background: human chorionic gonadotropin (hcg) has been used as a replacement for the mid-cycle luteinizing hormone (lh) surge for several years. the recent arrival of recombinant dna technology has made recombinant hcg (rhcg) accessible. objective: to assess efficacy of rhcg compared to urinary hcg (uhcg) for triggering of ovulation and induction of final oocyte maturation in assisted reproduc...

A mathematical model describing the biochemical interactions of the luteinizing hormone (LH), luteinizing hormone–releasing hormone (LHRH), and testosterone (T) is presented. The model structure consists of a negative feedback mechanism with transportation and secretion delays of different hormones. A comparison of stability and bifurcation analysis in the presence and absence of delays has bee...

Efforts to identify the manner in which human choriogonadotropin (hCG) contacts lutropin receptors (LHR) have been stymied by the complex structure of the hormone and the likelihood that it contacts the receptor at multiple sites. During studies of hCG assembly in mammalian cells, we found that addition of a cysteine to the long disordered beta-subunit COOH terminus (betaCT) enabled it to becom...

Recent research studies associate elevated gonadotropin levels with dementia. Specifically, an age associated increase in levels of luteinizing hormone has been linked to an increased risk of Alzheimer's disease. The objective of this study was to investigate the association between gonadotropin levels and cognition in older, healthy postmenopausal women. Cognitive functioning was compared with...

PCOS is one of the most common endocrine disorders among women between 12 and 45 years age, affecting 5-10% women. The patients were included in current study based on criteria Rotterdam diagnosis polycystic ovarian syndrome with at least two following three criteria: menstrual cycle disorder, chemical for high levels androgen, detection ovary using ultrasound (10 or more cysts 2-10 mm diameter...