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Biomedical subjects

N Räihä

Publications and source records attributed to N Räihä.

At least 19 recordsLinked to original sources
PubMed1997

The influence of dietary nucleotides on erythrocyte membrane fatty acids and plasma lipids in preterm infants.

OBJECTIVE: The objective of this study was to evaluate whether a regular formula for premature infants supplemented with nucleotides has any influence on plasma lipids and erythrocyte membrane fatty acids. METHODS: Preterm infants fed either human milk supplemented with human milk protein (HM, n = 14), nucleotide-supplemented preterm formula (NF, n = 13), or a regular preterm formula (F, n = 13) were included in the study. The NF was supplemented with 18.2 mg cytidine monophosphate/l (CMP), 7.0 mg uridine monophosphate/l (UMP), 6.4 mg adenosine monophosphate/l (AMP), 3.0 mg inosine monophosphate/l (IMP) and 3.0 mg guanosine monophosphate/l (GMP). RESULTS: There were significantly higher concentrations of triglycerides (TG) in infants fed NF compared to those fed F (191.42 +/- 79.58 vs 108.21 +/- 43.73, p < 0.001, mean +/- SD lipid concentrations, mg/100 ml plasma). Infants fed F had significantly lower concentrations of total cholesterol (94.34 +/- 11.71 vs 115.69 +/- 39.29, p < 0.01) and TG in plasma (108.21 +/- 43.73 vs 172.27 +/- 68.19, p < 0.001, mean +/- SD lipid concentrations, mg/100 ml plasma) when compared to HM-fed infants. There were no significant differences in any of the erythrocyte membrane fatty acids and total long-chain polyunsaturated fatty acids (LC-PUFA) between NF and F during the study period (6 weeks). Furthermore, total LC-PUFA and docosahexaenoic acid (DHA) concentrations in red blood cell were not significantly different when infants fed NF were compared to those fed HM. In contrast, however, infants fed F had significantly lower concentrations of total n-3 LC-PUFA (p < 0.01) and DHA (p < 0.01) than those found in HM-fed infants. CONCLUSIONS: These results do not suggest an effect of nucleotides on the red blood cell LC-PUFA profile in preterm infants. However, the nucleotides may increase the concentrations of triglycerides in plasma.

Cholesterol↗
PubMed1990

Antibody responses to parenteral and oral vaccines are impaired by conventional and low protein formulas as compared to breast-feeding.

The vaccine response to poliovirus, diphtheria and tetanus toxoids in relation to protein intake was studied in infants, either breast-fed or given low (1.1 g/100 ml) or conventional (1.5 g/100 ml) protein formula. Serum, saliva and faeces antibodies were measured by the enzyme-linked immunosorbent assay. Neutralizing poliovirus antibodies were determined. The serum, saliva and faeces antibody responses in the two formula-fed groups of infants did not differ significantly, but for the low protein formula group which had significantly higher serum neutralizing titres to poliovirus after the second vaccine dose than the conventional formula group. However, the breast-fed group had significantly higher antibody levels than the two formula-fed groups together: serum IgG to diphtheria toxoid (p less than 0.01) and serum neutralization of poliovirus (p less than 0.001) at 21-40 months of age, saliva secretory IgA to tetanus (p less than 0.01), diphtheria toxoid (p less than 0.01) and poliovirus (p less than 0.05), as well as faecal IgM to tetanus toxoid (p less than 0.05) and poliovirus (p less than 0.01 and p less than 0.05) at 3 and 4 months of age. Breast-fed infants thus showed better serum and secretory responses to peroral and parenteral vaccines than the formula-fed, whether with a conventional or low protein content.

Breast Feeding↗
PubMed1990

Postnatal adaptation of lipase- and trypsin-activities in duodenal juice of premature infants appropriate for gestational age.

In 17 very low birth weight and in 13 low birth weight infants appropriate for gestational age the activities of pancreatic lipase and trypsin, the pH value and the concentrations of total bile acids were measured in the preprandially aspirated duodenal juice between the 10th and the 40th day of postnatal life. The activities of both enzymes increased significantly with increasing postnatal age in both study groups but did not correlate with the gestational age between the 28th and 33rd week of gestation. The pH values were on a low but similar level in both study groups (mean for all infants 5.66 +/- 0.07), and there was no influence of the pH value on the activities of either pancreatic enzyme. The concentrations of total bile acids were also not different between the study groups (mean for all infants = 4.55 +/- 2.26 mmol/l) and no correlation could be found between the concentrations of total bile acids and the activities of both measured enzymes. The data suggest that the intrauterine development of the exocrine pancreas reaches a basal level by the 28th week of gestation and remains on this level up to the 33rd week of gestation. After birth there is a significant increase in enzyme activities for both studied enzymes.

Adaptation, Physiological↗
PubMed1989

Growth and plasma amino acid concentrations in very low birthweight infants fed either human milk protein fortified human milk or a whey-predominant formula.

In a prospective, study involving 20 VLBW-infants (AGA), divided into two study groups of 10 infants, we have evaluated the effects on growth and metabolism of human milk fortified with ultrafiltrated human milk protein and a whey-predominant (whey/casein = 60/40) formula containing 2 g/dl of protein. The study was initiated at a mean age of 30 days when an oral intake of 180 ml/kg/d was tolerated and continued until a weight of 2 kg was reached. The protein intake in both groups was about 3.7 g/kg/d. All infants in both groups reached intrauterine rates of growth for the age, weight gain 18.0 g/kg/d, and length 1.2 cm/week. BUN, acid-base status, total protein and albumin were normal and similar in the two groups. Plasma levels of threonine, glycine, citrulline and methionine were significantly greater in the formula-fed infants. Taurine and proline had higher concentrations in the protein fortified human milk group. There was good tolerance of protein from both sources but the differences in plasma amino acid profiles suggest that the dietary protein quality in formulas for preterm infants must be further modified, if the goal of formula feeding is to achieve metabolic indices of protein metabolism similar to those found when human milk protein is used.

Amino Acids↗
PubMed1989

Macromolecular absorption in preterm and term infants.

Human alpha-lactalbumin (alpha-LA) has been used as a marker for measuring macromolecular absorption. The serum concentration of human alpha-LA after a human milk feed has been studied in 32 healthy very low birthweight infants (VLBW), fed human milk (gestational age 26-32 weeks) and in 56 term, breast-fed infants, age 3-140 days. At 31 weeks of gestation the serum concentration of human alpha-LA was more than 10 times higher (mean value 3,000 and median value 2,101 micrograms/l serum/l human milk/kg body weight, n = 11) than in the term infants aged 3-30 days (mean value 257 and median value 152, n = 29). The serum concentration of alpha-LA decreased with increasing maturity in the VLBW-infants. At a postconceptional age of 37 weeks the values were similar (mean value 200 and median value 99, n = 8) to those found for term infants during the first month. In the term infants a decreasing absorption of alpha-LA was found with increasing postnatal age.

Female↗
PubMed1988

Protein and energy intake during weaning. III. Effects on plasma amino acids.

Preprandial plasma amino acid concentrations were measured at 5 and 6 months of age in 30 healthy term infants who were either breast-fed ad libitum or fed one of two different formulas (1.9 g of protein per 100 ml with a whey:casein ratio of 50:50; 2.9 g of protein per 100 ml with a whey:casein ratio of 20:80) ad libitum, plus the same supplementary food regimen. The mean plasma concentrations of total amino acids and especially total essential amino acids were higher in the formula-fed infants. Those fed formula also had plasma concentrations of methionine, isoleucine, phenylalanine, leucine, valine, threonine, aspartate, proline, lysine, tyrosine, histidine that exceeded plasma concentrations of breast-fed infants by 2 or more standard deviations. Concentrations of arginine, glutamic acid, glutamine, ornithine, serine, cystine did not differ and taurine was higher in the breast-fed infants. The data indicate that formulas in common use today during weaning (4-6 months) provide excessive protein intakes when compared to the breast-fed control infants. A lowering of protein concentration and a further manipulation of the whey:casein ratio is necessary if plasma amino acid patterns similar to those found in breast-fed infants is to be achieved with artificial feeding.

Amino Acids↗
PubMed1987

Protein and energy intake during weaning: I. Effects on growth.

The growth and food consumption of 30 healthy infants from 4 to 6 months of age have been measured. Two groups were assigned randomly to either a formula with 1.9 g of protein and 72 kcal per 100 ml (F1) or 2.7 g of protein and 69 kcal per 100 ml (F2). A third group of infants were fed breast milk (0.96 g of protein and 65 kcal per 100 ml (HM)). All infants received supplementary food according to the same regimen and were fed ad libitum. The mean protein intake was 1.3, 2.6 and 3.6 g/kg/day in the HM-, F1- and F2-groups respectively. The corresponding mean energy intake was 80, 101 and 94 kcal/kg/day. The formula-fed infants had significantly higher protein and energy intakes when compared to the breast-fed group. No significant differences were found in the rate of growth of crown-heel length, head circumference or in weight gain. The differences in protein intake between the breast- and formula-fed infants without differences in growth indicate that the formulas may provide a protein intake in excess to the needs.

Body Height↗
PubMed1987

Protein intake during weaning. II. Metabolic responses.

Metabolic responses to different feeding regimens during the weaning period have not previously been studied. In this study 30 healthy infants aged 4-6 months were divided into three feeding regimens with 10 infants in each. The regimens were: Human milk (HM-group), formula F1 with 1.9 g protein/100 ml (F1-group) or formula F2 with 2.7 g protein/100 ml (F2-group). All infants received the same supplementary food and were fed ad libitum. Concentrations of serum urea were significantly higher (p less than 0.001) in the formula groups as compared to the breast-fed infants throughout the entire study period. Serum albumin concentrations were within normal limits in the breast-fed infants indicating adequate protein nutritional status. There were no differences in the concentrations of creatinine and total nitrogen in urine between the artificially fed and the breast-fed infants at the beginning of the study (4 months), but at 6 months these concentrations were significantly higher in the formula-fed (infants (p less than 0.001). The results suggest that formulas now in common use during weaning provide amounts of protein which produce metabolic manifestations implying excessive protein intakes.

Blood Urea Nitrogen↗
PubMed1986

Evidence for amino acid induced cholestasis in very-low-birth-weight infants with increasing enteral protein intake.

In the present investigation 32 very-low-birth-weight (VLBW) infants fed at three different levels of protein intake (2.92 g/kg/d from human milk, 3.22 and 4.06 g/kg/d from formula) were studied at the mean age of 21 days. Serum total alpha-amino nitrogen concentration correlated directly to total bile acid concentration. The serum and urine alpha-amino nitrogen and the serum bile acid concentration correlated with protein intake. The increase in protein intake was accompanied by a concomitant decrease in the intraluminal bile acid concentration in the AGA infants. The results offer indirect evidence of decreased bile flow in VLBW-infants on excessive oral protein intake. The cholestatic effect could be mediated by an increase in the plasma amino acid concentration.

Amino Acids↗
PubMed1986

Milk protein intake in the term infant. I. Metabolic responses and effects on growth.

Thirty healthy term infants were studied during the three first months of life. The infants were divided into three feeding groups consisting of 10 infants in each. The feeding regimens were: human milk by breast feeding, a formula (F-I) containing 1.2 g/100 ml of protein and a control formula (F-II) containing 1.6 g protein/100 ml. Both formulas were whey predominant and isocaloric. Protein intake was significantly higher with formula F-II when compared to the human milk group and to formula F-I. No significant differences with respect to weight, length and head circumference were found among the groups, but the rate of growth between 2 to 12 weeks was higher in the control formula (F-II) group. Serum albumin concentrations were normal and similar in all feeding groups. Blood urea nitrogen and urine total nitrogen concentration was significantly lower in the low protein formula I group when compared to the control formula II. After the fourth week of life the low protein formula infants had similar blood urea nitrogen and urine nitrogen concentrations as those of the breast-fed infants. The results indicate that current formulas in use provide excessive protein intakes after the first months of life.

Breast Feeding↗
PubMed1986

Milk protein intake in the term infant. II. Effects on plasma amino acid concentrations.

The response of plasma amino acids to two bovine protein formulas with different protein content (1.6 and 1.2 g/100 ml containing 60% whey proteins and 40% caseins) was measured in term infants. These two groups of infants were compared with a group of infants that were breast-fed; all infants were fed ad libitum. Concentrations of threonine, valine and total branched chain amino acids reflected the amount of protein provided. Thus, the concentrations were higher in the higher protein formula infants from the second week of the study. In the low protein formula infants these amino acids were lower but differed from the infants on breast milk at eight and twelve weeks. Concentration of taurine was lower in the formula fed infants than they were in breast-fed infants at the end of the study. The valine/glycine ratio in the low protein formula group was lower than in the breast-fed group for the first four weeks of the study. After this time it was equal to that of the breast-fed group. These differences in plasma amino acid concentrations give further evidence that formulas now in common use for term infants provide a protein intake in excess of protein requirements after the first months of life.

Amino Acids↗
PubMed1984

Relationship between protein and energy in the feeding of preterm infants during the first month of life.

Energy and protein quantity and quality in the diet are factors regulating the rate of growth in the preterm infant. In the present study twenty infants 31-36 weeks of gestational age were fed with identical test formulas which varied only in the content of energy. One formula (F-81) contained 3.1 g protein (60 bovine whey: 40 bovine caseins) and 81 kcal per dl. The second formula (F-94) contained the same amount of protein but 94 kcal per dl. At an intake of 150 ml/kg/d the infants received 4.6 g protein/kg/d and either 121 or 141 kcal/kg/d. The infants on F-94 had a significantly higher rate of weight gain, but growth of length and head circumference was equal in the two groups. Significant differences were found in the plasma concentrations of glutamine and alanine between the two feeding groups. The other plasma amino acids were not statistically different in the two groups of infants. Urine excretion of threonine, serine, glycine, alanine, histidine, tyrosine, glutamine and cystathionine was significantly increased in the high caloric, F-94-group. The results indicate that increasing the caloric intake above 120 kcal/kg/d in preterm infants on a relatively high protein intake does not increase linear growth but does produce increased weight gain. The biochemical results provide indirect evidence that this weight increase is the result of increased fat accretion.

Acid-Base Equilibrium↗
PubMed1975

Oxidation of glucose and D-B-OH-butyrate by the early human fetal brain.

The isolated brains of 12 previable human fetuses obtained at 12 to 21 weeks' gestation, were perfused through the interval carotid artery with glucose (3 mM) and/or DL-B-OH-butyrate (DL-BOHB), 4.5 MM, plus tracer quantities of either glucose-6-14C (G6-14C) or beta-OH-butyrate-3-14C (BOHB3-14C). Oxidative metabolism was demonstrated by serial collection of gaseous 14CO2 from the closed perfusion system, and from the recirculating medium. Glucose and BOHB were utilized at physiological rates as indicated (mean plus or minus SEM): G6-14C at 0.10 plus or minus 0.01 mumoles/min g brain (n equal 7) or 17.5 plus or minus 1.9 mumoles/min kg fetus; and BOHB3-14C at 0.16 plus or minus 0.05 mumoles/min g (n equal to 5) or 27.3 plus or minus 7.4 mumoles/min kg. Based on fetal weight, glucose metabolism by brain apparently accounted for about 1/3 of basal glucose utilization in the fetus. On a molar basis BOHB3-14C was taken up at 1.47 times the rate of G6-14C. Both BOHB3-14C and G6 14C were converted to 14CO2. The rate of BOHB3-14C conversion to 14CO2 was equal to its rate of consumption, and exceeded the conversion of glucose to CO2 because 45% of the G6-14C was incorporated into lactate-14C. Accordingly, both substrates support oxidative metabolism by brain; and BOHB is a major potential alternate fuel which can replace glucose early in human development.

Blood Glucose↗