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G Schoeters

Publications and source records attributed to G Schoeters.

24 records · Page 2Linked to original sources
PubMed1991

Stromal cells in long-term cultures of liver, spleen, and bone marrow at different developmental ages have different capacities to maintain GM-CFC proliferation.

Measurements were made of the granulocyte-macrophage colony-forming cell (GM-CFC) yield in long-term cultures established from different combinations of stroma and hemopoietic recharge inocula derived from hemopoietic organs at different stages of their embryological development. Results indicated differences in the supporting capacity of the stroma, related to the hemopoietic activity of the organ of origin. Stroma derived from hemopoietically active organs (adult bone marrow, neonatal spleen, fetal liver) supported the proliferation of GM-CFC to a larger extent than stroma derived from organs with a low hemopoietic activity (neonatal bone marrow liver at 2 days; spleen at 3 weeks). Regardless of the origin of the hemopoietic cells, stroma from adult bone marrow displayed the highest ability to support GM-CFC proliferation. The capacity of GM-CFC from hemopoietic recharge cell populations to proliferate on stroma was not related to the hemopoietic activity of their organ of origin. Regardless of their organ of origin the GM-CFC present in each of the different hemopoietic recharge populations were able to proliferate provided that they were seeded on an appropriate stroma. These experiments showed that stromal cells cultured from hemopoietic organs at different developmental ages determine the hemopoietic activity of long-term cultures as measured via GM-CFC recovery.

Aging↗
PubMed1990

Distribution of 241Am in offspring from BALB/c mice injected with 241Am at 14 days of gestation: relation to calcium and iron metabolism and comparison with distribution of 241Am after injection of adults.

Pregnant mice were given intravenous injections of 241Am citrate at 14 days of gestation. The fetal skeleton had a higher or similar uptake of 241Am per gram of fresh tissue than the liver. In comparison, the liver in adults concentrated 5 to 20 times more 241Am per gram of fresh tissue than the bones. Measurement of changes in calcium and iron content and concentration with time, showed that in the developing mice intensive calcification of bones determined the uptake of 241Am. The 241Am uptake was related to the calcium concentration of the fetal bones, which was greater at 14 days of gestation in the anterior bones, the mandibles and calvaria, than in the ribs and femurs. Transfer of 241Am to pups via milk resulted in further accumulation of 241Am in the skeleton and liver. The incorporation in the skeleton persisted after weaning and contributed to the lifetime body burden. The 241Am concentration decreased rapidly with time after injection in relation to the growth of the organs. Radiation dose rates and cumulative radiation doses were calculated for liver and bones of contaminated offspring.

Age Factors↗
PubMedDate not supplied

A battery of DNA effect biomarkers to evaluate environmental exposure of Flemish adolescents.

The present paper deals with the evaluation of a battery of genotoxicity biomarkers in healthy Flemish adolescents and their relation with common pollutants occurring in their life environment. DNA damage as reflected by the comet assay appeared to be most sensitive to ozone (partial r(2) = 0.102, p < 0.00001), and to a lesser extent to ortho-cresol (partial r(2) = 0.055; p = 0.001) and 1-hydroxy-pyrene (1-OH-pyrene, partial r(2) = 0.031; p = 0.013). 8-hydroxy-deoxyguanosine (8-OHdG) was only related to ortho-cresol (r(2) = 0.069; p < 0.007). Interestingly, the comet assay results and urinary 8-OHdG concentrations were positively correlated with a Pearson r = 0.21 (p = 0.003, N = 200). Logistic regression models revealed significant relations between chromatid breaks and 1-OH-pyrene (relative risk (RR): 1.58; p = 0.008), and t,t-muconic acid (RR: 1.71; p = 0.014). There was no correlation between micronucleus formation or occurrence of chromosomal or chromatid breaks on the one hand and comet or 8-OHdG results on the other hand. Thus, in this study the comet assay on whole blood samples and urine 8-OHdG measurements especially appeared sensitive biomarkers for assessing the genetic effects of environmental pollutants to which adolescents may be exposed.

8-Hydroxy-2'-Deoxyguanosine↗
PubMedDate not supplied

Health risk assessment of dioxin emissions from municipal waste incinerators: the Neerlandquarter (Wilrijk, Belgium).

Two municipal waste incinerators in the vicinity of a residential area close to the city of Antwerp caused concern to local habitants. Risk assessment was performed combining chemical, toxicological measurements and model calculations. As the first step in risk assessment an inventory was made of historic emissions from both incinerators with emphasis on dioxins. The operational atmospheric transport and deposition model for priority substances (OPS) was used to calculate the deposition of dioxins in the vicinity of incinerators. The observed soil contamination pattern did not correspond to the calculated deposition pattern, indicating that other sources may contribute at least partly to the local PCDD/PCDF contamination of the area. Dioxin exposure of people in the Neerlandquarter as a function of the food consumption behavior was calculated using a mathematical model (VLIER-HUMAAN) combined with transfer factors. According to the results of these calculations, just residing in the impact area does not result in a meaningful risk. Only if locally produced food was consumed (milk, meat and vegetables), exposure in the Neerlandquarter was enhanced compared to the average dioxin exposure estimated for the Flemish population. Exposure in 1997 was below the exposure in 1980. As a consequence of different eating habits and lower bodyweight, children are subjected to significantly higher exposure than adults. Adverse health outcomes from dioxin exposure in the past cannot be excluded. There was no evidence for enhanced exposure to genotoxicants based on a comparison of chromosomal damage to blood cells of children from the study area to those from a control group.

Adolescent↗