Quantitative study on osteoconduction of apatite-wollastonite containing glass ceramic granules, hydroxyapatite granules, and alumina granules

The osteoconductive potential of apatite-wollastonite containing glass ceramic (A-W.GC), hydroxyapatite (HA), and alumina (AL) was quantitatively evaluated by implanting them as granules into rat tibiae. The amount of mature bone formed in contact with the ceramics varied depending on the ceramic materials; it reached a plateau earliest in A-W.GC and latest in AL. The bone mass at the interface showed the same results. The osteoconductive potential was suggested to be higher in bioactive ceramics than in bioinert ceramics, and to be related to the formation rate of the surface apatite layer of the bioactive ceramics.     

Lobular carcinoma with cytoplasmic granules

We report on a case of invasive lobular carcinoma of the breast with a previously undescribed cytologic feature. Diff-Quik-stained cytologic preparations showed uniform single cells with prominent coarse cytoplasmic granules. Ultrastructurally, the granules showed features suggestive of autophagosomes and/or degenerative mitochondria. The cytologic differential diagnosis included granulocytic sarcoma, metastatic melanoma, extramedullary hematopoiesis, large granulocytic leukemia/lymphoma, and mast-cell tumor. Adjunctive studies were helpful in the diagnosis of carcinoma. Histologic study of the mastectomy specimen showed classic type of invasive lobular carcinoma.     

Energy-coupling in adrenal chromaffin granules

The membrane of bovine adrenomedullary chromaffin granules contains a number of activities associated with cellular energy metabolism. The interrelationship of these activities and their sensitivity to mitochondrial inhibitors and uncouplers were explored using a fluorescent probe. The probe, 1-anilinonaphthalene-8-sulphonic acid, binds to chromaffin granule membranes resulting in an enhancement of its fluorescence.Hydrolysis of adenosine triphosphate by the adenosine triphosphatase of chromaffin granules produces a further time dependent increase in the fluorescence of the probe. This increase is caused by the binding of additional probe with no change in the fluorescence quantum yield of bound probe. A K⁺ diffusion potential across the membrane of chromaffin granules induced by the ionophore valinomycin changes the fluorescence quantum yield of bound 1-anilinonaphthalene-8-sulphonic acid. The fluorescence of 1-anilinonaphthalene-8-sulphonic acid bound to chromaffin granules increases as the external pH is lowered. The change in fluorescence on addition of a mitochondrial uncoupling agent suggests that the internal pH of chromaffin granules is low.The incorporation of catecholamines by chromaffin granules and their membrane vesicles in the presence of Mg²⁺ and adenosine triphosphate is inhibited by uncouplers and the specific transport inhibitor, reserpine. The oxidation of reduced nicotinamide adenine dinucleotide (NADH) by chromaffin granules is stimulated by dopamine in the presence of Mg²⁺ and adenosine triphosphate. Mitochondrial inhibitors antimycin A, oligomycin and KCN inhibit catecholamine incorporation by membrane vesicles prepared from chromaffin granules. They do not inhibit the adenosine triphosphatase but do inhibit the enhancement of NADH oxidation induced by dopamine in the presence of Mg²⁺ and adenosine triphosphate. The reagent dicyclohexylcarbodiimide inhibits in parallel catecholamine uptake, the activity of chromaffin granule adenosine triphosphatase and the associated fluorescence response of 1-anilinonaphthalene-8-sulphonic acid.The relationships between the energy producing and the energy consuming processes in chromaffin granules and the sites of action of different types of inhibitors are discussed in terms of proton movements within or across the membrane of chromaffin granules.     

Freeze-fracture of adrenal chromaffin granules

Freeze-fracture replicas of bovine adrenal chromaffin granules show convex and concave fracture faces. The concave fracture faces are studded with 9 nm diameter particles (on average 950/μm²) while the convex fracture faces are almost devoid of particles (approx 150/μm²). The asymmetry in particle distribution for the membranes of these intracellular organelles is consistent with that observed for plasma membranes. The significance of these results is discussed with reference to the exocytotic release of catecholamines from the adrenal medulla.     

Formation of secretory granules by chromogranins

This review article covers the molecular mechanisms of secretory granule formation by chromogranin transfection. Recently, a few investigators have reported that the transfection of chromogranin A and B produces the structures of secretory granules. We used the GFP-chromogranin A transfection method to nonendocrine cells, COS-7 cells, which are not equipped with secretory granules. Despite the absence of endogenous secretory granules in nontransfected COS-7 cells, COS-7 cells transfected with chromogranin A contained granule-like structures in electron micrographs. The granules were composed of an outer limiting membrane with core structures that were interpreted as secretory granules. Human chromogranin A (CgA) labeled with 5-nm gold particles was present in several dense-core granules in our previous electron microscopy study. This review depicts the role of chromogranin A in the formation of secretory granules. It emphasizes the application of recently developed new technologies and the genesis of secretory granules.     

Iron granules in plasma cells.

The curious and unusual finding of coarse iron granules in marrow plasma cells is reported in 13 patients, in whom the finding was incidental. In 10 of these patients there was known alcohol abuse and serious medical complications of that abuse. Previous reports of the finding are reviewed. Haematological data of the 13 patients are presented. A hypothesis is outlined which may account for the finding.     

Histamine release from mast cell granules

Rat peritoneal mast cells were separated from other cells by differential centrifugation in concentrated serum albumin. Granules were isolated from these cells by ultrasonic disintegration and subsequent centrifugation. 60–80% of the granules had intact membranes and retained their histamine store in a physiological salt solution. Histamine was released from the granules with intact membranes by Ca²⁺, 10 mM, in the presence of phosphatidyl serine, 25–50 g/ml. The release was initiated in 15 sec and completed in 16 min. Other divalent cations in 10 mM concentration, viz. Mg²⁺, Ba²⁺, Sr²⁺, Ni²⁺ and Mn²⁺, also released histamine from the granules in the presence of phosphatidyl serine. When histamine release was induced by calcium and phosphatidyl serine the calcium uptake in the granules was remarkably increased. Ca²⁺ could thus displace histamine from the granule matrix. The possibility that calcium with phosphatidyl serine may change the granule membrane permeability is discussed.     

Characterization of canine neutrophil granules.

The purpose of this study was to isolate distinct populations of canine neutrophil granules and to compare them with neutrophil granules from other species. Size, shape, density, and content of canine neutrophil granules were determined. Neutrophils obtained by Ficoll-Hypaque sedimentation were homogenized, and granule populations were separated by isopycnic centrifugation on a linear sucrose gradient (rho, 1.14 to 1.22 g/ml). The most dense granule population (rho, 1.197 g/ml) contained all of the myeloperoxidase, beta-glucuronidase, and elastase, more than half of the acid beta-glycerophosphatase, and most of the lysozyme. The population with intermediate density (rho, 1.179 g/ml) contained lactoferrin, vitamin B12-binding protein, and the remainder of the acid beta-glycerophosphatase and lysozyme. The least dense granule population did not contain a major peak of any of the enzymes or binding proteins tested but was distinguished by density and morphology. The size and shape of the granules were determined from scanning electron micrographs and assessment of shape was aided by transmission electron micrographs. By these methods three populations of canine neutrophil granules were characterized and named: myeloperoxidase granules, vitamin B12-binding protein granules, and low-density granules.     

Composite keratohyaline granules in striate keratoderma

The gross, light microscopic, and ultrastructural findings in a 55 year old man was striate keratoderma are presented. There was no family history of the disease. The lesions developed in his late teens and early adult years, and consisted of progressively worsening, raised, hyperkeratotic, linear plaques on the palm and volar surface of the third and fifth fingers bilaterally. There were also painful callositieson both heels, and thick, raised plaques on the heels and lateral plantar surfaces. The epidermis was papillomatous and acanthotic, with marked orthokeratosis, minimal parakeratosis, and a very thickened granular layer. No epidermolysis was seen. Electron microscopy showed increased tonofibrils in the stratum spinosum arranged in wavy, parallel bundles and a granular layer in which normal Odland bodies were present. However, the keratohyaline granules were large, with rounded bordersand a striped, alternating, dark and light content characteristic of composite granules. There was diminished contact of the granules with tonofibrils. The transition to the stratum corneum was abrupt. The ultrastructural and genetic features of keratodermas, with special emphasis on the striate type, are reviewed.     

Neutrophil granules in health and disease

The granules of the neutrophil, in addition to contributing to its distinctive morphologic appearance, are critical to its unique functions. Specific granules appear necessary for neutrophil recruitment to sites of inflammation, for upregulation of receptors important in the control of chemotaxis and the respiratory burst, for disaggregation, for bactericidal activity, and for chemoattractant generation. The azurophilic granules supply enzymes for digestive and bactericidal functions and supply MPO to the MPO-halide-hydrogen peroxide bactericidal system. Azurophilic granule contents also regulate inflammation by degrading inflammatory products. Both granules may play a role in intracellular calcium regulation. In addition to these activities that protect the host from infection, granules also, under certain circumstances, contribute to disease processes. For these reasons, greater knowledge about granule contents, control of degranulation, inactivation of toxic granule contents and products, and the role of granules in neutrophil membrane events and function has widespread implications for treatment of patients with neutrophil dysfunction syndromes and patients with multiple other systemic diseases.