Cellular origin of microfibrils explored by monensin-induced perturbation of secretory activity in embryonic primary cultures

Fibrillin is a primary component of elastin-associated microfibrils. Since microfibrils are distributed rather ubiquitously in embryonic tissues, attention has focused on the types of cells responsible for producing fibrillin. To clarify this issue, we employed monensin-induced perturbation of secretory activity in embryonic primary cultures, as this would allow examination of both the secreted protein and the formation of extracellular fibrils in the same culture. Micromasses of avian limb bud mesoderm, its ectodermal covering and several explants from other sources were cultured in the presence and absence of monensin, and evaluated immunohistochemically using antibodies against fibrillin and cell lineage markers. The results indicated that monensin perturbation induced intracellular accumulation of fibrillin and prevented the formation of microfibrils. It was shown specifically that not only mesodermally derived fibrogenic cells and myogenic cells of skeletal and smooth muscle cell lineage, but also epithelial-type cells such as endothelial and ectodermal cells, are producers of fibrillin. This dual cellular origin of fibrillin at the ectomesenchymal interface is considered significant for understanding the formation and remodeling of microfibrils originating from the basal lamina.     

Verification of responses of Japanese medaka (Oryzias latipes) to anti‐androgens,vinclozolin and flutamide,in short‐term assays

Various testing methods for the detection of the endocrine disruptive activities of chemicals have been developed in freshwater fish species. However, a few relatively easier specific methods for detecting anti‐androgenic activities are available for fish. The aim of this study was to verify the papillary process in Japanese medaka (Oryzias latipes) as an indicator of the anti‐androgenic activity of chemicals. Japanese medaka were exposed to two types of anti‐androgenic compounds, vinclozolin and flutamide, using two short‐term assays; one was conformed to the existing short‐term reproduction assay using adult fish (adult test) and the other was a test based on the same methods but using juvenile fish at the beginning of exposure (juvenile test). Significant decreases in male papillary processes were observed in the juvenile test treated with the highest concentration of both antiandrogens (640 µg l^–1 vinclozolin and 1000 µg l^–1 flutamide); however, no significant effects were observed in the adult test. Consequently, our results indicate that papillary processes in Japanese medaka can be used as the end‐point for screening the anti‐androgenic activity of chemicals using juvenile fish for a specific period based on the existing short‐term reproduction assay. Copyright © 2013 John Wiley & Sons, Ltd.     

MRI features of mucinous adenocarcinoma of the prostate: report of four cases

Abdominal Radiology - We report four patients with mucinous adenocarcinoma of the prostate, focusing on their magnetic resonance imaging (MRI) findings. The lesions appeared hyperintense on...