Effects of androgens on aromatase activity and 11C-vorozole binding in granulosa cells in vitro.

BACKGROUND: Locally produced androgens and estrogens are important in the hormonal regulation of follicular development. The present study aimed to further elucidate the mechanism through which androgens exert their ambivalent effects on aromatization. METHODS: Non-cultured human granulosa-luteal cells (GC) were treated with different concentrations of androstenedione (A4), testosterone (T), 5alpha-androstane-3,17-dione (5alpha-A) and dihydrotestosterone (DHT). The effects on aromatase activity were evaluated in a tritiated water assay (incubation time 2 h) and the availability of aromatase active sites was measured in a radiotracer-binding assay using the non-steroidal competitive aromatase inhibitor [11C]-vorozole (incubation time 15 min). RESULTS: A4, T and 5alpha-A caused dose-dependent inhibition of both aromatase activity and [11C]-vorozole binding; IC50-values for both inhibition processes were calculated for these three steroids, revealing A4 as the most potent inhibitor and T and 5alpha-A as moderate inhibitors. At low concentrations (0.01 and 0.1 micro M), DHT stimulated aromatase activity but did not affect [11C]-vorozole binding. At the higher concentrations tested (1 and 10 micro M) DHT suppressed both processes thus weakly binding the aromatase active site. CONCLUSION: Because the incubation time in the tritiated water assay was short, the stimulation by DHT at low concentrations might therefore most likely include mechanisms other than new synthesis of aromatase protein such as allosteric action of DHT upon aromatase or liganded androgen receptor-aromatase interaction.

Cytologic screening and human papilloma virus test in women undergoing artificial fertilization.

BACKGROUND: Infertile women in Sweden are offered in vitro fertilization (IVF) within the frame of the social security system. The present investigation was undertaken to evaluate the prevalence of genital human papilloma virus (HPV) infection in relation to the results of cytologic screening and to the infertility in these women. MATERIAL AND METHODS: Two hundred and fourteen women, mean age 32 years (range 20-40), admitted to the Center for Reproduction at Uppsala University Hospital for investigation of infertility and IVF were studied. Human papilloma virus tests were performed by a sensitive polymerase chain reaction-based technique in cervical smears obtained at a medical examination or during oocyte retrieval. Cytologic screening results were obtained from medical records or at the time of investigation. The infertile women were compared with 197 healthy female controls. RESULTS: Infertility resulted from female factors in 47% and male factors in 29% of the cases, and remained unexplained in 24%. Seven percent of the infertile women were HPV-positive compared with 9.1% of the controls. Only genital and oncogenic HPV types were identified. Human papilloma virus type 16 was most prevalent, and examination of the HPV 16 E6 gene showed that this prototype predominated over variants. No correlation was found between HPV infection and cause of infertility. Abnormal cytology was observed in 2.3% of the infertile women and 4.1% of the controls. CONCLUSIONS: Human papilloma virus infections might appear somewhat less frequently in infertile women admitted for IVF than in a control population. In both groups HPV infection was more common than cytologic abnormalities, possibly indicating that present HPV tests are more sensitive in detecting HPV infections than cytologic screening.

Follicles are found in the ovaries of adolescent girls with Turner's syndrome.

Infertility caused by ovarian failure is a characteristic feature in Turner's syndrome. Spontaneous pregnancies are seen in 2-5% of these women, and up to 30% have at least some pubertal development, indicating the presence of follicles in their ovaries in adolescence. It has not been clear at which age the follicles disappear. We analyzed the numbers and densities of follicles in ovarian cortical tissue from nine adolescent girls with Turner's syndrome who came to our clinics after having been informed about the study, with an aim to preserve ovarian tissue for possible infertility treatment later in life. A quarter to one whole ovary was laparoscopically removed for the procedure. Follicles were seen in the biopsy tissue in eight of nine subjects from whom ovarian tissue was laparoscopically obtained, the highest numbers being seen in the youngest girls and in those with mosaicism. In one 17-yr-old girl, no ovarian tissue was found. Follicle density was correlated with serum levels of FSH; individuals with the lowest FSH levels had the highest follicle density. One to 190 follicles were counted in the approximately 0.1-2.0 mm(3) of tissue analyzed, giving a density of 1.5-499 follicles/mm(3) of ovarian cortical tissue. Girls up to the age of 17 had primordial follicles in their ovaries. Three girls, two aged 15 yr and one aged 19, had only secondary follicles, with many being atretic. Our finding that adolescent girls with Turner's syndrome still have follicles in their ovarian cortical tissue raises the possibility of future fertility through cryopreservation of ovarian tissue. However, before such procedures can be recommended for clinical management, it is essential that future studies be performed to determine whether the oocytes retrieved from girls with Turner's syndrome have a normal chromosomal complement.

Embryo transfer after 2 or 5 days of IVF culture: a retrospective comparison.

BACKGROUND: To determine whether prolongation of embryo culture in vitro from day 2 to day 5 after ovum pick-up (OPU) and fertilization can improve the results of in vitro fertilization (IVF), and the morphology of the spare embryos on day 2 can predict the developmental capacity during prolonged culture. We also wanted to consider this as a strategy to avoid twin pregnancies if it could be possible to transfer only one blastocyst at a time in the future. METHODS: A retrospective analysis with embryo transfer timed according to the weekday of OPU. Embryo transfer was performed on day 2 in 103 cases and on day 5 in 120 cases. Only one cycle per couple was included. RESULTS: The pregnancy rates per embryo transfer on day 2 (27/103, 26%) and day 5 (36/120, 30%) were similar. There were significantly more miscarriages in the day 5 (50%) than in the day 2 group (22%, p = 0.02), but there was no significant difference in the baby take home rate (20% in day 2 group, 15% in day 5 group). The morphological appearance of the embryos on day 2 was poorly correlated to the developmental potential during prolonged culture in vitro. On day 5, transfer of one or two blastocysts resulted in a pregnancy rate that tended to be higher than that after transfer of morulae only. CONCLUSION: Prolongation of embryo culture from day 2 to day 5 did not improve the clinical outcome of the IVF treatment when measured as baby take home rate. Therefore, for the time being, this strategy does not increase our chances to move towards single embryo transfer.