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Semantic retrieval consistently activates left inferior frontal regions, yet lesions to these areas do not typically result in semantic deficits. This discrepancy has led to the hypothesis that left prefrontal areas are primarily involved in executive processes while semantic information is retrieved from temporal cortices. We investigated semantic(More)
Extracellular matrix remodeling occurs during ovarian follicular development, mediated by plasminogen activators (PAs) and PA inhibitors including protease nexin-1 (PN-1). In the present study we measured expression/activity of the PA system in bovine follicles at different stages of development by timed collection of ovaries during the first follicular(More)
Steroidogenic acute regulatory protein (StAR) transfers cholesterol from the outer to the inner mitochondrial membrane to initiate steroidogenesis. Our purpose was to determine the tissue distribution of StAR mRNA and the occurrence of StAR gene products in the bovine corpus luteum (CL). Tissues were taken from the slaughterhouse or by ovariectomy of cattle(More)
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been shown to impair reproductive function of males in animal models, possibly due to a reduction in serum androgen levels. Thus, TCDD may alter the testosterone biosynthetic pathway in the testis or the conversion of testosterone to 5alpha-dihydrotestosterone (DHT) in androgen target tissues. Pregnant Sprague(More)
OBJECTIVE To determine if initial cell plating density alters steroidogenesis and the E(2):P ratio in granulosa cells in long-term serum-free culture. DESIGN Experimental study. SETTING Academic institution. ANIMAL(S) Cattle of slaughterhouse origin. INTERVENTION(S) Culture of granulosa cells in vitro at different cell plating density. MAIN(More)
During ovarian follicle growth, there is expansion of the basal lamina and changes in the follicular extracellular matrix (ECM) that are mediated in part by proteolytic enzyme cascades regulated by tissue-type plasminogen activator (tPA) and urokinase plasminogen activator (uPA). One PA inhibitor, serine protease inhibitor-E2 (SERPINE2) is expressed in(More)
Paracrine cell signaling is believed to be important for ovarian follicle development, and a role for some members of the fibroblast growth factor (FGF) family has been suggested. In the present study, we tested the hypothesis that FGF-8 and its cognate receptors (FGFR3c and FGFR4) are expressed in bovine antral follicles. RT-PCR was used to analyze bovine(More)
The objective of this study was to determine if androgens regulate granulosa cell steroidogenesis at physiological doses found in small bovine follicles. Bovine granulosa cells were cultured under serum-free conditions that permit the induction and maintenance of FSH-dependent estradiol secretion. Increasing androstenedione concentrations from 0.1 to 1 or(More)
In cattle, most evidence suggests that granulosa cells express LH receptors (LHR) after (or as) the follicle becomes dominant, however there is some suggestion that granulosa cells from smaller pre-dominant follicles may express several LHR mRNA splice variants. The objective of this study was to measure LHR expression in bovine follicles of defined size(More)
Granulosa cells of small follicles differentiate in vitro in serum-free medium, resulting in increased estradiol secretion and abundance of mRNA encoding cytochrome P450aromatase (P450arom). We tested the hypothesis that differentiation in vitro also involves increased expression of 3beta- and 17beta-hydroxysteroid dehydrogenases (HSD) in the absence of(More)