To ensure normal immune function, mast cells employ different pathways to release mediators. Here, we report a thus far unknown capacity of mast cells to recycle and reuse secretory granules after an antigen-evoked degranulation process under physiological conditions; this phenomenon involves the existence of a recycling secretory granule pool that is available for release in a short time scale...

hCAP-18 is the only human member of the antibacterial and endotoxin-binding family of proteins known as cathelicidins. The antibacterial and endotoxin binding domains reside in the C-terminal 37 amino acids of the protein (LL-37) and this is believed to be unleashed from the neutralizing N-terminus by proteases from peroxidase positive granules. In human neutrophils, peroxidase positive and per...

Azurophil granules of myeloid cells form in promyelocytes. They store cytotoxic and digestive agents which when released are involved in the defense against infection. In order to characterize the intragranular distribution of these agents, ultrastructural methods using immunogold were used on promyelocytes. Azurophil granules were divided into nucleated, large spherical (large azurophil) and s...

A microgranule fraction, isolated from human neutrophils by using a novel high-resolution Percoll density gradient system contained granules with the lowest density and diameter when compared with 12 other isopycnic granule fractions. Ultrastructurally, from 34% to 50% of the microgranules showed homogeneous diaminobenzidine (DAB) staining under conditions for localizing peroxidase reactivity. ...

The iron storage macrophage has been isolated from the marrow of Imferon-treated mice and studied in vitro by morphologic, histochemical, and functional tests and isotope labeling techniques. These macrophages on stained preparations are large, many times binucleate cells (up to 150 mu), and show Prussian blue reactivity. In Epon-embedded, stained thick sections they contain elongated narrow ba...

Purpose: To develop and optimize controlled-release (CR) oxybutynin chloride matrix tablets. Methods: Oxybutynin CR tablets were prepared by embedding drug-containing granules into a hydrogel matrix of hydroxypropyl methylcellulose (HPMC). A coating layer was then applied with a mixture of HPMC, ethylcellulose, shellac, and HPMC phthalate. The effect of several formulation variables on in vitro...

The anterior pituitary is a complex secretory tissue known to contain several sulfated macromolecules. In the present study, we identified the major tyrosine-sulfated protein of the bovine anterior pituitary and investigated its cellular and subcellular localization. This protein consisted of two tyrosine-sulfated polypeptides of molecular weight 86,000 and 84,000 that were highly homologous to...

The classification of the acute leukemias depends mainly on the morphologic and cytochemical evaluation of the blast forms. One of the main accepted morphologic criteria in the differentiation between acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML) is the absence of granules in the blast cells of ALL. We evaluated a patient with ALL in whom granules were present in the ...

The effects of sublethal amounts of the cationic dye, neutral red, upon the structure of pancreatic exocrine cells, and upon the mitochondria of renal distal tubule cells, have been studied with the electron microscope. It was found that neutral red is a cytoplasmic toxin which causes reproducible and characteristic changes in the ergastoplasm, the zymogen granules, the mitochondria, and possib...

Natural abundance carbon-13 and proton NMR spectra of bovine chromaffin granules have been obtained and analyzed using computer simulation techniques. High resolution spectra show the presence of a fluid aqueous phase containing epinephrine, ATP and a random coil protein. The protein spectrum contains unusually intense resonances due to glutamic acid and proline and has been simulated satisfact...