Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 185-202).

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 96-104).

A three day mouse bio-assay procedure, using immature female mice 20-21 days old and weighing 8-11 gm., was developed for the determination of the estrogen-like substances in forages. With diethylstilbestrol (D.E.S.) as reference compound a dose response curve was constructed. From this curve the estrogenic activity of the samples of plant material was estimated and expressed in terms of D.E.S. An extensive study was undertaken on the effects of stage of maturity and frequency of cutting of alfalfa, white clover, red clover, birdsfoot trefoil and orchard grass, on the levels of estrogen-like substances in these plant species. The data of these experiments revealed that there was a great difference in estrogenic activity between samples taken from different plant species at the same time of the year. There also was a seasonal variation between first cuttings of second year growth of the different plant species. Alfalfa and white clover were high in estrogenic activity in the spring, showed a sharp decrease in June and July, and after August 1 possessed once again considerable potency. Birdsfoot trefoil and orchard grass showed estrogenic activity only in the spring, and this was, relatively small as compared to the activity of alfalfa, white clover and red clover. Red clover differed very much from the previously mentioned species. All samples studied showed considerable potency. There was no sharp decrease during June and July as was the case with alfalfa and white clover. Data obtained by varying the number of hours of daylight (photoperiod) received by red clover seemed to indicate that estrogenic potency was decreased when the hours of daylight were reduced. Proximate analysis of the plant material revealed that estrogenic potency was not correlated with nitrogen content. Studies on the stability of the estrogen-like compound in alfalfa, white clover and red clover showed that the activity of dried ground alfalfa and white clover plant material was easily destroyed during storage, while the potency of dried ground red clover remained fairly constant over a six month period. However, the estrogen-like compounds of these three species are much more stable after they had been extracted and the extract mixed with feed. Red clover and birdsfoot trefoil extract interfered with the reproduction in the mouse. Females were affected more severely than males, but both recovered their reproductive ability quickly after feeding of the estrogen-like compounds ceased. The growth rate of the female guinea pig weighing between 500-600 gm. was not significantly influenced when red clover extract was added to their diet. II . ABSTRACT A three day mouse bio-assay procedure, using immature female mice 20-21 days old and weighing 8-11 gm., was developed for the determination of the estrogen-like substances in forages. With diethylstilbestrol (D.E.S.) as reference compound a dose response curve was constructed. From this curve the estrogenic activity of the samples of plant material was estimated and expressed in terms of D.E.S. An extensive study was undertaken on the effects of stage of maturity and frequency of cutting of alfalfa, white clover, red clover, birdsfoot trefoil and orchard grass, on the levels of estrogen-like substances in these plant species. The data of these experiments revealed that there was a great difference in estrogenic activity between samples taken from different plant species at the same time of the year. There also was a seasonal variation between first cuttings of second year growth of the different plant species. Alfalfa and white clover were high in estrogenic activity in the spring, showed a sharp decrease in June and July, and after August 1 possessed once again considerable potency. Birdsfoot trefoil and orchard grass showed estrogenic activity only in the spring, and this was relatively small as compared to the activity of alfalfa, white clover and red clover. Red clover differed very much from the previously mentioned species. All samples studied showed considerable potency. There was no sharp decrease during June and July as was the case with alfalfa and white clover. Data obtained by varying the number of hours of daylight (photoperiod) received by red clover seemed to indicate that estrogenic potency was decreased when the hours of daylight were reduced. Proximate analysis of the plant material revealed that estrogenic potency was not correlated with nitrogen content. Studies on the stability of the estrogen-like compound in alfalfa, white clover and red clover showed that the activity of dried ground alfalfa and white clover plant material was easily destroyed during storage, while the potency of dried ground red clover remained fairly constant over a six month period. However, the estrogen-like compounds of these three species are much more stable after they had been extracted and the extract mixed with feed. Red clover and birdsfoot trefoil extract interfered with the reproduction in the mouse. Females were affected more severely than males, but both recovered their reproductive ability quickly after feeding of the estrogen-like compounds ceased. The growth rate of the female guinea pig weighing between 500-600 gm. was not significantly influenced when red clover extract was added to their diet. / Land and Food Systems, Faculty of / Graduate

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Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / "May 1998." Typescript. Vita. Includes bibliographical references (leaves 126-156). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves : 126-156). Also available on the Internet.

Thesis (M.S.)--University of Akron, Dept. of Biology, 2009. / "August, 2009." Title from electronic thesis title page (viewed 10/7/2009) Advisor, Bruce Cushing; Committee members, Qin Liu, Todd Blackledge; Department Chair, Monte Turner; Dean of the College, Chand Midha; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

published_or_final_version / Pharmacology and Pharmacy / Master / Master of Medical Sciences

Thesis (Ph.D.)--Boston University. Missing pages 78, 79. / The prime purpose of this investigation was the development of a rapid and sensitive procedure for the assay of estrogenic hormones. The advent of gas chromatography offered a possible solution to this problem. A pre-requisite of any gas chromatographic method is that the compounds to be chromatographed be volatile and thermally stable at the temperatures of vaporization and separation in the presence of the eluting gas. Accordingly, the thermal stability of certain free and acetylated estrogens was studied. The results of these studies indicated that decomposition was minimal when small quantities were subjected to gas chromatographic separation. Estrogen acetates were found to be stable up to 340°C by infrared spectroscopy, ultraviolet spectroscopy and by an evaluation of the gas chromatographic peak symmetry. Once suitable derivatives had been found, the parameters of separation and detection were evaluated. The optimum conditions for separation were found to be: 1) a temperature of 240°-280°C, 2) column length of 3 feet, 3) a silicone grease liquid phase, 4) flow rates of 50-500 cc/min, and 5) non-polar solvents. The lower limits of detector sensitivity were found to be 0.2ug for a sr90 detector and lOOug for the thermal conductivity cell detector. The ionization detector responded linearly in the range of 0.2 to 25 ug. The thermal conductivity cell detector responded linearly in the range of 100 to 400 ug. In order to have a quantitative procedure, it was necessary to determine the optimal conditions for the preparation of the estrogen acetates. It was found by means of gas chromatography, infrared spectroscopy and ultraviolet spectroscopy that estrone was converted to its acetate in 86-90 per cent yield in 2 x 10-3 M solutions in one hour at 65C. Estradiol, under the same conditions was found to be converted in 92 percent yield to the diacetate. The remaining 8 per cent was found to be estradiol-3- acetate. By allowing this reaction to proceed overnight only two per cent of the monoacetate was found. Estriol, in reactions which were carried out under similar conditions, was found to be converted in 98 per cent yield to the triacetate. In order to develop a urinary assay procedure, recovery studies from water and acid hydrolyzed urine, were carried out. The results indicated a 75-80 percent recovery of estrone and estradiol and a 90-95 per cent recovery of estriol. The lowest concentration studied was the recovery of steroid from a solution containing 1 ug/ml. Studies at this lower concentration showed that the recoveries were independent of concentration. The method described above has the advantage of chemical specificity, rapidity and reproducibility. As yet, it has not been developed to its highest sensitivity, however, coupled with prepurification procedures and with advances in instrumentation, it appears that the method will become useful for low level estrogen determination in biological media.