The method of parabiosis in rats was used in the analysis of the effects produced by continuous gonadotrophic overstimulation of ovaries. The source of constant gonadotrophin supply was the hypophysis of the castrate member of pairs. The reactor animal was either a hypophysectomized female (I), a male carrying an ovarian graft (II), or a constant-estrus female (III). The essential feature in ea...

BACKGROUND Despite the recognized role of hormones in the aetiology of breast cancer, there has been little evaluation of hormonal preparations used to treat infertility. METHODS A retrospective cohort study of 12,193 women evaluated for infertility between 1965 and 1988 at five clinical sites identified 292 in situ and invasive breast cancers in follow-up through 1999. Standardized incidence...

The use of ovulation induction combined with intrauterine insemination (IUI) as a treatment for subfertility in women with patent Fallopian tubes has increased in recent years. Little is known regarding the efficacy of this treatment in women aged >/=40 years. We reviewed our data in our ovulation induction with IUI programme for 168 consecutive patients aged >/=40 years undergoing a total of 4...

BACKGROUND Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic and potentially life threatening condition resulting from excessive ovarian stimulation. Reported incidence varies from 1% to 10% of in vitro fertilization (IVF) cycles. The factors contributing to OHSS have not been completely explained. The release of vasoactive substances secreted by the ovaries under human chorionic gonado...

BACKGROUND The aim of this study was to evaluate the effect of doubling the starting dose of gonadotrophins on the ovarian response in IVF patients with a low antral follicle count (AFC). METHODS Fifty-two patients with an AFC of <5 follicles of 2-5 mm diameter before starting their first IVF cycle participated in this randomized controlled trial. They were randomized by opening a sealed enve...

A bulk of studies on the assay of gonadotrophic hormone content of the anterior pituitary from the animals in various reproductive conditions has been done. Riley and Fraps(1942b) assayed pituitary glands from chickens in various reproductive stages, judging the gonadotrophic potency by the increment of uterine weights of immature mice, and concluded that glands from non-laying hens produced a ...

During follicular development, a co-ordinated gonadotrophin and endocrine environment is believed to be essential for normal function of the resulting corpus luteum. Whether differences in the gonadotrophins used to promote follicular development can have lasting effects on granulosa cells after they have undergone luteinization and culture, remains to be studied. We measured steroid production...

Human gonadotrophins undergo metabolic transformations which result in the presence of several smaller, structurally and immunologically related forms of gonadotrophins in the urine. For luteinizing hormone (LH), a beta core fragment (LHbeta cf) has been isolated from the pituitary and characterized. The corresponding urinary fragment is inferred from mass spectral and immunochemical analysis o...