To investigate ultrastructural characteristics of mast cells in urticaria pigmentosa in comparison to mast cells in other conditions and to search for the possible differences of ultrastuctural features amog different types of urticaria pigmentosa as well as those from normal mast cells, 4 cases of urticaria pigmentosa and 1 case of mastocytosis associated with capillary hemangioma were studied by both light and electron microscopic examinations. The cases of urticaria pigmentosa consisted of one case of blister type from a 3 month old ma1e infant, 2 cases of maculo-papular type both from 10 month old male infants, and a case of nodular type from a 14 month old boy. Ultrastructural features of mast cells in urticaria pigmentosa, in general; a) appeared relatively immature; b) mast cells in nodular type of urticaria pigmentosa were mostly round shaped while other types showed spindle or oblong shapes; c) mast cells in the maculo-papular type and those in hemangioma were similar and resembled normal mast cells; and d) marked degranulation of mast cells in the form of expulsion of granules, perigranular vacuole formation and intracellular disolution of granules for the blister type of urticaria pigmentosa.
Adolescent ; Cytoplasmic Granules/ultrastructure ; Human ; Male ; Mast Cells/ultrastructure ; Microscopy, Electron ; Urticaria Pigmentosa/pathology*

The effects of morphine HCI on the rat mesenteric mast cells were studied with the electron microscopy. The materials were prepared for electron microscopy by osmium tetroxide fixation and embedding in Epon. The rat mesenteric mast cells showed no distinct morphological changes due to morphine HCl, but the mast cell granlues were changed in various ways. For instance, they formed dusters, showed granular lysis, and an appearance of electron transparency. Frequently, some granules appeared in the extracellular space and the boundary of the granules was not evident. From the results mentioned above, it was suggested that rat mesenteric mast cell granules were affected by morphine HCl in the shape, the granular matrix, and the granular boundaries.
Animal ; Cell Nucleus/ultrastructure ; Cytoplasm/ultrastructure ; Cytoplasmic Granules/drug effects ; Cytoplasmic Granules/ultrastructure ; Golgi Apparatus/ultrastructure ; Male ; Mast Cells/drug effects ; Mast Cells/ultrastructure* ; Mesentery/drug effects ; Mesentery/ultrastructure* ; Microscopy, Electron ; Mitochondria, Muscle/ultrastructure ; Morphine/pharmacology* ; Rats

The morphdogical changes in mast cells, induced by horseradish peroxidase (HRP) and distilled water were studied, using light and electron microscopy. The mesenteries of rats sacrificed at 30 minutes; at 1, 2, 4 and 18 hours; and at 1, 2, 3 and 6 weeks after an intraperitoneal injection of 250 microgram or 500 microgram of HRP or 10 ml of distilled water were used for observation of degranulation rates and morphological changes in cell organelles during specified time intervals. The results were as follows: 1) A distinct increase in the mast cell degranulation was observed in the mesenteries after injection of HRP. In particular, all mast cells were disrupted or degranulated significantly 18 hours after injection of distilled water. 2) The degranulating mast cells of the group injected with HRP showed a progressive decrease in electron density of the granules, formation of perigranular cavities, and extrusion of the granules after partial loss of the plasma membrane. 3) At 2 weeks after injection of HRP, some indicators of the early stage of regeneration, that is, peripherally placed nucleus, the expanded Golgi area containing numerous vesicles, and progranules in these vesicles, were observed. 4) After 6 weeks, the morphological characteristics of most mast cells in the group injected with HRP were nearly the same as those of the control group. 5) In degranulating mast cells of the group injected with distilled water, partial rupture of the plasma and cytoplasm with wide dispersion of the granules.
Animal ; Cytoplasmic Granules/ultrastructure* ; Female ; Horseradish Peroxidase ; Male ; Mast Cells/ultrastructure* ; Microscopy, Electron ; Rats ; Rats, Inbred Strains

OBJECTIVETo study the pathological and clinical characteristics of a patient with spontaneous platelet aggregation of his giant and morphologically abnormal platelets.

METHODSPlatelet size and structure were observed under light microscope and electron microscope. Platelet aggregation was measured turbidometrically. Platelet glycoproteins (GP) were analyzed using flow cytometry. PCR and DNA sequencing were performed to identify the gene abnormality.

RESULTSThe patient had spontaneous platelet aggregation of giant platelets with thickened plasma membrane and increased number of granules in various shapes. Aspirin and ticlopidine did not affect the spontaneous aggregation. The expression of GP I b, GP II b, GP III a and P-selectin in the platelet membrane were in normal range. Results of gene analyses for GP I balpha, GP I bbeta and GPIX were also normal.

CONCLUSIONBoth morphological and functional abnormalities of the platelets from the patient were clearly distinguishable from that of other hereditary giant platelet disorders. It would probably represent a novel platelet disorder which had not been reported to date.

Aspirin ; pharmacology ; Bernard-Soulier Syndrome ; metabolism ; pathology ; Blood Platelet Disorders ; metabolism ; pathology ; Cell Size ; physiology ; Child ; Cytoplasmic Granules ; pathology ; ultrastructure ; Female ; Humans ; Platelet Aggregation ; drug effects ; physiology ; Platelet Aggregation Inhibitors ; pharmacology ; Platelet Membrane Glycoproteins ; genetics ; metabolism ; Ticlopidine ; pharmacology