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A new, precise, and very selective method for increasing the impact and assessment of histidine as a biomarker for early diagnosis of histidinemia disease in new born children was developed. The method depends on the formation of the ion pair associate between histidine and the nano optical samarium tetracycline [Sm-(TC) 2 ] + complex doped in sol-gel matrix in a borate buffer of pH 9.2. The [Sm-(TC) 2 ] + complex has +I net charge which is very selective and sensitive for [histidine] - at pH 9.2 in serum and urine samples of histidinemia disease. Histidine enhances the luminescence intensity of the nano optical [Sm-(TC) 2 ] + complex at 645 nm after excitation at 400 nm, in borate buffer, pH 9.2. The remarkable enhancement of the luminescence intensity at 645 nm of nano [Sm-(TC) 2 ] + complex doped in sol-gel matrix by various concentrations of the histidine was successfully used as an optical probe for the assessment of histidine in different serum and urine samples of new born children infected by histidinemia. The calibration plot was achieved over the concentration range 1.4×10 −5 – 6.5×10 −10 mol L −1 histidine with a correlation coefficient of (0.998) and a detection limit of (3.2×10 −10 mol L −1 ). The sensitivity (98.88%) and specificity (97.41%) of histidine as a biomarker were calculated. [ABSTRACT FROM AUTHOR]

Kinetics of the metabolism of the heterocyclic amino acid histidine exposed to the L-histidine ammonia-lyase enzyme has been investigated and the technology of extraction of histidine biotransformation products (urocanic acid and ammonia) from casein hydrolyzates enabling the subsequent use of these hydrolyzates as a milk protein concentrate for the production of specialized dietary products for the nutrition of histidinemia patients has been developed.

Los trastornos de la comunicación oral en el niño son causa frecuente de asistencia a la consulta de Logopedia y Foniatría, donde el especialista debe realizar el examen clínico funcional en busca de posible etiología para imponer el tratamiento rehabilitador. Dentro de estos trastornos se encuentran los trastornos específicos del lenguaje y del habla, donde no se conoce la causa. La histidinemia se asocia frecuentemente con trastornos de la comunicación oral. Se realizó un estudio analítico de casos y controles. Se estudiaron 27 niños con trastornos de la comunicación (casos) y 102 controles. A todos se les determinó los niveles de histidina en suero mediante un método ultramicroanalítico. Presentaron niveles elevados de histidina el 29,6% para los casos y en los controles solo el 1%, determinándose que la diferencia en los niveles de histidina es significativa entre los niños con TEL y los controles mientras que los niños con dislalia no se diferencian significativamente ni de los controles, ni de los niños con TEL. Los resultados obtenidos muestran que la probabilidad de encontrar concentraciones de histidina elevadas en los niños con trastornos de la comunicación oral es más alta que en el grupo control.

Histidase (histidine ammonia-lyase) is a cytosolic enzyme responsible for catalyzing the non-oxidative deamination of histidine to urocanic acid. Full-length cDNAs encoding rat histidase have been isolated from a λZAP liver cDNA library using a partial cDNA fragment obtained by PCR. Whereas the initial description of the rat histidase 3′ untranslated sequence contained a rare polyadenylation signal sequence, the data presented encompass a more distant 28-bp region, possessing a nucleotide stretch (AATATAAA), identical to that in the mouse histidase cDNA. Dideoxynucleotide chain termination sequencing of two clones obtained by in vivo excision yielded an additional 376 bp and 105 bp of 5′ and 3′ untranslated sequences, respectively. A selected rat histidase cDNA clone was introduced into the pET-16b prokaryotic vector and expressed in BL21 (DE3)pLysS Escherichia coli. After purification by nickel-chelation chro- matography, recombinant histidine-tagged protein was employed to raise anti-(rat histidase) immunoglobulin in a Japanese white rabbit. The polyclonal rabbit antibody recognized and formed immune complexes with rat and recombinant human histidase proteins. Immunoblots of crude rat organ extracts detected a spectrum of histidase expression extending beyond that observed in liver and skin. Among other histidase-positive cells were those of the renal cortex tubular epithelium, fundic mucosal glands of stomach, gastric intramuscular (Auerbach's) plexus, and adrenal cortex. Immunohistochemical studies of histidase in rat liver produced discrete staining of hepatocytes in association with portal triads (Rappaport zone 1). Furthermore, in contrast with previous reports of activity confined to epidermal stratum corneum, our findings demonstrate immunoreactive protein within and limited to the adjacent stratum granulosum. [ABSTRACT FROM AUTHOR]

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The urocanic acid content of the skin was measured photometrically in a large number of normal and histidinemic infants. A very high content was demonstrated in the normal newborn infants, followed by a rapid decrease throughout early infancy. In contrast, 36 measurements in 17 infants with histidinemia revealed a much lower content even in their newborn periods. Thus, the quantification of skin urocanic acid was considered to be simple and useful for confirming the diagnosis of histidinemia, especially in a neonatal mass-screening program. [ABSTRACT FROM AUTHOR]