Evidence for Hypertyraminemia in Reye's Syndrome

PEDIATRICS ◽  
1979 ◽  
Vol 64 (1) ◽  
pp. 76-80
Author(s):  
Bahjat A. Faraj ◽  
Stephen L. Newman ◽  
Daniel B. Caplan ◽  
Farouk M. Ali ◽  
Vernon M. Camp ◽  
...  
Keyword(s):  
Amino Acid ◽  
Liver Biopsy ◽  
Hospitalized Patients ◽  
Reye's Syndrome ◽  
Positive Correlation ◽  
Tyrosine Metabolism ◽  
Plasma Tyrosine

Utilizing a specific and sensitive radioimmunoassay, plasma and urine tyramine were measured in 14 consecutive patients with liver biopsy-proven Reye's syndrome. Plasma tyrosine was measured in 11 of these patients. The results revealed significant (P < .003) elevation in plasma (3.4 ± .52 ng/ml) (mean ± SEM) and urine (1.00 ± .26 mg/24 hr) tyramine as well as plasma tyrosine (204 ± 52.5 µmole/liter) at the onset of the disease when compared to the levels of tyramine and tyrosine in a group of hospitalized patients without hepatic disorders. Furthermore, there was a positive correlation between plasma tyramine and days in coma (r = .86; P < .001), and between plasma tyramine and tyrosine (r = 0.80; P < .001). These data suggest that there is a substantial disturbance of tyrosine metabolism in Reye's syndrome and that the accumulation of this amino acid and its metabolite, tyramine, may contribute to the encephalopathy of this disease.

Hypercatecholaminemia in Reye's Syndrome

PEDIATRICS ◽  
1984 ◽  
Vol 73 (4) ◽  
pp. 481-488
Author(s):  
Bahjat A. Faraj ◽  
Daniel B. Caplan ◽  
Stephen L. Newman ◽  
Peter A. Ahmann ◽  
Vernon M. Camp ◽  
...  
Keyword(s):  
Liver Biopsy ◽  
Cerebral Edema ◽  
Plasma Catecholamines ◽  
Hospitalized Patients ◽  
Control Population ◽  
Reye's Syndrome ◽  
Positive Correlation ◽  
Radioenzymatic Assay ◽  
Csf Concentration

To evaluate the role of catecholamines in Reye's syndrome, a specific and sensitive radioenzymatic assay was used to study plasma and CSF concentration of dopamine, norepinephrine, and epinephrine in 14 patients with liver-biopsy-proven Reye's syndrome. The results (median and range) revealed significant (P < .04, P < .0024, and P < .030, respectively) elevation in plasma dopamine (131, 0 to 1,193 pg/mL), norepinephrine (1,455, 20 to 5,271 pg/mL), and epinephrine (345, 7.6 to 2,504 pg/mL) at the onset of the disease when compared with the level of these neurotransmitters in a group of hospitalized patients without hepatic disorders. There was a positive correlation between plasma catecholamines and stage of coma on admission (r = .54 to .86; P < .001 to .024). Furthermore, the concentration of dopamine, norepinephrine, and epinephrine in the CSF increased significantly during the development of cerebral edema in all patients with Reye's syndrome as compared with concentrations in a control population. Hypercatecholaminemia may contribute to the encephalopathy of Reye's syndrome.

Amino Acid and Protein Metabolism in Hospitalized Patients as Measured by l-[U-14C]Tyrosine and l-[1-14C]Leucine

1983 ◽  
Vol 65 (5) ◽  
pp. 499-505 ◽  
Author(s):  
Sukumar P. Desai ◽  
Lyle L. Moldawer ◽  
Bruce R. Bistrian ◽  
George L. Blackburn
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Chloride ◽  
Hospitalized Patients ◽  
Whole Body ◽  
Protein Kinetics ◽  
Body Protein ◽  
Sodium Chloride Solutions ◽  
Isotonic Sodium Chloride ◽  
Plasma Tyrosine

1. Plasma amino acid kinetics were determined in hospitalized patients receiving one of three intravenous solutions: isotonic amino acids, isotonic sodium chloride, or total parenteral nutrition. 2. Whole body amino acid appearance, oxidation and incorporation into protein were estimated with two different isotopically labelled amino acids: l-[1-14C]leucine and l-[U-14C]tyrosine. 3. A positive correlation was obtained between whole body amino acid appearance, oxidation and incorporation into protein with the two isotopically labelled amino acids. 4. Derivation of whole body protein kinetics with l-[U-14C]tyrosine consistently gave higher values than those obtained from l-[1-14C]leucine, presumably due in part to the contribution of phenylalanine hydroxylation to plasma tyrosine appearance. However, the percentages of amino acid appearance oxidized and used for protein synthesis were similar. 5. It can be concluded that estimates of whole body protein kinetics are qualitatively similar when measured with l-[U-14C]tyrosine and l-[1-14C]leucine in hospitalized patients receiving either isotonic sodium chloride solutions or balanced amino acid intakes.

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.

Aromatic amino acid metabolism of neonatal piglets receiving TPN: effect of tyrosine precursors

1994 ◽  
Vol 267 (5) ◽  
pp. E672-E679 ◽  
Author(s):  
L. J. Wykes ◽  
J. D. House ◽  
R. O. Ball ◽  
P. B. Pencharz
Keyword(s):  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Central Line ◽  
High Plasma ◽  
Control Group ◽  
Neonatal Piglets ◽  
Aromatic Amino Acid Metabolism ◽  
Plasma Tyrosine

Low tyrosine solubility in total parenteral nutrition (TPN) solutions complicates meeting the aromatic amino acid needs of infants. This study compared the effectiveness of two tyrosine precursors to supply the aromatic amino acid needs of TPN-fed neonatal piglets with a control group in which total aromatic acid needs were met by the addition of phenylalanine (Phe). Eighteen 3-day-old male Yorkshire piglets (6/group) received TPN for 8 days by central line. The solution was supplemented with Phe or one of the following two tyrosine precursors: N-acetyltyrosine (N-AcTyr) or glycyltyrosine (GlyTyr). Aromatic amino acid metabolism, growth, and nitrogen utilization were measured. Average amino acid and energy intakes were 14.6 g.kg-1.day-1 and 1,050 kJ.kg-1.day-1. Nitrogen balance and utilization were significantly higher (P < 0.05) in piglets in the control Phe group and on the GlyTyr regimen. The high urinary excretion of N-AcTyr (65%) confirms its low bioavailability. Flux and oxidation were significantly higher (P < 0.05) in the Phe group. High plasma Phe levels and excretion of Phe catabolites, as well as the high plasma tyrosine in the GlyTyr group, indicate that current strategies employed to meet the aromatic amino acid needs of neonates on TPN need further refinement.

L-[U-14C] Tyrosine Metabolism of the Perfused Cat Brain with High Plasma Phenylalanine or without Plasma Tyrosine

1970 ◽  
Vol 24 (4) ◽  
pp. 219-226
Author(s):  
Shosuke WATANABE ◽  
Katsusuke MITSUNOBU ◽  
Takanori SANNOMIYA ◽  
Saburo OTSUKI
Keyword(s):  
High Plasma ◽  
Plasma Phenylalanine ◽  
Cat Brain ◽  
Tyrosine Metabolism ◽  
Plasma Tyrosine

scholarly journals Developmental roles of tyrosine metabolism enzymes in the blood-sucking insect Rhodnius prolixus

2017 ◽  
Vol 284 (1854) ◽  
pp. 20162607 ◽  
Author(s):  
Marcos Sterkel ◽  
Pedro L. Oliveira
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Wide Spectrum ◽  
Aromatic Amino Acids ◽  
Degradation Pathway ◽  
Rhodnius Prolixus ◽  
Blood Sucking ◽  
Metabolism Enzymes ◽  
Tyrosine Metabolism

The phenylalanine/tyrosine degradation pathway is frequently described as a catabolic pathway that funnels aromatic amino acids into citric acid cycle intermediates. Previously, we demonstrated that the accumulation of tyrosine generated during the hydrolysis of blood meal proteins in Rhodnius prolixus is potentially toxic, a harmful outcome that is prevented by the action of the first two enzymes in the tyrosine degradation pathway. In this work, we further evaluated the relevance of all other enzymes involved in phenylalanine/tyrosine metabolism in the physiology of this insect. The knockdown of most of these enzymes produced a wide spectrum of distinct phenotypes associated with reproduction, development and nymph survival, demonstrating a highly pleiotropic role of tyrosine metabolism. The phenotypes obtained for two of these enzymes, homogentisate dioxygenase and fumarylacetoacetase, have never before been described in any arthropod. To our knowledge, this report is the first comprehensive gene-silencing analysis of an amino acid metabolism pathway in insects. Amino acid metabolism is exceptionally important in haematophagous arthropods due to their particular feeding behaviour.

scholarly journals Trends in Prokaryotic Evolution Revealed by Comparison of Closely Related Bacterial and Archaeal Genomes

2008 ◽  
Vol 191 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Pavel S. Novichkov ◽  
Yuri I. Wolf ◽  
Inna Dubchak ◽  
Eugene V. Koonin
Keyword(s):  
Amino Acid ◽  
Genome Rearrangement ◽  
Selective Pressure ◽  
Protein Sequences ◽  
Purifying Selection ◽  
Amino Acid Sequences ◽  
Strong Positive Correlation ◽  
Effective Population ◽  
Data Set ◽  
Positive Correlation

ABSTRACT In order to explore microevolutionary trends in bacteria and archaea, we constructed a data set of 41 alignable tight genome clusters (ATGCs). We show that the ratio of the medians of nonsynonymous to synonymous substitution rates (dN/dS) that is used as a measure of the purifying selection pressure on protein sequences is a stable characteristic of the ATGCs. In agreement with previous findings, parasitic bacteria, notwithstanding the sometimes dramatic genome shrinkage caused by gene loss, are typically subjected to relatively weak purifying selection, presumably owing to relatively small effective population sizes and frequent bottlenecks. However, no evidence of genome streamlining caused by strong selective pressure was found in any of the ATGCs. On the contrary, a significant positive correlation between the genome size, as well as gene size, and selective pressure was observed, although a variety of free-living prokaryotes with very close selective pressures span nearly the entire range of genome sizes. In addition, we examined the connections between the sequence evolution rate and other genomic features. Although gene order changes much faster than protein sequences during the evolution of prokaryotes, a strong positive correlation was observed between the “rearrangement distance” and the amino acid distance, suggesting that at least some of the events leading to genome rearrangement are subjected to the same type of selective constraints as the evolution of amino acid sequences.

TYROSINOSIS: A PATIENT WITHOUT LIVER OR RENAL DISEASE

PEDIATRICS ◽  
1971 ◽  
Vol 48 (3) ◽  
pp. 393-400
Author(s):  
James L. Holston ◽  
Harvey L. Levy ◽  
Gary A. Tomlin ◽  
Ruby J. Atkins ◽  
T. H. Patton ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Mental Retardation ◽  
Renal Disease ◽  
Urinary Excretion ◽  
Hepatic Disease ◽  
Severe Mental Retardation ◽  
Primary Defect ◽  
Biochemical Evidence ◽  
Tyrosine Metabolism ◽  
Plasma Tyrosine

A child institutionalized because of severe mental retardation was found to have biochemical evidence of tyrosinosis. He has had no evidence of hepatic disease. In addition, he has had no hyperaminoaciduria, glycosuria, or rickets. Plasma tyrosine concentrations while he was on a regular diet ranged from 16.0 to 25.6 mg per 100 ml. Urinary excretion of tyrosine and tyrosine metabolites, including p-hydroxyphenylpyruvic acid, p-hydroxyphenyllactic acid, and p-hydroxyphenyl-acetic acid, were markedly increased. This patient appears to have a primary defect in tyrosine metabolism and represents individuals with persisting tyrosinemia and tyrosyluria in whom no hepatorenal disease is found.

Sign in / Sign up

Export Citation Format

Share Document