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Biomedical subjects

R Lauwerys

Publications and source records attributed to R Lauwerys.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Impact of air pollution by lead on the heme biosynthetic pathway in school-age children.

Blood-lead level (Pb-B), erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity, free erythrocyte porphyrin (FEP) concentration, delta-aminolevulinic acid concentration in urine (ALAU), hematocrit value, and hemoglobin concentration were compared for groups of children 10-13 years old from areas differently polluted by lead (rural area and lead smelter area). The biological responses of the children were also compared with those observed in adults similarly exposed to lead (Pb-B: 10-40 mug/100 ml). Compared with the rural children, children living less than 1 km from the smelter exhibited a significant increase of Pb-B and FEP, a significant inhibition of ALAD, and a slight positive correlation of ALAU with Pb-B; however, they showed no biological signs of anemia. In children living approximately 1.5 km from the smelter, there was still a significant increase of Pb-B and a concomitant inhibition of ALAD, but no change in FEP concentration. Comparison of the dose-response curves between Pb-B and FEP in adult males, adult females, and children indicates that the sensitivity to lead is in the order of children larger than or equal to women greater than men. Based on the FEP response, it is proposed that 25 mug Pb/100 ml blood be regarded as the maximum biologically allowable concentration of lead in blood of school-age children.

Adolescent↗
PubMedDate not supplied

[Evaluation of the advantage of determination of urinary pseudouridine for the early detection of a malignant transformation process].

The catabolism of tRNA gives rise to modified nucleosides, among which pseudouridine, which are excreted in urine. An increased cell turnover is associated with an enhanced excretion of these products. Some authors have also reported an increased urinary excretion of pseudouridine in asbestos workers without clinical signs of malignancy. In two experimental models of carcinogenesis (i.e. injection of Lewis carcinoma cells in C57/B1C mice and oral administration of 7,12 dimethyl-benz(a)anthracene in female Sprague-Dawley rats), we have confirmed that the occurrence of the tumor is associated with an increased urinary excretion of pseudouridine. This metabolic change, however, does not precede the detection of the tumor. In control human subject, no sex and age effect was found in the urinary concentration of pseudouridine. Patients with a malignant disease excrete an enhanced amount of pseudouridine. A pilot study among workers exposed to polycyclic aromatic hydrocarbons in a coke oven did not reveal any change in the urinary concentration of pseudouridine.

Adolescent↗