.29/4.14 mmol/l) and apo B (0.72/0.68 g/l). There were no significant correlations between serum lipid values and body weight or length at birth, but adolescents with high LDL-C (upper quartile) seemed to have lower attained heights during infancy and childhood. In conclusion, this study shows that serum lipids in adolescence are primarily related to age and sex but also to early determinants like family history of cardiovascular diseases, infant feeding, and early physical growth.
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| 23. |
- 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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| 24. |
- Bergström, S, et al.
(författare)
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Cloning and sequencing of human kappa-casein cDNA.
- 1992
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Ingår i: DNA Sequence. - 1042-5179 .- 1029-2365. ; 3:4, s. 245-6
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Tidskriftsartikel (refereegranskat)abstract
- A cDNA encoding kappa-casein of human milk was cloned and sequenced. The kappa-casein cDNA was isolated from a lambda gt11 library generated from mRNA prepared from a mammary gland biopsy obtained from a lactating woman. The library was screened with polyclonal rabbit antibodies raised against purified native kappa-casein. The obtained nucleotide sequence contained an ORF sufficient to encode the entire amino acid sequence of a kappa-casein precursor protein consisting of 182 amino acids. This includes a tentative signal peptide of 20 amino acids and a processed protein of 162 amino acids.
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| 25. |
- 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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