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P De Sutter

Publications and source records attributed to P De Sutter.

At least 73 records · Page 4Linked to original sources
PubMed1994

Is there a role for cervicography in the detection of premalignant lesions of the cervix uteri?

The characteristics of cervicography and the Papanicolaou smear test have been compared for the detection of cervix lesions classified as CIN I or more. A total of 4,015 women were entered into the study. The sensitivity of cervicography is significantly higher (McNemar test, P < 0.0001), but its specificity remains significantly lower (McNemar test, P < 0.0001), and its higher sensitivity does not apply to lesions classified as CIN II or more (high-grade lesions). Hence, if patients with a positive screen result are to be referred for colposcopy-biopsy, cervicography is not a suitable alternative to the smear test for the screening of cervical cancer. However, cervicography can be envisaged as a complementary tool to the smear test because of (a) its higher capability to detect high-grade lesions among women less than 35 years old and (b) its potential superiority in following low-grade lesions. It may also serve as a tool for quality assurance audit of the smear test.

Adult↗
PubMed1994

Behaviour of spermatozoa in human oocytes displaying no or one pronucleus after intracytoplasmic sperm injection.

The behaviour of sperm cells after intracytoplasmic sperm injection (ICSI) was investigated by analysing 192 unfertilized and 37 one-pronuclear (1PN) oocytes following ICSI. Eighty-two unfertilized oocytes were directly fixed whereas 110 were first parthenogenetically activated by puromycin. In contrast to the findings in unfertilized oocytes after in-vitro fertilization, most unfertilized oocytes after ICSI (n = 76) contained evidence of the presence of spermatozoa in the cytoplasm. Few oocytes (n = 6) contained prematurely condensed sperm chromosomes (PCC), whereas the majority contained either intact sperm heads (n = 31) or swollen sperm nuclei (n = 39) along with metaphase II chromosomes of the oocyte. Following activation by puromycin, swollen sperm nuclei and PCC were no longer observed, whereas unchanged sperm heads persisted in 12 oocytes displaying a single pronucleus. A non-decondensed sperm nucleus along with decondensed maternal chromatin were also discovered in 32 out of 37 oocytes displaying a single pronucleus after ICSI. The findings in unfertilized and 1PN oocytes after ICSI indicate that successful sperm injection, even followed by oocyte activation, is not sufficient to guarantee normal fertilization. It seems that partial sperm membrane damage prior to injection is also required to ensure normal sperm decondensation.

Cell Nucleus↗
PubMed1993

Okadaic acid induces premature chromosome condensation reflecting the cell cycle progression in one-cell stage mouse embryos.

Haploid parthenogenetic embryos as well as fertilized mouse eggs were treated in vitro with 1-10 microM okadaic acid (OA) at the one-cell stage. Cytogenetic analysis detected that OA induces nuclear envelope breakdown (NEBD) and premature condensation of interphase chromosomes in pronuclei as well as in 2nd polar body (PB) nuclei. G1-, S-, and G2-type prematurely condensed chromosomes (PCC) were found in pronuclei of embryos of different age, which reflects their progression through the first cell cycle. In nuclei from 2nd PBs only G1- and S-type PCC were observed. Using the types of PCC as a criterion of different phases of the cell cycle, it was possible to estimate that in haploid parthenogenetic embryos G1-phase lasts until 5.5 hr post activation (hpa), S-phase takes from 4.5 to 9.5 hpa, and from 8.5 hpa G2-phase had started. Second PBs were found to be in G1-phase until 6.5 hpa and S-phase started in some as early as 5.5 hpa, but in most not before 7.5 hpa. Treatment with OA visualizes G1-chromosomes in pronuclei as well as in 2nd PBs, and it is easy to count the number of these chromosomes and recognize a T6 marker chromosome. The possibility to apply cytogenetic analysis of G1-chromosomes from 2nd PBs for a more accurate detection of maternal meiotic nondisjunction is discussed.

Animals↗
PubMed1993

The ovarian hyperstimulation syndrome in in-vitro fertilization: a Belgian multicentric study. II. Multiple discriminant analysis for risk prediction.

The considerable overlap of distributions of values for different parameters between control and ovarian hyperstimulation syndrome (OHSS) populations makes any single variable inefficient for risk prediction. Combinations of variables were studied in a discriminant function in order to increase predictivity and decrease the false negative rate. Such analyses were performed on two groups of in-vitro fertilization (IVF) patients: all OHSS cases (n = 128) (group A) and only severe OHSS cases (n = 92) (group B). Progressive introduction and automated stepwise selection of variables were applied to both groups. The best prediction (78.5%) was obtained in group A under post-oocyte retrieval conditions using log oestradiol, slope of log oestradiol increment, human menopausal gonadotrophin (HMG) dosage, number of oocytes retrieved and ratio of luteinizing hormone/follicle stimulating hormone (LH/FSH), in the formula. The corresponding false negative rate was 18.1%. However, effective prevention of OHSS implies the ability to withhold human chorionic gonadotrophin injection. Therefore a formula for pre-oocyte retrieval conditions was established yielding a prediction rate of 76.1% with a false negative rate of 18.1%. To be validated, such formulae have to be applied to another population of IVF cases used as a 'testing-set'.

Belgium↗
PubMed1992

Deletion of chromosome 11p13-11p15.5 sequences in invasive human ovarian cancer is a subclonal progression factor.

In human ovarian cancer, multiple specific chromosomal deletions can be found by cytogenetic analysis or molecular techniques such as restriction fragment length polymorphism probing. This work confirms the loss of HRAS alleles in 1 out of 2 cases of invasive ovarian cancer as determined in 32 samples or cell lines derived from 19 patients. Results with other polymorphic probes indicate that a consensus deletion probably includes 11p15.5-11p13. Tumor suppressor genes might be located in the deleted area, and deletion of the gene might then play a role in disease progression. Examination of DNA from distinct tumor sites of individual patients indicates clonal heterogeneity in the malignant cell population, indicating that loss of 11p sequences is a late event in the disease progression. Loss of alternate 11p alleles at different disease sites in one patient is inconsistent with the current model of tumor suppressor gene inactivation. The 11p deletion seems to be limited to ovarian cancers in younger patients. Eight novel permanent ovarian cancer cell lines, previously not described in the literature and derived from tumor sites from five patients, were included in the current analysis.

Adult↗
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

Parthenogenetic activation of human oocytes by puromycin.

OBJECTIVE: Our objective was to obtain parthenogenetic activation of unfertilized human oocytes by puromycin and to try to use this procedure for cytogenetic purposes. SETTING: The setting was our IVF laboratory. METHODS: Eighty-two spare oocytes from 34 IVF patients were used. In the first series of experiments 39 unfertilized oocytes were cultured in medium containing 100, 50, or 10 micrograms/ml puromycin for 6 to 24 hr. After the appearance of pronuclei they were transferred to plain medium, further cultured, and cytogenetically analyzed. In the second series of experiments 43 oocytes were cultured for 5 to 10 hr in 10 micrograms/ml puromycin, transferred to plain medium, and fixed for cytogenetic analysis 2 hr after nuclear envelope breakdown. RESULTS: Ninety-one percent of the oocytes in the first experiment showed the presence of one or more nuclei. From the pronucleate oocytes additionally cultured in puromycin-free medium, 46% developed further to the metaphase of the first mitotic division or the two-cell stage and 54% remained arrested at the pronuclear stage. In the second experiment 88% of the treated oocytes showed pronuclei or had cleaved, and after withdrawal from puromycin 96% of the pronucleate oocytes entered mitosis. CONCLUSION: Puromycin induces haploid as well as diploid parthenogenesis in aged human oocytes. A 5- to 10-hr treatment of oocytes with 10 micrograms/ml puromycin yields the highest percentage of activation, and almost all parthenogenetically activated oocytes enter or develop beyond the first cleavage mitosis. Analysis of mitotic metaphase chromosomes from parthenogenetically activated human oocytes may be a promising new approach to preimplantation cytogenetics.

Cell Division↗
PubMed1992

Visualization of second polar body chromosomes in fertilized and artificially activated mouse oocytes treated with okadaic acid.

OBJECTIVE: Our objective was to develop a new reliable method for cytogenetic analysis of the chromosome set in second polar bodies (PBs) from one-cell-stage mouse embryos. SETTING: The study took place at the Reproductive Biology and Experimental Cytogenetics Laboratories. METHODS: Oocytes from F1 hybrid and T6/T6 mice were fertilized in vitro and artificially activated with ethanol. Zygotes, parthenogenetic embryos, and isolated second PBs were treated with 10 microM okadaic acid (OA) for 1-2 hr, further cultured in plain medium, and fixed. Chromosomal preparations were made and C-banded, and the number of chromosomes in second PBs and embryos was counted. RESULTS: OA-induced nuclear envelope breakdown in pronuclei as well as in second PB nuclei. Countable chromosome plates were obtained in 92-93% of second PBs treated 4-4.5 hr after activation. The T6 marker chromosome could easily be recognized in second PBs from T6/T6 mice. A haploid set of chromosomes was obtained in 18 of 19 isolated second PBs treated with OA 4-5 hr after activation. CONCLUSION: Treatment of second PBs with OA allows visualization of the PB chromosomes. Cytogenetic analysis of the second PB and the corresponding oocyte constitutes a new approach for the study of meiotic nondisjunction in experimental cytogenetics. The chromosomal study of isolated second PBs seems to be promising for clinical preimplantation cytogenetics.

Animals↗
PubMed1992

Contralateral tubal pregnancy after gamete intrafallopian transfer.

A case of EP after GIFT into the contralateral tube is presented. Hydrotubation with Earle's medium immediately before the GIFT cannot be excluded as a possible cause of gamete migration. The complete demise of the CL also demonstrates that trophoblast can implant and develop without steroidal support.

Adult↗
PubMed1992

Propofol anaesthesia for ultrasound guided oocyte retrieval: accumulation of the anaesthetic agent in follicular fluid.

Propofol (2,6-diisopropylphenol, Diprivan, ICI-Pharmaceuticals, Manchester, UK) is widely used either as an adjunct in general anaesthesia or as sole anaesthetic agent by the continuous intravenous route and intermittent bolus injections for minor surgical interventions. For several years, we have been using this kind of anaesthesia in transvaginal oocyte retrieval for in-vitro fertilization (IVF), allowing a completely painless puncture on an out-patient basis. From in-vitro studies on mouse oocytes, it appeared that propofol could be deleterious for fertilization in a dose- and time-dependent manner. We therefore investigated the concentrations of propofol in follicular fluid during oocyte retrieval in women. We measured propofol levels in serum and follicular fluid of nine patients at fixed intervals during ultrasound guided oocyte retrieval. Serum levels fluctuated randomly, due to interference from top-off doses of propofol. In follicular fluid, however, we found a steady increase of propofol levels, which was proportional to the total dose of propofol administered. These data indicate that propofol accumulates in follicular fluid. Although it seems unlikely that propofol as used in the present protocol exerts a clinically significant unfavourable effect on IVF, we suggest that the oocyte retrieval procedure should be kept as short as possible, in order to limit the accumulation of the anaesthetic in follicular fluid.

Dose-Response Relationship, Drug↗
PubMed1991

Influence of nebivolol on the cardiovascular hemodynamics during postural changes and isometric exercise.

Nebivolol (R67555), a drug with beta 1 receptor antagonizing properties, was administered once daily (5 mg) for 7 days in 10 healthy volunteers. The hemodynamic parameters were measured noninvasively during postural changes (supine, sitting, standing) and during isometric handgrip at 50% maximal voluntary contraction, before and 3, 8, and 23 hours after the first nebivolol intake of 5 mg; the same measurements were done 23 hours after the last intake. Nebivolol lowered arterial blood pressure acutely and chronically due to a decrease in heart rate and cardiac output. The stroke volume seemed to be preserved, while the total peripheral vascular resistance did not change. Nebivolol did not change the orthostatic responses, except that the absolute value was lowered. Nebivolol was unable to prevent the blood pressure increase during isometric handgrip. However, this blood pressure increase was obtained by an increase in the total peripheral vascular resistance and not by an increase in the cardiac output, as observed during control measurements before nebivolol intake.

Adrenergic beta-Antagonists↗
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

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↗
PubMed1987

Clinical manifestations in HLA-B27-positive patients.

The clinical manifestations of rheumatic diseases have been studied in a population of 440 HLA-B27-positive patients. Fifty-eight per cent had peripheral joint involvement. After statistical analysis and clustering of characteristics, three patterns of peripheral joint involvement were found. They were referred to as the X, Y and Z type for mnemotechnical reasons. The X type includes male patients with sacroiliitis, spondylitis, uveitis and uni- or bilateral arthritis of hip and/or shoulder. Y type patients present sacroiliitis, pauci-articular asymmetrical joint involvement and tendinitis. Z type patients are characterized by sacroiliitis, polyarticular symmetrical joint involvement and a positive IgM rheumatoid factor. This classification enables a new approach to the pathology, diagnosis and therapy of the seronegative spondyloarthropathies.

Adolescent↗