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Biomedical subjects

E Van Royen

Publications and source records attributed to E Van Royen.

8 recordsLinked to original sources
PubMed1995

Triggering of ovulation in human menopausal gonadotrophin-stimulated cycles: comparison between intravenously administered gonadotrophin-releasing hormone (100 and 500 micrograms), GnRH agonist (buserelin, 500 micrograms) and human chorionic gonadotrophin (10,000 IU).

We studied the peri-ovulatory and luteal phases in 38 human menopausal gonadotrophin (HMG)-stimulated cycles, in which ovulation was triggered with four different i.v. bolus ovulation triggers: 100 micrograms gonadotrophin-releasing hormone (GnRH; group A, n = 9), 500 micrograms GnRH agonist (GnRHa; group B, n = 10), 10,000 IU human chorionic gonadotrophin (HCG; group C, n = 10) and 500 micrograms GnRH (group D, n = 9). Endogenous luteinizing hormone (LH) surges occurred in all cycles of groups A, B and D. The rise was slowest but highest in group B (P < 0.0001) and lowest in group A. Although the t0 serum oestradiol values were similar in all groups, day +8 oestradiol and day +4 and +8 progesterone concentrations were higher in group C (P < 0.05). At day +4 and +8, serum LH concentrations were lowest (P < 0.01) but follicle stimulating hormone (FSH) concentrations were higher. Clinically, day +8 luteal scores showed a more conspicuous degree of ovarian hyperstimulation in the HCG group (P = 0.0292). Luteal insufficiency, defined as cycles with progesterone concentrations of < 8 ng/ml, occurred much more frequently in groups A, B and D than in group C (day +4: P < 0.0003; day +8: P < 0.0001), despite progesterone supplementation. Three pregnancies (one in group C and two in group D) and one moderate case of ovarian hyperstimulation syndrome (OHSS) (in a non-conceptional group D cycle) occurred. These findings show that (i) ovulation occurs and pregnancy can be achieved following an endogenous LH surge induced by GnRH and its agonists, (ii) a high frequency of luteal insufficiency occurs in such cycles even with luteal supplementation and (iii) OHSS cannot be totally prevented by this approach, although cycles with an endogenous LH surge in general result in fewer subclinical signs of ovarian hyperstimulation.

Buserelin↗
PubMed1994

Pregnancy after intracytoplasmic sperm injection of metaphase II oocytes with spermatozoa from a man with complete retrograde ejaculation.

Retrograde ejaculation is an uncommon cause of infertility, which has been treated successfully with different kinds of artificial reproduction technique, e.g. cervical cap artificial insemination by husband, intra-uterine and intraperitoneal insemination, standard in-vitro fertilization, pronuclear stage transfer and gamete intra-Fallopian transfer. All these techniques require a minimal number and motility of spermatozoa obtained after post-masturbation voiding. In some cases, only very few spermatozoa with very poor or no motility are found in the urine voided immediately after masturbation. In such a case, where no more than 14 spermatozoa were recovered over a 3 h search, intracytoplasmic sperm injection of metaphase II oocytes led to the development and replacement of three fair embryos, resulting in an ongoing twin pregnancy. This technique opens up perspectives for the treatment of men with complete retrograde ejaculation and quasi-azoospermic post-voiding specimens.

Adult↗
PubMed1993

Clinical and endocrine effects of laser vaporization in patients with polycystic ovarian disease.

Responses to laparoscopic ovarian laser vaporization were studied in 17 anovulatory patients with clomiphene citrate-resistant polycystic ovarian disease (PCOD). Ovulatory cycles were obtained in 14 patients (82%). A total of 11 patients (65%) conceived within 1-8 months. Measurements of basal serum hormone levels before and after the procedure in 12 patients revealed a significant decline in testosterone, dihydrotestosterone and androstenedione. In addition, luteinizing hormone (LH) levels decreased, but not significantly. On the other hand estradiol levels slightly increased and a surge in luteal progesterone levels was noted. Serum levels of sex hormone binding globulin, prolactin, dehydroepiandrosterone (DHEA) sulfate, 17-OH-progesterone and follicle stimulating hormone (FSH) remained unchanged. These results suggest that ovarian laser vaporization is very useful when clomiphene citrate fails in PCOD, and has no risk of ovarian hyperstimulation syndrome or multiple gestation, which is frequently observed in ovulation induction with drugs. Most of the endocrine abnormalities associated with PCOD are corrected by the laser procedure.

Adult↗
PubMed1990

In vivo characterisation of 3-iodo-6-methoxybenzamide 123I in humans.

3-Iodo-6-methoxybenzamide (123I-IBZM), a new Dopamine D2 receptor ligand, was used in conjunction with SME 810 brain tomography to study six subjects (one normal volunteer, four schizophrenics and one DAT patient). Initial Dynamic SPET was followed by multislice SPET. High-resolution images of the D2 receptor distribution in the basal ganglia were obtained. The specific binding in D2 receptors of the basal ganglia is highest from 2-4 h p.i. Patients on anti-psychotic drugs showed significantly lower specific binding. Dopamine D2 brain receptor availability in man may now be studied with SPET. Continuous data acquisition with single slice tomography is particularly important in the study of this type of radiotracers.

Adult↗
PubMed1978

The influence of serum folate on urinary excretion of vitamin B12.

It was found that in patients with decreased serum folate concentration, urinary excretion of vitamin B12 was increased in a statistically highly significant way with both oral administration of 58 Co-labeled vitamin B12 and with a 57Co-labeled vitamin B12 intrinsic factor complex. This increased vitamin B12 excretion may account for some false normal Schilling test results. Furthermore, in folate deficiency, the intrinsic factor no longer seems required for vitamin B12 to pass the intestinal wall. It is also questionable whether vitamin B12 absorbed through the intestine under these circumstances could be properly metabolized. Besides statistical evidence, some clinical support for this theory is presented. These findings offer a possible clue for some literature reports that have lacked a satisfactory explanation.

Folic Acid↗