SYNOPSIS
In order to assess whether an increased brain serotonin tone prevents migraine symptoms, eight migraine patients were treated with levotryptophan in the controlled trial. Plasma and lumbar CSF were collected approximately one hour after the last dose of amino acid on the second week during the headache‐free interval. Samples were also taken 4 hours after the onset of the headache attack. Visual evoked cortical potentials were recorded one hour after the ingestion of 500 mg of levotryptophan.In four of the eight migraine patients, headache indices were markedly lower during typptophan treatment than during placebo (levoleucine) treatment. Levotryptophan caused an elevation of plasma free and total tryptophan, and CSF‐tryptophan from their basal values obtained during placebo treatment. Therefore levotryptophan may be a worthwhile alternative for a selective and still incompletely characterized group of migraine patients.
A pilot plant study in four parallel filter runs was performed in order to determine the effect of ozonation and two-step granular activated carbon (GAC) filtration on the removal of disinfection by-product (DBP) precursors. The results showed that ozonation significantly decreased the adsorbable organic halogens (AOX) (35%), simulated distribution system (SDS) AOX (37%) and SDS trihalomethanes (THM) (76%) from chemically treated and sand-filtered lake water, but did not decrease either short-term or the long-term chlorine demand. Biofiltration with exhausted GAC had a minor importance in the precursor removal (0-20%). The performance of adsorptive GAC filtration was strongly dependent on the age of the GAC filter bed, which was also seen as a strong correlation between the natural organic matter (NOM) measurements and DBP formation potential. Disinfection with chloramine produced lower THM, AOX, mutagenicity and MX (Z-3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone) levels compared to chlorine disinfection.
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