T he bulletins from the nation’s therapeutic frontiers continue to read like the casualty reports from a lost war. At least once or twice a year, yet another pharmaceutical company or regulatory agency or biomedical journal releases yet another melancholic communiqué on the terrible effects of a drug that previously had been thought to be the greatest advance in medicine since aspirin or penici...

To the Editor: We feel compelled to comment on the Brief Review “Should progestins be blamed for the failure of hormone replacement therapy to reduce cardiovascular events in randomized controlled trials?” by Koh and Sakuma.1 Specifically, although we agree with the suggestion that the effects of estrogen on the vasculature may depend on the extent and severity of existing atherosclerosis, we d...

To the Editor: We feel compelled to comment on the Brief Review “Should progestins be blamed for the failure of hormone replacement therapy to reduce cardiovascular events in randomized controlled trials?” by Koh and Sakuma.1 Specifically, although we agree with the suggestion that the effects of estrogen on the vasculature may depend on the extent and severity of existing atherosclerosis, we d...

To the Editor: We feel compelled to comment on the Brief Review “Should progestins be blamed for the failure of hormone replacement therapy to reduce cardiovascular events in randomized controlled trials?” by Koh and Sakuma.1 Specifically, although we agree with the suggestion that the effects of estrogen on the vasculature may depend on the extent and severity of existing atherosclerosis, we d...

Previously, we demonstrated that progesterone (P(4)) promoted adult rat neural progenitor cell (rNPC) proliferation with concomitant regulation of cell-cycle gene expression via the P(4) receptor membrane component/ERK pathway. Here, we report the efficacy of seven clinically relevant progestins alone or in combination with 17β-estradiol (E(2)) on adult rNPC proliferation and hippocampal cell v...

Most oral contraceptives (OC) contain a progestin in combination with an estrogen, and the progestin component in OC includes one of the following 19-nortestosterone derivatives: norethynodrel; norethindrone; or norgestrel (levonorgestrel). It is well known that estrogens promote the growth of breast cancer. However, progestins have recently also been implicated in the development of breast can...

The relationship between the use of menopausal hormone therapy (ERT, unopposed estrogen therapy; HRT, combined estrogen and progestin therapy) and the development of breast cancer remains controversial. Mechanistic studies examining progestins in human breast cancer cell lines have demonstrated a biphasic cellular response to progesterone; initial exposure to hormone results in a proliferative ...

Premature delivery (PTD), defined as birth prior to 37 weeks’ gestation, remains one of the major problems that lead to perinatal morbidity and mortality in the developed countries (Goldenberg et al., 2008). It affects approximately 12.7% of all deliveries in the United States and 4.4 – 8.2% in many other developed countries such as Australia, New Zealand, Sweden, Canada and Japan (Hamilton et ...

In the last two decades the prevailing opinion, supported by the "estrogen augmented by progesterone" hypothesis, has been that progesterone contributes to the development of breast cancer (BC). Support for this opinion was provided by the finding that some synthetic progestins, when added to estrogen in hormone replacement therapy (HRT) for menopausal complaints, increase the BC risk more than...

Most oral contraceptives (OC) contain a progestin in combination with an estrogen, and the progestin component in OC includes one of the following 19-nortestosterone derivatives: norethynodrel; norethindrone; or norgestrel (ievonorgestrel). It is well known that estrogens promote the growth of breast cancer. However, progestins have recently also been implicated in the development of breast can...