|
Estrogen Provocation Test
The estrogen provocation test, also known as the estrogen stimulation test or estrogen challenge test, is a diagnostic procedure used to evaluate the function of the hypothalamic–pituitary–gonadal axis. It involves the administration of a large amount of estrogen, resulting in estrogenic exposure similar to or greater than normal preovulatory estradiol levels, in an attempt to induce a positive feedback surge in levels of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Estrogens that have been used in the estrogen provocation test include estradiol benzoate, estradiol valerate, ethinylestradiol, and high-dose transdermal estradiol patches. The test involves sustained estrogenic exposure equivalent to estradiol levels of 200 to 300 pg/mL or more for at least 50 hours and results in a surge in gonadotropin levels about 32 to 72 hours following initiation of estrogenic exposure. Levels of LH and FSH increase during the gonadot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen Provocation Test And Gonadotropin Surge With A Single Injection Of Estradiol Benzoate In Premenopausal Women
Estrogen (also spelled oestrogen in British English; American and British English spelling differences#ae and oe, see spelling differences) is a category of sex steroid, sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogeny (biology), endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy. Estrogens are synthesized in all vertebrates and some insects. Quantitatively, estrogens circulate at lower levels than androgens in both men and women. While estrogen levels are significantly lower in males than in females, estrogens nevertheless have important physiological roles in males. Like all steroid hormones, estrogens readily diffusion, diffuse across the cell membrane. Once inside the cell, they bin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Follicle-stimulating Hormone
Follicle-stimulating hormone (FSH) is a gonadotropin, a glycoprotein polypeptide hormone. FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, puberty, pubertal maturation, and reproductive processes of the body. FSH and luteinizing hormone (LH) work together in the reproductive system. Structure FSH is a 35.5 kDa glycoprotein protein dimer, heterodimer, consisting of two polypeptide units, alpha and beta. Its structure is similar to those of luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and human chorionic gonadotropin (hCG). The chorionic gonadotropin alpha, alpha subunits of the glycoproteins LH, FSH, TSH, and hCG are identical and consist of 96 amino acids, while the beta subunits vary. Both subunits are required for biological activity. FSH has a beta subunit of 111 amino acids (FSH β), which confers its specific biologic action, and is responsible for interaction with the follicl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmacodynamics Of Estradiol
The pharmacology of estradiol, an estrogen medication and naturally occurring steroid hormone, concerns its pharmacodynamics, pharmacokinetics, and various routes of administration. Estradiol is a naturally occurring and bioidentical estrogen, or an agonist of the estrogen receptor, the biological target of estrogens like endogenous estradiol. Due to its estrogenic activity, estradiol has antigonadotropic effects and can inhibit fertility and suppress sex hormone production in both women and men. Estradiol differs from non-bioidentical estrogens like conjugated estrogens and ethinylestradiol in various ways, with implications for tolerability and safety. Estradiol can be taken by mouth, held under the tongue, as a gel or patch that is applied to the skin, in through the vagina, by injection into muscle or fat, or through the use of an implant that is placed into fat, among other routes. Mechanism of action Estradiol is an estrogen, or an agonist of the nuclear estrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progestogen Challenge Test
The progestogen challenge test, or progesterone withdrawal test, is a test used in the field of obstetrics and gynecology to evaluate a patient who is experiencing amenorrhea. Due to readily available assays to measure serum estradiol levels, this test is now rarely used. The test is performed by administering a progestogen (medication), progestogen, such as progesterone (medication), progesterone either as an intramuscular injection or oral administration, oral medroxyprogesterone acetate (Provera). If the patient has sufficient serum estradiol (greater than 50 pg/mL), withdrawal bleeding should occur 2–7 days after the progestin is withdrawn, indicating that the patient's amenorrhea is due to anovulation. However, if no bleeding occurs after progesterone withdrawal, then the patient's amenorrhea is likely to be due to either a) low serum estradiol (i.e. premature ovarian failure), b) hypothalamic-pituitary axis dysfunction (such as low GNRH or low FSH that lead to low estrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transdermal Estradiol Patch
Transdermal is a route of administration wherein active ingredients are delivered across the skin for systemic distribution. Examples include transdermal patches used for medicine delivery. The drug is administered in the form of a patch or ointment that delivers the drug into the circulation for systemic effect. Techniques Obstacles Although the skin is a large and logical target for drug delivery, its basic functions limit its utility for this purpose. The skin functions mainly to protect the body from external penetration (by e.g. harmful substances and microorganisms) and to contain all body fluids. There are two important layers to the human skin: (1) the epidermis and (2) the dermis. For transdermal delivery, drugs must pass through the two sublayers of the epidermis to reach the microcirculation of the dermis. The stratum corneum is the top layer of the skin and varies in thickness from approximately ten to several hundred micrometres, depending on the region of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethinylestradiol
Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. Ethinylestradiol was widely used for various indications such as the treatment of menopausal symptoms, gynecological disorders, and certain hormone-sensitive cancers. It is usually taken by mouth but is also used as a patch and vaginal ring. The general side effects of ethinylestradiol include breast tenderness and enlargement, headache, fluid retention, and nausea among others. In males, ethinylestradiol can additionally cause breast development, feminization in general, hypogonadism, and sexual dysfunction. Rare but serious side effects include blood clots, liver damage, and cancer of the uterus. Ethinylestradiol is an estrogen, or an agonist of the estrogen receptors, the biological target of estrogens like estradiol. It is a synthetic derivative of estradiol, a natural estrogen, and differs from it in various ways. Compared to estradiol, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol Valerate
Estradiol valerate (EV), sold for use oral administration, by mouth under the brand name Progynova and for use by injection (medicine), injection under the brand names Delestrogen and Progynon Depot among others, is an estrogen (medication), estrogen medication. It is used in menopausal hormone therapy, hormone therapy for menopausal symptoms and hypoestrogenism, low estrogen levels, transgender hormone therapy (male-to-female), hormone therapy for transgender people, and in hormonal contraception, hormonal birth control. It is also used in the treatment of prostate cancer. The medication is taken oral administration, by mouth or by intramuscular injection, injection into muscle or subcutaneous injection, fat once every 1 to 4 weeks. Side effects of estradiol valerate include breast tenderness, breast enlargement, nausea, headache, and water retention (medicine), fluid retention. Estradiol valerate is an estrogen (medication), estrogen and hence is an agonist of the estrog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol Benzoate
Estradiol benzoate (EB), sold under the brand name Progynon-B among others, is an estrogen medication which is used in hormone therapy for menopausal symptoms and low estrogen levels in women, in hormone therapy for transgender women, and in the treatment of gynecological disorders. It is also used in the treatment of prostate cancer in men. Estradiol benzoate is used in veterinary medicine as well. When used clinically, the medication is given by injection into muscle usually two to three times per week. Side effects of estradiol benzoate include breast tenderness, breast enlargement, nausea, headache, and fluid retention. Estradiol benzoate is an estrogen and hence is an agonist of the estrogen receptor, the biological target of estrogens like estradiol. It is an estrogen ester and a prodrug of estradiol (medication), estradiol in the body. Because of this, it is considered to be a natural product, natural and bioidentical hormone replacement therapy, bioidentical form of e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luteinizing Hormone
Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus. In females, an acute rise of LH known as an LH surge, triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone. It acts synergistically with follicle-stimulating hormone ( FSH). Etymology The term luteinizing comes from the Latin "luteus", meaning "yellow". This is in reference to the corpus luteum, which is a mass of cells that forms in an ovary after an ovum (egg) has been discharged. The corpus luteum is so named because it often has a distinctive yellow color. The process of forming the corpus luteum is known as " luteinization", and thus the hormone that triggers th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Test
A medical test is a medical procedure performed to detect, diagnose, or monitor diseases, disease processes, susceptibility, or to determine a course of treatment. Medical tests such as, physical and visual exams, diagnostic imaging, genetic testing, chemical and cellular analysis, relating to clinical chemistry and molecular diagnostics, are typically performed in a medical setting. Types of tests By purpose Medical tests can be classified by their purposes, including diagnosis, screening or monitoring. Diagnostic A diagnostic test is a procedure performed to confirm or determine the presence of disease in an individual suspected of having a disease, usually following the report of symptoms, or based on other medical test results. This includes posthumous diagnosis. Examples of such tests are: * Using nuclear medicine to examine a patient suspected of having a lymphoma. * Measuring the blood sugar in a person suspected of having diabetes mellitus after periods of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonadotropin
Gonadotropins are glycoprotein hormones secreted by gonadotropic cells of the anterior pituitary of vertebrates. They are central to the complex endocrine system that regulates normal growth, sexual development, and reproductive function. The hormone family includes the mammalian hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the placental/ chorionic gonadotropins, human chorionic gonadotropin (hCG) and equine chorionic gonadotropin (eCG), as well as at least two forms of fish gonadotropins. LH and FSH are secreted by the anterior pituitary gland, while hCG and eCG are secreted by the placenta in pregnant women and mares, respectively. The gonadotropins act on the gonads, controlling gamete and sex hormone production. Gonadotropin is sometimes abbreviated ''Gn''. The alternative spelling ''gonadotrophin'' which inaccurately implies a nourishing mechanism is also used. There are various preparations of gonadotropins for therapeutic use, main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Feedback
Positive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop where the outcome of a process reinforces the inciting process to build momentum. As such, these forces can exacerbate the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in the magnitude of the perturbation. That is, ''A produces more of B which in turn produces more of A''.Keesing, R.M. (1981). Cultural anthropology: A contemporary perspective (2nd ed.) p.149. Sydney: Holt, Rinehard & Winston, Inc. In contrast, a system in which the results of a change act to reduce or counteract it has negative feedback. Both concepts play an important role in science and engineering, including biology, chemistry, and cybernetics. Mathematically, positive feedback is defined as a positive loop gain around a closed loop of cause and effect. That is, positive feedback is Phase (waves), in phase with the input, in the sense that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
