Osmotic nephrosis Osmotic nephrosis Osmotic nephrosis refers to structural changes that occur at the cellular level in the human kidney. Cells, primarily of the straight proximal tubule, swell due to the formation of large vacuoles in the cytoplasm. These vacuoles occur in the presence of large amounts of certain solutes circulating in the tubules. However, despite the condition's name, the solutes do not cause change through osmotic forces but through pinocytosis. Once inside the cytoplasm, pinocytic vacuoles combine with each other and with lysosomes to form large vacuoles that appear transparent under microscopic examination. There may be no symptomatic presentation with this
Transneuronal degeneration neurons in the substantia nigra pars reticulata. The reorganization of cellular structures that results from transneuronal degeneration can be seen in Alzheimer's disease. It is hypothesized that anterograde transneuronal degeneration causes the hyperphosphorylation of the tau protein and redistributing those proteins from the axon to the dendrites, which begins the breakdown of routing and sorting mechanisms. Cockayne syndrome results from a mutation in genes that interfere with transcription-coupled repair of nuclear and mitochondrial DNA, replication, and transcription. Neuronal death is predominantly in the cerebellum, but this disease also causes apoptosis in purkinje cells and causes them to have dystrophic dendrites.