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R M van der Weiden

Publications and source records attributed to R M van der Weiden.

At least 19 recordsLinked to original sources
PubMed2001

The Mozart effect.

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Automobile Driving↗
PubMed2000

CA-125 levels are related to the likelihood of pregnancy after in vitro fertilization and embryo transfer.

PROBLEM: To assess the relationship between serum cancer antigen (CA)-125 concentrations and the likelihood of pregnancy after in vitro fertilization/embryo transfer (IVF ET). METHOD OF STUDY: A prospective longitudinal follow-up study was conducted in 44 IVF patients receiving luteinizing hormone-releasing hormone (LHRH) suppression, followed by human menopausal gonadotrophin (hMG). There were no indications of endometriosis. Progesterone or human chorionic gonadotrophin (hCG) were given as luteal support. Serum samples were taken just before oocyte pick-up (OPU), 14 days after ET and, after the establishment of a clinical pregnancy, on day ET + 21. Samples were stored at -80 degrees C until analysis. CA-125 was measured using a commercially available enzyme immunoassay (IMx CA-125; Abbott, North Chicago, IL, USA). The signed rank (paired samples) and Wilcoxon tests were used for statistical analysis. RESULTS: There were no differences in CA-125 concentrations at the time of OPU between pregnant (n = 18) and non-pregnant (n = 26) IVF patients. After OPU. the CA-125 concentrations rose both in pregnant (P<0.0001) and in non-pregnant (P <0.001) patients. This rise was greater after successful implantation, and 14 days after ET, higher CA-125 concentrations were found in the pregnant patients (P< 0.01). CONCLUSIONS: Differences in serum CA-125 concentrations between pregnant and non-pregnant IVF patients appear to be related to the likelihood of successful implantation.

Adult↗
PubMed1998

Which prostanoid metabolites should be determined for the study of reproductive processes?

The non-enzymatic metabolites of prostacyclin (PGI2) and thromboxane A2 (TXA2), 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha) and thromboxane B2 (TXB2), and their 2,3-dinor metabolites, 2,3-dinor-6-keto-PGF1alpha and 2,3-dinor-TXB2, were measured in early morning urine samples in 24 in vitro fertilization (IVF) cycles in 24 women and in 27 women who became pregnant after IVF and embryo transfer (ET). The sum of the non-enzymatic metabolites and their 2,3-dinor metabolites was considered to be a reflection of total PGI2 and total TXA2 production in vivo. Both the ratio of 'total' PGI2/'total' TXA2 and the ratio of the 2,3-dinor metabolites were calculated. TXB2 concentrations showed virtually no change and the ratios of the non-enzymatic metabolites of PGI2 and TXA2 versus their 2,3-dinor metabolites remained relatively constant. As a consequence, the ratio of 2,3-dinor-6-keto-PGF1alpha/2,3-dinor-TXB2 was a close reflection of the ratio of 'total' PGI2/'total' TXA2, although the latter ratio was significantly higher all the time. We conclude that for comparative studies on the balance between PGI2 and TXA2 in IVF cycles and during gestation, the determination of the 2,3-dinor metabolites alone can replace the measurement of all four metabolites.

Biomarkers↗
PubMed1996

Prostanoid excretion in incipient singleton and twin pregnancies.

OBJECTIVE: Our purpose was to examine the urinary excretion of metabolites of prostacyclin, 6-keto-prostaglandin F(1 alpha) and 2,3-dinor-6-keto-prostaglandin F(1 alpha), and thromboxane A2, thromboxane B2 and 2,3-dinor-thromboxane B2, in early twin and singleton pregnancies resulting from in vitro fertilization-embryo transfer. STUDY DESIGN: Overnight urine samples were obtained from 23 women at regular intervals for 20 weeks after embryo transfer. Prostanoids were measured by high-pressure liquid chromatography-radioimmunoassay. RESULTS: All prostanoids, most markedly 6-keto-prostaglandin F(1 alpha) and 2,3-dinor-6-keto-prostaglandin F(1 alpha), increased in both singleton and twin pregnancies. This resulted in an increased ratio of prostacyclin over thromboxane A2 both in the dinor compounds (from 1.3 to 2.8) and the total metabolites (from 1.7 to 3.5). No marked differences were observed between twin and singleton pregnancies. CONCLUSIONS: Twin and singleton pregnancies show a similar increase in the prostacyclin to thromboxane A2 ratio in the first half of pregnancy.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Immunohistochemical and ultrastructural localization of prostaglandin H synthase in the preimplantation mouse embryo.

The immunohistochemical and ultrastructural localization of prostaglandin H synthase (PGH synthase) was studied in the Albino Swiss CF-1 mouse at different stages of embryonic development (two-cell stage, four-eight cell stage, morula and blastocyst). Flushed embryos and sections of uteri and oviducts containing embryos were treated with a mouse IgG monoclonal anti-PGH synthase antibody. The second antibody (rabbit anti-mouse) was conjugated with peroxidase or fluorescein isothiocyanate for light microscopy, fluorescence microscopy and confocal scanning. For reflection contrast microscopy and transmission electron microscopy a second antibody, goat anti-mouse, was conjugated with ultrasmall gold particles. Controls without anti-PGH synthase were used concurrently. All embryos demonstrated PGH synthase reactivity. Immunostaining appeared to be more intense at the two-cell stage, four-eight cell stage embryos and morulae than in blastocysts. Further examination indicated an intracytoplasmic location for PGH synthase, which was confirmed by stereoscopic photographs made during confocal scanning microscopy and by the immunostaining patterns observed with reflection contrast microscopy and transmission electron microscopy. Transmission electron microscopy immunostaining patterns support the localization of PGH synthase in the endoplasmic reticulum. This is the first demonstration of the ultrastructural localization of PGH synthase in the mouse embryo. Its presence before the apposition with the endometrial epithelium supports the hypothesis that arachidonic acid metabolism via the PGH synthase pathway may be crucial for implantation.

Animals↗
PubMed1995

Prostanoid excretion before in vitro fertilization relates to the likelihood of pregnancy.

The objective of this study was to determine the urinary excretion of prostacyclin (PGI2) and thromboxane A2 (TXA2) metabolites during in vitro fertilization (IVF) in relation to the clinical outcome of IVF. Urine was obtained overnight every 3 to 4 days from 24 women during IVF cycles. TXB2, 6-keto-PGF1 alpha and their 2,3-dinor derivatives were measured by high-pressure liquid chromatography with radioimmunoassay. The patients were women with (n = 16, 119 samples) and without (n = 8, 53 samples) a clinical IVF pregnancy. Concentrations of 2,3-dinor-TXB2 and 2,3-dinor-6-keto-PGF1 alpha were lower before embryo transfer in women who achieved a pregnancy than in those who did not conceive (p < 0.05). Contrary to women who did not conceive, women who achieved pregnancy had an increase in 6-keto-PGF1 alpha excretion after embryo transfer (p = 0.04). In women who did not conceive, levels of 2,3-dinor-TXB2 were higher before embryo transfer than after transfer (p = 0.04) and than levels in women who did conceive (p = 0.01). We concluded that differences in urinary prostanoid metabolite excretion before embryo transfer appear to relate to the likelihood of pregnancy, but the nature of this relationship remains elusive.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Prostanoid levels in in vitro fertilization culture medium are not related to the likelihood of implantation.

OBJECTIVE: To determine prostanoid levels (prostaglandin E2, prostaglandin F2 alpha, 6-keto-prostaglandin F1 alpha, and thromboxane B2 [TXB2]) in embryo culture medium containing inactivated maternal serum and their correlation with the clinical outcome of IVF-ET. DESIGN: Prostanoid levels were measured in blank control medium and in medium containing an embryo or nonfertilized oocyte with a high-pressure liquid chromatography (HPLC-RIA) method. Comparisons of HPLC-RIA, Seppak C18-RIA, and RIA directly in the medium demonstrated identical results for TXB2, allowing the use of direct RIA in the large investigation of 129 media. SETTING: Leiden University Hospital, The Netherlands. PATIENTS: Patients with (n = 12) and without (n = 15) an ongoing pregnancy after IVF-ET. MAIN OUTCOME MEASURES: Prostanoid levels in embryo culture medium and relationship between prostanoid levels and successful implantation. RESULTS: Thromboxane B2 is the only prostanoid consistently found in these media. In both groups there was no difference in TXB2 levels between control media, media containing a nonfertilized oocyte, and media containing an embryo. There was no difference in TXB2 levels between media that had harbored the beginning of a successful pregnancy and those that had not produced a pregnancy. CONCLUSION: Thromboxane B2 in the embryo culture medium originates from maternal serum and bears no relationship with the likelihood of fertilization and implantation.

Chromatography, High Pressure Liquid↗
PubMed1993

The influence of indomethacin on the hatching of mouse blastocysts.

In order to investigate the effect of indomethacin for inhibition of the cyclooxygenase pathway on the hatching process of mouse blastocysts, 508 mouse blastocysts were cultured in modified HAM F10 medium containing 0, 8, 79 or 788 microM indomethacin, added after 24 h of incubation. Hatching was scored after 72 h of incubation. In another series of experiments, indomethacin was added only after blastulation had occurred. Indomethacin in doses of 8 microM and 79 microM, added after 24 h of incubation or after blastulation had occurred, did not influence successful hatching. A dose of 788 microM indomethacin interfered with hatching, but this dose appeared to be toxic for the embryo.

Animals↗