Walter Kochen

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A 7-year-old boy developed a severe unilateral grand mal seizure at the age of 5 years (phenobarbitone therapy); 1.5 years later valproate (2-propylpentanoic acid, VPA) was added to the therapy. After a seizure-free period of 3 months the patient died from hepatic failure resembling Reye syndrome. Several plasma and urine samples from the final stage before(More)
Microbiologically determined plasma biotin levels in 404 epileptics under long-term treatment with anticonvulsants were markedly lower than in 112 controls (p less than 0.0005). Patients with partial epilepsy had lower biotin levels and higher average daily intake of AC than those with generalized epilepsy. Epileptics treated with valproate sodium in(More)
Volatile hydrocarbons such as ethane and n-pentane are known to originate from peroxidation of polyunsaturated fatty acids in membrane lipids and they are accepted as a sensitive and direct index of lipid peroxidation both in vitro and in vivo. Until now, an appropriate and commonly accepted method for the analysis of volatile hydrocarbons in exhalation air(More)
The causative interrelationship between long-term, low level exposure to chlorinated volatile organic solvents (VOSs) and neurodegenerative diseases (polyneuropathy, encephalopathy) are still an issue of controversial debate. Endogeneously formed chlorinated tetrahydro-beta-carbolines found by Bringmann 1995 (TaClo hypothesis) may contribute, in particular,(More)
The data of 16 children who died while receiving valproate (VPA) therapy in West Germany were analyzed. Five were normally developed, 5 were receiving VPA-monotherapy, and only 2 patients were aged less than 3 years. The first clinical symptoms of impending hepatotoxicity usually included nausea, vomiting, and apathy; pathologic laboratory tests reflected(More)
Urinary organic acids, known to be elevated in children with biotin deficiency, were determined in 7 epileptics under long-term therapy with anticonvulsants and in three controls. Four patients administered phenytoin, primidone, phenobarbital, or carbamazepine, alone or in combination, had reduced plasma biotin levels (less than 250 ng/l) and an elevated(More)
Tryptophan and some indolic metabolites were studied in urine, plasma and dialysate of uraemic patients using thin-layer- and high-pressure liquid chromatography. Some new metabolites: indole-3-carboxylic acid, indole-3-carbaldehyde, indolelactic acid and N-acetyltryptophan were detected. Levels of the latter two metabolites in urine, dialysate and(More)
A method is described for the determination of cortisol in human plasma by high-pressure liquid chromatography. The simplified extraction procedure makes the method applicable to routine clinical assays. Partition chromatography is carried out on a Zorbax-Sil column with the eluent system dichloromethane-ethanol-water. A 78% recovery was obtained for(More)