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Biomedical subjects

J Couturier

Publications and source records attributed to J Couturier.

At least 109 records · Page 6Linked to original sources
PubMed1980

The use of high resolution banding in comparative cytogenetics: comparison between man and Lagothrix lagotricha (Cebidae).

New techniques for obtaining high resolution banding are used in comparative cytogenetics. They make possible a direct comparison of the chromosomes of two distantly related primates, man and Lagothrix lagotricha (Platyrrhine). For many chromosomes, the homoeologies of banding are surprisingly clear. These new results strongly strengthen the interpretations proposed with the use of more conventional banding techniques.

Animals↗
PubMed1980

[Increase of LDH A and partial trisomy 11p (author's transl)].

An increase of LDH A activity is observed in an adolescent patient trisomic for 11p with the exception of band 11p13. The clinical syndrome is delineated: broad faces, abundant eyebrows in their internal portion, enophtalmia, hypoplasic nasal bridge, hypertelorism, epicanthus, cleft palate or lip, macroglossia, hypotrophic muscles, soft and abundant skin, mental retardation.

Abnormalities, Multiple↗
PubMed1980

Chromosomal evolution of 19 species of sub-species of Cercopithecinae.

Chromosome analysis by handling techniques of 19 species and sub-species of Cercopithecinae shows an important accumulation of chromosome rearrangements (51). With a clear predominance of fissions (26) and of inversions (17). It is impossible to reconstruct a simple genealogy of these species because chromosomal evolution did not follow the principle of a strict dichotomy. The progressive increase of the number of chromosomes, by fission, corresponds to the inverse of the Robertsonian evolution and suggests the existence of numerous interstitial centromeres and telomeres.

Animals↗
PubMed1979

Evidence for a correlation between late replication and autosomal gene inactivation in a familial translocation t(X;21).

A familial translocation t(X;21)(q2700;q11) is studied. A girl, trisomic for almost all the chromosome 21, has a mildly abnormal phenotype. A second girl, phenotypically abnormal, is monosomic for the juxtacentromeric region of chromosome 21 only. A comparison of the replication pattern and of the activity of superoxide dismutase (gene located on chromosome 21) shows a clear correlation between late replication, gene inactivation and phenotype expression of chromsome 21.

Chromosomes, Human, 21-22 and Y↗
PubMed1979

[Cytogenetics of two Lorisidae (Nycticebus coucang and Perodicticus potto). Comparison with the lemurs and the simians (author's transl)].

The karyotypes of two Lorisidae (Prosimians) Nycticebus coucang and Perodicticus potto have been studied, using many banding techniques. These karyotypes are compared with each other and also with those of Microcebus murinus (Lemur) and of Cebus capucinus (Simian, platyrrhine). The karyotype of M. murinus appears ancestral to the other. That of the Lorisidae cannot be an intermediatry stage between the karyotypes of the lemurs and of the simians. An important part (12 p. cent) of the genome of N. coucang is comprised of heterochromatin ; it and the juxta centromeric heterochromatin stain negatively with C-banding techniques. C-banding therefore is insufficient to delineate constitutive heterochromatin, late replication being the only universal criterion.

Animals↗
PubMed1979

[De novo monosomy 4q32.1 leads to 4qter in a newborn with multiple malformations (author's transl)].

In a newborn with multiple malformations, deletion 4q32.1 leads to 4qter was observed after BrdU incorporation and staining with acridine orange. The patient's phenotype and that of five children monosomic for 4qter reported in the literature define a syndrome with a high rate of mortality due to major respiratory difficulties, laryngeal hypotonia and oedema, and complex congenital heart malformations.

Abnormalities, Multiple↗
PubMed1978

Identity of euchromatic bands from man to cercopithecidae (Cercopithecus aethiops, Cercopithecus sabaeus, Erythrocebus patas, and Miopithecus talapoin).

The karyotypes of four species of Cercopithecidae: Cercopithecus aethiops tantalus, C. sabaeus, Erythrocebus patas, and Miopithecus talapoin are analysed with nearly all the banding techniques. They are compared with each other, and with the karyotypes of the Baboon P. papio and with that of man. It can be concluded that the quasi-totality or the totality of the euchromatin is common to all, but has undergone structural rearrangements, generally detectable. The heterochromatin, defined by C-band staining, and late-replicating DNA, in contrast, appears very variable: In particular, E. patas has acquired very large heterochromatic segments. The significance of these modifications is discussed.

Animals↗
PubMed1978

Human somatic chromosome chains and rings. A preliminary note on end-to-end fusion.

Chain and ring chromosome configurations were detected in a small percentage of the lymphocytes of a patient suffering from Thiberge-Weissenbach syndrome. Precise recognition of the chromosomes involved in the rearrangements did not indicate a systematic order of end-to-end fusions. A relationship between these configurations and the chromosome arrangement in the interphase nucleus is possible.

Calcinosis↗
PubMed1978

[Presence of abundant heterochromatin in the karyotype of Cebus: C. cappucinus and C. nigrivittatus].

The karyotypes of Cebus capucinus and C. nigrivittatus (Primates, Platyrrhini) are compared after applying several banding techniques. The chromosomes have abundant intercallary heterochromatin which can be stained by R-, T- and C-band techniques and which are late replicating. The X chromosome resembles that of man and of numerous primates. However, the late replicating pattern of the X in female lymphocytes resembles that of the late replicating X of human fibroblasts rather than of human lymphocytes. Banding patterns of certain chromosomes appear analogous in Cebus and Cattarhini, including Man.

Animals↗
PubMed1978

[Chronology of the replication of sex chromosome bands in lymphocytes of normal subjects and patients].

The replication sequence of the bands carried by chromosomes X and Y has been studied in normal individuals and in patients with structural abnormalities of the X. By comparing the segment with that of the autosomal bands (which had been previously studied), it was shown that the normal early X replicates in early X-phase for its R-bands and in late S-phase for its Q bands. The late X replicates entirely in late S-phase, and the sequence of band replication is not as stringent as for the early X and the autosomes. The study of fourteen cases of anomalies of chromosome X in females showed the following: in balanced reciprocal X-autosome translocations the rearranged X most often replicates early and the normal X late. Both show a normal replication sequence of their bands. In non-balanced X-autosome translocations, inactivation of the autosome fragment attached to the AUTOSOME FRAGMENT ATTACHED TO THE X may take place. In Xq- or in ter rea (X;X) (pter;pter), band p22 has a delayed replication. In iso-Xor Xp-, the long-arm-band sequence of replication shows a variation comparable to that of the late X in fibroblasts. These replication modifications are likely to induce partial inactivations or changes in activity which correspond to the so-called position effect in Drosophila.

DNA Replication↗
PubMed1977

Localization chromatid breaks in Fanconi's anemia, using three consecutive stains.

The location of 339 break points was analyzed in three patients with Fanconi's anemia, using three consecutive stains: ordinary Giemsa, Q-banding, and R-banding. Almost all the breaks seem to take place in the Q bands, using R-banding, and in the R bands, using Q-banding. A very important artifact, varying according to the method used, is thus demonstrated. In fact, the breaks take place in the interbands, between R and Q bands. The breaks were also localized in relation to sister chromatid exchanges (SCEs), seen after BUDR treatment. There is a clear excess of breaks at place of SCE (29%). This may indicate a possible correlation between breaks and SCEs.

Anemia, Aplastic↗
PubMed1977

[Possible localization of the glutathione reductase (EC 1.6.4.2) on the 8p21 band].

Glutathione reductase (EC 1.6.4.2.) (GSR) activity was measured in the red cells of patients with different rearrangements of chromosome 8. Of three patients with mosaic trisomy 8, two had a high GSR activity. The lack of correlation between GSR levels and the degree of mosaicism in lymphocytes is discussed. In six patients with trisomy 8qter the mean value of GSR activities was normal. In one patient with trisomy pter leads to q22.1 and in two with trisomy p11 leads to p22, a significant increase (+60%) of GSR activity was observed. In two patients with monosomy p22 leads to pter and p21 leads to pter, respectively, the GSR levels were normal. It is concluded that the gene locus of GSR can be assigned to the 8p11 leads to p22 segment. A comparison of these results with one other case from the literature suggests a more precise assignment of the GSR locus to band p21.

Chromosome Mapping↗
PubMed1977

[Chromosome 8 : complete trisomy and segmental trisomies].

The phenotypic effects of trisomy of various segments of chromosome 8 have been recognized through the analysis of twelve different patients: five mosaic cases of trisomy 8, one case of trisomy for the short arm and the proximal segment of the long arm, two cases of trisomy for a portion of the short arm, and four cases of trisomy for the terminal segment of the long arm. Analysis of the data from the literature and of these personal observations allows the definition of three syndromes: trisomy 8, trisomy 8p and 8q proximal, and trisomy 8q terminal. Three clinical signs are common to the three syndromes: vertebral anomalies, depression of the mesosternum, and bulging of the forehead. This suggests that different segments of chromosome 8 carry genes affecting osseous growth. Trisomy 8p causes, in addition to severe mental deficiency, a thick nose, a large mouth, and microcephaly. Other clinical signs can be assigned to three groups corresponding to the short arm, the proximal part, and the distal part of the long arm.

Abnormalities, Multiple↗
PubMed1977

[Partial trisomy for the long arm of chromosome 2 due to malsegregation of a maternal insertion : ins(6;2)(p22;q24q34)].

A 6p+ chromosome was observed in a dysmorphic and mentally retarded child. The mother was found to be carrier of an insertion: ins(6;2) (p22;q24;q34). The patient was therefore trisomic for 2q24 leads to 2q34. The same insertion was found in his brother in the balanced state. A comparison of this observation and four other cases from the literature allows a description of the symptoms characteristic of trisomy 2q24 leads to 2q34 : mid-face hypoplasia, carp-shaped mouth, neurological disorders, severe mental retardation.

Child↗
PubMed1977

[Ring of the chromosome 4. I - With 4p- phenotype].

A ring chromosome derived from a No. 4 chromosome was found in the complement of an 8-year-old boy with mental retardation and growth retardation and developmental defects characteristic of 4p deletion. Break points were at 4p15 and 4q35.

Abnormalities, Multiple↗
PubMed1976

Sequence of DNA replication in 277 R- and Q-bands of human chromosomes using a BrdU treatment.

Replication times for all important chromosome bands, of both types R and Q (277 structures) are analysed. The R-bands form a group of structures whose DNA replicates during the early S-phase, while the DNA situated in the Q-bands replicates during the late S-phase. There may not exist overlapping between replication times of these two types of structures. The widest R-bands are those which are the earliest to replicate; in general, the most intense Q-bands are those which are the latest to replicate. Especially among these last ones, a certain asynchronism exists between the replication times. Finally the heterochromatin of chromosomes 1, 16 and Y and of the short arms of the acrocentrics could contain two types of DNA which replicate at different times.

Bromodeoxyuridine↗