J. C. Commentz

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A method for measuring the lipophilic antioxidants alpha-tocopherol, gamma-tocopherol, ubiquinol-10, ubiquinone-10, beta-cryptoxanthin, and beta-carotene in 5 or 10 microliters neonatal plasma is presented. First lipid extraction together with the internal standards gamma-tocotrienol, ubiquinone-7, ubiquinol-9, ubiquinone-9, and ethyl(More)
Inadequate resistance to oxidative stress has been implicated in several diseases of premature children. Antioxidative defences at the membrane level can be studied by measuring haemolysis induced through exposure of erythrocytes to the free radical generator AAPH (2,2'-azobis (2-amidinopropane)dihydrochloride). We developed a micromodification of this(More)
In the present study the effects of artificial magnetic fields on pineal serotonin-N-acetyltransferase (NAT) activity and melatonin content in male Sprague-Dawley rats were investigated to study the secretory activity of the pineal gland. Experimental inversion of the horizontal component of the natural magnetic field, performed at night-time, led to a(More)
Four cases of hypothalamic hamartoma leading to gelastic epilepsy, precocious puberty and behavioural disorders are reported. Cerebral neuroradiologic examinations revealed a tumor-like mass attached to the hypothalamus in the region of the mamillary bodies in all cases. Precocious puberty developed in the two girls at 4 and 13 months but in neither of the(More)
A retrospective study was conducted to determine the significance of intensive care management on outcome after liver transplantation (LTx) in children. Of 195 transplants performed in 162 children, factors affecting morbidity and mortality were documented during the post-operative intensive care unit (ICU) stay. To assess the gain in experience of ICU(More)
We investigated the ontogeny of melatonin synthesis during fetal maturation by measuring the melatonin (MLT) and 6-hydroxymelatonin sulfate (MLTS) excretion in the urine of male infants aged 2-7 days and gestational age 26-42 weeks. We found a negative correlation between advancing gestational age and the MLT and MLTS excretion expressed as total 24-h(More)
To delineate the development of melatonin (MLT) production during childhood, we measured the excretion of MLT and 6-hydroxymelatonin sulfate (MLTS) in the urine of children (n = 134) from the 26th week of gestation until the age of 20 years. MLTS excretion showed a diphasic pattern with declining values in preterm babies with lowest values around term.(More)
Hypothalamic hamartomata are benign malformations of the brain consisting of heterotopic nervous tissue, and are often associated with precocious puberty and gelastic seizures in early childhood. We report for the first time the melatonin plasma values of a girl with central precocious puberty and gelastic seizures due to a hypothalamic hamartoma. The(More)
In 3 groups of 8 children and adolescents each with Prader-Willi-Labhart's Syndrome (PW-S), obese patients matched for body weight (control I), and normal weight subjects matched for pubertal stage (control II) plasma concentrations of melatonin, cortisol, growth hormone (hGH), insulin, gonadal hormones, and gonadotropins were measured every 1 to 4 hours in(More)
A micromethod for the rapid simultaneous determination of several lipophilic antioxidants in plasma from newborn infants is presented. Because only 5 microliters of plasma is required, the procedure lends itself for repetitive use in very immature infants at risk for developing so-called "oxygen radical diseases of the premature." The method allows(More)