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Biomedical subjects

B Lejeune

Publications and source records attributed to B Lejeune.

At least 73 records · Page 4Linked to original sources
PubMed1992

Role of the independent duty corpsman on the USNS Comfort (T-AH 20): the Operation Desert Shield/Desert Storm experience.

Independent duty corpsmen (IDCs) have a significant role in providing health care on the USNS Comfort (T-AH 20). The IDCs are responsible for staffing sick call, emergency response teams, and resuscitation/stabilization teams. IDCs are trained in advanced patient care and in medical administrative and logistical duties. During peacetime, their function often focuses on primary care to the decrement of skills necessary to perform in medical emergencies. The Operation Desert Shield/Desert Storm mobilization has emphasized the need for Navy medicine to continue its support of IDC training so that they are kept in a state of preparedness to competently deliver the full spectrum of care that is expected of them.

Allied Health Personnel↗
PubMed1991

Are there predictive criteria of complicated ovarian hyperstimulation in IVF?

Among 599 trials of in-vitro fertilization (IVF) treatment, complicated ovarian hyperstimulation (OHSS) was diagnosed in 14 cases (2.5%) on the basis of heavy abdominal discomfort and echographic findings (ascites, ovarian enlargement with cysts). Among eight hospitalized patients, four presented with a haemoconcentration and/or electrolytic disturbances. OHSS cases were compared with two control groups for a series of criteria: age, aetiology of infertility, total dose of human menopausal gonadotrophin (HMG), day of oocyte collection, oestradiol (E2) peak level, rate of E2 increase, number of oocytes, number of embryos transferred and embryonic vitality scores. Comparison with a random group of normal IVF trials showed a significant difference for the following parameters: E2 peak level and rate of increase, E2/dose of HMG, E2/day of egg collection and number of oocytes. When OHSS cases were compared to another control group consisting only of high E2 responders (peak E2 greater than 2700 pg/ml), no significant difference was found for any of the above-mentioned criteria. In view of this lack of predictive power of individual criteria, stepwise discriminant analysis was applied, showing that this method might provide a predictive mathematical function for evaluating the risk of OHSS before human chorionic gonadotrophin (HCG) administration. Such a formula, however, should be validated by a multicentric study in which a greater number of OHSS cases would be tested.

Adult↗
PubMed1991

A trans-splicing model for the expression of the tripartite nad5 gene in wheat and maize mitochondria.

The mitochondrial single-copy gene nad5 of wheat and maize consists of 5 exons located on three widely separated regions of the genome that are independently transcribed. The first region contains exons I and II separated by an atypical group II intron; in the second region is exon III (only 22 bp long), which is flanked upstream by a maturase-related open reading frame (ORF) and exon e of the nad1 gene, and downstream by a previously unidentified ORF (ORF143); in the third region are exons IV and V separated by a group II intron. In maize, this last domain is flanked upstream by the genes rps12, nad3, and tRNA(Ser) and downstream by a chloroplast tRNA(Cys). RNA editing occurs in wheat exons IV and V as C-to-U changes. A detailed analysis of the transcription of the nad5 gene in wheat and maize reveals that the exons are assembled into a 2.4-kb mRNA after two cis-splicing (between exons I and II and exons IV and V) and two trans-splicing events. The trans-splicing process involves the sequences flanking exons II, III, and IV that feature group II introns. A model is proposed for the assembly and maturation of the nad5 transcripts.

Amino Acid Sequence↗
PubMed1991

Evaluation of a screening test for detecting urinary tract infection in newborns and infants.

The results of a study of a screening test for urinary tract infection (UTI) in infants under 18 months is reported. Two hundred and forty three urine specimens were tested in the laboratory using AMES Multistix 8SG reagent strips read by photometer. The strips included three potential markers for urinary tract infection: leucocyte esterase, nitrite, and protein. The predictive value of a positive result (PPV) was low. The predictive value of negative test (NPV) when combining the screen of leucocyte esterase, nitrite, and protein was 99.4% with no difference between boys and girls. The test for leucocyte esterase had a 97.6% negative predictive value. An examination of the results by age confirms the good NPV in all age groups. Paediatricians should find Multistix 8SG strips a useful aid in the diagnosis of urinary tract infection in infants, and that costly culture of samples with negative strip tests can be avoided.

Humans↗
PubMed1991

Pregnancy in patients with mild thyroid abnormalities: maternal and neonatal repercussions.

A prospective study was undertaken during pregnancy in 120 euthyroid women presenting with mild thyroid abnormalities (TA): 11 with a past history of thyroid disorder, 44 with goiter, 20 with nodules, and 45 with thyroid autoantibodies. The aims of the study were to assess whether the pattern of thyroid alterations during gestation was different in women with TA compared to that in healthy control pregnant subjects and to evaluate possible obstetrical and neonatal repercussions. The overall prevalence of underlying subtle thyroid abnormalities in the cohort was 17%, probably as the result of the environmental moderately low iodine intake. Despite the intrinsic heterogeneity of the four groups of women with TA, the adaptation of the thyroid to the stress of pregnancy was different from that of the control subjects. Noteworthy were 1) the marked elevation of serum thyroglobulin in women with past history of thyroid disorder, goiter and thyroid nodules; 2) the increase in goiter size in a third of the goitrous women, associated with biochemical evidence of functional stimulation of the gland; 3) the indirect evidence of partial thyroidal autonomy in goitrous patients; and 4) the increase in the number and size of thyroid nodules during gestation. Taken together, the data indicated that pregnancy was associated with a greater thyroidal risk in patients with TA compared to healthy subjects. In relation to thyroid autoimmunity, most patients remained euthyroid during gestation, but in a few cases, TSH was elevated at delivery, suggesting diminished thyroidal reserve. Also, 40% of newborns from mothers with thyroid autoimmunity had elevated thyroid peroxidase antibody titers at birth, and there was a highly significant correlation between maternal and neonatal thyroid peroxidase antibody titers. Finally, thyroid autoimmunity was clearly associated with an increased risk of spontaneous abortion (13.3 vs. 3.3%; P less than 0.001). Thyroid function in newborns from mothers with TA was normal and not different from that in controls; similarly, obstetrical features were similar in patients with TA and control subjects. In conclusion, pregnancy is associated with a greater thyroidal risk in women with TA, thereby emphasizing a potential link between pregnancy and thyroid disorders. It is recommended that patients with known, even subtle, thyroid abnormalities be closely monitored during pregnancy, in particular those with a goiter, nodules, or thyroid autoimmunity, especially in areas with a moderately low iodine intake, where the prevalence of mild thyroid disturbances is high.

Adult↗
PubMed1991

[Prevention of iatrogenic multiple pregnancies].

A significant increase of twin and multiple pregnancies induced by infertility treatment has been observed. These high-risk pregnancies should be efficiently prevented. Gonadotrophin treatment for anovulation being the main culprit, it should be undertaken: 1) if other induction methods have failed. 2) under strict echographic and hormonal monitoring. After in vitro fertilization, number of embryos replaced should be selectively limited (to 2 or 3) on the basis of their vitality scores. Partial reduction of a multiple pregnancy should remain an exceptional solution.

Anovulation↗
PubMed1991

[Prevention of complications of ovarian stimulation in in-vitro fertilization].

The ovarian hyperstimulation syndrome which is the most severe iatrogenic complication of ovulation induction, may range from mere abdominal discomfort to lethal thromboembolism. It is therefore, mandatory to be able to evaluate the risk of such complications. In in vitro fertilization treatment, maximal level and growth rate of oestradiol and also the number of oocytes retrieved, are significantly higher among patients who will develop an hyperstimulation syndrome than in a group of healthy controls. However, due to the large distribution of individual values, none of these variables can be predictive by itself. Only multiple discriminant analysis effected within the frame of a multicentric study might be able to define a specific and sensitive predictive function.

Adult↗
PubMed1990

An internal part of the chloroplast atpA gene sequence is present in the mitochondrial genome of Triticum aestivum: molecular organisation and evolutionary aspects.

An internal part of the chloroplast atpA gene has been identified in the mitochondrial DNA of Triticum aestivum. It is located near the 18S-5S ribosomal genes and partially contained within a repeated sequence. Comparison of the transferred sequence with the original ct sequence reveals several nucleotide changes and shows that neither 5' nor 3' ends are present in the mt genome. No transcript of this region could be detected by Northern analysis. This sequence is present in mitochondrial genomes of other tetraploid and diploid species of Triticum, also in the vicinity of the 18S-5S ribosomal genes, suggesting a unique transfer event. The date of this event is discussed.

Adenosine Triphosphatases↗
PubMed1990

Use of buserelin acetate in an in vitro fertilization program: a comparison with classical clomiphene citrate-human menopausal gonadotropin treatment.

A comparison has been established retrospectively between clomiphene citrate-human menopausal gonadotropin (CC-hMG) and buserelin acetate-hMG treatments in in vitro fertilization trials performed over a 3-year period. The analysis of 466 CC-hMG and 319 buserelin acetate-hMG trials shows that buserelin acetate-hMG stimulation generates a greater ovarian response resulting in higher numbers of oocytes being retrieved (6.2 + 3.8 versus 9.3 + 5.2) and fertilized (2.8 + 2.7 versus 4.3 + 3.8). More embryos are thus obtained, allowing a wider choice for intrauterine replacement and cryopreservation. Mean embryonic vitality scores do not differ (4.33 + 1.51 versus 4.44 + 1.54), implying that the embryonic quality remains similar in both treatments. A premature demise of the corpus luteum occurs in a large proportion of buserelin acetate-hMG cycles. However, when suppletive progesterone treatment is given, there is a trend toward a better implantation rate per embryo, and a significantly higher ongoing pregnancy rate is observed in relation to buserelin acetate-hMG treatment (20%) as compared with CC-hMG cycles (14%).

Adult↗
PubMed1990

Fertilization failure in IVF: why and what next?

Among 297 couples who underwent 587 oocyte collection procedures, 95 (16%) total fertilization failures (FF) were observed. This frequency is similar in couples with either normal or only mildly deficient spermatozoa (16.2 and 13.7% respectively) but is almost doubled in cases of moderately and severely defective sperm (26.5%). However, this latter group accounts for only 19% of FF events. The fertilization rate per oocyte (FR) follows an inverse trend. FR was correlated with the final (i.e. after swim-up) sperm count and with initial and final motility of the sperm sample. If the final count and motility were less than 2 x 10(6)/ml and 40% respectively, the FF frequency in the group with partner's spermatozoa was significantly higher and FR significantly lower. FR was inversely correlated with the number of oocytes recovered but FF was found significantly more frequently only when fewer than three eggs were retrieved. No correlation was found between FF and either female causes of infertility, age or dosage of stimulation treatment. However, in the group with donor spermatozoa the FR was significantly lower amongst tubal, endocrinopathic and endometriotic patients (67.6, 67.2 and 56.6 respectively versus 79.7% in harvests from idiopathic cases). FR was decreased and FF increased when ovulation induction resulted from a spontaneous LH peak supplemented with human chorionic gonadotropin (HCG), as compared to induction by HCG alone. In the group using normal or mildly defective spermatozoa, if FF occurs at the first attempt, the frequency of recurrence in further trials is high (29%) and the probability of pregnancy after completed trials is low (12.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1990

Regulation of maternal thyroid during pregnancy.

A prospective study was undertaken in 606 healthy women during pregnancy to evaluate the changes occurring in maternal thyroid economy as a result of 1) the increased thyroid hormone-binding capacity of serum, 2) the effects of increased levels of hCG on TSH and on the thyroid, and 3) a marginally low iodine intake in the population (50-75 micrograms/day). Four main features were observed. First, thyroidal activity adjusted to the marked increase in serum T4-binding globulin: pregnancy was accompanied by an overall reduction in the T4/T4-binding globulin ratio, with lower free T4 and T3 levels, although in most cases free hormone levels remained within the normal range. The adjustment of thyroidal output of T4 and T3 did not occur similarly in all subjects. In approximately one third of the women, there was relative hypothyroxinemia, higher T3/T4 ratios (presumably indicating preferential T3 secretion), and higher, although normal, serum TSH concentrations. Second, high hCG levels were associated with thyroid stimulation, both functionally (lower serum TSH) and anatomically (increased thyroid size). The data are consistent with a TSH-like effect of hCG on the thyroid. Hence, regulation of the maternal thyroid is complex, resulting from both elevated hCG (mainly in the first half of gestation) and increasing TSH (mainly in the second half of gestation). Third, a significant increase in serum thyroglobulin levels was observed throughout gestation, especially during the last trimester. Fourth, increased thyroid volume was common, and goiter formation not uncommon (goiter was found in 9% of women at delivery). In conclusion, the alterations in maternal thyroid function during gestation are intricate and far from fully understood. In areas of marginally low iodine intake, gestation is associated in a significant number of women with relative hypothyroxinemia, increased thyroglobulin, and enlarged thyroid.

Chorionic Gonadotropin↗
PubMed1989

Is fresh or frozen semen to be used in in vitro fertilization with donor sperm?

Sixty-six partners of either severely oligoasthenospermic or azoospermic men were treated by in vitro fertilization with donor sperm (IVF-D), usually (86%) after failure of artificial insemination with donor sperm. One hundred twenty-nine IVF trials were performed with either fresh (59%) or frozen-thawed (41%) donor sperm. Characteristics of sperm preparations were significantly lower in the frozen-thawed group (P less than 0.001). In the latter group, fertilization rates had slightly decreased (but without statistical significance); embryonic vitality scores and cryopreservable spare embryos had significantly decreased (P less than 0.05). However, cumulative ongoing pregnancy rates were strictly equivalent in both groups (40% after three trials). Frozen-thawed sperm thus can be substituted for fresh donor sperm without entailing impairment of the outcome of IVF, and this method must be preferred for its greater safety regarding transmission of human immunodeficiency virus.

Female↗
PubMed1989

Fertility prognosis in IVF treatment of patients with cancelled cycles.

Among 429 patients admitted in our in-vitro fertilization (IVF) programme during the last 3 years, 106 experienced cancellation of one or more treatment cycles. A low oestrogen (E2) response represented by far the main reason for cancellation (144/184). Significantly lower clinical pregnancy rates were found in the group of patients with low E2-cancelled cycles (E2CC) as compared to the rest of the IVF population (13 versus 37%). Further comparison between these groups showed only little or no difference in the mean age of patients, basal FSH levels, number of egg collections, rate of oocytes obtained and fertilized per trial and mean embryonic vitality score. A large majority of E2CC patients were found to belong to the tubal infertility group (75%) as opposed to a lower proportion of tubal cases among other IVF patients (56%). E2CC tubal patients showed a lower pregnancy rate than other cases with abandoned cycles and also than other tubal patients (8.9 versus 25 and 35%, respectively). Mean numbers of previous laparotomies, of attempts at oocyte retrieval and of oocytes recovered per trial were similar in tubal patients with or without E2CC. However, in the E2CC tubal group mean age and basal FSH levels were somewhat higher, whereas E2 peak values and fertilization rates were lower, leading to a greater proportion of trials without embryo transfer. Embryonic scores and the E2/P ratio at day 3 of the luteal phase did not differ significantly. It may be concluded that cancelling of a cycle because of a low E2 response in a patient with tubal infertility is indicative of a poor prognosis in further IVF trials.

Adult↗
PubMed1989

[Should one use fresh or frozen sperm in in-vitro fertilization with donors?].

Between 1984 and 1987, 66 women whose partner had severe oligo-asthenoteratospermia or azoospermia underwent in vitro fertilization (IVF) with donor sperm. The mean duration of sterility was 7.5 +/- 3.2 years. Investigations performed in the women showed no abnormality in 30%, pure endocrinopathies in 21% or tubal diseases isolated or associated with other pathologies in 40%. Most of these women (86%) had had previous unsuccessful inseminations with donor sperm. Our study involves 129 attempts of IVF with donor sperm (1 to 3 attempts per patient); the sperm was fresh in 59% of the cases and cryopreserved in 41%. Initial and final motility and sperm density are significantly lower for cryopreserved sperm (p less than 0.001). The fertilization rate is lower with cryo-preserved sperm but the difference is not statistically significant. Moreover, the score of embryonal vitality and the number of embryos that can be cryopreserved are lower with cryopreserved sperm (p +/- 0.05). However the number of pregnancies is identical with one or another type of sperm (40% of the women after 3 IVF). To conclude, cryopreserved sperm may be used for IVF without lowering the percentage of success. In fact, the fertilization rate, the embryonal score and the number of embryos to deep freeze are slightly less with cryopreserved sperm and this difference could reveal to be significant with a larger cohort of patients. But the advantage of fresh sperm must be balanced by the risk of AIDS contamination, avoided with cryopreserved sperm.

Acquired Immunodeficiency Syndrome↗