Alveolar hydatid disease of the liver: Brief review and spectrum of adjacent organ invasion

The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.     

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.     

Brainstem control of sensory information: a mechanism for perception

We have proposed a theory in which pathways ascending from the brainstem reticular formation control sensory centers in the dorsal thalamus and neocortex. We assumed that the sensory messages received at a given level are transformed by a stochastic process, called Alopex, in a way which maximizes responses in central feature analyzers. Perception is seen as a process involving a close cyclic interaction between brainstem and sensory relays. We discuss the specific case of visual information flow and the proposed modification of visual images at the level of the dorsal lateral geniculate nucleus (dLGN). Computer simulations of a simple model, representing the dLGN and reafferent control emanating from the reticular formation, show that sensory features are effectively enhanced and--in the absence of sensory input--quasi-sensory features may be generated by feedback of a simple scalar variable that is formed by the non-linear superposition of the responses of any number of feature analyzers. The model proposes a specific mechanism for such processes as visual imagery, hallucinations, and dreaming, and provides a framework for further studies into the nature of cognitive brain functions.