UNLABELLED Paragangliomas are rare neoplasms arising from undifferentiated cells of the primitive neural crest. We report a case of a 57-year-old patient with renal pigmented paraganglioma that was an incidental finding. Histopathological examination showed typical morphology of paraganglioma, as well as the unusual feature of large amounts of pigment in the cytoplasm of the tumor cells which w...

Melanins are notoriously difficult to study because they are amorphous, insoluble and often associated with other biological materials. Consequently, there is a dearth of structural techniques to study this enigmatic pigment. Current models of melanin structure envision the stacking of planar structures. X ray diffraction has historically been used to deduce stacking parameters. In this study w...

Functional neuroimaging of small brainstem structures in humans is gaining interest due to their potential importance aging and many clinical conditions. Researchers have used different methods measure activity the locus coeruleus (LC), main noradrenergic nucleus brain. However, extent which these LC localization yield similar results unclear. In present article, we compared four approaches est...