Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Nutritional evaluation of the patient with phenylketonuria (PKU)

In order to diagnose the nutritional status and to provide a personalized treatment in PKU patients, an evaluation of nutritional status should be conducted. Several components are involved in the nutritional assessment; among the parameters there are anthropometric evaluation: weight, height, head circumference; biochemical: proteins, amino acids, vitamins, inorganic nutrients, essential fatty acids; clinical: deficiencies in hair, skin, oral cavity , eyes, etc.; dietary assessment: quantification of energy intake, macronutrients and micronutrients through several tools such as the 24-hour recall; finally it must be taken into account the interaction of nutrients such as carnitine, fatty acids, vitamin B complex, among others, with drugs, which are often anticonvulsants, in order to plan the diet and prevent a future nutritional deficiency. It is important to perform the nutritional status assessment frequently in patients with PKU because the dietary management is essential to prevent neurological problems

Use of sapropterin in Mexican patients with yperphenylalaninemia

Hyperphenylalaninemia is caused by deficient enzyme activity of phenylalanine hydroxylase. It was one of the first genetic disorders susceptible to treatment with a natural protein restricted diet for life. While this treatment has proven effective in preventing mental retardation, eliminating certain foods from the diet entails the risk of nutritional deficiencies. For these reasons, new non-nutritional therapeutic strategies have been developed. One is the administration of sapropterin dihydrochloride, the synthetic form of tetrahydrobiopterin (BH4), which is the natural cofactor of phenylalanine hydroxylase, whose purpose is to reduce blood phenylalanine levels. We studied 6 patients with confirmed diagnosis of hyperphenylalaninemia or phenylketonuria. Sapropterin dihydrochloride was administered for 28 days and the intake of phenylalanine was calculated in each patient. To evaluate the response to sapropterin phenylalanine blood levels were measured at zero, eight and 24 hours and on days seven, 14, 21 and 28. The 24-hours recall was used to establish the intake of phenylalanine before and during the study. A positive response was determined as a reduction of phenylalanine blood levels ≥30% Four of the six patients responded positively to sapropterin dihydrochloride. The aim of this paper is to present the experience with sapropterin dihydrochloride in a group of Mexican patients with hyperphenylalaninemia

Biochemical evaluation of phenylketonuria (PKU): from diagnosis to treatment

Non treated phenylketonuria (PKU) has serious consequences such as growth retardation and intellectual impairment along with symptoms like erythematous eczema, fair skin and hair, seizures, autistic conduct and aggressive behavior. Pre-symptomatic biochemical diagnosis consists of identifying patients by blood phenylalanine (Phe) quantification through newborn screening. The confirmation is based on determining serum Phe and tyrosine levels. There is a wide spectrum of hyperphenylalaninemia clinical presentation, which ranges from mild forms which do not require nutritional treatment to the most severe form of the disease known as classic PKU. The aim of treatment is to avoid irreversible neurological impairment by stabilizing blood Phe level and keeping it within therapeutic concentration range. Once PKU diagnosis has been established, there are several criteria to decide when it is necessary to initiate treatment, we start it if Phe level is > 360 micromol/L (6 mg/L). Besides periodical Phe and Tyr testing, biochemical follow-up includes the measurement of necessary elements that guarantee normal physical and intellectual development such as selenium, zinc, B12 vitamin, folates, iron and long chain fatty acids. Clinical context is as important as biochemical status so periodic evaluation of nutritional, medical, social and psychological aspects should be included

Tyrosinemia type I: clinical and biochemical analysis of patients in Mexico

Introduction. Hepatorenal tyrosinemia (HT1) is a treatable, inherited, metabolic disease characterized by progressive liver failure with pronounced coagulopathy. The aim of this study is to describe the clinical, biochemical, and histopathological findings in a group of Mexican HT1 patients and their outcome.Material and methods. Medical records of HT1 patients diagnosed between 1995 and 2011 were analyzed. The diagnosis of HT1 was confirmed by detection of succinylacetone in urine or blood.Results.Sixteen non-related HT1 cases were analyzed. Mean age at clinical onset was 9 months, and the mean age at diagnosis was 16.3 months. Main clinical findings were hepatomegaly, splenomegaly, cirrhosis, liver failure, tubulopathy, nephromegaly, Fanconi syndrome, seizures and failure to thrive. Histopathological findings were cirrhosis, fibrosis and steatosis. The HT1 group had a mortality rate of 78%. Patients who received supportive care or nutritional treatment had a 3-year survival rate of 10%. For those who underwent liver transplantation, the 6-year survival rate was 60%. In most cases pharmacological treatment with nitisinone and special dietary products were not available. The leading causes of death were fulminant liver failure, metastatic hepatocellular carcinoma, and porphyria-like neurologic crisis. Newborn screening programs in combination with the availability of orphan drugs, proper monitoring, genetic counseling, and clinical practice guidelines are needed to enable physicians to identify the disease, delay its progression, and improve patients’ quality of life.Conclusion. The devastating natural history of HT1 is still observed in Mexican patients because they are not diagnosed and treated during the early stages of the disease

Crisis neuropática por suspensión de nitisinona en una paciente con tirosinemia: informe de un caso

Se presenta el caso de una paciente con tirosinemia hepatorrenal (TYR- 1) que, debido a la interrupción por cuatro semanas de tratamiento con nitisinona, tuvo una grave crisis neurológica de pseudoporfiria caracterizada por vómito, dolor abdominal, irritabilidad e hipertensión arterial, con gran elevación de la succinilacetona y alfafetoproteína. La crisis requirió tratamiento intrahospitalario. Una semana después de reiniciar la administración del fármaco revirtió totalmente. Este caso enfatiza la importancia de mantener el tratamiento ininterrumpido con nitisinona en pacientes con tirosinemia hepatorrenal. También es útil para reconocer el cuadro clínico y la fisiopatología de las crisis neurológicas características de esta enfermedad

Inborn Errors of Intermediary Metabolism in Critically Ill Mexican Newborns

Inborn errors of intermediary metabolism (IEiM) are complex diseases with high clinical heterogeneity, and some patients who have severe enzyme deficiencies or are subjected to stress (catabolism/infections) actually decompensate in the neonatal period. In this study, we performed metabolic tests on 2025 newborns in Mexico admitted to 35 neonatal intensive care units or emergency wards (NICUs/EWs) over a 6-year period, in whom a metabolic disorder was clinically suspected. Of these 2025 newborns with sickness, 11 had IEiM, revealing a prevalence of 1:184. Clinical characteristics and outcomes of the newborns with confirmed IEiM are shown. Of these 11 patients, 4 had isolated methylmalonic acidemia, 3 had maple syrup urine disease, 2 had urea cycle disorders, 1 had 3-hydroxy-3-methylglutaric acidemia, and 1 had isovaleric acidemia. During the first week of life (average 3 days), all of these newborns presented with impaired alertness, hypotonia, feeding difficulties, and vomiting along with metabolic acidosis and hyperammonemia. Of the 11 newborns with IEiM, 7 died, leading to a mortality rate of 64%. In conclusion, the differential diagnosis of newborns admitted to the NICU/EW must include IEiM, requiring systematic screening of this population

An Updated PAH Mutational Spectrum of Phenylketonuria in Mexican Patients Attending a Single Center: Biochemical, Clinical-Genotyping Correlations

Establishing the genotypes of patients with hyperphenylalaninemia (HPA)/phenylketonuria (PKU, MIM#261600) has been considered a cornerstone for rational medical management. However, knowledge of the phenylalanine hydroxylase gene (PAH) mutational spectrum in Latin American populations is still limited. Herein, we aim to update the mutational PAH spectrum in the largest cohort of HPA/PKU Mexican patients (N = 124) reported to date. The biallelic PAH genotype was investigated by Sanger automated sequencing, and genotypes were correlated with documented biochemical phenotypes and theoretical tetrahydrobiopterin (BH4) responsiveness. Patients were biochemically classified as having classic PKU (50%, 62/124), mild PKU (20.2%, 25/124) and mild HPA (29.8%, 37/124). Furthermore, 78.2% of the included patients (97/124) were identified by newborn screening. A total of 60 different pathogenic variants were identified, including three novel ones (c. 23del, c. 625_626insC and c. 1315 + 5_1315 + 6insGTGTAACAG), the main categories being missense changes (58%, 35/60) and those affecting the catalytic domain (56.6%, 34/60), and c. 60 + 5G > T was the most frequent variant (14.5%, 36/248) mainly restricted (69.2%) to patients from the central and western parts of Mexico. These 60 types of variants constituted 100 different biallelic PAH genotypes, with the predominance of compound-heterozygous ones (96/124, 77%). The expected BH4 responsiveness based on the PAH genotype was estimated in 52% of patients (65/124), mainly due to the p. (Val388Met) (rs62516101) allele. Instead, our study identified 27 null variants with an allelic phenotype value of zero, with a predominance of c. 60 + 5G > T, which predicts the absence of BH4 responsiveness. An identical genotype reported in BIOPKUdb was found in 92/124 (74%) of our patients, leading to a genotype–phenotype concordance in 80/92 (86.9%) of them. The high number of variants found confirms the heterogeneous and complex mutational landscape of HPA/PKU in Mexico