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Biomedical subjects

B Dutrillaux

Publications and source records attributed to B Dutrillaux.

At least 325 records · Page 18Linked to original sources
PubMed1985

[Cytogenetic study of Cercopithecus wolfi, Cercopithecus erythrotis and a hybrid Cercopithecus ascanius X Cercopithecus pogonias grayi].

The karyotypes of two species of Cercopithecus, C. wolfi and C. erythrotis, as well as that of a hybrid C. ascanius X C. pogonias grayi, are described and compared. The karyotype of C. erythrotis is similar to that of C. ascanius and C. cephus described previously. The karyotypes of C. wolfi and C. p. grayi differ by a single inversion. The karyotype of the hybrid shows that the two parental species differ by five rearrangements, three fissions and two inversions, an observation in agreement with our previous interpretation.

Animals↗
PubMed1985

[Exact localization of several fragile sites remains uncertain. The example of fra(10) sensitive to folate].

The localization of the folate-sensitive fragile site first proposed to be at 10q24.2 was further assigned to 10q23. The study of one case using several banding techniques, and of 12 other unpublished cases studied with R-banding confirm the original localization, at the junction between 10q24.1 and 10q24.2. Because many reports propose that fragile sites induce further anomalies, we suggest that a re-study of the exact location of these sites with accurate methods is in order if misinterpretations are to be avoided.

Chromosome Banding↗
PubMed1985

Consistent deficiencies of chromosome 18 and of the short arm of chromosome 17 in eleven cases of human large bowel cancer: a possible recessive determinism.

Cytogenetic study of 11 cases of colorectal carcinoma was performed after R-banding. In all instances, there was a rearrangement involving chromosome 17 in its juxtacentromeric region, leading to the loss of its short arm. There was also a relative lack of chromosome 18, unrelated to a rearrangement of this chromosome in all but one case. Other anomalies, involving chromosomes 1 and 8 among others, were frequently but not systematically observed. The consistent lack of chromosome 18 and of the short arm of chromosome 17, leading to a complete or partial monosomy of these chromosomes in near diploid cells suggests that the passage to the hemizygous status of recessive genes carried by these chromosomes may play an important role in the development of colorectal carcinoma.

Adult↗
PubMed1985

Aberrations of the synaptonemal complexes in a male 46,XY,-14,+der(14)t(Y;14).

An unbalanced translocation 46,XY,-14,+der(14)t(Y;14)(q11;p11) was observed in an azoospermic male, with reduced spermatogenesis and absent spermiogenesis. At the pachytene stage of spermatocyte 1, the segments of the 2 Y chromosomes, fluorescent with quinacrine mustard, were always found close together. This proximity was also demonstrated by the study of synaptonemal complexes, which showed, in addition, an unusual hypercondensation of the proximal segment of bivalent 14, adjacent to the translocated Y chromosome. This allows us to propose that this hypercondensation might correspond to an inactivation of the translocated autosome, which could be responsible of the degeneration of the germ cells.

Adult↗
PubMed1985

[Rearrangement of the chromosome 17 in colonic adenocarcinoma].

Chromosome studies on five cases of large bowel adenocarcinoma show a systematic rearrangement of chromosome No. 17 after breakage in its juxtacentromeric region (band 17 q 11). A frequent involvement of chromosome No. 8 (juxtacentromeric break) and the loss of chromosome No. 18 are also noticed. A review of the literature strengthens the hypothesis of a preferential involvement of these chromosomes in large bowel cancer.

Adenocarcinoma↗
PubMed1984

Characterisation of a very complex constitutive heterochromatin in two Gerbillus species (Rodentia).

A large amount of heterochromatin is observed in two species of the genus Gerbillus, G. nigeriae and G. hesperinus. The C-band material represents about one-half of the total karyotype length in the former species, and about one-third in the latter. Several banding techniques and various 5-bromodeoxyuridine (BrdU) treatments were used to characterise these heterochromatic segments. After applying the R-banding technique, three different staining responses of the heterochromatin can be distinguished. In G. nigeriae, strongly stained segments (R-band positive) appear in most chromosomes and, in particular, constitute the short arms of all the larger chromosomes. Palely staining heterochromatic segments (R-band negative) are less abundant in G. nigeriae but predominate in G. hesperinus. In addition, in both species an intermediate staining of heterochromatin is observed near the centromere or in the heterochromatic short arms of some acrocentric and small submetacentric chromosomes. Very short BrdU treatment during the end of the last cell cycle results in asymmetrical staining of chromatids in heterochromatic segments after applying the acridine orange or FPG (fluorescence plus Giemsa) technique. The alternating location of strongly staining segments in one or the other chromatid simulates sister chromatid exchanges ("pseudo-SCE"). This pattern persists after longer BrdU treatment during different stages of the last cell cycle and is independent of the R-staining properties of the heterochromatin. The lateral asymmetric appearance of the large heterochromatic segments in Gerbillus is interpreted as reflecting an uneven distribution of adenine and thymidine between the two strands of DNA.

Animals↗
PubMed1984

Diagrammatic representation for chromosomal mutagenesis studies. I. Karyotypes most similar to that of man.

In an attempt to discover which primate species have the karyotypes most similar to that of man, the chromosome numbers, the Nombre Fondamental and the numbers of chromosomal rearrangements separating the karyotypes of many species were considered. In addition to man, 6 species were selected for their karyotypic similarities and 1 for its dissimilarity. A model representing the karyotypes, by 2 diagrams, is proposed for these 8 species. These diagrams characterize each karyotype, as well as the theoretical random distribution of break-points, after the effect of a clastogenic agent. This allows one to make quantitative analyses of any type of chromosomal rearrangement, with objective criteria, and should improve the study of chromosomal mutagenesis, and particularly interspecies comparisons.

Animals↗
PubMed1984

Diagrammatic representation for chromosomal mutagenesis studies. II. Radiation-induced rearrangements in Macaca fascicularis.

A qualitative study is presented of chromosomal rearrangements induced in peripheral blood lymphocytes of Macaca fascicularis, after exposure to gamma-irradiation at 2 Gy and 3 Gy. The use of a new diagrammatic representation allowed us to compare, for each type of rearrangement, the distribution of the observed break-points with the theoretical random distribution. It was concluded that chromosomal mutagenesis does not occur at random: an excess of involvement of small chromosomes is found for dicentrics and reciprocal translocations; an excess of telomeric breaks exists in dicentrics and paracentric inversions. In our sample of 27 pericentric inversions, the larger chromosomes are too frequently involved, 2 different inversions are observed at least twice and 7 (or 8) reproduce chromosomes of other primates.

Animals↗
PubMed1984

Chromosome study of Presbytis cristatus: presence of a complex Y-autosome rearrangement in the male.

The karyotypes of a female and of a male Presbytis cristatus are analysed. In the latter, there is a complex Y-autosome rearrangement. The phyletic position of this species, in relation to genus Colobus, previously studied, is proposed, considering the sequence of chromosomal rearrangements which occurred during their evolution. These rearrangements, in addition to the t(Y-autosome), are characterized by a high frequency of inversions, and above all, by several non-Robertsonian translocations which occurred very rarely during evolution of other Primates.

Animals↗
PubMed1984

Study of chromosome lesions induced by gamma-rays during the G2 and mitotic phases of the cell cycle.

Irradiation with 2 Gy of gamma-rays was performed on synchronized human lymphocytes 5 to 120 min before harvesting in order to study chromosome sensitivity during the G2-phase and during the different stages of mitosis. It was found that chromosome lesions, consisting mostly of chromatid breaks, could be induced at any stage and that radiation must occur at least 10 min before chromosome harvest for the chromosome damage to be exhibited. Chromatid exchanges were rarely observed and required a much long lapse time between radiation treatment and harvest. The most radiation sensitive period was found to be the end of G2.

Adult↗
PubMed1984

[Great degree of homology between the ancestral karyotype of squirrels (rodents) and that of primates and carnivores].

The karyotype of 7 species of Sciurinae representative of 6 tribes were compared: Atlantoxerus getulus, Menetes berdmorei, Callosciurus flavimanus, Heliosciurus gambianus, Sciurus vulgaris, Eutamias sibiricus, and Marmota monax. Homoeologies between almost all chromosome segments were found. Numerous similarities with the karyotypes of certain Primates and Carnivora were observed. A presumed ancestral karyotype of the Sciurinae is proposed.

Animals↗
PubMed1984

[Chromosomal phylogeny of Gerbillidae. III. Species study of the genera Tatera, Taterillus, Psammomys and Pachyuromys].

The karyotypes of six species of Gerbillidae (Rodentia)--Taterillus congicus, Tetarillus sp d'Oursi, Tatera sp cf. nigrita, Tatera guineae, Psammomys obesus, and Pachyuromys duprasi--are described and compared to those of species already studied. Many chromosomal homoeologies are demonstrated, as well as the existence of many rearrangements. Some genera, e.g., Taterillus, have undergone a very complex chromosomal evolution, while others have kept their karyotypes fairly close to that of the common ancestor.

Animals↗
PubMed1984

[Tentative classification of radial figures and an evaluation of the consequences of their radiation induction].

A classification is proposed of the tri- and quadriradials, based on theoretical and observed anomalies induced by radiation. Mitotic consequences of radials during S-phase are analysed, and it is shown that the rate of induction of unbalanced rearrangements is very much higher than that of balanced ones. After extrapolation to germ cells, it can be assumed that irradiation during S-phase will induce a high risk of chromosome imbalance for progeny which will be restricted almost entirely to the first generation.

Chromosome Aberrations↗
PubMed1983

Tandem translocation t(14;14) in isolated and clonal cells in ataxia telangiectasia are different.

In a patient affected by ataxia telangiectasia (AT), an invading clone with a t(14;14) was found in PHA-, but not in pokeweed-stimulated, lymphocytes. With high resolution R-banding, the proximal breakage was visualized at the junction of bands q11.1-q11.2. This breakpoint differs from that (q12) of noninvading rearrangements of chromosome 14 in AT and non-AT patients. These differences are discussed.

Ataxia Telangiectasia↗
PubMed1983

Risk of chromosomal disease due to radiation. Tentative estimate from the study of radiation-induced translocations in human fibroblasts.

A sample of 214 reciprocal 2-break translocations observed in fibroblasts, both after accidental 'in vivo', and experimental 'in vitro' gamma-irradiation, was studied. The distribution of the breaks along the chromosomes does not seem at random. The minimal possible imbalance that these translocations could induce by malsegregation, if they existed in germ cells, was estimated. These imbalances were compared with the chromosomal trisomies and monosomies known to be compatible with life after birth in man. It is concluded that about 2/5 of the radiation-induced translocations might induce a viable trisomy and/or monosomy. This result, similar to that previously obtained in human lymphocytes, indicates the validity of the extrapolation from one tissue to another, and hopefully to germ cells.

Chromosome Aberrations↗
PubMed1983

Z-DNA immunoreactivity in fixed metaphase chromosomes of primates.

Antibodies against Z-DNA bind to fixed metaphase chromosomes of man and Cebus albifrons (Platyrrhini, Primate). By indirect immunofluorescence and indirect immunoperoxidase techniques, a heavy staining is detected in some segments of chromosomes of C. albifrons. These segments correspond to R-band-positive heterochromatin, which has a high G + C-base content. Euchromatin of human and Cebus chromosomes show a weak and heterogeneous staining that consistently reproduces an R- and T-banding pattern in both species. Because chromosome homologies previously were demonstrated between these distantly related species by chromosome banding, our results suggest that Z-DNA has been conserved during the course of primate evolution.

Animals↗