We describe here a variety of autophagous forms encountered in the terminal stages of two models of scrapie in hamsters. We also show that the number of autophagic vacuoles increased through the incubation period in the 263K strain scrapie model. In addition, we demonstrated for the first time the presence of aggresomes in the neuronal cytoplasm in scrapie-affected hamster brains. We observed n...

Although concentrated soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) drive liposome fusion and lysis, the fusion of intracellular membranes also requires Rab GTPases, Rab effectors, SM proteins, and specific regulatory lipids and is accompanied by little or no lysis. To rationalize these findings, we generated yeast strains that overexpress all four vacuolar SNA...

The trichloroacetic acid-soluble radioactivity released during incubation of mouse liver particles containing intravenously injected formaldehyde-treated (131)I-albumin consisted almost entirely of (131)I-iodotyrosine. The material was shown to be excreted into the medium and was not due to disruption of the particles by acid. Triton X-100 or the absence of sucrose in the medium inhibited hydro...

LAZZARO, M. D., and THOMSON, W. W. 1989. Ultrastructure of organic acid secreting trichomes of chickpea (Cicer arietinum). Can. J. Bot. 67: 2669-2677. The acid-secreting trichomes of chickpea (Cicer arietinum L.) were composed of 18 cells, including 1 basal cell, 3 elongate stalk cells, and 14 head cells. A subcuticular secretion chamber with cuticular pores was present above the head cells at ...

Protozoan parasites of Leishmania spp. invade macrophages as promastigotes and differentiate into replicative amastigotes within parasitophorous vacuoles. Infection of inbred strains of mice with Leishmania major is a well-studied model of the mammalian immune response to Leishmania species, but the ultrastructure and biochemical properties of the parasitophorous vacuole occupied by this parasi...

This paper represents the first ultrastructural descriptions of the cloacal glands of a male salamander. All male salamanders in the suborder Salamandroidea possess these glands, which are required for internal fertilization. These glands are responsible for producing spermatophores and, in some species, certain glands produce female-attracting pheromones. Both scanning and transmission electro...

Here we describe a technique that allows us to visualize in real time the formation and dynamics (fusion, changes of shape, and translocation) of vacuoles in living cells. The technique involves infusion of a dextran-bound fluorescent probe into the cytosol of the cell via a patch pipette, using the whole-cell patch-clamp configuration. Experiments were conducted on pancreatic acinar cells stim...

The redistribution of beta-thromboglobulin (beta TG), platelet Factor 4 (PF4), and fibrinogen from the alpha granules of the platelet after stimulation with thrombin was studied by morphologic and immunocytochemical techniques. The use of tannic acid stain and quick-freeze techniques revealed several thrombin-induced morphologic changes. First, the normally discoid platelet became rounder in fo...

Autophagic cell death is morphologically characterized by an accumulation of autophagic vacuoles. Here, we show that inactivation of LAMP2 by RNA interference or by homologous recombination leads to autophagic vacuolization in nutrient-depleted cells. Cells that lack LAMP2 expression showed an enhanced accumulation of vacuoles carrying the marker LC3, yet a decreased colocalization of LC3 and l...

mAbs specific for calmodulin were used to examine the distribution of calmodulin in vegetative Dictyostelium cells. Indirect immunofluorescence indicated that calmodulin was greatly enriched at the periphery of phase lucent vacuoles. The presence of these vacuoles in newly germinated (non-feeding) as well as growing cells, and the response of the vacuoles to changes in the osmotic environment, ...