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Biomedical subjects

G Deknudt

Publications and source records attributed to G Deknudt.

At least 37 records · Page 2Linked to original sources
PubMed1980

[Repair of chromosomal aberrations in a human peripheral blood lymphocyte system after single and split-dose x-irradiation].

Whole human peripheral blood was exposed either acutely to 125 or 250 R X-rays or in fractions to 125+125 R X-rays at varying cell cycle times, namely, 0, 2, 4, 6, 8, 12, 16, 24, 30, 40 or 45 hours after culture initiation. Well spread metaphase chromosomes were examined for the following types of structural chromosome aberrations: dicentrics, rings, interstitial deletions, symetrical translocations, chromatid and chromosome fragments. Most noteworthy were found to be the polycentric + ring data. With acute radiation given at any of the times over the presynthetic period, the yields of these aberrations were consistently within the range of 17-20% for the 125 R dose and 66-73% for 250 R. For either acute dose given at later times, the aberration yields decreased to fall to 1% by the end of the synthetic period. With fractionated 125+125 R exposures the following rates were obtained: irradiation at 2 hr time in culture, 44.15%; 4 hr, 50.82%; 6 hr, 55.16%; 8 hr, 58,32% (peak rate): 12 hr, 55.48%. The downward trend persisted to the end of the presynthetic period and during the synthetic period. Statistical data treatment indicated acute and fractionated exposures to differ significantly in production of polycentric+ring yields, as well as in those of other aberration types and total breakage per cell. It may be concluded from our findings that the time course of repair processes is of an undulated pattern, with peak intensity within the first hours of the presynthetic period, a fall by 8 hr and a following renewed rise; repair was found to occur nearly to the end of the synthetic period.

Cell Cycle↗
PubMed1980

[Chromosome aberrations in human peripheral blood lymphocytes after single and split-dose x-irradiation].

Effects of single exposures to 125 or 250 R and those of fractionated irradiations of 2.125 R on human lymphocytes were studied upon the chromosome aberration yields in blood maintained in a refrigerator at 5 degrees C for the intervals between the irradiations. Single irradiations succeeded venepuncture; the same holds for the first dose from the fractionated one, while he second was delivered at one of the following intervals: 2.8 or 24 hours. Immediately after completion of irradiation, blood was cultured to obtain metaphase slides for cytogenetic analysis. No repair processes were observed in the hereditary cell structures of fractionatedly irradiated blood if it was maintained at 5 degrees C for the intervals between irradiations. More chromosomes fragments, interstitial deletions, aberrant cells, and breakage of cells were scored, on the opposite, in fractionatedly irradiated blood, which was stored for 24 hours. These were even with high statistically significant differences when compared with singly exposed cells to the same doses. This effect was likely to be due to blood stirage.

Chromosome Aberrations↗
PubMed1979

Chromosomal aberrations in bone-marrow cells of mice given a normal or a calcium-deficient diet supplemented with various heavy metals.

Mice kept on a normal (1.1% calcium) or low-calcium (0.03%) diet were exposed for one month to zinc chloride (0.5% Zn), lead acetate (0.5% Pb) or cadmium chloride (0.06% Cd) or to a mixture of these salts at half the above concentrations. These concentrations, given in a poor calcium diet, represent an LD 50/30 days. After the mice were killed bone-marrow cells were assayed for chromosomal aberrations, and serum calcium was determined. Chromosomal aberrations were detected in the mice maintained on a low-calcium diet and exposed to lead, zinc or a mixture of lead, zinc and cadmium. The possible mechanism for the synergistic action on genetic effects of the lack of calcium and intoxication by heavy metals are discussed, and it is recommended that routine attention be given to the state of calcium metabolism in heavy-metal intoxication.

Animals↗
PubMed1978

Chromosome studies in human lymphocytes after in vitro exposure to metal salts.

The toxic concentration of different heavy metal salts was determined in normal stimulated human lymphocyte cultures and was found to be 3 X 10(-3), 1 X 10(-2) and 5 X 10(-4) for zinc chloride, lead acetate and cadmium chloride respectively. Furthermore 3 subtoxic doses of each salt (2, 10 and 100 times less than the toxic dose) were added to 48- and 72-h cultures at 0 h and 24 h after initiation. Chromosome preparations were made and 100 well spread metaphases from each culture were analysed for the presence of numerical and structural aberrations. The most common aberration found for all tested metal salts was the occurrence of chromosome fragments. Dicentric chromosomes were only recorded in lymphocyte cultures treated with the lowest concentration of zinc chloride (3 X 10(-5) M) added at time 0, regardless whether the cultures were fixed after 48 or 72 h.

Cadmium↗
PubMed1977

Chromosomal abnormalities in lymphocytes from monkeys poisoned with lead.

Cynomolgus monkeys (Macaca irus) were given 0, 1.5, 6 or 15 mg of lead acetate 6 days a week for 16 months. Another group, also receiving 6 mg, was kept on a low-calcium diet. Each experimental group consisted of 2 monkeys. Chromosome analysis on cultured lymphocytes was carried out after 3, 10 and 16 months of lead treatment. The frequency of severe abnormalities (dicentrics, rings, translocations and exchanges) was significantly increased only in the group on a low calcium diet, whereas "light" abnormalities (gaps and fragments) increased with time in all groups receiving lead irrespective of the diet. The blood lead data indicate the severity of the lead poisoning.

Animals↗
PubMed1977

Chromosomal aberrations in workers professionally exposed to lead.

Chromosomes in cultured lymphocytes from the following groups were analyzed: 16 workers from a smelting plant for storage batteriers in Lyon, France; 7 workers from a factory where tin dishes are made at Nerem, Belgium; and 20 controls. The choice of the workers was made on the basis of either elevated blood lead (Lyon) or elevated urinary delta-aminolevulinic acid (Nerem). An increased number of severe aberrations--rings and dicentrics--were detected in the persons from Lyon, whereas no such aberrations but an increased number of fragments were seen in those from Nerem.

Belgium↗
PubMed1977

Hereditary anophthalmia in the progeny of an X-irradiated female rat.

Inherited anophthalmia was observed in the progeny of a female rat irradiated with 50 R of X-irradiation at 17 days of age. Observations on the inheritance of the condition indicated that this anophthalmia can be considered as the result of polygenic factors with incomplete penetrance.

Animals↗
PubMed1975

Cytogenetic investigations on leucocytes of workers from a cadmium plant.

Chromosome analysis has been performed on workers from a cadmium plant who were exposed to fumes and dust of cadmium and lead. The 35 workers were classified, according to the type and duration of exposure, into a group (cadmium service) exposed to high levels of lead and cadmium in the absence of zinc (23 people) and a group of rolling-mill workers subjected mostly to zinc but also to lower levels of lead and cadmium (12 people). A higher yield of severe chromosome anomalies (chromatid exchange, disturbance of spiralization, chromosome translocation, ring and dicentric chromosomes) together with a total lower number of structural aberrations was observed in the cadmium workers when compared with the rolling-mill group.

Adult↗