| atrazine concentrations, gonadal gross morphology and histology in ranid frogs collected in michigan agricultural areas. | the triazine herbicide atrazine has been suggested to be a potential disruptor of normal sexual development in male frogs. the goals of this study were to collect native ranid frogs from sites in agricultural and non-agricultural areas and determine whether hypothesised atrazine effects on the gonads could be observed at the gross morphological and histological levels. juvenile and adult green frogs (rana clamitans), bullfrogs (r. catesbeiana) and leopard frogs (r. pipiens) were collected in the ... | 2006 | 16300839 |
| plasma steroid hormone concentrations, aromatase activities and gsi in ranid frogs collected from agricultural and non-agricultural sites in michigan (usa). | the triazine herbicide atrazine has been hypothesized to disrupt sexual development in frogs by up-regulating aromatase activity, resulting in greater estradiol (e2) concentrations and causing feminization in males. the goal of this study was to collect native ranid frogs from atrazine-exposed ponds and determine whether relationships exist between measured atrazine concentrations and the gonadosomatic index (gsi), plasma concentrations of testosterone (t), e2 or 11-ketotestosterone (kt), or wit ... | 2006 | 16427146 |
| sediment tcdd-eqs and erod and mrod activities in ranid frogs from agricultural and nonagricultural sites in michigan (usa). | in vitro studies have demonstrated atrazine-mediated induction of 7-ethoxyresorufin o-deethylase (erod) activity. erod is an enzyme active in the metabolism of many compounds, including many xenobiotics. these studies have suggested that atrazine may affect reproductive function by altering steroid metabolism. the goal of this study was to determine whether relationships could be detected between measured atrazine concentrations in surface waters and the liver-somatic index (lsi) and erod and 7- ... | 2006 | 16788744 |
| origin, evolution, and virulence of porcine deltacoronaviruses in the united states. | a novel porcine deltacoronavirus (pdcv) was first discovered in ohio and indiana in february 2014, rapidly spread to other states in the united states and canada, and caused significant economic loss in the swine industry. the origin and virulence of this novel porcine coronavirus are not known. here, we characterized u.s. pdcv isolates and determined their virulence in gnotobiotic and conventional piglets. genome analyses revealed that u.s. pdcv isolates possess unique genetic characteristics a ... | 2015 | 25759498 |
| variations in the expressed antimicrobial peptide repertoire of northern leopard frog (rana pipiens) populations suggest intraspecies differences in resistance to pathogens. | the northern leopard frog (rana pipiens or lithobates pipiens) is historically found in most of the provinces of canada and the northern and southwest states of the united states. in the last 50 years, populations have suffered significant losses, especially in the western regions of the species range. using a peptidomics approach, we show that the pattern of expressed antimicrobial skin peptides of frogs from three geographically separated populations are distinct, and we report the presence of ... | 2009 | 19622371 |