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Biomedical subjects

C Laurent

Publications and source records attributed to C Laurent.

At least 199 records · Page 11Linked to original sources

Sister chromatid exchange frequency in workers exposed to high levels of ethylene oxide, in a hospital sterilization service.

Blood samples were taken from a group of 25 subjects professionally exposed to high levels of ethylene oxide (EO) during the past two years; the samples were compared to those from 22 control subjects, using sister chromatid exchange (SCE) methodology. The quantity of ethylene oxide inhaled during the two previous years was subsequently evaluated to fall between 500 and 5800 mg. When compared with the control group, the exposed group demonstrated a significant increase in the SCE rate. For certain individuals, the rate of increase rose 100% beyond the control mean. Smoking habits significantly influenced the data observed for the control group, but no significant differences in the SCE rate were found for the exposed group, regardless of smoking habits. Senior workers had the highest SCE mean levels. This observation indicated that the effect of exposure to EO was sufficient to produce a genetic reaction, was cumulative and in some cases persistent.

Air Pollutants, Occupational↗

Catalase determination in various etiologic forms of Wilms' tumor and gonadoblastoma.

We have previously mapped the gene coding for catalase to 11p13 by gene dosage analysis. Deletion of this chromosomal region causes aniridia, mental retardation, and predisposition to Wilms' tumor (WT). In the present study, 22 patients with various etiologic forms of WT and/or aniridia were investigated. The catalase (CAT) level and karyotype were examined in order to determine the linkage and the gene ordering on chromosome number 11 of the different loci involved. The CAT concentration was normal in the 19 cases without detectable chromosomal abnormalities.

Adolescent↗

[Syndrome of terminal deletion of the long arm of chromosome 4. Apropos of a personal case with a review of the literature].

With one personal case and thirteen cases from literature about distal deletion of the long arm of chromosome 4 (4 q-), authors try to describe a clinical syndrome related to deletion of segment 4 q 31 leads to q ter. This syndrome includes a normal intrauterine growth, a growth and mental retardation. Morphological abnormalities consist in microcephaly, palato-cheiloschisis with micrognathia, hypertelorism with epicanthald folds, large nose bridge with anteverted nases, various anomalies of ears; clinodactily of Vth finger and toe, various cardiac defects. New banding techniques (prometaphase) have led to more precise delineation of break point, but this very distal deletion could not bring any new information for the gene mapping.

Abnormalities, Multiple↗

[Increased frequency of sister chromatid exchange in persons occupationally exposed to ethylene oxide].

Mutagenic effects of ethylene oxide have been demonstrated by short-term testing in vitro and in vivo in several organisms. Its oncogenic activity for man has been suspected and recently supported by experiments in mice. Exposure can occur during ethylene oxide gas sterilization of medical materials. We have tested effects on chromosomes by estimating sister chromatids exchange (SCE) frequency. Our results, reported here, show that exposure to this substance during work is followed by a very highly significant increase of SCE frequency as compared with controls. Thus, the SCE test may, under particular conditions, represent a reliable test for exposure to certain toxic agents.

Adult↗

The use of surface spreading in the pachytene analysis of a human t (Y;17) reciprocal translocation.

This paper describes a human Y;17 reciprocal translocation in an azoospermic male ascertained through infertility. Meiotic studies made on both air-dried and surface-spread preparations are reported in addition to a somatic chromosome analysis carried out by high resolution R-banding on pro-metaphase chromosomes. The possible cause of spermatogenic disturbance in Y-autosome heterozygotes is discussed.

Chromosome Aberrations↗

[Cytogenetic effects of ethylene oxide poisoning].

Mutagenic effects of ethylene oxide have been demonstrated by short-term testing in vitro and in vivo in several organisms. Oncogenic activity in human has been suspected and recently supported by experiments in mice. Exposure can occur during ethylene oxide gas sterilization of medical materials. We have tested effects on chromosomes by evaluative sister chromatids exchange frequency. A statistically significant increase in the rate of SCE has been observed in workers exposed occupationally to ethylene oxide, compared with controls.

Adult↗

[Gonadic dysgenesis and dicentric chromosome Y. A report of two cases, one of which had a gonadoblastoma (author's transl)].

The authors report two new cases of primary amenorrhoea due to the presence of a dicentric Y with a chromosome formula of 45,X/46,X,dic(Y). These two patients show how variable the clinical manifestations of these gonosome anomalies can be, since one had a Turner's syndrome and the other is a woman who looks completely normal but only has primary amenorrhoea. A review of the literature has brought to light only 45 cases similar to ours and shows the different clinical aspects of these patients who are 45,X/46,Xdic(Y). Finding that one of our patients had a gonadoblastoma has confirmed the need to carry out bilateral castration when there is a dysgenetic gonad with a Y chromosome, in order to treat or prevent a dysgenetic tumour from arising.

Adult↗

Comparison of the karyotypes of four Cercopithecoidae: Papio papio, P. anubis, Macaca mulatta, and M. fascicularis.

The karyotypes of two species of baboons, Papio papio and P. anubis, and of two species of Macaca, M. mulatta and M. fascicularis, are compared after the use of numerous banding techniques. No difference was detected between the karyotype of the two Papio species. However, a minor change in the T-staining of a short segment, probably heterochromatic, could be detected between the Papio species and M. mulatta. A paracentric inversion exists between these three and M. fascicularis. These karyotypes are briefly compared with those of the Pongidae and man. The value of the karyotypic criteria and of the methods used for taxonomy is discussed.

Animals↗

[7 cases of trisomy 2q34 leads to 2qter resulting from a familial t(2;8)(q34;23)].

Seven patients from two different families are trisomic 2q34 leads to 2qter due to segregation of a familial t(2;8)(q34;p23). The clinical features are characteristic: microcephaly, a narrow forehead with bossing and temporal retraction, hypertelorism, palpebral fissures slanted downwards, large irides, and a very concave margin of the lower eyelid. Mental retardation is severe with a mean IQ of 50.

Abnormalities, Multiple↗