What's new in the pathology of neuronal cytoskeleton: the significance of neurofibrillary tangles.

Neurofibrillary tangles are a neuronal change observed in various conditions, linked with dementia when affecting the cerebral cortex as in Alzheimer's disease. They may be found locally close to fibrous or vascular tumors, or affect extensive regions of the neocortex while the cerebellum and the medulla are not affected. Recent immunological and biochemical studies demonstrate that the MT-associated protein tau is the main component of the tangles, in an abnormally phosphorylated state.

[The centennial of the discovery of the antimitotic properties of colchicine].

Pernice, a sicilian pathologist active mainly in Italy (Palermo) from 1884 to 1906, published one hundred years ago the first observation of the mitotic changes observed in two dogs injected with a large dose of tincture of Colchicum. His description of the considerable increase in mitotic figures in the gastric and intestinal mucosa, and the absence of ana-telophases, clearly illustrate the well-known effect of a spindle poison. They were however completely forgotten until 1949.

[Pathology of the cytoskeleton].

In the last years, considerable advances have been made in the study of the proteins and polypeptides of the cytoskeleton, and its three main components: microfilaments (MF), intermediate filaments (IMF) and microtubules (MT). The principal properties of these elements and those of many associated proteins are recalled. The actin MF are mainly involved in cell contractility, the IMF in cell shape, while the MT and their associated proteins are involved in intracellular transport.