Creatine metabolism: detection of creatine and guanidinoacetate in saliva of healthy subjects / Metabolismo de creatina: detección de creatina y guanidinoacetato en saliva de sujetos sanos

Creatine (Cr) plays an important role in storage and transmissionof phosphate-bound energy. Cerebral creatine deficiencysyndromes comprise three inherited defects in Cr biosynthesis andtransport. The aim of this study was to investigate whether Cr andGuanidinoacetate (GAA) can be detected in saliva of healthysubjects and to establish the relationship between salivary andplasma levels of these molecules. An adapted gas chromatography(GC) method is described for the quantification of Cr and GAAbiomarkers in saliva. Reference values were established for GAAand Cr in saliva. These values were age dependent (p= 0.001). Nodifference between genders was observed. We detected a differencebetween GAA and Cr concentrations in saliva and in plasma. TheGC method for simultaneous determination of GAA and Cr inhuman saliva is fast, reliable, sensitive, non-invasive and preciseto use as a biochemical approach in early detection of cerebralcreatine deficiency syndromes.

La creatina (Cr) juega un importante rol en el almacenamiento y el transporte de energía unida al fosfato. Los síndromes de deficiencia de creatina cerebral comprenden tres defectos genéticos en la biosíntesis y transporte de creatina. Es propósito de este estudio investigar si el guanidinoacetato (GAA) y la Crpueden ser detectados en saliva de sujetos sanos e investigar la relación entre los valores de GAA y Cr en saliva con los niveles en plasma de estas moléculas. Se describe un método modificado de cromatografía gaseosa para la cuantificación de los biomarca -dores, Cr y GAA en este biofluído. Se establecieron valores de referencia para GAA y Cr. Estos valores dependen de la edad (P=0.001). No se observaron diferencias entre género. Se detectóuna diferencia entre la concentración de GAA y Cr en saliva con respecto al plasma. El método adaptado de cromatografía gaseosa para la determinación simultánea de GAA y Cr en saliva humana es fácil, seguro, sensible, no invasivo y preciso para utilizar como aproximación bioquímica en la detección temprana de lossíndromes de deficiencia de creatina cerebral.

Morphogenesis in short-term and long-term anther derived calli of Oenothera hookeri de vries

Anther culture of O. hookeri on Murashige and Skoog (1962) medium supplemented with 2 mg l-1 2,4-dichlorophenoxyacetic acid and 2 mg-1 1-naphthaleneacetic acid produced callus formation. When subcultured onto medium lacking auxin, the callus regenerated through the organogenic pathway. Non-organogenic and organogenic callus was observed using histological methods after 2, 3 and 24 weeks in culture. Three types of calli were recognized: non-organogenic friable calli, organogenic friable calli with roots and organogenic hard calli with shoots. The microscopical sections showed striking differences in tissue organization among friable and compact calli. Vascular bundles were prominent in compact calli, but were not found in friable calli. Calli sections showed at light microscopy cells at two developmental stages; differentiated highly vacuolated cells and meristematic small isodiametric cells with densely stained cytoplasm. At electron microscopy level abnormal chloroplasts were present in non-organogenic calli, while chloroplasts were well developed in organogenic hard calli. Peroxisomes with paracrystalline protein bodies were abundant in both types of calli.