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Biomedical subjects

D Vandekerckhove

Publications and source records attributed to D Vandekerckhove.

At least 19 recordsLinked to original sources
PubMed1992

Hormonal stimulation for in vitro fertilization: a comparison of fertilization rates and cytogenetic findings in unfertilized oocytes.

OBJECTIVE: The purpose of this study was to compare fertilization and aneuploidy rates after two stimulation protocols in an IVF program. DESIGN: This was a retrospective study. SETTING: The study took place in the IVF laboratory of an Infertility Department. METHODS: In 349 treatment cycles, clomiphene citrate (CC) and human menopausal gonadotropin (hMG) were used in one group (N = 233) and hMG after treatment with a gonadotropin-releasing hormone agonist (GnRHa) in two other groups (long protocol): goserelin (N = 73) and buserelin (N = 43). Cytogenetic analysis was performed on all unfertilized oocytes in both groups. RESULTS: Fertilization rates were significantly higher in the GnRHa/hMG group than in the CC/hMG group, but cleavage rates and embryo quality were not different. Of 736 oocytes prepared for cytogenetic analysis, 256 were karyotyped: 172 were found to be euploid and 84 aneuploid. More oocytes were aneuploid in the GnRHa/hMG group than in the CC/hMG group and this difference was statistically different after analysis of the data using a specially designed mathematical model. CONCLUSION: If no selection against chromosomally abnormal oocytes takes place at the time of fertilization, more abnormal oocytes are harvested with GnRHa/hMG protocols than with CC/hMG. If, on the other hand, there is a selection against oocytes with some chromosomal imbalance, there is no intrinsic effect of GnRH agonists on the chromosomal complement of the oocyte, and the real aneuploidy frequency in all oocytes, fertilized and unfertilized, is the same in the GnRHa/hMG and in the CC/hMG group.

Aneuploidy↗
PubMed1992

Delayed implantation. A case report.

In cycles in which conception takes place, serum human chorionic gonadotropin (hCG) becomes detectable between 8 and 12 days after ovulation. A delayed appearance of hCG has been reported in a limited number of cases, most of them ending in spontaneous abortion. We encountered a case of ectopic pregnancy characterized by a delayed appearance of hCG and accompanied by a complete, albeit temporary, halt in the steroidogenic activity of the corpus luteum. Although the patient was at risk of developing an ectopic pregnancy, the findings made an early diagnosis extremely difficult.

Adult↗
PubMed1992

Direct enzyme immunoassay of estradiol in serum of women enrolled in an in vitro fertilization and embryo transfer program.

We present a fast and simple direct enzyme immunoassay for the sexual steroid hormone estradiol-17 beta in serum of women enrolled in an in vitro fertilization and embryo transfer program. We added 25 microL of standards or samples and 125 microL of a mixture of monoclonal antibody and displacing agents to the wells of a microtiter plate previously coated with a second antibody. After 30 min 50 microL estradiol-horseradish peroxidase conjugate is added. Total incubation time is 75 min. The immunoassay is stopped by washing the microtiter plate. The amount of bound conjugate is then measured at 450 nm with hydrogen peroxide as a substrate and 3,3',5,5'-tetramethylbenzidine as chromogen. The detection limit is 0.24 nmol/L. The assay is thus limited in its application. Analytical recovery is 90.8% (range 80.4-102.9%); within- and between-assay CVs range between 1.3% and 15.4%. Total assay time, including preparation of reagents and data reduction, is only 2.5 h. Results of this enzyme immunoassay compare well with those obtained with four different commercial radioimmunoassays (r = 0.88-0.93).

Embryo Transfer↗
PubMed1991

Steroid determinations in human ovarian follicular fluid using reversed phase liquid chromatography.

A method is presented, based on high performance liquid chromatography (HPLC) with u.v. absorbance detection, to simultaneously analyse all major unconjugated steroids in ovarian follicular fluids. The total analysis time is only 30 min. The use of a 3 mm i.d. column allows us to obtain detection limits for 3-oxo-4-ene steroids of 2 ng/ml. Calibration curves are linear in the 10-20,000 ng range per injection. Excellent agreement is obtained with the results using a previously published gaschromatography method.

Calibration↗
PubMed1991

Follicular fluid steroid levels in relation to oocyte maturity and in vitro fertilization.

Steroid levels in follicular fluid (FF) obtained from stimulated ovaries in patients undergoing in vitro fertilization (IVF) were measured by capillary gas chromatography. The correlation between these levels and the maturity of the oocyte, judged from the morphology of the oocyte corona cumulus complex (OCCC) and the fertilizability of the oocytes was analysed. Oocyte maturity was associated with higher FF levels of progesterone, 17-hydroxyprogesterone, 16 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone. Follicular fluids containing oocytes that became fertilized had significantly higher levels of 20 alpha-dihydroprogesterone and progesterone and lower levels of androstenedione. Of all the steroids determined, 20 alpha-dihydroprogesterone provides the most significant group differences. Enhanced 20 alpha-dihydrogenation in the presence of decreased 16 alpha- and 17-hydroxylation appears to be an important characteristic of the ultimate ripening stages and early luteinization, at least in stimulated cycles.

Chromatography, Gas↗
PubMed1991

Correlations between follicular fluid steroid analysis and maturity and cytogenetic analysis of human oocytes that remained unfertilized after in vitro fertilization.

OBJECTIVE: Is there any correlation between follicular fluid (FF) steroid levels and the occurrence of cytogenetic abnormalities in unfertilized human oocytes? DESIGN: Cytogenetic analysis was carried out on 397 oocytes, and the steroid content of 104 corresponding FF was analyzed using high-pressure liquid chromatography. Ovarian stimulation was performed by clomiphene citrate and human menopausal gonadotropin (hMG) or by hMG combined with a gonadotropin-releasing hormone agonist (GnRH-a) pretreatment. RESULTS: Oocyte maturity was correlated with an increasing FF progestin content and a significant decrease of androstenedione (A) levels. Chromosomal analysis revealed 84 of all oocytes to be abnormal (polyploid or aneuploid and/or prematurely condensed chromosomes present). In this group, A levels and A to estradiol ratios were significantly higher. Although progestin levels were higher in GnRH-a/hMG cycles, the incidence of oocyte normality was not different between the two stimulation schemes. More abnormal oocytes were found in patients with good sperm morphology. CONCLUSIONS: Oocyte abnormality correlates with higher A levels in the corresponding FF. Oocyte fertilization is also determined by intrinsic oocytic factors other than maturity.

17-alpha-Hydroxyprogesterone↗
PubMed1991

Normal survival and in-vitro development after cryopreservation of zona-drilled embryos in mice.

The importance of the zona pellucida on survival after freezing and thawing was investigated. Zona-drilled and zona-intact mouse embryos were fertilized in vitro, cultured to the 2, 4 and 8-cell stages and frozen using conventional methods. Zona drilling did not affect the survival or development of frozen embryos to the blastocyst stage in vitro. We conclude that partial damage to the zona pellucida during micromanipulation procedures is compatible with rates of survival and development which are not different to those observed in zona-intact control embryos.

Animals↗
PubMed1991

Chromosome analysis in human oocytes unfertilized in vitro: a mathematical model for the estimation of the first meiotic non-disjunction frequency.

The results of cytogenetic analysis of unfertilized human oocytes in an in-vitro fertilization programme are to a large extent influenced by the methodology used. Exact conclusions cannot be drawn due to technical and interpretational errors. A mathematical model was constructed, therefore, to estimate the weight of these errors and to calculate the exact frequency of first meiotic non-disjunction in IVF oocytes. Of 246 prepared oocytes only 105 could be karyotyped exactly. Using the classical method of calculation, an aneuploidy frequency of 39% was obtained. By applying the maximum likelihood method a correlation between the frequency of first meiotic non-disjunction and the interpretational error level was found. Loss of chromosomes by anaphase lagging seemed to be undetectable, but the probability of chromosome loss due to fixation and unhomogeneous spreading was found to be 20%. Accepting an error level of 10-20%, the true non-disjunction frequency expected should range between 20 and 40%. This model yields a standard curve which can offer a basis for comparison of results obtained in different studies.

Anaphase↗
PubMed1990

The neu-oncogene protein as a predictive factor for haematogenous metastases in breast cancer patients.

In a prospective study with a median follow-up of 13 months on a series of 71 breast cancer patients, 9 developed haematogenous metastases. The neu protein was found on the cell membranes in 27 of the 71 carcinomas (38%) by an immunohistochemical technique using a monoclonal antibody (MAb). Eight of the 9 patients with haematogenous metastases showed overexpression of the neu protein. Immunohistochemical staining of the cell membrane was inversely correlated with the oestrogen and the progesterone receptor status. There was no correlation with lymph-node involvement. The immunohistochemical detection of the neu protein in breast adenocarcinomas is an independent factor in predicting the patients at risk for haematogenous tumour spread and is therefore correlated with unfavourable prognosis.

Biopsy↗
PubMed1990

Steroid determinations in human ovarian follicular fluid using capillary gas chromatography.

A method is presented based on capillary GLC using both a thermionic and a flame ionization detector to simultaneously analyse all major unconjugated steroids in ovarian follicular fluids (FF). Although specificity can not always be guaranteed for the smaller concentrations of androstenedione and cortisol, accuracy and reproducibility are excellent for the major progestagens and estrogens (progesterone, 17- and 16 alpha-hydroxyprogesterone, pregnenolone, 20 alpha-dihydroprogesterone, estradiol and estrone). Above all the analysis is performed with relatively cheap instrumentation and products. Apart from the "profiles" of unconjugated steroids, a semi-quantitative analysis of steroid conjugates is possible if a preliminary group separation with disposable anion exchanger columns is included.

17-alpha-Hydroxyprogesterone↗
PubMed1990

Correlation between peripheral CA-125 levels and ovarian activity.

Serum CA-125 concentrations were measured at three different times in normal cycles, pill-suppressed cycles, and cycles stimulated for intrauterine insemination (IUI) or oocyte retrieval, i.e., (1) during the first half of the cycle, (2) at midcycle or at the moment of oocyte retrieval, and (3) the second half of the cycle. Significant variations of serum CA-125 concentrations were not seen during the cycle in normally cycling women or in women taking oral contraceptives: mean +/- SD 28.9 +/- 13.3 U/mL and 26.9 +/- 11.3 U/mL, respectively. In patients stimulated for in vitro fertilization, luteal phase CA-125 levels (60.6 +/- 38 U/mL) were significantly higher than during stimulation (21.5 +/- 5.9 U/mL) or at oocyte retrieval (19.6 +/- 6.4 U/mL). In stimulated cycles for IUI, without laparoscopy or follicular puncture, a comparable rise of CA-125 was observed in the luteal phase (49.6 +/- 37.8 U/mL). However, in patients undergoing laparoscopic sterilization, serum CA-125 concentrations before and after laparoscopy were not significantly different (22.8 +/- 6.3 U/mL and 25 +/- 4.2 U/mL, respectively).

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

Possibilities and limitations of techniques of assisted reproduction for the treatment of male infertility.

Since relatively few spermatozoa are needed for oocyte fertilization during gamete intra-Fallopian transfer (GIFT) or in-vitro fertilization (IVF), these methods have been applied in couples with infertility due to male causes. Forty-six couples with male factor infertility were enrolled in this study and results were compared with those attained in 48 couples treated with the same techniques for other than male causes. Overall, GIFT resulted in 26% ongoing pregnancies. GIFT seems to be particularly successful when the sperm concentration is 20 x 10(6)/ml or more, but sperm motility and/or morphology are poor. Nine pregnancies occurred out of 26 GIFT cycles in 18 cases selected on this basis. The ongoing pregnancy rate after IVF was 16% per patient. The latter treatment should be attempted in male immune infertility and in cases with a low sperm concentration, with or without abnormal sperm motility and/or morphology. In these circumstances, five pregnancies were attained out of 28 cycles in 14 cases. For similar sperm concentrations, the conception rate per cycle attained with techniques of assisted reproduction was more than twice that attained with conventional treatment of male infertility.

Female↗
PubMed1990

Value of sperm characteristics and the result of in-vitro fertilization for predicting the outcome of assisted reproduction.

The outcome of procedures for assisted reproduction, namely in-vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) were used as end-points to assess the capacity of particular sperm characteristics to predict the fertilizing potential of semen. In addition, the result of IVF performed with spare oocytes from the GIFT procedure, was used to predict the pregnancy outcome of GIFT. The power of sperm characteristics to predict the outcome of assisted reproduction procedures was poor. With regard to the outcome of IVF, sperm morphology was the best discriminant. The threshold value of 16% normal sperm morphology could be used as a good predictor of successful IVF, but could not be applied as a criterion to reject an IVF trial. For the latter purpose, the limit of 5% sperm with normal morphology should be used. The proportion of sperm with grade A motility in native semen provided the best discrimination between GIFT-fertile and GIFT-infertile cases. A negative result from IVF performed with spare oocytes was 93% accurate in predicting unsuccessful outcome of GIFT. Hence, diagnostic IVF is the most sensitive assay for male fertility. The occurrence of oocyte fertilization during IVF predicts a successful outcome of GIFT in only 50% of cases. Hence, a negative result in IVF indicates that semen is almost certainly infertile, but a positive result does not guarantee the successful outcome of GIFT.

Adult↗
PubMed1989

The expression of the neu oncogene product in breast lesions and in normal fetal and adult human tissues.

The expression of the neu oncogene product was investigated in invasive and non-invasive ductal carcinomas of the breast, non-neoplastic lesions of the breast, fragments of normal adult and fetal breasts and in several other normal and fetal tissues at different weeks of pregnancy by means of an immunohistochemical study with monoclonal antibodies. The staining pattern along the cytoplasmic membrane was specific for malignancy and occurred in 29% of the breast carcinomas. It was observed in invasive carcinomas as well as in ductal carcinoma in situ and it showed a significantly higher expression in premenopausal women than in postmenopausal women. This higher expression was also present in oestrogen receptor-negative tumours. The tubules of the fetal and adult kidney, the absorption cells of the fetal and adult small and large intestine, the sebaceous glands of the fetal and adult small and large intestine, the sebaceous glands of the fetal and adult skin, the adult endocervix, the endometrium, the C-cells of the thyroid, hepatocytes and all ductal cells of the fetal breast showed a constant diffuse intracytoplasmic granular staining. staining. The same granular intracytoplasmic staining pattern was focally observed in rare cases of normal breast tissue in adults and in some cases of epitheliosis, aprocrine metaplasia and some breast carcinoma cells, which did not express neu oncogene product on their membrane. Western blot experiments showed that the cytoplasmic protein had a molecular weight of 155 kD (kilodaltons); the membrane protein is the known 185 kD neu protein.

Adult↗
PubMed1988

Group fractionation of free and conjugated steroids by means of disposable silica-based anion-exchange columns.

Adsorption and desorption modes have been elaborated which allow the separation of complex steroid mixtures of biological fluids into an unconjugated, a glucuronic acid conjugated and a sulphuric acid and mixed conjugated fraction. Capillary gas chromatographic analysis of the fractions obtained provides "total steroid profiles" of urine, blood, ovarian follicle fluid and amniotic fluid.

Chromatography, Gas↗
PubMed1988

Clinical and hormonal effects of long-term veralipride treatment in post-menopausal women.

The clinical and hormonal effects of long-term, continuous treatment with veralipride, a benzamide derivative, were investigated in 10 post-menopausal women. The efficacy of veralipride in relieving hot flushes was confirmed. No significant change was detected in depressive mood scores. Except for the late appearance of moderate extrapyramidal side effects in one patient, the clinical tolerance of veralipride was good. As regards hormonal effects, veralipride, by virtue of its antidopaminergic action, raised prolactin levels. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels declined significantly, while the serum concentration of dehydroepiandrosterone sulphate (DHEAS) increased. These hormonal changes were presumably secondary to the chronic hyperprolactinaemia.

Aged↗
PubMed1986

Laparoscopic diagnosis of mesenteric venous thrombosis.

Diagnosis of mesenteric venous thrombosis is almost always delayed, due to the aspecificity of the complaints and the clinical findings, as well as the laboratory investigations. Earlier diagnosis is essential to improve the present grim mortality rate. We report a case of mesenteric venous thrombosis in a 25-year-old female. Early diagnosis was made by gynecological laparoscopy. After resection and anastomosis, the outcome was uneventful.

Adult↗