Estradiol methods

R.M. Pemberton, T.T. Mottram, and J.P. Hart, Development of a screen-printed carbon electrochemical immunosensor for picomolar concentrations of estradiol in human serum extracts. J. Biochem. Biophys. Methods 63, 201-212 (2005). 

Decreased contraceptive effect Use OCs containing 50 meg ethinyl estradiol and a second method of contraception or IUD Possible decreased contraceptive effect Use second method of contraception Possible decreased contraceptive effect Use IUD... 

Biological techniques, e.g., immunoassays, are among the most sensitive analytical methods, but are limited by the availability of the specific antisera and are subject to cross-reactivity. Huang et al. [36] employed an enzyme-linked immunosorbent assay (ELISA) for determination of estradiol, its conjugates, and ethynylestradiol in wastewaster treatment plant effluents (see Table 4). The reported limit of detection (LOD) of 0.1 ng L 1 reflects the sen-... 

Fig. 7.3.2. Effect of estradiol and BP-5 on MCF7 cell proliferation and gene expression. MCF7 cells were grown in estrogen-depleted medium. Estradiol or BP-5 were added to cultures and cell number (proliferation), protein determination (PgR and pS2), gene expression (pS2 mRNA) and luciferase expression were estimated at the appropriate times, as indicated in the Methods Section.

Reifenstein and Dempseyl9 using Talbot s colorimetric method found the urinary "estrone" to vary from 10 to 39 ig. per day in 5 normal women and from 27 to 40 ig. per day for 5 normal men. Attention was not paid to the question of whether the observed differences were primarily inter-individual. In another study20 involving 3 men and 2 women, Pincus found about a 12-fold variation between the two women. One woman excreted over a period of several days estradiol + estrone + estriol to the extent of 155.2 ig. per day for the other woman and the 3 men, the corresponding values were respectively 13.4 ig., 12.4 ig., 7.6 ig. and 16.8 ig. 

K. Katayama, Y. Ohshima, M. Tomi, and K. Hosoya. Application of microdialysis to evaluate the efflux transport of estradiol 17-/7 glucuronide across the rat blood-retinal barrier. J. Neurosci. Methods 156 249-256 (2006). 

Scheme 159) [549, 550]. Temperature and electrolyte concentration are found to have a profound effect on the reaction rate. The Bu4N(Hg) can be used for the reduction of -estradiol 3-methyl ether and the reaction has been shown to be more selective than the conversion methods based on alkali metal-ammonia reduction [551]. 

Yamada H, Kuwahara Y, Takamastu Y, Hayase T. 2000. A new sensitive determination method of estradiol in plasma using peroxyoxalate ester chemiluminescence combined with an HPLC system. Biomed Chromatogr 14(5) 333-337. 

Stumpf WE, Roth LJ. 1966. High resolution autoradiography with dry mounted, freeze-dried frozen sections. Comparative study of six methods using two diffusible compounds H-estradiol and H-mesobilirubinogen. J Histochem Cytochem 14 274-287. 

Use after childbirth - Women who elect not to breast-feed should start contraceptive therapy with the norelgestromin/ethinyl estradiol transdermal patch no sooner than 4 weeks after childbirth. If a woman begins using the patch postpartum and has not yet had a period, consider the possibility of ovulation and conception occurring prior to use of the patch, and instruct her to use an additional method of contraception (eg, condoms, spermicide, diaphragm) for the first 7 days. 

Hydrolysis of the acetal group then gives estrone (6-2). The 17 ketone can be reduced by any of several methods, such as borohydride, to give the 17 3 alcohol estradiol (6-3). 

Nelson et al. [60] published a method for estrone and estradiol measurement using the dansyl derivatives with analysis by APCI. After adding di-estrone and ck-estradiol to 0.5 ml serum, the steroids are extracted with 6 ml methylene chloride. After drying the solvent, 50 pi of sodium bicarbonate and (100 mmol/1, pH 10.5) 50 pi of dansyl chloride (1 g/1) are added. The samples can be injected after heating at 60 C for 1 min. 

The routine measurement of estrone and estradiol by immunoassay techniques has also given rise to the familiar problems of poor sensitivity, cross-reactivity, and poor intermethod reproducibility. Most automated methods cannot measure these steroids in sera of children and men. Development of LC-MS/MS methods has also proven challenging as most investigators have found that estrone and estradiol are poor ionizers and the desired sensitivity has not been achieved. The Mayo group [60] published the LC-MS/MS quantification of estradiol and estrone using dan-syl chloride derivatives (described above) and 2H5 estradiol and 2H4 estrone internal standards. 

Despite the distinct advantages of pneumatic nebulizers, ultrasonic nebulizers may alternatively be used, in some instances, with success. In a recent application, a variation of ultrasonic nebulizer called spray nozzle-rotating disk FTIR interface was successfully applied to confirm the presence of methyltestosterone, testosterone, fluoxymesterone, epitestosterone, and estradiol and testosterone cyp-ionate in urine, after solid-phase extraction and reversed-phase LC separation (151). Using a commercial infrared microscopy spectrometer, usable spectra from 5 ng steroid deposits could be readily obtained. To achieve success with this interface, phosphate buffers in the mobile phase were not used because these nonvolatile salts accumulate on the collection disk and their spectra tend to swamp out small mass deposits. Another limitation of the method was that only nonvolatile analytes could be analyzed because volatile compounds simply evaporated off the collection-disk surface prior to scanning. 

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