Salmonella 3, 10:r: toxicity in rabbit ileum and liver by light and electron microscopy.

Salmonella 3, 10:r:- (a monophasic variety of otherwise diphasic serotypes such as S. weltevreden and S. simi) Cell_free filtrate, when introduded into rabbit ligated ileal loops causes fluid exsorption, as studied 18-hr after treatment. Light microscopic histology of treated ileum shows denudation of the columnar epithelium at several places, thereby allowing the passage of the toxic principle into circulation. An important target organ, liver shows extensive centrilobular necrosis, as observed by light microscopy. Transmission electron microscopy of ileum reveals opening of membrane junctions between the adjacent cells of epithelial lining of the treated ileum at places, and focal devitalization including formation of intra-cellular membranous inclusinos. Electron microscopy of liver shows extensive damage and swelling of cytoplasmic membranes. However, the areas of darkly staining lamellae of granulated endoplasmic reticulum are also seen in stacks as will as dispersed. These studies stress that Salmonella toxic substances can cause extensive damage to intestine and liver both.

Propagation of Salmonella 3, 10: r in ileum: a transmission electron microscope study.

Salmonella 3, 10: r organisms were examined ultrastructurally for their role in the initiation of infection in chicken ileum and studied 18 hr after, the organisms were seen located free as well as in contact with food particles. The surface features of the organisms revealed marked changes when they were located close to the ileal epithelial cell microvilli. The organisms were also seen having penetrated into intercellular spaces located in the interior of ileum. Many of them were seen phagocytosed by phagocytic cells.

Location of chloroplast membrane resonances in high resolution 13C-NMR spectrum of spinach leaves.

Spinach leaves were studied by high resolution 13C-NMR spectroscopy. The spectra obtained, though highly complex, showed some distinct resonances assignable to carbons of lipids of the chloroplast membranes, thereby offering a novel way for studying the chloroplast membranes in situ.