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Biomedical subjects

M Roussel

Publications and source records attributed to M Roussel.

At least 55 records · Page 3Linked to original sources
PubMed1982

[Agnathia, apropos of a case].

A male 32 weeks still-born with agnathia is reported. Other malformations are pointed out: microstomia, microglossia, type III microtia and meatal atresia. There are vertebral clefts of D7 et D10. Probands and parents chromosomal analysis are normal. Mother is 28 years old, gravida 7, para 3 and father is 46 years old. They are algerian, healthy, non related. A single one male child is alive and in good health.

Abnormalities, Multiple↗
PubMed1981

Characterization of the oncogene (erb) of avian erythroblastosis virus and its cellular progenitor.

Avian erythroblastosis virus (AEV) induces primarily erythroblastosis when injected intravenously into susceptible chickens. In vitro, the hematopoietic target cells for transformation are the erythroblasts. Occasional sarcomas are also induced by intramuscular injection, and chicken or quail fibroblasts can be transformed in vitro. The transforming capacity of AEV was shown to be associated with the presence of a unique nucleotide sequence denoted erb in its genomic RNA. Using a simplified procedure, we prepared radioactive complementary DNA (cDNAaev) representative of the erb sequence at a high yield. Using a cDNAaev excess liquid hybridization technique adapted to defective retroviruses, we determined the complexity of the erb sequence to be 3,700 +/- 370 nucleotides. AEV-transformed erythroblasts, as well as fibroblasts, contained two polyadenylated viral mRNA species of 30 and 23S in similar high abundance (50 to 500 copies per cell). Both species were efficiently packaged into the virions. AEV-transformed erythroblasts contained additional high-molecular-weight mRNA species hybridizing with cDNAaev and cDNA5' but not with cDNA made to the helper leukosis virus used (cDNArep). The nature and the role, if any, of these bands remain unclear. The erb sequence had its counterpart in normal cellular DNA of all higher vertebrate species tested, including humans and fish (1 to 2 copies per haploid genome in the nonrepetitive fraction of the DNA). These cellular sequences (c-erb) were transcribed at low levels (1 to 2 RNA copies per cell) in chicken and quail fibroblasts, in which the two alleged domains of AEV-specific sequences corresponding to the 75,000- and 40,000-molecular-weight proteins seemed to be conserved phylogenetically and transcribed at similar low rates.

Alpharetrovirus↗
PubMed1981

[Not Available].

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Biology↗
PubMed1980

Cell transformation by avian defective leukaemia viruses.

A comparative study of seven independently isolated defective leukaemia viruses has been carried out. Phenotypic analysis of the chicken bone marrow cells transformed in vitro allowed the separation of these seven viruses into three groups based on the differentiation phenotype of the transformed cell. Nucleic acid hybridization studies revealed that these seven viruses had acquired cellular sequences. Interestingly, these studies also showed that the viruses within the same biological grouping had acquired related sequences. This indicates that viruses that have acquired the same or similar cellular sequences have very similar oncogenic capabilities. Analysis of proteins expressed in cells transformed by these viruses demonstrated that the cellular sequences were usually inserted within the gene for the viral core proteins, gag. Therefore the cellular sequences are expressed as a gag-related fusion protein which has an amino-terminal region derived from the gag gene and a carboxy-terminal half derived from the cellular sequences. Two exceptions to this are discussed. The general conclusion from these studies is that defective leukaemia viruses transform cells by virtue of acquired host cellular sequences. The ability of these viruses to transform cells and the target cell specificity of the transformation depends on these cellular sequences.

Alpharetrovirus↗
PubMed1980

[Origin of the transforming genes in avian acute leukemia retroviruses].

The avian defective leukemia viruses are recombinants between an avian virus of low oncogenicity and specific host nucleotide sequences. The types of hematological neoplasms correlate with the specificity of the sequences transduced. These could be differentiation genes escaping cellular control after their transduction by the virus.

Acute Disease↗
PubMed1979

Three new types of viral oncogene of cellular origin specific for haematopoietic cell transformation.

The RNAs of seven replication-defective leukaemia virus (DLV) strains contain three types of unique sequences, which correlate with the capacity of a given virus strain to transform erythroblasts, macrophage-like cells and myeloblasts, respectively. These sequences, termed erb, mac and myb, have their counterparts in the normal DNA of avian and mammalian species. Our results indicate that DLVs represent recombinants between a common 'vector' related to a chicken endogenous virus and one of three types of cellular gene possibly involved in haematopoietic differentiation.

Avian Leukosis Virus↗
PubMed1979

The distribution of endogenous chicken retrovirus sequences in the DNA of galliform birds does not coincide with avian phylogenetic relationships.

The chicken is a domesticated form of Red Jungle-fowl (Gallus gallus), which belongs to the Pheasant family (Phasianidae) within the order Galliformes. Domestic chickens carry the genome of the endogenous retrovirus RAV-O as DNA sequences integrated into host chromosomes transmitted through the germ line. We have examined the presence and distribution of RAV-O-related sequences in the DNA of Red Junglefowl and other closely related species of Junglefowl, as well as more distantly related Pheasants and Quail. DNA sequences homologous to RAV-O were analyzed by molecular hybridization in liquid and after electrophoresis of restriction endonuclease fragments. The presence of RAV-O-related sequences in avian DNA does not correlate with phylogenetic relationships. Under stringent conditions of hybridization in liquid, DNA sequences homologous to RAV-O cDNA were detected at high levels (greater than 80% homology( only in the genomes of the domestic chicken and its phylogenetic ancestor, the Red Junglefowl (Gallus gallus). The DNA of two other species of Gallus (G. sonnerati, Sonnerat's Junglefowl and G. varius, Green Junglefowl), of Ring-necked Pheasant and of Japanese Quail contained sequences with less than 10% homology to RAV-O cDNA. Under conditions permitting mismatching, however, Ring-necked Pheasant DNA hybridized up to 50% of the RAV-O cDNA, and Quail DNA 24%, whereas the extent of hybridization to Sonnerat's and Green Junglefowl DNA was not markedly increased. Analysis of restriction enzyme digests revealed several distinct fragments of DNA hybridizing to chick retrovirus cDNA in both Red Junglefowl and domestic chicken, and multiple fragments in DNA from two species of Phasianus. No fragments with sequences related to chicken retroviruses were found, however, in digests of DNA prepared from Sonnerat's, Ceylonese and Green Junglefowl, from two other Pheasant genera (Chrysolophus and Lophura), or from one Quail genus (Coturnix). Thus the DNA of three Junglefowl species closely related to Gallus gallus lacked RAV-O sequences while the DNA of more distantly related Phasianus species showed significant homology. These results show that RAV-O-related sequences have not diverged together with the normal host genes during the evolution of the Phasianidae. Although RAV-O sequences are endogenous in all domestic chickens and Red Junglefowl studied thus far, it appears that the RAV-O genome has been introduced relatively recently into the germ line of Gallus gallus, following speciation but before domestication, and independently of the related sequences found in members of the genus Phasianus.

Alpharetrovirus↗
PubMed1977

[Viral RNAs from cells infected by an oncornavirus. I. Characterization of viral RNAs associated with cytoplasmic particles].

Oncornaviral particles on the way of their synthesis have been isolated from cytoplasm of a Friend virus-producing murine cell line. By use of electron microscopy and retrotranscriptase assay, it was found that the majority of the viral structures is pelleted by sedimentation at 90.000 g. The Poly (A) RNA of this pellet contains principally 70S and 35S RNA species which, as judged by size determination and hybridization with Friend-virus c-DNA are the species embedded into the virions. We verified that conditions which were used in the course of isolation, effectively dissociate polysomes and prevent them from co-sedimenting with viruses.

Cell Line↗
PubMed1976

[Not Available].

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Animal Population Groups↗
PubMedDate not supplied

Epileptic nystagmus: electroclinical study of a case.

Epileptic nystagmus (EN) is a rare form of nystagmus that occurs only during epileptic seizures. We report a case in which EN was first noted in an 8 year-old boy. Neuro-imaging was normal. Sharp waves from the left occipital lobe characterised the interictal EEG. Ictal video-EEG showed the aspects of electric seizures during clinical manifestations e.g. nystagmus. Ambulatory EEG displayed numerous diurnal and nocturnal seizures, but exclusively in REM sleep. After two weeks of sodium valproate treatment, the seizures, EEG focus spikes and nystagmus, as well as the squint, disappeared. During a two-year follow-up the child had no further seizures, EEG was normal and the school performance was unaffected. This case has the main features of benign epilepsy, although there are unusual features such as epileptic nystagmus, permanent squint, reduction of EEG paroxysmal abnormalities during NREM, and the presence of seizures during REM sleep. The observation and the significance of EN are discussed with reference to the literature.

Anticonvulsants↗