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Biomedical subjects

K Sasaki

Publications and source records attributed to K Sasaki.

At least 37 records · Page 2Linked to original sources

Cytometric analysis of small lymphocytes in the bone marrow and lymphatic tissues in neonatally thymectomized and nude mice, with particular reference to differentiation of B-lymphocytes.

In neonatally thymectomized mice and nude mice, small lymphocytes in the bone marrow, Peyer's patches, lymph nodes and spleen were studied qualitatively and quantitatively by electron microscopy. Marrow lymphocytes which are mostly small lymphocytes are classified into dark and light types. The greater proportion of marrow small lymphocytes are of the dark type. Small lymphocytes in Peyer's patches, lymph nodes and spleen are of the light type. The nuclear and cellular sizes of small lymphocytes were estimated stereologically. The nucleus-cell ratio, the volumetric proportions of mitochondria, Golgi apparatus, tubular complexes and dense bodies to the cell body and the proportions of nucleoli and nuclear bodies to the nucleus were also determined. The quantitative results thus obtained suggest that light small lymphocytes in the bone marrow are cytometrically similar to small lymphocytes in Peyer's patches, lymph nodes and spleen and that dark small lymphocytes in the bone marrow are different from other small lymphocytes. The findings are discussed in particular relation to morphological differentiation of B-lymphocytes.

Animals

Thermal regulation of fatty acid synthetase from Brevibacterium ammoniagenes.

The fatty acid composition of Brevibacterium ammoniagenes was affected by the temperature of growth. As the growth temperature was lowered, the proportion of unsaturated fatty acids increased. The fatty acid synthetase obtained from B. ammoniagense produced oleic acid as well as saturated fatty acids. The ratio of unsaturated to saturated fatty acids synthesized by this enzyme in vitro was dependent on the temperature of the enzyme reaction but not on the growth temperature of B. ammoniagenes from which the enzyme was prepared. These results suggest that the changes of composition in cellular fatty acids reflect the temperature dependence of the fatty acid synthetase.

Brevibacterium

A case of generalized amyloidosis associated with cyclic neutropenia.

A case of generalized amyloidosis associated with cyclic neutropenia is presented. A 24-yr-old female with cyclic neutropenia died from intestinal obstruction caused by necrosis and perforation of the small intestine. Post-mortem examination revealed generalized amyloidosis involving almost all organs. Amyloid deposits were prominent, especially in the alimentary tract, kidneys, spleen, and small blood vessels. As has been suggested in gray collie dogs with congenital cyclic neutropenia known to develop secondary amyloidosis in adulthood, an increase of antigenic stimulation during the intermittent bouts of acute infections may be one of the factors responsible for the development of secondary amyloidosis in this case. Although the association of amyloidosis and cyclic neutropenia in man has rarely been described, it is probable that amyloidosis is not a rare complication of human cyclic neutropenia, considering that patients with this hematologic disorder are chronically exposed to excessive antigenic stimulation.

Adult