Amino Acids in Premature Infants

PEDIATRICS ◽  
1988 ◽  
Vol 82 (4) ◽  
pp. 680-681
Author(s):  
WILLIAM C. HEIRD
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Clinical Significance ◽  
Premature Infants ◽  
Developmental Delays ◽  
Plasma Amino Acid ◽  
Central Vein ◽  
Older Children ◽  
Peripheral Vein ◽  
Term Infants

In Reply.— Dr Raiha is correct. Our data1 do not necessarily "refute" the concept of the LBW infant's metabolic immaturity. However, they raise the issue of the clinical significance of the well-documented developmental delays in hepatic activities of several enzymes involved in metabolism of amino acids. Specifically, these data suggest that enzymatic immaturities are of limited clinical significance with respect to the LBW infant's tolerance of parenterally administered amino acids. No differences in plasma amino acid pattern were observed between LBW infants weighing less than 1,250 g at birth and those weighing more than 1,250 g, between the LBW infant population1 and the population of term infants and older children studied earlier,2 or between LBW infants who received a typical peripheral vein regimen and those who received a typical central vein regimen.

CIRCADIAN PERIODICITY OF BLOOD AMINO ACIDS IN THE NEONATE

PEDIATRICS ◽  
1970 ◽  
Vol 45 (5) ◽  
pp. 782-791
Author(s):  
Ralph D. Feigin ◽  
Morey W. Haymond
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Detailed Analysis ◽  
Normal Values ◽  
Time Of Day ◽  
Plasma Amino Acids ◽  
Older Children ◽  
Total Blood ◽  
Term Infants ◽  
Plasma Tyrosine

Blood amino acids were obtained every 4 hours for 24 hours from 46 full-term infants who were between 1 hour and 120 hours of age when first sampled. Blood was also obtained at 0400 and 1200 hours on the same day from 10 additional infants, aged 48 to 72 hours at the time of study, for more detailed analysis of individual blood amino acids. Periodicity of total blood amino acids was demonstrated as early as the first day of life in some infants. This blood amino acid rhythmicity was similar but not identical to that previously observed in adults and older children. Concentrations of blood amino acids were minimal at 0400 hours and peaked between 1200 and 2000 hours. Periodicity of individual blood amino acids was similar to that for total blood amino acids but much less consistent. The presence of periodicity for plasma tyrosine was demonstrable even in two patients with neonatal tyrosinemia. Since plasma amino acids vary normally as a function of time, "normal values" must be standardized for time of day.

Amino Acids in Premature Infants

PEDIATRICS ◽  
1988 ◽  
Vol 82 (4) ◽  
pp. 680-680
Author(s):  
NIELS C. R. RÄIHÄ
Keyword(s):  
Amino Acids ◽  
Birth Weight ◽  
Amino Acid ◽  
Parenteral Nutrition ◽  
Premature Infants ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Metabolic Capacity ◽  
Low Birth Weight Infants ◽  
Term Infants

To the Editor.— In a recent paper in Pediatrics, Heird et al1 reported their evaluation of the use of a new amino acid mixture for parenteral nutrition in low birth weight infants. On the basis of their results the authors made the following statement: "These observations refute the concept that the metabolic capacity of LBW infants for amino acids is limited in comparison to that of term infants, older infants, and chi1dren."1(p49) Such a conclusion is not justified on the basis of the presented data.

Plasma Amino Acid Concentrations in 108 Children Receiving a Pediatric Amino Acid Formulation as Part of Parenteral Nutrition

2010 ◽  
Vol 15 (2) ◽  
pp. 110-118
Author(s):  
Chasity M. Shelton ◽  
Amanda J. Clark ◽  
Michael C. Storm ◽  
Richard A. Helms
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Parenteral Nutrition ◽  
Glutamic Acid ◽  
Normal Control ◽  
Reference Range ◽  
Plasma Amino Acid ◽  
Confidence Limits ◽  
Older Children ◽  
Z Scores

ABSTRACT BACKGROUND Plasma amino acid (PAA) levels can be largely normalized during parenteral nutrition (PN) in infants and children using a pediatric-specific amino acid (AA) formulation. However, these previous results were based on individual clinical studies of small populations of neonates and infants. OBJECTIVE We have now examined AA levels in 108 children (0–7 years of age) receiving a pediatric-specific AA formulation in PN using a single analytical methodology. METHODS Infants and children were enrolled in specific protocols and parents/caregivers gave informed consent. Patients were stable and receiving age-appropriate intakes of AA and non-protein calories. Samples were obtained between 8 and10 am, processed immediately, deproteinized, and AA concentrations (μmol/L) were determined on a Beckman 6300 analyzer. Means and SD were calculated for sub-populations stratified by age: 0–1 month (48 patients, n=139), 1–6 months (36 patients, n=124), 7–12 months (11 patients, n=41), and 1–7 years (13 patients, n=51). Z scores were calculated for each amino acid [(observed mean - normal control mean)/normal control SD]. RESULTS When compared to the neonatal reference range, nonessential AA had Z scores that ranged from −1.84 (asparagine) to +1.48 (threonine). Only plasma free cystine, free tyrosine, and phenylalanine had Z scores outside the −2.0 to +2.0 range (95% confidence limits). Plasma free cystine values were low in all groups except neonates. Free tyrosine levels were low in all groups despite the presence of N-acetyl-L-tyrosine in the pediatric AA formulation. Phenylalanine levels were elevated only in neonates. When children 1 to 7 years old were compared with an age-matched reference range, plasma free cystine values were low (Z score −2.47), as were plasma glutamine values (−3.11), but elevations were found in the dicarboxylic amino acids aspartic acid (+2.5) and glutamic acid (+4.27). Regardless of reference range used for comparison, all essential amino acids, except phenylalanine in neonates, were within range (−2 to +2 of the 95% confidence limits). CONCLUSIONS While most AAs were within the normal range, formulation modifications are needed to normalize free cystine in infants and young children, free tyrosine in all children, and phenylalanine in neonates. The decrease in glutamine concentrations in older children has been noted by our group before, and may imply limited ability to convert glutamic acid to glutamine, or increased consumption of glutamine. In either case, increased concentrations of glutamine in older children, especially those receiving home parenteral nutrition, should be considered.

Source and function of urinary ammonia in the alligator

1959 ◽  
Vol 197 (4) ◽  
pp. 873-879 ◽  
Author(s):  
Roland A. Coulson ◽  
Thomas Hernandez
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Level ◽  
Amino Acid Level ◽  
Plasma Amino Acid ◽  
Plasma Amino Acids ◽  
Renal Reabsorption ◽  
And Function ◽  
Phosphate Solutions

The rate of renal deamination of 18 amino acids was determined by injecting them into alligators and measuring the ammonia excreted. Not only did glycine, alanine, glutamine and leucine account for nearly half of the plasma amino acids, they were also deaminated more rapidly than any of the others. In view of this it was concluded that these four amino acids are the natural precursors of urinary NH3 in the alligator. Increased NH3 and CO2 excretion following glycine injections resulted in increased renal reabsorption of Na and Cl when NaCl was injected and increased Na reabsorption when NaHCO3 or Na phosphate solutions were injected. The fact that excess NH4HCO3 excretion enhances salt reabsorption independent of plasma pH makes it probable that the excretion of N is the chief function of the ammonia mechanism and that salt conservation is incidental. Insulin decreased the plasma amino acid level and drastically reduced the NH3 excretion. With the decrease in ammonia, NaCl and NaHCO3 were excreted in increased amounts.

Nutritional Aspects of CAPD and the Potential Use of Amino Acid Containing Dialysis Solutions

1983 ◽  
Vol 3 (1_suppl) ◽  
pp. 10-12 ◽  
Author(s):  
Oimitrios G. Oreopoulos ◽  
Errol Marliss G. Harvey ◽  
Anderson Arie Oren ◽  
Nicholas Oombros Paul ◽  
Williams Ramesh Khanna ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Amino Acid ◽  
Plasma Amino Acids ◽  
Effective Solution ◽  
Nutrient Losses ◽  
Protein Meal ◽  
Dialysis Solution ◽  
Dialysis Solutions ◽  
Potential Use

As a result of a combination of a decreased appetite with increased nutrient losses in the dialysate, a number of CAPO patients may develop malnutrition. A decrease in appetite is also observed in normal animals undergoing CAPO which suggests that some factors related to CAPO influence appetite so that these animals eat less. In addition to protein losses, CAPO patients are losing approximately two grams of amino acids a day, and they have plasma amino acid abnormalities similar to those produced by malnutrition and uremia. An amino acid-containing dialysis solution (2%) is an effective solution with respect to ultrafiltration and solute removal. Amino acids can be absorbed by the peritoneal route and produce an increase in plasma amino acids to levels similar to those observed after a protein meal. These observations indicate that administration of amino acids via the peritoneal route may prevent or correct malnutrition developed in patients on CAPO.

scholarly journals Effect of zinc deficiency on appetite and plasma amino acid concentrations in the rat

1981 ◽  
Vol 45 (1) ◽  
pp. 127-136 ◽  
Author(s):  
J. C. Wallwork ◽  
G. J. Fosmire ◽  
H. H. Sandstead
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Eating Habits ◽  
Plasma Amino Acid ◽  
Zn Deficiency ◽  
Feeding Cycle ◽  
Cyclic Feeding ◽  
Amino Acid Concentrations ◽  
Cell Volumes ◽  
Deficient Group

1. Levels of zinc in liver and plasma of the Zn-depleted rats fluctuated with the feeding cycle and were significantly higher at the bottom than at the top of the cycle. As Zn deficiency became more severe fluctuations in plasma Zn diminished. Concentrations of Zn in liver, in contrast to levels in plasma and femur, were not markedly lowered by day 15.2. In contrast to udlib.-fed (AL) and overnight-fasted (OF) controls, some pair-fed (PF) controls had elevated levels of Zn in liver and plasma.3. Intakes of water and food were sigdicantly correlated in Zn-deficient rats. Packed cell volumes were significantly higher for Zn-depleted than for AL and PF rats.4. Food intakes and plasma glucose concentrations were related in AL, OF and PF control rats but not in Zn-deficient rats.5. At day 15 of Zn deficiency the order of total plasma amino acid concentrations in the groups of rats was AL > Zn-deficient > OF > PF. Many of the differences between the AL and OF groups for individual plasma amino acids also appeared in the Zn-deficient group at the top and bottom of the feeding cycle. Differences in individual amino acid conmntrations at the top and bottom of the feeding cycle tended to be opposite in the PF and the Zn-ddicient group. Levels of tyrosine and tryptophan in plasma were correlated (P ≶ 0.05) with the cyclic feeding pattern of the Zn-deficient group; however, the ratios tryptophan or tyrosine: sum of other large neutral amino acids did not correlate significantly with the eating habits of Zndeficient rats.

Amino acid metabolism in leg muscle after an endotoxin injection in healthy volunteers

2005 ◽  
Vol 288 (2) ◽  
pp. E360-E364 ◽  
Author(s):  
Rokhsareh F. Vesali ◽  
Maria Klaude ◽  
Olav Rooyackers ◽  
Jan Wernerman
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Healthy Volunteers ◽  
Initial Phase ◽  
Plasma Amino Acid ◽  
Human Model ◽  
Endotoxin Administration ◽  
Leg Muscle ◽  
Amino Acid Concentrations

Decreased plasma amino acid concentrations and increased net release of amino acids from skeletal muscle, especially for glutamine, are common features in critically ill patients. A low dose of endotoxin administered to healthy volunteers was used as a human model for the initial phase of sepsis to study the early metabolic response to sepsis. Six healthy male volunteers were studied in the postabsorptive state. Blood samples from the forearm artery and femoral vein were taken during 4 h before and 4 h after an intravenous endotoxin injection (4 ng/kg body wt). In addition, muscle biopsies from the leg muscle were taken. Plasma concentration of the total sum of amino acids decreased by 19% ( P = 0.001) and of glutamine by 25% ( P = 0.004) the 3rd h after endotoxin administration. At the same time, muscle concentrations of the sum of amino acids and glutamine decreased by 11% ( P = 0.05) and 9% ( P = 0.09), respectively. In parallel, the efflux from the leg increased by 35% ( P = 0.004) for the total sum of amino acids and by 43% ( P = 0.05) for glutamine. In conclusion, intravenous endotoxin administration to healthy volunteers, used as a model for the initial phase of sepsis, resulted in a decrease in plasma amino acid concentrations. At the same time, amino acid concentrations in muscle tissue decreased, whereas the efflux of amino acids from leg skeletal muscle increased.

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