Although Chediak-Higashi syndrome (CHS) has been found in various mammalian species, it has not been described in rats. Since giant granules characterizing CHS are easily recognizable in mast cells of beige (CHS) mice, we screened mast-cell granules in the auricle of some mutant rats, of which coat color was diluted by mutation. Giant granules of mast cells were found in a mutant trait that occ...

The occurrence of fluorescent, pigmented inclusion bodies in muscle, nerve, and other non-dividing cell lines has been known since the turn of the century. These pigments, variously known as age pigments, lipofuscin, or abnutzungspig-mente (wear and tear pigments), have been subjected to numerous histochemical and histo-logical studies. Little has been firmly established, however, regarding the...

Pigment epithelial cells of the frog's retina have been examined by methods of electron microscopy with special attention focused on the fine structure of the endoplasmic reticulum and the myeloid bodies. These cells, as reported previously, send apical prolongations into the spaces between the rod outer segments, and within these extensions, pigment migrates in response to light stimulation. T...

Phagocytosis of latex spheres was studied in explant cultures of retinal pigment epithelium from rabbit, calf, and rat (normal and dystrophic). Calf and rabbit pigment epithelial cells showed a "latent period" of about 12 and 17 hr, respectively, during which latex spheres were not ingested even when the cultures were pre-incubated for up to 24 hr prior to exposure. Scanning electron microscopy...

To identify the role of avitaminosis E in the production of histological lesions and the distribution of an acid-fast pigment in the young cotton rat, weanling animals were maintained on a vitamin E deficient diet for 41 to 179 days. Since the pigment, lipofuscin, cannot be degraded by any cell, including the macrophage, it accumulates linearly with age of the animal and the length of the avita...

To elucidate the biogenetic pathways for the generation of lysosome-related organelles, we have chosen to study the Drosophila eye pigment granules because they are lysosome-related and the fruit fly provides the advantages of a genetic system in which many mutations affect eye color. Here, we report the molecular identification of two classic Drosophila eye-color genes required for pigment gra...

To determine whether portal lymphadenopathy in primary biliary cirrhosis is caused by deposition of lipofuscin pigment in sinus histiocytes and to compare primary biliary cirrhosis with other liver diseases a retrospective study on a consecutive series of 169 livers obtained at transplantation was carried out. There were grouped into eight diagnostic categories: primary biliary cirrhosis (n = 5...

Microtubule (MT)-based transport of organelles driven by the opposing MT motors kinesins and dynein is tightly regulated in cells, but the underlying molecular mechanisms remain largely unknown. Here we tested the regulation of MT transport by the ubiquitous protein MAP4 using Xenopus melanophores as an experimental system. In these cells, pigment granules (melanosomes) move along MTs to the ce...

In pernicious anemia and hemochromatosis an iron-containing pigment, hemosiderin, ordinarily derived from hemoglobin, is deposited in organs free from such pigment in most conditions that involve blood destruction. When sudden hemolysis takes place in a previously healthy human being, as after cutaneous burns or the action of a "blood poison," hemosiderin granules appear in the spleen, the red ...

We studied the phagocytic-like capacity of human CD34+ stromal cells/telocytes (TCs). For this, we examined segments of the colon after injection of India ink to help surgeons localize lesions identified at endoscopy. Our results demonstrate that CD34+ TCs have endocytic properties (phagocytic-like TCs: phTCs), with the capacity to uptake and store India ink particles. phTCs conserve the charac...