We consider toric deformations of complex structures, described by the symplectic potentials of Abreu and Guillemin, with degenerate limits of the holomorphic polarization corresponding to the toric Lagrangian fibration, in the sense of geometric quantization. This allows us to interpolate continuously between quantizations in the holomorphic and real polarizations and show that the monomial ho...

Invasion of human tissues by the parasitic protozoan Entamoeba histolytica is a multistep process involving, as a first step, the recognition of surface molecules on target tissues by the amebas or trophozoites. This initial contact is followed by the release of proteolytic and other activities that lyse target cells and degrade the extracellular matrix. In other parasitic diseases, as well as ...

The lipids of Acanthamoeba castellanii (Neff) consist of 52% neutral lipids and 48% polar lipids. Triglycerides account for 75% and free sterols for 17% of the neutral lipids. The major phospholipids are phosphatidylcholine (45%), phosphatidylethanolamine (33%), phosphatidylserine (10%), a phosphoinositide (6%), and diphosphatidylglycerol (4%). The phosphoinositide is unique in that it contains...

The protozoan parasite Entamoeba histolytica is the causative agent of amoebiasis, a human disease characterized by dysentery and liver abscess. The physiopathology of hepatic lesions can be satisfactorily reproduced in the hamster animal model by the administration of trophozoites through the portal vein route. Hamsters were infected with radioactively labeled amoebas for analysis of liver abs...

The role of filaments in consistency changes and movement in a motile cytoplasmic extract of Amoeba proteus was investigated by correlating light and electron microscopic observations with viscosity measurements. The extract is prepared by the method of Thompson and Wolpert (1963) . At 0 °C, this extract is nonmotile and similar in structure to ameba cytoplasm, consisting of groundplasm, vesicl...

Encystation of unicellular organisms is of considerable medical relevance since cysts are encapsulated by resilient cell walls, rendering them resistant to biocides and immune clearance. This survival strategy makes it complicated to produce effective treatment of diseases caused by many protozoan pathogens, e.g. species of Acanthamoeba which causes fatal granulomatous amebic encephalitis (GAE)...

The capacity of Acanthamoeba to distinguish nutritive yeast particles from nonnutritive plastic beads during phagocytosis was investigated. When cells were allowed to phagocytose yeast to capacity, endocytosis stopped and subsequent presentation of particles (either yeast or beads) did not result in further uptake. By contrast, when cells were allowed to phagocytose plastic beads to capacity an...

Upon application of hydrostatic pressure to Amoeba proteus, all movement stops and the organism assumes a spherical shape (1). The attainment of a completely spherical shape is a gradual process requiring from 5 to 20 minutes, depending upon the pressure and temperature level. This "spher-ing" under pressure has been attributed to the reversible disruption of the plasmagel integrity and consequ...

Free-living amebas are widely distributed in soil and water, particularly members of the genera Acanthamoeba and NAEGLERIA: Since the early 1960s, they have been recognized as opportunistic human pathogens, capable of causing infections of the central nervous system (CNS) in both immunocompetent and immunocompromised hosts. Naegleria is the causal agent of a fulminant CNS condition, primary ame...

The molecular mechanisms by which Entamoeba histolytica causes amebic liver abscess (ALA) are still not fully understood. Amebic mechanisms of adherence and cytotoxic activity are pivotal for amebic survival but apparently do not directly cause liver abscess. Abundant evidence indicates that chronic inflammation (resulting from an inadequate immune response) is probably the main cause of ALA. R...