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S Aizu

Publications and source records attributed to S Aizu.

5 recordsLinked to original sources

Formation of Hassall's corpuscles in vitro by the thymic epithelial cell line IT-26R21 of the rat.

In the monolayer of an established epithelial cell line from the rat thymus, IT-26R21, characteristic cell aggregates quite similar to Hassall's corpuscles were formed. These aggregates were examined by light and electron microscopy, and immunohistochemically. Their interpretation as Hassall's corpuscles is based n the following observations: (1) The aggregates are formed in the monolayer of cells that greatly resemble medullary epithelial cells of the thymus. (2) They consist of flattened epithelial cells in a concentric pattern with one or ore degenerating cells in the center. (3) Loss of microvilli suggests that these cells are keratinizing. (4) The aggregates show strongly positive reactions in immunofluorescent staining with antikeratin and antiprekeratin. When Hassall's corpuscles increase in size, cellular proliferation is somewhat suppressed. Both in vivo and in vitro, they may be interpreted as an expression of a changing growth pattern in confined spaces and thus seem to have little immunological function.

Animals↗

Morphological differences between excitatory and inhibitory nerve terminals in cockroach coxal muscles.

Two morphologically distinct types of neuromuscular junction on the coxal leg muscles of the cockroach, Periplaneta americana, which have been physiologically described as innervated by fast, slow and inhibitory nerve fibers, have been found. In one type of neuromuscular junction the axon terminal contains many round clear synaptic vesicles and contacts several sarcoplasmic extensions from the muscle fiber. The muscle processes adhere to the axon terminal for a short distance (short contact or SC type). The axon terminal of the other type of neuromuscular junction directly contacts the muscle fiber and no extensions of the muscle fiber are formed. The contact region is comparatively long (long contact or LC type). The nerve terminal contains many polymorphic synaptic vesicles. From a correlation of the present morphological findings and the previous physiological results, it may be suggested that the SC type of nerve terminal represents both fast and slow nerve terminals and the inhibitory terminal is of the LC type.

Animals↗

A simple method for whole-cell preparation in electron microscopy.

A simple method for whole-cell preparation without using gold or platinum grids as substrata for culture is described. Cells were cultured on formvar film over round pores, each 3 mm in diameter, of Thermonox coverslips. The cells on the formvar coated coverslip are fixed, stained, dehydrated in situ, and introduced into a critical point drying apparatus. A small quantity of 0.2% mesh-cement is applied to slot grids, and they are laid onto the formvar film over the pores of the coverslip. After the grids are removed from the plastic substratum, they are ready for observation under the electron microscope.

Cells↗

Fine structure of cardiac ganglion trunk in prawn, Penaeus japonicus bates.

The cardiac ganglion trunk of prawn, Peneaus japonicus Bates, is on the middle line of ventral wall of the cardiac tube and consists of nine ganglion cells, many nerve fibers and neuropils. These neuronal elements are insulated by supporting cells and connective tissue fibers. The peripheral area of the perikaryal cytoplasm of the ganglion cell is separated into many compartments by deep invaginations of the cell membrane. Each compartment is packed with a tight network of the agranular endoplasmic reticulum. Among nerve fiber bundles are many small areas of neuropil. Most of the synapses in the ganglion trunk are observed in the neuropil, but there are a few nerve terminals which form synapses with the somata of ganglion cells.

Animals↗