Pathogenesis and microchemical anatomy of the protozoan parasite Leishmania

infectious organisms. Examples are round things (e.g., ribosomes, vesicles; vacuoles, secretory granules, lipid, calyseal bodies, membrane blebs off cells, lipid droplets, tangential sections of nuclear pores); crosssections of microvilli, microtubules, other filaments, and collagen; spiked things (e.g., clathrin-coated vesicles; microvilli of intestine, lung, and brain cells; inside-out mitochondrial membranes); and small dark things (e.g., ribosomes, glycogen, nuclear granules and bodies, myelin figures, unsaturated lipid droplets that stain darkly with osmium). Also, melanosomes can resemble poxviruses. If uncertain about a diagnosis, it is imperative to seek help. With the availability of electronic communication, it is easy to collaborate with individuals that have extensive experience in ultrastructural identification of infectious disease agents (see references below or search ultrastructure of viruses, bacteria, fungi, protozoa, algae, parasites, etc.).