Masafumi Aoki

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The prevalence of obesity is increasing globally, and obesity is a major risk factor for type 2 diabetes and cardiovascular disease. We investigated the effects of coffee polyphenols (CPP), which are abundant in coffee and consumed worldwide, on diet-induced body fat accumulation. C57BL/6J mice were fed either a control diet, a high-fat diet, or a high-fat(More)
Osmium tetroxide, commonly used as a fixative in electron microscopy, can destroy actin filaments. Thiocarbohydrizide (TCH) is a bipolar substance that binds to the osmium. By sandwiching TCH between two phases of osmium treatment, tissue exposure to osmium could be minimized without destroying actin filaments. The contrast of osmophilic components of cells(More)
Insulin resistance-related obesity and diabetes mellitus are the predominant causes of fatty liver disease. Here we examine the effects of dietary diacylglycerol (DG), which is a minor component of plant oils, on lipid accumulation and the expression of genes involved in lipid metabolism in the liver. The animals were fed diets containing either 10%(More)
We used fast (seconds) and ultrafast (milliseconds) microwave energy-assisted chemical fixation protocols, postembedding immunogold staining, and a morphometric analysis to investigate the early morphological changes and the TNF-alpha immunoreactivity in the cytoplasmic granules of rat peritoneal mast cells that had been stimulated to secrete by exposure to(More)
The subcellular events responsible for release of mediators by mast cells may help to clarify roles for mast cells in health and disease. In this study we show that the granule-associated protease chymase is also within cytoplasmic vesicles in appropriately stimulated rat peritoneal mast cells. Rat peritoneal mast cells were recovered before or 1-10 sec(More)
Electron microscopic evidence is presented to indicate that entire megakaryocytes traverse the marrow--blood barrier and enter the circulation. Passage occurs through apertures of 6 micrometer in diameter, located in the parajunctional areas of the marrow sinus endothelium. Serial sectioning indicates that these apertures are transendothelial rather than(More)
Red cells of different species respond differently to the treatment with the membrane mobility agent, A2C, with respect to both the A2C interaction and the subsequent cell-cell interaction. Depending on whether both, one or neither of the processes are effective, some red cells (e.g., nucleated Leghorn hen red cells, rat red cells) fuse easily, some (human(More)
To study the dynamics of red cell egress from the marrow, the demand for red cell delivery was enhanced in splenectomized rats by removing 25% of the blood volume, which was then immediately replaced by plasma. Within 15 min, packed cell volume declined by 22% of the initial value. Corrected reticulocyte count followed a biphasic pattern: an initial peak(More)
Marrow sinuses have been shown to undergo rhythmic dilatations and this has been suggested as a mechanism controlling cell egress from the marrow. Within the rigid frame of bone where the volume of the marrow is fixed, dilatation of sinuses can only lead to the displacement of cells into the lumen. The absence of tight junction between sinus endothelial(More)