Blur adaptation: clinical and refractive considerations

The human visual system is amenable to a number of adaptive processes; one such process, or collection of processes, is the adaptation to blur. Blur adaptation can be observed as an improvement in vision under degraded conditions, and these changes occur relatively rapidly following exposure to blur. The potential important future directions of this research area and the clinical implications of blur adaptation are discussed.     

The Peutz-Jeghers syndrome. Case reports.

Two additional cases of Peutz-Jeghers syndrome are described. One of them, a 19 year-old female, is a sporadic case, whereas in the other case, also a 19 year-old female, there are two members of the family with the Peutz-Jeghers syndrome. A review of some salient features of this entity is made. These include clinical presentation, histopathological features, malignant potential and treatment.     

Immunohistological study of grumose degeneration of the dentate nucleus in progressive supranuclear palsy

The grumose degeneration observed in the dentate nuclei of 7 cases of progressive supranuclear palsy (PSP) was studied with a panel of antibodies which included 2 neurofilaments, Tau and ubiquitin. Dentate nucleus neurons were negative with all antibodies except ubiquitin which showed a slightly positive homogeneous pattern of staining. The amorphous material surrounding swollen or normal neurons was strongly positive for neurofilament and subunits and numerous torpedoes were observed in the granular layer of the cerebellar cortex. Our results confirm that grumose degeneration consists in degeneration of terminal axons of Purkinje cells in the dentate nucleus. The positivity of dentate nucleus neurons for ubiquitin may support the concept of synaptic dysfunction between Purkinje cells and dentate nucleus neurons.