Effect of the route of nutrition and L-alanyl-L-glutamine supplementation in amino acids' concentration in trauma patients.

PURPOSE: Our purpose was to assess the amino acids' (AAs) profile in trauma patients and to assess the effect of the route of nutrition and the exogenous ALA-GLN dipeptide supplementation on plasma AAs' concentration. METHODS: This is a secondary analysis of a previous randomized controlled trial. On day 1 and day 6 after trauma, plasma concentration of 25 AAs was measured using reverse phase high-performance liquid chromatography. Results were analyzed in relation to the route of nutrition and supplementation of ALA-GLN dipeptide. Differences between plasma AAs' concentrations at day 1 and day 6 were evaluated using the Student's t test or Mann-Whitney-Wilcoxon test. One-way ANOVA and the Kruskal-Wallis test were used to compare groups. A two-sided p value less than 0.05 was considered statistically significant. RESULTS: Ninety-eight patients were analyzed. Mean plasma concentrations at day 1 were close to the lower normal level for most AAs. At day 6 we found an increase in the eight essential AAs' concentrations and in 9 out of 17 measured non-essential AAs. At day 6 we found no differences in plasma concentrations for the sum of all AAs (p = .72), glutamine (p = .31) and arginine (p = .23) distributed by the route of nutrition. Administration of ALA-GLN dipeptide increased the plasma concentration of alanine (p = .004), glutamine (p < .001) and citrulline (p = .006). CONCLUSIONS: We found an early depletion of plasma AAs' concentration which partially recovered at day 6, which was unaffected by the route of nutrition. ALA-GLN dipeptide supplementation produced a small increase in plasma levels of glutamine and citrulline.

Mujer de 18 años con metahemoglobinemia tras utilización de crema anestésica tópica / An 18 year old female with methaemoglinaemia after using EMLA(R) topical anaesthetic cream

La metahemoglobinemia es una entidad poco frecuente, cuyo diagnóstico se basa en la aparición de niveles elevados de metahemoglobina en sangre, tanto en adultos como en niños. Es una de las causas importantes de cianosis, y en ocasiones la severidad de su presentación puede requerir el ingreso en Unidades de Cuidado Intensivo. Las causas pueden ser adquiridas o congénitas, siendo ésta última debida a mutación en el gen de la hemoglobina reductasa dependiente de NADPH. La forma adquirida o metahemoglobinemia tóxica se produce cuando los hematíes son expuestos a sustancias químicas oxidantes que aumentan la producción de metahemoglobina, sobrepasando los mecanismos reductores de protección que actúan normalmente. Se presenta el caso de una mujer de 18 años, con cuadro de cianosis de aparición súbita diagnosticada de metahemoglobinemia tóxica tras utilización de crema anestésica tópica EMLA(R) (mezcla de anestésicos locales, lidocaína y prilocaína(AU)

Methaemoglobinaemia is a very uncommon disorder, with its diagnosis being based on the appearance of high levels of methaemoglobin in the blood, both in adults and children. It is an important cause of cyanosis, and occasionally its severity of its presentation may require admission to an Intensive Care Unit. It may be acquired or hereditary; the latter being due to a mutation of the NADPH-dependent haemoglobin reductase gene. The acquired form or toxic methaemoglobinaemia is produced when red cells are exposed to oxidising chemicals that increase methaemoglobin production, overwhelming the regulatory mechanisms that function normally (AU)

Control de calidad de la fase analítica / Quality control in analytical phase

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Lithogenic risk factors for renal stones in patients with Crohn's disease.

OBJECTIVES: Calcium oxalate kidney stones are more common in patients with Crohn's disease (CD). The aims of this study were to verify the prevalence of the main risk factors for calcium oxalate nephrolithiasis in patients with CD and to evaluate the degree of urinary relative supersaturation for calcium oxalate (CaOx), dihydrogen uric acid (DHUA) and monohydrogen calcium phosphate (MHCaP). SUBJECTS AND STUDY PROTOCOL: 42 patients with CD (22 male and 20 female, aged 15-72 years) and 18 controls (8 male and 10 female, aged 26-65) were studied. Nine patients were evaluated during an active episode and 33 in a quiescent phase. All patients had normal glomerular filtration rate. All subjects collected a 24-hr urine sample and fasting venous blood was drawn. Good compliance of urine collection was assessed by the Cockcroft and Gault formula. In urine pH and oxalate (Ox), calcium (Ca), phosphate (P), uric acid (UA), citrate (Cit), magnesium (Mg), sulphate (Sulph), sodium, potassium and chloride concentrations were measured and their excretions calculated. Urinary RS index was obtained using the software EQUIL93. RESULTS: A decreased urinary volume (61.9%) was the most frequent finding. A decreased excretion of Cit, Mg and Sulph (38.1%, 31.0% and 31.0%, respectively) and increased excretion of P, Ox, UA and Ca (33.3%, 23.8%, 16.7% and 14.3%, respectively) were found. Thirty four patients (81.0%) showed at least 2 lithogenic risk factors and only 2 patients showed none. Urine of patients had a higher urinary CaOx and DHUA relative super saturation. Patients studied in an active episode showed a higher urinary CaOx and MHCaP RS than those studied in the quiescent period. CONCLUSIONS: The majority of patients with CD have a multifactorial high risk for calcium oxalate and a single patient usually has several metabolic disturbances which are more evident in an active episode.

[Biochemical, enzymatic and genetic study of hypoxanthine guanine phosphoribosyl transferase (HPRT) deficiency]. / Estudio bioquímico, enzimático y genético de la deficiencia de hipoxantina guanina fosforribosiltransferasa (HPRT).

OBJECTIVE: The objective of this study was to analyze the diagnosis of HPRT deficiency, perform a thorough purine metabolism study and to establish the carrier and prenatal diagnosis in 16 HPRT deficient families. PATIENTS AND METHODS: Plasma and urinary concentrations of uric acid, creatinine and oxypurines, APRT and HPRT activities in hemolysates and HPRT in intact erythrocytes and adenine 8-C14 urinary excretion were analyzed. Carrier diagnosis was made by hair root enzyme analysis and genetic studies. RESULTS: These studies allowed the diagnosis of HPRT deficiency in 20 patients. Carrier diagnosis could be performed in 23 women at risk and in a 9 week old female fetus. CONCLUSIONS: The study results suggest that HPRT deficiency accounts for increased purine nucleotide degradation. This increase results in elevated urinary and plasma concentrations of hypoxanthine, xanthine and uric acid. The clinical severity of the disease is not related to the degree of urinary or plasma concentrations of oxypurines. Hair root analysis generally allows the diagnosis of carrier status, but the carrier state cannot be fully excluded in women at risk. When the familial mutation causing the defect in HPRT is known, analysis of the differences in the restriction pattern of the HPRT gene (natural or due to directed mutagenesis) allow a rapid and reliable diagnosis of carrier status and HPRT deficiency.

[Hyperoxaluria and renal calculi]. / Hiperoxaluria y litiasis renal.

Urolithiasis is one of the most frequent causes of morbidity in developed countries and its incidence is close to 5%. In our experience, 67.4% of urinary stones contain calcium oxalate as the main component, and hyperoxaluria plays an important role in the pathophysiology of this type of stone. The mechanisms responsible for the increment in urinary excretion of oxalate could involve oxalic acid synthesis. This increase could be due either to an increment of its endogenous formation or to an exogenous load of its precursors. Furthermore, an increased intestinal oxalate absorption is a frequent cause of hyperoxaluria and urolithiasis. Ingestion of oxalate rich foods, imbalance in the supply of other nutrients that influence oxalic acid absorption and GI disorders with malabsorption and/or decreased degradation of intraluminal oxalate can increase intestinal oxalate transport and cause hyperoxaluria. In this article we review the physiological mechanisms that control the oxalate pool: endogenous synthesis, exogenous supply, intestinal absorption and renal excretion of oxalic acid. We analyze the causes and the pathophysiological mechanisms that increase urinary oxalate excretion. We describe a protocol for the biochemical study of patients with hyperoxaluria and the therapeutic measures to reduce urinary oxalate are reviewed. Finally, possible research that may provide further insight into oxalate metabolism in patients with hyperoxaluria are discussed.