Autistic children exhibit distinct plasma amino acid profile.

In order to ascertain whether autistic children display characteristic metabolic signatures that are of diagnostic value, plasma amino acid analyses were carried out on a cohort of 138 autistic children and 138 normal controls using reverse-phase HPLC. Pre-column derivatization of amino acids with phenyl isothiocyanate forms phenyl thio-carbamate derivates that have a λmax of 254 nm, enabling their detection using photodiode array. Autistic children showed elevated levels of glutamic acid (120 ± 89 vs. 83 ± 35 mmol/L) and asparagine (85 ± 37 vs. 47 ± 19 mmol/L); lower levels of phenylalanine (45 ± 20 vs. 59 ± 18 mmol/L), tryptophan (24 ± 11 vs. 41 ± 16 mmol/L), methionine (22 ± 9 vs. 28 ± 9 mmol/L) and histidine (45 ± 21 vs. 58 ± 15 mmol/L). A low molar ratio of (tryptophan/large neutral amino acids) × 100 was observed in autism (5.4 vs 9.2), indicating lesser availability of tryptophan for neurotransmitter serotonin synthesis. To conclude, elevated levels of excitatory amino acids (glutamate and asparagine), decreased essential amino acids (phenylalanine, tryptophan and methionine) and decreased precursors of neurotransmitters (tyrosine and tryptophan) are the distinct characteristics of plasma amino acid profile of autistic children. Thus, such metabolic signatures might be useful tools for early diagnosis of autism.

Nutrición en el paciente grave: el talón de aquiles de la terapéutica en el intensivismo / Nutrition in the critically ill: Achilles' heel in the therapeutic at the intensive care

La insuficiencia nutricional que sigue a estados de hipercatabolismo, inanición, infecciones severas y enfermedades consuntivas crónicas, entre otras, puede afectar a pacientes graves con ingesta insuficiente de nutrientes y reservas nutricionales inadecuadas. Por lo general el paciente debilitado desde el punto de vista nutricional muere por sepsis y fallo multiorgánico asociados con deficiencias de aminoácidos y nitrógeno, síntesis inadecuada de proteínas y fracaso de los mecanismos inmunes. Se realizó una revisión de la nutrición en el paciente crítico, para confeccionar una guía práctica de alimentación donde se expusieron todos los elementos a tener en cuenta en un paciente que se necesite nutrir

Detection of metabolic disorders in high-risk patients: a pilot study in Salvador, Bahia

The purpose of this pilot-study was to evaluate the applicability of a screening protocol for the detection of inborn errors of metabolism (IEM) in high-risk patients. The protocol was applied in 65 patients referred to the Medical Genetics Laboratory of the University Hospital Professor Edgard Santos due to the suspicion of an IEM. Eight of these patients (12.3 percent) displayed an abnormal result in the screening protocol. These patients, along with 22 who displayed normal results in the screening protocol but who presented clinical symptoms or signs suggestive of an IEM not detectable by the tests applied, were selected for a further diagnostic investigation. In 5 of these 30 patients (7.7 percent of the total sample) it was possible to establish the diagnosis of an specific IEM. The results indicate that the designed screening protocol was sucessfully applied, allowing the detection of affected patients in a frequency comparable to that observed in larger studies performed elsewhere. The continuation of this study and the enlargement of the sample will help to delineate the profile of IEM in northeast of Brazil and will allow the identification of a significative number of patients and families. who could benefit from the therapeutic and preventive measures available for these diseases.

Effects of corn feeding and protein restriction on free amino acid concentration in the rat cerebellum

To determine the effect of low protein and cornbased diets on the maturation of cerebellum, three groups of young rats were fed during a period of 6 weeks with different diets; 23 and 8 percent of protein (purina-Chow base) and a corn-based diest (8 percent protein). At the end of that period, the concentrations of free amino acids in the cerebellum was measured. Glutamic acid, glucine, glutamine and serine showed the highest values in all groups studied. Corn-based diet group showed the lowest free amino acid concentration compared to that of the control group, with a significant diminutions in the concentration of glutamic acid, lysine, tyrosine and histidine. Differences between essential and nonessential amino acids were not observed in all groups studied. Although corn-based diet did not induce specific changes as those reported in severe malnutrition, its effects on the concentration of some amino acids other than tryptophan could have some physiological correlations which need to be further studied