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Biomedical subjects

B Lejeune

Publications and source records attributed to B Lejeune.

At least 109 records · Page 6Linked to original sources
PubMed1984

Evidence for homologous recombination between repeated sequences containing 18S and 5S ribosomal RNA genes in wheat mitochondrial DNA.

Closely linked genes for 18S and 5S rRNAs have been located on four different cloned SalI restriction fragments of wheat (Triticum aestivum L.) mitochondrial DNA. Restriction analysis has revealed that in each of the cloned fragments, the 18S and 5S rRNA genes are contained within the same basic structural unit, R, which is at least 4 kbp long. This unit is flanked by sequences designated u (0.8 kbp), v (13.7 kbp), w (0.7 kbp), and y (1.4 kbp), in the orientations v-R-w, v-R-y, u-R-w, and u-R-y in the four different SalI fragments. We conclude that 18S + 5S rRNA genes are located at several distinct sites in the wheat mitochondrial genome, and suggest that reciprocal intra- and/or intermolecular recombination between such repeated sequences could promote extensive genomic rearrangement and thus contribute to the physical heterogeneity that is a hallmark of most plant mitochondrial DNAs.

Journal Article↗
PubMed1983

Salmonella-infected subdural haematoma.

Post-traumatic chronic subdural haematoma infected by Salmonella sandiego is reported in a 55-year-old alcoholic man. Treatment involved a four-weeks' course of chloramphenicol and also subdural drainage. The patient ultimately recovered. Only four such cases have been reported in the literature. The mode of infection of the subdural haematoma is presumed to have been haematogenous in the absence of an otorhinological focus, meningitis or previous neurosurgery.

Chloramphenicol↗
PubMed1983

[Evaluation of 80 virologically-confirmed cases of ocular herpes. Study of the correlation between the type of virus and the epidemiologic characteristics of the disease].

80 strains were isolated from patients with herpetic ocular infection during the period May 1979 to May 1981: 17 patients with herpetic blepharitis, 40 patients with superficial keratitis and 23 with deep stromal keratitis or kerato-uveitis. Among 63 patients treated with antiviral agents, clinical resistance to the drug was observed in 17 cases. The strains were typed as HSV 1.1, 1.2 or 2.2 by seroneutralization and thermosensitivity in cellular cultures. No relationship between the viral types and the patient age, previous history of corticosteroid therapy and the response of ocular lesions to antiviral treatment were detected. It appeared that there was a relationship between the viral type and the clinical type of infection: 70% of herpetic blepharitis and 83% of superficial keratitis were due to HSV 1.1 while 71% of stromal keratitis were due to HSV 1.2. No HSV 2.2 was isolated. These results seem to support the hypothesis that genetic differences between herpetic virus strains may determine their virulence.

Adult↗
PubMed1982

[Accidental localized vaccinia. A report of six recent cases (author's transl)].

Vaccination against smallpox should be discontinued in all countries except for individuals with a high risk of exposure (WHO, 1980). Since this vaccination is performed less and less often, one must expect complications to occur, the etiology of which may not be recognized. This course of events leads the authors to point out the difficulties in diagnosis and therapy of localized accidental vaccinia encountered in six patients hospitalized in Brest (1971-1979). Diagnosis is considered if the patient himself, or a person he came in contact with, was recently vaccinated. Diagnosis should always be established by virology. Such accidents can be avoided by a faultless vaccination technique and by giving sufficient information to the inoculated subject or to his relatives.

Adolescent↗
PubMed1982

Satellite versus total DNA replication in relation to endopolyploidy of decidual cells in the mouse.

In rodents, decidualization produces large endopolyploid cells. Amongst the various endocycles which have been demonstrated in animals and plants, different modes of DNA replication have been characterized: either total reproduction of all DNA types, or else, underreplication or amplified synthesis affecting specific parts of the genome. A double labelling method was used to determine to which of these categories the case of decidual cells belongs. A mixture of purified DNA from hormonally-stimulated control endometrium labelled by 3H-thymidine and from decidua labelled by 14C-thymidine was ultra-centrifuged to equilibrium in a Cs2 SO4-Ag gradient. Optical density at 260 nm and 14C/3H ratio were evaluated in serial fractions along the gradient. Since the 14C/3H ratio did not significantly vary along the gradient, it may be concluded that in the case of decidual cells, endopolyploidy corresponds to uniform replication of all nuclear DNA.

Animals↗
PubMed1982

Changes in the pattern of endometrial protein synthesis during decidualization in the rat.

Ovariectomized rats were given hormonal treatment mimicking progestational ovarian secretions. At maximal sensitivity a decidual reaction was induced by scratching the endometrium. After incubation of tissue with [35S]methionine, proteins were extracted from decidualizing and control endometrium and submitted to two-dimensional polyacrylamide gel electrophoresis (pH range 5--7), followed by staining or autoradiography. A total of about 800 different peptides could be distinguished on the gels. By 24 h after the decidual stimulus the most prominent changes were the appearance of 4 new peptides (mol. wt 12 000, 25 000, 42 000 and 56 000) and the disappearance of 5 others (mol. wt 31 000, 35 000, 100 000, 110 000 and 140 000). This new pattern remained grossly unchanged up to 72 h after decidual induction.

Animals↗
PubMed1982

Induction of implantation in the rat by intraparametrial injection of uterine RNA from oestrogen-treated animals.

Crude RNA preparations from uteri of oestradiol-treated rats induced the implantation of delayed blastocysts when injected into the parametrium of ovariectomized pregnant rats. Treatment of donor animals with labelled oestradiol showed that this effect could not be due to contamination of the RNA extracts by oestradiol. RNase digestion of these extracts suppressed their capacity to induce implantation. Purified poly (A)-rich RNA from oestrogen-treated uteri failed to elicit implantation although it was capable of increasing epithelial height when repeatedly injected into uterine horns of ovariectomized rats. These results suggest that uterine RNA synthesis might somehow mediate the effects of oestrogen in causing implantation and that RNAs other than messenger RNA might be involved.

Animals↗
PubMed1981

Regeneration of uterine epithelium after experimental ablation in the rat.

Regeneration of the uterine luminal epithelium was studied after its mechanical removal in progesterone-primed rats, leaving one control horn intact. Pulse labelling with [3H]TdR during regeneration, showed a rapid peak of labelling index in remaining glands. A differentiated and highly labelled luminal epithelium reappeared at 34 hr, thereafter showing a rapidly declining LI. After initial depletion, the glandular cell population size was restored within 64 hr, whereas luminal epithelium cell numbers became stabilized at about half normal level. Grain counts after prelabelling showed more rapid dilution in gland cells of stripped uterine horns, indicating accelerated cycling of previously dividing cells. Thymidine labelling indices also showed that, after removal of the epithelium, almost all gland cells became rapidly committed to divide. On average, less than two cell cycles were necessary to restore stable glandular and epithelial population sizes. Numbers of labelled cells were also drastically increased in myometrium and serosa of treated horns. This suggests a non-specific mechanism for stimulation of mitotic activity after ablation of epithelium.

Animals↗
PubMed1981

Transmitter role of the luminal uterine epithelium in the induction of decidualization in rats.

Ovariectomized rats were given hormonal treatment mimicking progestational ovarian secretions. At maximal uterine sensitivity, the luminal epithelium was squeezed out of one or both horn(s) transected at the isthmus. Simultaneous bilateral scratching and saline injection induced virtually no response in stripped horns while contralateral intact horns exhibited a maximal decidual reaction (DCR). The luminal epithelium regenerated after ablation and a 65% DCR was again elicited after 9 days. The inability of de-epitheliated horns to decidualize was not overcome by intraluminal injections of the supernatant or sediment of the 60 000 g homogenate of epithelium, PGF-2 alpha, PGE-2, arachidonic acid or histamine. Detachment of the epithelium without removal also prevented DCR induction. These results indicate that the luminal epithelium is an obligatory transmitter of the stimulus to DCR and cannot be by-passed by trauma. Release of the appropriate epithelial message to the stroma requires local preservation of membrane relationships between both tissues.

Animals↗