Periodic acid, detection basicity

An interesting topic is related to the data of trace element contents in human hair. The results of analysis of trace element contents in human hair are useful for the diagnosis of some diseases. These data can also provide valuable information about the influence of environment on human health. Like the trace element analysis of serum or urine, hair analysis can provide valuable information. Contrary to the results of the analysis of serum or urine, the results of hair analysis can reflect metabolic process in the body over a period of several months. Metal ions, moreover, are permanently built into the a-helical structure of hair keratin, thereby creating chelate links with the acid and basic radicals of amino acids, as a result of which the content of some metallic elements in hair is much higher than that in other tissues. Up to now, 78 elements have been detected in human hair. 

In order to relate mRNA-, and protein level of the LOX forms with the total LOX activity, the extractable enzymatic activity was measured at pH 6.5 during the incubation period in leaf segments treated with water, JM, and sorbitol. In contrast to the induced LOX forms by osmotic stress and JM at the transcriptional- and protein level, the general LOX activity was only induced by JM, whereas the LOX activity of leaves which were stressed for 72 h with sorbitol was even significantly lower than the control. To exclude the possibility of the induction of LOX forms with more acidic or basic pH-optima, the activity was also measured at pH 5.0 and in the range of pH 7.0 to 9.0. Under these conditions no significant activity was detectable. 

Recent work, whereby the spectrum and concentrations of dissolved free amino acids were monitored by direct analysis of seawater from a fixed station over the period of a day at hourly intervals (K. Mopper, pers. comm., 1979), showed pronounced variations in both composition and concentration. Particularly striking was the sharp increase in basic amino acids (low C N) at the expense of a decrease in acidic-neutral acids (high C N) outside the daylight hours. An explanation can at present only be speculative, but the results suggest that the phenomenon is directly linked with photosynthetic activity. This suggests, therefore, that the approach to study excretion in situ requires the detection of bioactive compounds at their natural levels, which generaUy lie several orders of ms itude below those of bulk parfuneters. 

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