Fig. 1

A Phase contrast image of human neuroblastoma SH-SY5Y cells under a light inverted microscope at 4× (left panel, scale bar: 100 μm) and 20× (right panel, scale bar: 50 μm) magnification. Arrowheads, neuroblast-like morphology with a few short neurite-like projections. B Microscopic images of the Balamuthia mandrillaris trophozoites cocultured with human neuroblastoma SH-SY5Y cells at 4× (left panel, scale bar: 100 μm) and 20× (right panel, scale bar: 50 μm) magnification. Dotted line, human cell-free area; Arrowheads, round shaped trophozoites; Arrows, cytoplasm-protruding trophozoites.  C Higher-magnification views of the insets in Fig. 1B. Scale bar: 25 μm. D Trypan blue-stained human neuroblastoma SH-SY5Y cells. Scale bar (left panel): 50 μm; scale bar (right panel): 25 μm. Arrows, trypan blue-positive human neuroblastoma cells. E Relative level of mRNA encoding human anti-apoptotic BCL2 and apoptotic BAX protein at 1 and 3 h post coculture. The levels are the mean ± SD of triplicate experiments. F Microscopic image of B. mandrillaris trophozoites on day 3 of coculture with the monolayer of human neuroblastoma SH-Sy5Y cells. Abbreviations: BAX, BCL2-associated X; BCL2, B-cell lymphoma 2; SD, standard deviation