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Biomedical subjects

D Lagunoff

Publications and source records attributed to D Lagunoff.

At least 91 records · Page 5Linked to original sources
PubMed1976

Effect of colchicine on rat mast cells.

In the mast cell, a well-developed array of microtubules is centered around the centrioles. Complete loss of microtubules is observed when mast cells are treated with 10(-5) M colchicine for 4 h at 37 degrees C. The loss of ultrastructurally evident microtubules is associated with a marked change in the shape of mast cells from spheroids to highly irregular, frequently elongated forms with eccentric nuclei. In colchicine-treated cells the association of nucleus, Golgi apparatus, and centrioles is also lost. Mast cells exposed to 10(-5) M colchicine for 4 h at 37 degrees C retain 80% of their capacity to release histamine when stimulated by polymyxin B. Exocytosis is evident in stimulated cells pretreated with colchicine and lacking identifiable microtubules. When the conditions of exposure of mast cells to colchicine are varied with respect to the concentration of colchicine, the length of exposure, and the temperature of exposure, dissociation between deformation of cell shape and inhibition of histamine secretion is observed. These observations indicate that microtubules are not essential for mast cell histamine release and bring into question the assumption that the inhibitory effect of colchicine on mast cell secretion depends on interference with microtubule integrity.

Animals↗
PubMed1976

Abnormally large lamellar bodies in type II pneumocytes in Chediak-Higashi syndrome in beige mice.

Lamellar bodies in type II pneumocytes are markedly enlarged in beige mice. The irregular shapes of some of these enlarged specialized lysosomes suggest fusion of smaller ellipsoidal bodies to form the giant organelles, consistent with the proposal of others for the mechanism of formation of abnormal lysosomes in Chediak-Higashi syndrome. Examination of the structure of lamellar bodies by the freeze-fracture technique reveals highly ordered stacking or concentric wrapping of the constituent lamellae. The corrugated patterns evident on the surfaces of normal lamellae are also present in Chediak-Higashi syndrome lamellae. Both normal and Chediak-Higashi syndrome lamellae appear free of typical intramembranous particles. The corrugations seen in the lamellae closely resemble those seen on freeze-fracture of dispersions of lecithin in water.

Animals↗
PubMed1975

Abnormal mast cell granules in the beige (Chédiak-Higashi syndrome) mouse.

Mast cells of beige (C57BL/6J) (bg-j/bg-j) mice were examined histochemically and ultrastructurally. Mast cell granules in the beige mice were markedly enlarged and irregular in shape. Granule contents stained uniformly with acidified toluidine blue, but with ruthenium red and Alcian Blue-safranin, two components were evident. The rims of the abnormal granules stained with ruthenium red and with Alcian Blue; the centers of the granules were clear with ruthenium red and stained with safranin. Mast cell granules thus represent another abnormal organelle in the Chédiak-Higashi syndrome.

Animals↗
PubMed1974

Immunological responses to Candida albicans. I. Mouse-thigh lesion as a model for experimental candidiasis.

A mouse-thigh lesion model for experimental candidiasis is described. A standard inoculum of 5 x 10(8) yeast cells of Candida albicans, injected into the thigh muscle of C57BL/Ks mice, produced an easily measured thigh lesion that was self-limiting by 4 to 6 weeks, permitting a study of immunological responses to the infection. Examination of the histopathology of the lesion reveals that the cellular infiltrate is predominately granulocytic, and gives little evidence for an active, specific, cell-mediated immune response.

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