Preparation of Low-Phenylalanine Macro Peptides and Estimation of its Phenylalanine Content by Fluorometric Technique

The aims of the study were to prepare macro peptides low in phenylalanine (Phe) from non-conventional raw materials, and to demonstrate the feasibility of using the fluorometric technique to measure the diminution of their Phe content. Aqueous solution of flours of legumes, and amaranth panicles were used to elaborate the concentrates by using isoelectric precipitation. These protein concentrates, and a whey solution were incubated with proteolytic enzymes to hydrolyze the peptide link at the aromatic amino acids, and then these macro peptides were filtrated through activated charcoal, in order to reduce its phenylalanine concentration. The Phe concentration, of the each prepared macro peptides, was analyzed by using fluorometric technique, and it was later validated by using HPLC. The crude protein contents in the concentrates have varied from 90% in the protein isolate from lentils, 76% in those from the frijol white, and 44% in those from amaranth panicles. Protein concentrates, and whey were hydrolyzed by using the following enzymes: pepsin from the pig gastric mucosa, protease from Aspergillus oryzae, and protease type XIV from Streptomyces griseus. It was determined that the enzymes with the better hydrolysis capacity, were the proteases from S. griseus and A. oryzae. The macro peptides with non-linked phe were filtered through activated charcoal. Reductions of Phe of up to 99% in the second and third filtrate were observed and this reduction was corroborated by using HPLC technique. It was also established the higher sensitivity of the fluorometric method to detect Phe, than the HPLC technique

Guidelines for diagnosis and treatment of Hunter Syndrome for clinicians in Latin America

This review aims to provide clinicians in Latin America with the most current information on the clinical aspects, diagnosis, and management of Hunter syndrome, a serious and progressive disease for which specific treatment is available. Hunter syndrome is a genetic disorder where iduronate-2-sulfatase (I2S), an enzyme that degrades glycosaminoglycans, is absent or deficient. Clinical manifestations vary widely in severity and involve multiple organs and tissues. An attenuated and a severe phenotype are recognized depending on the degree of cognitive impairment. Early diagnosis is vital for disease management. Clinical signs common to children with Hunter syndrome include inguinal hernia, frequent ear and respiratory infections, facial dysmorphisms, macrocephaly, bone dysplasia, short stature, sleep apnea, and behavior problems. Diagnosis is based on screening urinary glycosaminoglycans and confirmation by measuring I2S activity and analyzing I2S gene mutations. Idursulfase (recombinant I2S) (Elaprase®, Shire) enzyme replacement therapy (ERT), designed to address the underlying enzyme deficiency, is approved treatment and improves walking capacity and respiratory function, and reduces spleen and liver size and urinary glycosaminoglycan levels. Additional measures, responding to the multi-organ manifestations, such as abdominal/inguinal hernia repair, carpal tunnel surgery, and cardiac valve replacement, should also be considered. Investigational treatment options such as intrathecal ERT are active areas of research, and bone marrow transplantation is in clinical practice. Communication among care providers, social workers, patients and families is essential to inform and guide their decisions, establish realistic expectations, and assess patients' responses.Hospital de Clinicas de Porto Alegre Serviço de Génetica MédicaUniversidade Federal do Rio Grande do Sul Departamento de GéneticaInstituto Nacional de Genética Médica PopulacionalAsociación Colombiana de Neurología InfantilInstituto Mexicano del Seguro SocialInstituto de Estudios AvanzadosHospital de NiñosLa Misericordia University HospitalUniversidade Federal de São Paulo (UNIFESP) Centro de Referência em Erros Inatos do MetabolismoUniversidade Federal de BahiaUniversidad de Chile Instituto de Nutrición y Tecnología de los AlimentosHospital Italiano Instituto de Genética MédicaHospital Pequeno Príncipe Departamento de NeuropediatraHospital Universitario AustralUNIFESP, Centro de Referência em Erros Inatos do MetabolismoSciEL

Current practices and challenges in the diagnosis and management of pku in Latin America: A multicenter survey

This study aimed to describe the current practices in the diagnosis and dietary management of phenylketonuria (PKU) in Latin America, as well as the main barriers to treatment. We developed a 44-item online survey aimed at health professionals. After a pilot test, the final version was sent to 25 practitioners working with inborn errors of metabolism (IEM) in 14 countries. Our results include 22 centers in 13 countries. Most countries (12/13) screened newborns for PKU. Phenylalanine (Phe) targets at different ages were very heterogeneous among centers, with greater consistency at the 0–1 year age group (14/22 sought 120–240 µmol/L) and the lowest at >12 years (10 targets reported). Most countries had only unflavored powdered amino acid substitutes (10/13) and did not have low-protein foods (8/13). Only 3/13 countries had regional databases of the Phe content of foods, and only 4/22 centers had nutrient analysis software. The perceived obstacles to treatment were: low purchasing power (62%), limited/insufficient availability of low-protein foods (60%), poor adherence, and lack of technical resources to manage the diet (50% each). We observed a heterogeneous scenario in the dietary management of PKU, and most countries experienced a lack of dietary resources for both patients and health professionals.Fil: Poloni, Soraia. Hospital de Clínicas de Porto Alegre; BrasilFil: Dos Santos, Bruna Bento. Universidade Federal do Rio Grande do Sul; Brasil. Hospital de Clínicas de Porto Alegre; BrasilFil: Chiesa, Ana Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Fundación de Endocrinología Infantil. Centro de Investigaciones Endocrinológicas "Dr. César Bergada"; ArgentinaFil: Specola, Norma. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Pereyra, Marcela. Gobierno de la Provincia de Mendoza. Hospital Pediátrico Humberto Notti; ArgentinaFil: Saborío Rocafort, Manuel. Universidad de Costa Rica; Costa RicaFil: Salazar, María Florencia. Universidad de Chile; ChileFil: Leal-Witt, María Jesús. Universidad de Chile; ChileFil: Castro, Gabriela. Universidad de Chile; ChileFil: Peñaloza, Felipe. Universidad de Chile; ChileFil: Wong, Sunling Palma. Hospital Nacional de Niños; Costa RicaFil: Badilla Porras, Ramsés. Hospital Nacional de Niños; Costa RicaFil: Ortiz Paranza, Lourdes. Ministerio de Salud Pública y Bienestar Social; ParaguayFil: Sanabria, Marta Cristina. Hospital de Clínicas; ParaguayFil: Vela Amieva, Marcela. Instituto Nacional de Pediatría; MéxicoFil: Morales, Marco. No especifíca;Fil: Caro Naranjo, Amanda Rocío. Pontificia Universidad Javeriana; ColombiaFil: Mahfoud, Antonieta. Pontificia Universidad Javeriana; ColombiaFil: Colmenares, Ana Rosa. Hospital Clinica Caracas-Materno Infantil de Caricuao; VenezuelaFil: Lemes, Aida. Instituto de Seguridad Social; UruguayFil: Sotillo Lindo, José Fernando. Hospital de especialidades Pediátricas “Omar Torrijos Herrera"; PanamáFil: Perez, Ceila. Robert Reid Cabral Children’s Hospital; República DominicanaFil: Martínez Rey, Laritza. Centro Nacional de Genética Médica; CubaFil: Zayas Torriente, Georgina María. Centro de Nutrición e Higiene de los Alimentos del Instituto Nacional de Higiene, Epidemiología y Microbiología; CubaFil: Farret Refosco, Lilia. Hospital de Clínicas de Porto Alegre; BrasilFil: Doederlein Schwartz, Ida Vanessa. Universidade Federal do Rio Grande do Sul; Brasil. Hospital de Clínicas de Porto Alegre; BrasilFil: Cornejo, Veronica. Universidad de Chile; Chil

ERRORES INNATOS DEL METABOLISMO: UNA APROXIMACION DIAGNOSTICA.

Los errores innatos del metabolismo (EIM), son enfermedades hereditarias, que obedecen generalmente a alteraciones enzimáticas.Al considerarlas en particular son raras, pero en conjunto representan una importante causa de morbi-mortalidad en la edad pediatrica. El diagnóstico es complicado, ya que las presentaciones clínicas  son variadas y poco específicas y además requiren de laboratorio especializadas. Se clasifican en tres grandes grupos de acuerdo a los mecanísmos fisiopatológicos: los trastornos del metabilismo intermedio, los que obedecen al deficit de producción de energía y por deposito de macromoléculas. El conocimiento de los EIM por parte del clínico es fundamental, eso permitiría identificar los datos orientadores de la historia médica y del laboratorio y solicitar las investigaciones requeridas para un diagnóstico temprano y un tratamiento oportunoABSTRACT: The inborn errors of metabolism are hereditary diseases caused in most of the cases by enzimatic disturbs. These diseasesare rare, but all of them are a very much important cause of morbi – mortality in children. The diagnoses is complicatedbecause clinical presentations are so many and some specific and besides require specialized laboratory investigations.These diseases are classified in three groups, in order to the pshysiopathological mechanisms implicated:intermediary metabolism trastorns, energy production deficit and macromolecules depots.The clinician knowledgement about these diseases is crucial, because it will allow to identify clinical andlaboratory dates and apply for required investigations in order to an early diagnosis and opportune treatment

Obtención de hidrolizados proteicos bajos en fenilalanina a partir de suero dulce de leche y chachafruto (Erythrina edulis Triana)

La fenilcetonuria (PKU) es causada por una actividad deficiente de la enzima fenilalanina hidroxilasa. En los pacientes con esta deficiencia la fenilalanina (Phe) no puede ser convertida en tirosina, aumentando sus niveles en sangre y de otros metabolitos neurotóxicos, provocando un retraso mental irreversible. El tratamiento fundamentalmente se basa en una dieta controlada de Phe. Sin embargo, los alimentos libres o bajos en Phe son escasos. El objetivo de esta investigación es obtener hidrolizados proteicos con bajo contenido de Phe a partir del suero dulce de leche en polvo y harina de E. edulis Triana. El aislado proteico (96,01% proteína cruda) se obtuvo por solubilización y precipitación de las proteínas de la harina, mientras que las proteínas del suero (15,69% proteína cruda) fueron tratadas en su matriz original. Las proteínas del suero y el asilado fueron hidrolizadas enzimáticamente con pepsina y proteasa de Streptomyces griseus. La concentración de Phe se determinó por fluorometría y por HPLC, de lo cual la Phe de las proteínas del suero es liberada una hora antes que las del chachafruto, debido a que las proteínas del suero en parte fueron hidrolizadas en la elaboración del queso. Además, los resultados de la utilización del carbón activados como captor de Phe indican la reducción total del contenido de este aminoácido en los hidrolizados y la reducción de la concentración de otros aminoácidos.Phenylketonuria (PKU) is caused by a low activity of the enzyme phenylalanine hydroxylase. In patients with this deficiency, phenylalanine (Phe) cannot be converted to tyrosine, increasing blood levels and other neurotoxic metabolites, causing irreversible mental retardation. The treatment is fundamentally based on a controlled diet of Phe. However, free or low-Phe foods are scarce. The objective of this research is to obtain protein hydrolysates with low Phe content from sweet milk powder and E. edulis Triana flour. The protein isolate (96.01% crude protein) was obtained by solubilization and precipitation of the flour proteins, while the whey proteins (15.69% crude protein) were treated in their original matrix. Serum and asylated proteins were enzymatically hydrolyzed with pepsin and Streptomyces griseus protease. The concentration of Phe was determined by fluorometry and by HPLC, from which the Phe of whey proteins is released one hour earlier than those of chachafruto, due to the fact that the whey proteins were partially hydrolyzed in the elaboration of the cheese. In addition, the results of the use of charcoal activated as Phe captor indicate the total reduction of the content of this amino acid in the hydrolysates and the reduction of the concentration of other amino acids

Independent origin for m.3243A>G mitochondrial mutation in three Venezuelan cases of MELAS syndrome

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a multisystem and progressive neurodegenerative mitochondrial disease, caused by point nucleotide changes in the mtDNA where 80 % of cases have the mutation m.3243A>G in the MT-TL1 gene. In this work, we described the clinical, biochemical and molecular analysis of three Venezuelan patients affected with MELAS syndrome. All cases showed lactic acidosis, cortical cerebral atrophy on magnetic resonance imaging and muscular system deficit, and in two of the cases alteration of urine organic acid levels was also registered. A screening for the mutation m.3243A>G in different patients’ body samples confirmed the presence of this mutation with variable degrees of heteroplasmy (blood = 7–41 %, buccal mucosa = 14–53 %, urine = 58–94 %). The mitochondrial haplogroups for the three patients were different (H, C1b, and A2), indicating an independent origin for the mutation.Fil: Florez, Ingrid. No especifíca;Fil: Pirrone Berecibar, Irune Itziar. Universidad Simón Bolívar; Venezuela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Casique, Liliana. Universidad Simón Bolívar; VenezuelaFil: Domínguez, Carmen Luisa. No especifíca;Fil: Mahfoud, Antonieta. No especifíca;Fil: Rodríguez, Tania. No especifíca;Fil: Rodríguez, Daniel. No especifíca;Fil: De Lucca, Marisel. No especifíca;Fil: Ramírez, José Luis. No especifíca

Guidelines for diagnosis and treatment of Hunter Syndrome for clinicians in Latin America

This review aims to provide clinicians in Latin America with the most current information on the clinical aspects, diagnosis, and management of Hunter syndrome, a serious and progressive disease for which specific treatment is available. Hunter syndrome is a genetic disorder where iduronate-2-sulfatase (I2S), an enzyme that degrades glycosaminoglycans, is absent or deficient. Clinical manifestations vary widely in severity and involve multiple organs and tissues. An attenuated and a severe phenotype are recognized depending on the degree of cognitive impairment. Early diagnosis is vital for disease management. Clinical signs common to children with Hunter syndrome include inguinal hernia, frequent ear and respiratory infections, facial dysmorphisms, macrocephaly, bone dysplasia, short stature, sleep apnea, and behavior problems. Diagnosis is based on screening urinary glycosaminoglycans and confirmation by measuring I2S activity and analyzing I2S gene mutations. Idursulfase (recombinant I2S) (Elaprase®, Shire) enzyme replacement therapy (ERT), designed to address the underlying enzyme deficiency, is approved treatment and improves walking capacity and respiratory function, and reduces spleen and liver size and urinary glycosaminoglycan levels. Additional measures, responding to the multi-organ manifestations, such as abdominal/inguinal hernia repair, carpal tunnel surgery, and cardiac valve replacement, should also be considered. Investigational treatment options such as intrathecal ERT are active areas of research, and bone marrow transplantation is in clinical practice. Communication among care providers, social workers, patients and families is essential to inform and guide their decisions, establish realistic expectations, and assess patients' responses