Cystathionine beta synthase deficiency and brain edema associated with methionine excess under betaine supplementation: Four new cases and a review of the evidence.

CBS deficient individuals undergoing betaine supplementation without sufficient dietary methionine restriction can develop severe hypermethioninemia and brain edema. Brain edema has also been observed in individuals with severe hypermethioninemia without concomitant betaine supplementation. We systematically evaluated reports from 11 published and 4 unpublished patients with CBS deficiency and from additional four cases of encephalopathy in association with elevated methionine. We conclude that, while betaine supplementation does greatly exacerbate methionine accumulation, the primary agent causing brain edema is methionine rather than betaine. Clinical signs of increased intracranial pressure have not been seen in patients with plasma methionine levels below 559 μmol/L but occurred in one patient whose levels did not knowingly exceed 972 μmol/L at the time of manifestation. While levels below 500 μmol/L can be deemed safe it appears that brain edema can develop with plasma methionine levels close to 1000 μmol/L. Patients with CBS deficiency on betaine supplementation need to be regularly monitored for concordance with their dietary plan and for plasma methionine concentrations. Recurrent methionine levels above 500 μmol/L should alert clinicians to check for clinical signs and symptoms of brain edema and review dietary methionine intake. Levels approaching 1000 μmol/L do increase the risk of complications and levels exceeding 1000 μmol/L, despite best dietetic efforts, should be acutely addressed by reducing the prescribed betaine dose

Cystathionine beta synthase deficiency and brain edema associated with methionine excess under betaine supplementation: Four new cases and a review of the evidence

CBS deficient individuals undergoing betaine supplementation without sufficient dietary methionine restriction can develop severe hypermethioninemia and brain edema. Brain edema has also been observed in individuals with severe hypermethioninemia without concomitant betaine supplementation. We systematically evaluated reports from 11 published and 4 unpublished patients with CBS deficiency and from additional four cases of encephalopathy in association with elevated methionine. We conclude that, while betaine supplementation does greatly exacerbate methionine accumulation, the primary agent causing brain edema is methionine rather than betain

Cystathionine beta synthase deficiency and brain edema associated with methionine excess under betaine supplementation: Four new cases and a review of the evidence.

CBS deficient individuals undergoing betaine supplementation without sufficient dietary methionine restriction can develop severe hypermethioninemia and brain edema. Brain edema has also been observed in individuals with severe hypermethioninemia without concomitant betaine supplementation. We systematically evaluated reports from 11 published and 4 unpublished patients with CBS deficiency and from additional four cases of encephalopathy in association with elevated methionine. We conclude that, while betaine supplementation does greatly exacerbate methionine accumulation, the primary agent causing brain edema is methionine rather than betaine. Clinical signs of increased intracranial pressure have not been seen in patients with plasma methionine levels below 559 μmol/L but occurred in one patient whose levels did not knowingly exceed 972 μmol/L at the time of manifestation. While levels below 500 μmol/L can be deemed safe it appears that brain edema can develop with plasma methionine levels close to 1000 μmol/L. Patients with CBS deficiency on betaine supplementation need to be regularly monitored for concordance with their dietary plan and for plasma methionine concentrations. Recurrent methionine levels above 500 μmol/L should alert clinicians to check for clinical signs and symptoms of brain edema and review dietary methionine intake. Levels approaching 1000 μmol/L do increase the risk of complications and levels exceeding 1000 μmol/L, despite best dietetic efforts, should be acutely addressed by reducing the prescribed betaine dose

Anales de Edafología y Agrobiología Tomo 36 Número 11-12

Utilización de antibióticos en el cebo precoz de corderos. Efectos de la Virginiamicina, por E. Zaera Jimeno, J. P. Gómez Ballesteros y V. González González.-- Evaluación de suelos para diferentes usos agrícolas. Un sistema desarrollado para regiones mediterráneas, por D. de la Rosa, F. Cardona y G. Paneque.-- Fraccionamiento de ácidos húmicos de vertisol por geles de Sephadex. Comportamiento según los métodos empleados, por F. J. G. Vila y F. Martín.-- Composición y evolución de la fracción arcilla en suelos hidromorfos de zonas semiáridas. II. Suelos pseugleyzados, por M. Ledesma García y M. Sánchez Camazano.-- Composición y evolución de la fracción arcilla en suelos hidromorfos de zonas semiáridas. III. Suelos de vega, gleyzados y planosuelos, por M. Sánchez Camazo y M. Ledesma García.-- Variations saisonnieres dans l'ultrastructure d'un lichen foliace: Parmclia conspersa S. L., par María Carmen Ascaso et Jesús Galván.-- Evolución de la materia orgánica de un suelo clímax y de un suelo de repoblación de la vertiente norte de la Sierra de Gata (Salamanca}, por M. l. M. González, J. F. Gallardo y J. A. Egido.-- Estudio de los ácidos húmicos de dos fertilizantes orgánicos, sirle y turba, en suelos calizos. III. Aminoácidos, por J. Cegarra y F. Costa.-- Estudio crítico sobre la utilización de Azotobacter y fosfobacterias como fertilizantes microbianos, por J. M. Barca, J. A. Ocampo y E. Montoya.-- Estudio de la acción del boro sobre la absorción y metabolismo de elementos esenciales, rendimientos e índice de calidad en el cultivo de tomate. I. Influencia sobre absorción y metabolismo de elementos esenciales, por N. T. Piñero, C. Cadahia, V. Hernando e l. Bonilla.-- Estudio de la acción del boro sobre la absorción y metabolismo de elementos esenciales, rendimientos e índice de calidad en el cultivo de tomate. II. Influencia sobre rendimientos e índices de calidad nutritiva, por M. T. Piñero, C. Cadahia y V. Hernando.-- Estudio de tierras pardas sobre material calizo del Pirineo. II. Estudio de suelos: comportamiento de los principales constituyentes, por A. Hoyos, A. M. Moreno y J. González Parra.-- de tierras pardas sobre material calizo del Pirineo. III. Estudio de la fracción arcilla, por A. Hoyos, A. M. Moreno y J. González Parra.-- Estudio de la nutrición del aguacate por análisis foliar. l. Hojas procedentes de ramas fructíferas, por Serafín Jaime Palacios y Eduardo Esteban Velasco.—Nota preliminar.-- Determinación analítica del boro asimilable en suelos de cultivo, por A. Aguilar-Ros y A. Aguilar.—Estudios recapitulativos.-- Estudio de los factores ecológicos que afectan a las poblaciones microbianas en la rizosfera, por J. A. Ocampo, J. M. Barca y E. Montoya.-- Notas Prof. Tames Alarcón.-- Fallecimiento del Dr. Claver Aliod.-- El Prof. Mückenhansen cumple 70 años.-- Nombramiento de Presidente de la Comisión Asesora de Investigación Científica y Técnica.-- Nombramiento de Director General de Política Científica El Prof. Suárez cesa en la Dirección General de E. G. B.-- Distinción a D. Julio Rodríguez Martínez.-- El Prof. Balcells, Miembro de Honor de la Société Zoologique de France.-- Visita del Prof. Gómez Gutiérrez a la República Argentina.-- XIII Curso Internacional de Hidrología General y Aplicada y VII Curso Internacional de Ingeniería de Regadíos.-- Tenth International Congress of Sedimentology.-- Conferencia del Prof. H. Vu.-- Fundación del I. N. I. .-- Jornadas Técnicas sobre Ganado Porcino.-- Congreso Internacional de Técnicas Analíticas en la Química Ambiental.-- XV Premio Agrícola AEDOS.-- Sociedad Española de Ciencia del Suelo.-- Aprobación del Reglamento del C. S. I. C.-- BibliografíaPeer reviewe

Chelated Assisted Metal-Mediated N–H Bond Activation of β‑Lactams: Preparation of Irida‑, Rhoda‑, Osma‑, and Ruthenatrinems

2-Azetidinones substituted with pyridine (<b>2a</b>), quinoline (<b>2b</b>), isoquinoline (<b>2c</b>), imidazole (<b>2d</b>), and benzimidazole (<b>2e</b>) at the 4-position of the four-membered ring have been prepared in order to synthesize tribactams containing a transition metal and its associated ligands, L_<i>n</i>M, at the 2-position of the tricyclic skeleton. The developed procedure is compatible with a wide range of transition-metal starting complexes. Thus, the iridium and rhodium dimers [M­(η⁵-C₅Me₅)­Cl₂]₂ react with <b>2a</b>–<b>e</b>, in the presence of sodium acetate, to afford irida- and rhodatrinems (<b>1a</b>–<b>j</b>) containing the half-sandwich d⁶ metal fragments M­(η⁵-C₅Me₅)Cl (M = Ir, Rh). The reactions of [M­(μ-OMe)­(η⁴-COD)]₂ (M = Ir, Rh) with <b>2a</b> lead to irida- and rhodatrinems (<b>1k</b>,<b>l</b>) with the d⁸ moieties M­(η⁴-COD). The coordination sphere and oxidation state of the metal center in these compounds can be modified, without affecting the 2-azetidinone backbone, by means of substitution and oxidative addition reactions. As a proof of concept, metallatrinems with the M­(CO)₂ (M = Ir (<b>1m</b>), Rh (<b>1n</b>)) and Ir­(Me)­I­(CO)₂ (<b>1o</b>) units are also reported. Osmatrinems <b>1p</b>,<b>q</b> containing the d⁴ metal fragment OsH₃(PⁱPr₃)₂ have been obtained starting from the d² hexahydride OsH₆(PⁱPr₃)₂, by reaction with <b>2a</b>,<b>b</b>, whereas the treatment of the tetrahydroborate complexes MH­(η²-H₂BH₂)­(CO)­(PⁱPr₃)₂ (M = Os, Ru) with <b>2a</b> yields osma- and ruthenatrinems (<b>1r</b>,<b>s</b>) containing six-coordinate bis­(phosphine) d⁶ metal fragments. The IR stretching frequency of the lactamic carbonyl, the bent angle between the five- and four-membered rings of the tricycle, and the N–CO bond length in the lactamic ring are clearly infuenced by the L_<i>n</i>M fragment