Coffee's country of origin determined by NMR: the Colombian case.

The determination of the origin of coffee beans by NMR fingerprinting has been shown promising and classification has been reported for samples of different countries and continents. Here we show that this technique can be extended and applied to discriminate coffee samples from one country against all others, including its closest neighbors. Very high classification rates are reported using a large number of spectra (>300) acquired over a two-year period. As original aspects it can be highlighted that this study was performed in fully automatic mode and with non-deuterated coffee extracts. This is achieved using a series of experiments to procure a robust suppression of the solvent peaks. As is, the method represents a cost effective opportunity for countries to protect their national productions.

Atencion primaria: diagnostico precoz de hipoacucia / Primary health care: early diagnosis of hearing loss

Resumen: La hipoacusia neurosensorial severa o profunda es un importante handicap o discapacidad que afecta del 1 a 3 por ciento de los recién nacidos vivos y del 2 al 4 por ciento de los neonatos egresados de las UTI neonatales. El pronóstico para el intelecto, condición psico-emocional, lenguaje y desarrollo del habla, es mejor cuando el diagnóstico es efectuado tempranamente y la intervención comienza antes de los 6 meses de vida. La edad habitual deldiagnóstico de hipoacusia es entre los 18 y los 30 meses, o aún más tarde, en casos de pérdida auditiva leve a moderada, cuando no hay implementados programas de screening auditivos. El screening auditivo universal efectuado a los RN, puededarle al niño discapacitado por sordera, la mejor oportunidad para un óptimo cuidado y desarrollo. El criterio “universal” es necesario, porque cuando el tamizaje es restringido al grupo de neonatos de alto riesgoauditivo, no son diagnosticados entre el 30 y el 50 por ciento de los RNcon pérdida auditiva.

Atencion primaria: diagnostico precoz de hipoacucia / Primary health care: early diagnosis of hearing loss

Resumen: La hipoacusia neurosensorial severa o profunda es un importante handicap o discapacidad que afecta del 1 a 3 por ciento de los recién nacidos vivos y del 2 al 4 por ciento de los neonatos egresados de las UTI neonatales. El pronóstico para el intelecto, condición psico-emocional, lenguaje y desarrollo del habla, es mejor cuando el diagnóstico es efectuado tempranamente y la intervención comienza antes de los 6 meses de vida. La edad habitual deldiagnóstico de hipoacusia es entre los 18 y los 30 meses, o aún más tarde, en casos de pérdida auditiva leve a moderada, cuando no hay implementados programas de screening auditivos. El screening auditivo universal efectuado a los RN, puededarle al niño discapacitado por sordera, la mejor oportunidad para un óptimo cuidado y desarrollo. El criterio ¶universal÷ es necesario, porque cuando el tamizaje es restringido al grupo de neonatos de alto riesgoauditivo, no son diagnosticados entre el 30 y el 50 por ciento de los RNcon pérdida auditiva.(AU)

Familial clustering of infantile cirrhosis in Northern Germany: A clue to the etiology of idiopathic copper toxicosis.

Two cases of infantile liver cirrhosis of unknown origin occurred in a circumscribed rural area of Northern Germany. Both children had increased dietary copper exposure. The search for additional cases of what appeared to be idiopathic copper toxicosis (ICT) revealed a cluster of affected infants in this region, raising questions about the relative importance of genetic and environmental factors that are considered to be etiologic. We gathered clinical and pathologic data concerning the patients, analyzed the pedigrees of affected families, and searched for possible environmental factors contributing to the pathologic process. We encountered 8 cases of infantile liver cirrhosis in 5 families in Emsland, a circumscribed and predominantly rural area of Northern Germany; ICT was definitely proven in 2 cases. Clinical presentation and liver pathology in 6 additional cases were consistent with the diagnosis of ICT. Pedigrees of affected families revealed complex relationships with occasional consanguinity of parents, suggesting autosomal recessive inheritance. The households were served by private wells with water of low pH flowing through copper pipes, suggesting the possibility of increased alimentary copper exposure. These findings support earlier conclusions that ICT develops when an infant with a genetic predisposition is exposed to a copper-enriched diet.

Photoaffinity labeling and photoaffinity crosslinking of enzymes.

Photoaffinity labeling is a special type of chemical modification, where the label is activated by the action of light. This article presents the general principles and limitations of this technique, its application to the study of Micrococcus luteus ATPase and the use of photoaffinity crosslinking to probe the structure of this enzyme.

Photoaffinity labeling and photoaffinity crosslinking of enzymes

Photoaffinity labeling is a special type of chemical modification, where the label is activated by the action of light. This article presents the general principles and limitations of this technique, its application to the study of Micrococcus luteus ATPase and the use of photoaffinity crosslinking to probe the structure of this enzyme

Photoaffinity labeling of pyruvate kinase from rabbit muscle.

Several studies have been performed on the structure of muscle pyruvate kinase. X-ray diffraction has provided a three-dimensional picture of the active site, and chemical modification studies have revealed essential amino acid residues for substrate binding or catalysis. We have shown that 8-azido-ADP (N3 ADP) behaves as a photoaffinity label for the enzyme. This reagent upon irradiation produces inactivation of the enzyme, and the activity loss is protected by nucleotides. The partially modified enzyme shows the same Km for ADP as the native one suggesting an "all or none" inactivation effect. The incorporation of 1 mole of 14C-N3 ADP per subunit correlates with complete inactivation. A radioactive peptide was isolated from the enzyme labeled with 14C-N3 ADP. The partial sequence of this peptide showed that it corresponds to the same peptide isolated from rabbit muscle pyruvate kinase labeled with dialdehyde-ADP and with trinitrobenzenesulfonate. This peptide is identical to a region in the cat and chicken muscle enzymes, and also a high degree of homology is found in a region of the rat liver and yeast enzymes. These studies show that N3 ADP binds to the same site as dialdehyde-ADP in rabbit muscle pyruvate kinase, and this site seems to be the nucleotide binding site.