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Biomedical subjects

B Lejeune

Publications and source records attributed to B Lejeune.

At least 91 records · Page 5Linked to original sources
PubMed1988

Molecular epidemiology of two consecutive outbreaks of adenovirus 8 keratoconjunctivitis.

Eleven strains of adenovirus 8 (Ad 8) isolated during two consecutive outbreaks of epidemic keratoconjunctivitis (EKC) in the Ophthalmology Department of a University Hospital in France were compared by DNA restriction analysis. The results indicated that isolates from the two outbreaks belong to the same genome type, which is also the most predominant genome type of Ad 8. The usefulness of molecular epidemiology in Ad 8 infections is briefly discussed.

Adenoviridae Infections↗
PubMed1988

Early pregnancy loss and obstetrical risk after in-vitro fertilization and embryo replacement.

Between March 1983 and March 1986, 108 pregnancies were obtained at the IVF clinic of St Pierre Hospital in Brussels. There were 29 chemical pregnancies (26.8%), five ectopic pregnancies (4.6%), 15 abortions (14%) and 59 ongoing pregnancies of over 20 weeks (54%). Patients who had experienced a chemical pregnancy at first trial displayed a significantly higher rate of ongoing pregnancy at their second attempt. Among the 15 cases of abortion, a chromosomal anomaly was detected in two cases and suspected in a third. Four of the five ectopic pregnancies occurred in patients with previously documented tubal pathology. The ongoing pregnancies were distributed as 44 singletons, 13 pairs of twins, one set of triplets and one set of quadruplets. The Caesarian section rates were 21 and 40% for single and multiple pregnancies, respectively. The prematurity rate was low for singletons (4.5%) but reached 46.6% in multiple pregnancies. Two minor malformations were observed and five perinatal deaths occurred; among these latter, four cases were twins. It appears that perinatal pathology is substantially higher among IVF pregnancies than in the normal population. It is clear, however, that most of this difference is accounted for by the considerably higher rate of twin pregnancy displayed by the former group.

Abortion, Spontaneous↗
PubMed1988

[2 outbreaks of adenovirus 8 keratoconjunctivitis. Clinical, epidemiological and preventive approach].

Adenovirus 8 represents the main agent of Epidemic Keratoconjunctivitis (EKC) and outbreaks mainly occur in hospital wards, colleges and metallurgy industry. Adenovirus 8 conjunctivitis are generally severe lasting two to three weeks, and keratitis with persistent infiltrates may be observed for more than a year. There is no actual treatment of EKC and therefore preventive measures appear as essential to avoid and/or limit such outbreaks in hospital wards. We have observed two consecutive outbreaks of Adenovirus 8 EKC in the Ophthalmology Department of the University Hospital in Brest, France. One outbreak lasted from December 1st, 1983, to March 20, 1984, and the second from July 13, 1984, to November 6, 1984. All patients were selected on the basis of positive virus isolation and they were divided into three epidemiological groups: Group 1 concerned patients who came for EKC treatment at the Ophthalmology Department for the first time; Group 2 resembled either infected staff members or patients which came for EKC and which had already been at the Ophthalmology Department for less than a month with another disease; Group 3 corresponded to hospitalized patients which had contracted EKC during their stay in the ward. Virus isolations were attempted at the virus laboratory in Brest (Pr Chastel) using human diploid fibroblastic cells, MRC 5 strain (Bio-Mérieux, France) and virus isolates were identified by neutralisation tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoviridae Infections↗
PubMed1987

Homology in the region containing a tRNA(Trp) gene and a (complete or partial) tRNA(Pro) gene in wheat mitochondrial and chloroplast genomes.

We have used bean mitochondrial (mt) and chloroplast (cp) tRNA(Trp) as probes to locate the corresponding genes on the mt and cp genomes of wheat and we have determined the nucleotide sequences of the wheat mt and cp tRNA(Trp) genes and of the flanking regions. Sequence comparisons show that the wheat mt and cp tRNA(Trp) genes are 97% homologous. On the wheat cp DNA, a tRNA(UGGPro) gene was found 139 bp upstream of the cp tRNA(Trp) gene. On the wheat mt DNA, a sequence of 23 nucleotides completely homologous with the 3' end of this cp tRNA(Pro) gene was found 136 bp upstream of the mt tRNA(Trp) gene, but there is only 38% homology between cp and mt wheat genomes in the intergenic regions. The overall organization of this region in the chloroplast genome (a tRNA(Trp) gene separated by about 140 bp from a tRNA(Pro) gene) is also found in the mitochondrial genome, suggesting that this mitochondrial fragment might have originated from a chloroplast DNA insertion. A comparison of the genes and of the intergenic regions located between the tRNA(Trp) gene and the tRNA(Pro) (or partial tRNA(Pro)) gene shows that there is an almost complete conservation of these sequences in the mitochondrial DNA of wheat and maize, whereas wheat mt and cp intergenic regions show more sequence divergence. Wheat mt tRNA(Trp) gene is encoded by the main mt genome (accounted for by the master chromosome) but, in the case of maize mitochondria, this gene was found to be encoded by the 2.3 kb linear plasmid, indicating that this plasmid is not dispensable in maize mitochondria.

Base Sequence↗
PubMed1987

Higher pregnancy rates after in vitro fertilization and embryo transfer in cases with sperm defects.

One hundred thirty-three couples were classified into four groups according to previous sperm analyses. These couples underwent 237 in vitro fertilization trials that led to 46 clinical pregnancies (19.4%/trial). Clinical pregnancy rate per laparoscopy of the group with male defects was significantly higher than that of the normospermic couples (25 versus 14%, P less than 0.05). The fertilization rate was significantly reduced only if two sperm anomalies were present (P less than 0.05). However, the mean number of embryos transferred did not differ significantly among the four groups, but the proportion of trials without transfer was increased with regard to the severity of sperm defect. Implantation rate per embryo in cases of triple transfer was significantly higher in the group with sperm anomalies as compared with the normospermic cases (18 versus 10%, P less than 0.02). Correction of the male problem through IVF treatment allows higher female fertility to be disclosed in these cases.

Adult↗
PubMed1987

Endometrial morphology in stimulated in vitro fertilization cycles and after steroid replacement therapy in cases of primary ovarian failure.

Endometrial morphology and ultrastructure are studied in 17 spontaneous, 23 stimulated, and 18 artificial cycles in cases of primary ovarian failure. Normal light-microscopic aspect was found, but impaired development of nucleolar channel system and stronger intercellular junction have been observed by electron-microscopic studies in stimulated cycles with relative excess of luteal estrogen. Normal glandular maturation can be obtained in patients with premature menopause, given adequate steroid replacement, but an abnormally dense fibrocytic aspect of the stroma is characteristic of the first treatment cycles.

Biopsy↗
PubMed1986

Differences in the luteal phases after failed or successful in vitro fertilization and embryo replacement.

Luteal phases after in vitro fertilization (IVF) and embryo replacement have been studied in 241 cycles. A positive correlation was observed between the follicular estradiol (E2) peak and the progesterone (P) level on day 3 of the luteal phase, but no correlation was found between the E2-peak value and the luteal-phase duration or midluteal P concentration. When the trials were classified in relation to their outcome (i.e., clinical pregnancies, chemical pregnancies, or failures), the mean P level on day 3 of the luteal phase was significantly higher in clinical pregnancies than in chemical pregnancies and in failures. Mean E2 levels on day 3 were not significantly different among the three groups. Values of the E2/P ratio were significantly higher in chemical pregnancies than in the other groups. No significant differences were observed among the three groups on day 8. When comparing trials ending in failure to those leading to clinical pregnancy for the same patients, pregnancies were obtained in cycles in which early luteal P was higher and the early luteal E2/P ratio was lower than in failures cycles. These data suggest that high P levels and a low E2/P ratio in the early luteal phase might have a favorable influence on the implantation process in human IVF.

Embryo Implantation↗
PubMed1986

In vitro fertilization and embryo transfer as related to endogenous luteinizing hormone rise or human chorionic gonadotropin administration.

After ovarian stimulation with clomiphene citrate combined with human menopausal gonadotropin for in vitro fertilization, the appearance of a spontaneous luteinizing hormone (LH) surge before fulfillment of the minimal criteria of follicular maturity (at least one follicle greater than 19 mm and serum estradiol [E2] greater than 400 pg/ml/follicle greater than 17 mm) is associated with reduced pregnancy rates. In these cases, follicles are smaller and serum E2 values are lower at the time of the LH surge. Oocyte recovery rate is reduced, embryonic anucleate fragments are more frequently observed, and the level of luteal progesterone on day 4 after oocyte retrieval is lower. Hyperandrogenic patients are more prone to display such premature spontaneous LH surge. We concluded that in case of an untimely LH rise, laparoscopy for oocyte retrieval should be cancelled.

Adult↗
PubMed1986

A comparison between multiple and single pregnancies obtained by in-vitro fertilization.

Thirty-eight single and 10 multiple pregnancies obtained after in-vitro fertilization were compared. In the group of multiple gestations, maternal age was lower and the amounts of ovulatory drugs given were significantly smaller than in relation to single pregnancies. All multiple pregnancies arose from triple embryo transfers and the embryos from this group exhibited significantly higher vitality scores. In both groups, plasma levels of oestradiol and progesterone followed the same pattern until day 8 after oocyte retrieval. Following implantation, the secretion of these hormones increased more rapidly in multiple pregnancies pointing at greater luteal activity in this group. HCG levels became significantly higher in multiple gestation on day 25 after oocyte collection. Echographic examination showed that, compared to normal pregnancy, growth in both groups of IVF conceptuses was initially retarded but caught up with normal evolution at approximately 30 days after egg retrieval. The need for adjusting the number of embryos transferred not only to expected success rates but also to the risk of high rank multiples is emphasized.

Embryo Transfer↗
PubMed1985

Growth rate of follicular estrogen secretion in relation to the outcome of in vitro fertilization and embryo replacement.

Estradiol growth rate (EGR) during active follicular development was calculated for 89 stimulated in vitro fertilization cycles by exponential curve fit (r = 0.83). Cycles could be divided into four groups with very low, low, moderate, and high EGR values. Cases without oocyte fertilization and/or embryo replacement did not occur in the moderate EGR range, which also corresponded to a significantly better ratio of replaceable embryos versus oocytes recovered. This group was also endowed with a pregnancy rate amounting to 28.5% per laparoscopy and per replacement, i.e., about three times higher than in the three other groups. Very low or high EGR entailed significantly higher percentages of missed oocyte recovery and/or fertilization failure. The frequency of occurrence of a spontaneous luteinizing hormone peak was negatively correlated with EGR. The data indicate that a better outcome of in vitro fertilization may be expected when the estrogen rise starts early in the cycle and adopts a moderate growth rate (0.3 to 0.4).

Embryo Transfer↗
PubMed1985

Patterns of protein synthesis in endometrial tissues from ovariectomized rats treated with oestradiol and progesterone.

Groups of ovariectomized rats were taken as controls or given hormonal treatment mimicking the successive steps in the sequence of ovarian secretions leading to implantation. Total endometrium or separated epithelium and stroma were incubated in vitro with [35S]methionine. Dissolved proteins were submitted to two-dimensional polyacrylamide gel electrophoresis (pH range 5-7), followed by autoradiography. Priming with oestradiol (2 days) and subsequent treatment with progesterone (3 days) enhanced the synthesis of 12 and 14 polypeptides, respectively, which are specific for each of these treatments. Progesterone also suppressed the production of 10 oestrogen-dependent proteins both in the epithelium and the stroma. When an oestrogen-progesterone-oestrogen treatment was given, synthesis of all but 4 of the progesterone-induced polypeptides in the epithelium was inhibited while 5 of the proteins abolished by progesterone in this tissue compartment reappeared. These results are compatible with a mechanism of implantation acting at the epithelial level by lifting of intrauterine inhibition and stimulation by embryotrophic substances.

Animals↗