” Estrogens have important effects on bone turnover in both humans and experimental animals models. Moreover, the decreased level of estrogen after menopause appears to be one of the key factors in determining postmenopausal osteoporosis. The presence of estrogen receptor in both osteoblasts and osteoclasts has suggested a direct role of these steroid hormones on bone tissue. Thus, this tissue is now regarded as a specific estrogen target tissue. Exposure to estrogens during various stages of development has been shown to irreversibly influence responsive target organs. We have recently shown that transient developmental neonatal exposure (days 1-5 of life) of female mice to estrogen resulted in an augmented bone density in the adult animals. The aim of the present study was to evaluate whether short-term modification of maternal estrogen levels during pregnancy would induce changes in the skeleton of the developing fetuses and to identify any long-term alterations that may occur. Pregnant mice were injected with varying doses (0.1-100 micrograms/kg maternal BW) of the synthetic estrogen diethylstilbestrol (DES) from day 9-16 of pregnancy. Offspring were weaned at 21 days of age, and effects on bone tissue of the female mice were evaluated in adulthood (6-9 months of age). Prenatal DES treatment(s) did not significantly affect BW. However, a dose-dependent increase in bone mass, both in the trabecular and cortical compartments, was observed in the prenatal DES-exposed female offspring. Furthermore, long bones of DES-exposed females were shorter than controls. Normal skeletal mineralization accompanied these changes in the bone tissue, as shown by a parallel increase in skeletal calcium content. Double tetracycline labeling performed in 6-month-old DES-exposed animals showed an increase in mineral apposition rate in adult DES-exposed mice as compared with untreated control animals, although no significant difference in the circulating estrogen levels was found in animals of this age. Experiments were then performed to evaluate whether perturbation of the estrogen surge at puberty in these diethylstilbestrol (DES)-exposed mice could reverse the observed changes. Femur length was chosen as a marker of potential estrogenic effect. Prepubertal ovariectomy of the prenatally DES-treated animals could only partially reverse the effects observed in the skeleton of the DES-treated animals. Further experiments were performed to evaluate whether these changes could have occurred in utero. CD-1 pregnant female mice were injected with DES (100 micrograms/kg maternal BW) from days 9-15 of gestation. On day 16 of gestation, fetuses were examined and stained by a standard Alizarin Red S and Alcian Blue procedure to visualize calcified and uncalcified skeletal tissue. Estrogen treatment induced an increase in the amount of calcified skeleton as compared with untreated controls and also a decrease in the length of long bones, strongly suggesting a change in both endochondral ossification and endosteal and periosteal bone formation. In summary, these data show, for the first time, that alterations in the maternal estrogenic levels during pregnancy can influence early phases of fetal bone tissue development and subsequently result in permanent changes in the skeleton. Finally, the effect of this short-term estrogen treatment can be seen in the fetal skeleton, suggesting an estrogen-imprinting effect on bone cell-programming in fetal life because treatment effects on bone cell turnover can be observed later in adult life. ”
” My name is Stacey. My sister and I have been close since the moment my parents brought her home from the hospital.
We went through the ups and downs of puberty, high school, college, and then marriage together… … My husband and I tried to get pregnant for a couple years on our own, and were disappointed that it wasn’t happening. Finally, I got pregnant but then miscarried. It was devastating... ”
In a new study from China, men who were exposed to BPA – because they worked in a chemical plant for at least six months – had lower levels of testosterone in their blood compared with those who worked in a tap water factory.
” My name is Laura. My sister Stacey and I were born a year apart and grew up sharing everything – clothes, toys, books, and even friends. When we both got married, we assumed that we’d share maternity leaves together and that our children would be the best of friends. My husband and I started trying about a year after we got married, and were thrilled that we became pregnant fairly quickly. My sister’s experience was very different. Year after year, she and her husband tried to get pregnant, with no success. She managed to get pregnant a few times, but each time she miscarried. ”
Lymphoma drug, Enzastaurin, fails In late-stage trial
” Eli Lilly said it will stop development of Enzastaurin experimental cancer drug after it failed in a late-stage trial to delay a worsening of symptoms in patients with lymphoma, but continues with late-stage trials of two other experimental cancer drugs. ”
Liberty, Fertility, and the Pursuit of High-tech Babies
Cracked Open is Miriam Zoll’s eye-opening account of growing into womanhood with the simultaneous opportunities offered by the women’s movement and new discoveries in reproductive technologies. Influenced by pervasive media and cultural messages suggesting that science had finally eclipsed Mother Nature, Zoll –– like millions of women –– delays motherhood until the age of 40.
When things don’t progress as she had hoped, she and her husband enter a science-fiction world of medical seduction, capitalist conception and bioethical quagmires. Desperate to conceive, they turn to unproven treatments and procedures only to learn that the odds of becoming parents through reproductive medicine are far less than they and their generation had been led to believe.