Background: Many research works showed that menstruation is caused by the sudden reduction of the estrogens and progesterone to low levels of secretion at the end of the menstrual cycle. However, it should be investigated to which levels the concentration of these two hormones sharply reduces to cause menstruation. Objective: To determine estradiol concentration at the beginning of menstruation, the second day of menstruation and the ending of menstruation during the menstrual cycle. Subject and methods: 30 women with the normal menstrual cycle and 30 women with the long menstrual cycle were used as subjects to determine estradiol concentration at the day at the beginning of menstruation, the second day of menstruation and the last day of menstruation during the menstrual cycle. Result and Conclusion: In the women group with the normal menstrual cycle, the estradiol concentration: at the day at the beginning of menstruation is 159.93 \xb1 51.29 pmol/L, at the second day of menstruation is 170.58 \xb1 46.54 pmol/L and at the lastday of menstruation is 177.55 \xb1 46.42 pmol/L. In women in the group with long menstrual cycle, the estradiol concentration: at the day of beginning of menstruation is 154.55 \xb1 61.60 pmol/L and at the last day of menstruation is 154.55 \xb1 61.60 pmol/L.
menstrual cycle ; estrogen ; estradiol

No abstract available.
Estrogen Replacement Therapy* ; Female

No abstract available.
Selective Estrogen Receptor Modulators*

Estrogen replacement therapy (ERT) is known to significantly decrease menopausal health risks, thus, a survey of 200 women attending a tertiary hospital was conducted. Assess their attitudes toward menopause and ERT to determine factors that might increase its use revealed that women taking their ERT were more likely to know that decreased estrogen hormone causes osteoporosis. All groups however believed that natural approaches to menopause are more preferable and ERT should be reserved for women with distressing symptoms. The study suggests that a systematic educational approach could increase awareness and use of ERT especially if the recommended therapy will not cause vaginal bleeding and will cost minimally.
Human ; MENOPAUSE ; ESTROGEN REPLACEMENT THERAPY

Breast cancer is a malignant tumor that occurs in the epithelial tissues of the breast gland. The cause of the disease is not fully understood and may be related to genetic, endocrine and other factors. For estrogen or progesterone receptor-positive early breast cancer, endocrine therapy is efficient, simple, and fewer side-effect, so endocrine therapy plays an important role in the treatment for early breast cancer. But most of them will develop drug-resistant after 8 to 14 months and have to combine with chemotherapy or molecule targeted therapy. However, there are still different ideas in the effects of endocrine therapy drugs alone or in combination with chemotherapy or molecule targeted drugs, pre-menopausally or post-menopausally.
Breast Neoplasms ; Humans ; Receptors, Estrogen

One third of estrogens in the male are from the testis and the others from outside the testis. Aromatase P450 (CYP19) is an enzyme responsible for the conversion of androgens to estrogens. Estrogens regulate cell function via specific receptors--estrogen receptors (ER) which include ER alpha and ER beta. It has been found that the role of estrogens in male reproduction is complex and important, particularly during the neonatal life. Males lacking ER alpha are completely infertile because ER alpha-induced estrogens regulate the reabsorption of luminal fluid in the head of the epididymis and disruption of this essential function causes sperm to enter the epididymis diluted, rather than concentrated, resulting in infertility. Whereas males lacking aromatase or ER beta are fully fertile. Therefore, it is concluded that ER alpha, but not aromatase or ER beta, is essenitial for normal male fertility.
Animals ; Aromatase ; physiology ; Estrogen Receptor alpha ; Estrogen Receptor beta ; Estrogens ; physiology ; Humans ; Male ; Receptors, Estrogen ; physiology ; Reproduction ; physiology

Estrogen plays an important role in the regulation of male reproduction. Through binding with the estrogen receptor (ER), estrogen produces genomic and non-genomic effects. Estrogen receptors include ERalpha and ERbeta which distribute in the male reproductive system including the testis, epididymis, prostate and penis. The spermatogenesis is impaired in mice with ERalpha gene knockout; however, it remains normal in mice with ERbeta gene knockout. This phenomenon suggests that the two subtypes of ER play different roles in spermatogenesis. Moreover, ERalpha or ERbeta may also act as a substitute of another.
Animals ; Estrogen Receptor alpha ; metabolism ; Estrogen Receptor beta ; metabolism ; Genitalia, Male ; metabolism ; Male ; Mice ; Receptors, Estrogen ; metabolism

No abstract available.
Estrogens* ; Humans* ; Pituitary Neoplasms* ; Receptors, Estrogen*

No significant difference was noted in canine hookworm infection due to hormone influence between the control group and the gonadectomized rats which were sacrificed 17 days after gonadectomy and 7 days after the infection. However in the rats which were infected 20 days after oophorectomy a significant difference was thought to be present in this group(176 +- 12.9 larvae/rat) compared with the control group (138 +- 21.2 larvae/rat). On the other hand, in the castrated group the number of larvae (138 +- 37.1 larvae/rat) was less than that in the control group (208 +- 43.4 larvae/rat). In the estrogen-injected male and female groups, there were no difference compared to the control, but the testosterone-injected groups of males and females showed more susceptibility to infection by A. caninum than in the control group. The Capillaria hepatica infection to the castracted host showed no significant difference between the gonadectomized and the control group. (oophorectomy; 214 +- 28.0), castration; 250 +- 36.5 and control; 191 +- 58.2 and 270 +- 30.1 adults/rat). Concerning the influence of the host's sex hormone on egg production of canine hookworm, there was a significantly decreased egg production in castrated dogs(6,578 +- 664.0 egg per gram) compared to the control dogs(9,711 +- 1,322.3 egg per gram). The same results were observed in vitro test. In the host, the susceptibility to hookworm infection was reduced in castrated rats, while oophorectomy group had a little or no effect. In the favorable or unfavorable hosts, testosterone gave the tendency of increasing susceptibility of the host to infection, while estrogen did a little or no effect.
parasitology-helminth-nematoda ; hookworm ; estrogen ; testosterone ; rat ; dog Ancylostoma caninum ; Capillaria hepatica ; gonadectomy ; estrogen ; testosterone

OBJECTIVETo study the expression of the estrogen receptor (ER) and type II collagen in the mandibular condylar cartilage of the human embryo.

METHODSThe expression and localization of ERalpha, ERbeta, and type II collagen in the mandibular condylar cartilage of the human embryo were examined through hematoxylin-eosin (HE) and immunohistochemistry staining.

RESULTSType II collagen was primarily localized in the transitional and hypertrophic layers of the condylar cartilage. ERa was mostly expressed in the transitional and hypertrophic cartilaginous layers of the condylar cartilage. ERa was evenly distributed in the cell, whereas ERbeta was localized in the nuclei. No expression of type II collagen and ER was found in the fibrage and the proliferative layer although minimal expression was found in the calcified cartilage.

CONCLUSIONThe distribution of ER and type II collagen in the mandibular condylar cartilage was consistent. Estrogen can selectively combine with different subtypes of ER that regulate the ability of the condylar cartilage cells to secrete type II collagens.