Genesis of concentric laminated inclusions in the nucleus

Summary Single-membrane-bound inclusions containing zymogen granules were found in pancreatic acinar cells. Images were seen suggesting that the concentric laminated inclusion is derived by hydration and fusion of such granules within the inclusion.     

Peroxidase activity of neutrophil granules in two cases of congenital myeloperoxidase deficiency]

The neutrophils and monocytes of two patients with hereditary myeloperoxidase deficiency lacked myeloperoxidase activity as determined by light and electron microscopic cytochemical staining. Using Graham-Karnovsky media, azurophils of neutrophils were devoid of peroxidase whereas all eosinophilic and basophilic granules exhibited normal peroxidase activity. After incubation in alkaline diaminobenzidine media which stains the catalase of microperoxisomes, some small granules were seen to be strongly stained in both immature and mature neutrophils. These small granules were distinct from all other neutrophilic granules which lacked a positive reaction. Only, in the presence of cyanide or aminotriazole, peroxidatic activity was also detected in some ellipsoid azurophils. This observation suggests that these substances activated an oxidase whose nature is discussed.     

Reinterpretation of the ultrastructure of cartilage matrix.

The epiphyseal cartilage from new-born mouse was treated with collagenase in two ways: either before fixation or after glutaraldehyde fixation. The electron dense granules of the matrix were not seen in the micrographs of cartilage treated with collagenase before fixation. It is concluded that collagen plays a definite role in the formation of the granules at the time of tissue fixation and that the granules are fixation artifacts.     

Pigment granules in choroidal melanophores of the albino goldfish.

Pigment granules in choroidal melanophores of the albino goldfish contained fine particulate materials which were in various degrees aggregated in clumps. Tyrosinase was considered to be present in an inhibited state in these pigment granules.     

Preliminary observations on the co-existence of regulatory peptides in cells of the baboon endocrine pancreas

Summary Immunocytochemical procedures at ultrastructural and light microscopy level revealed, in the Chacma baboon endocrine pancreas, cells which were immunoreactive for glucagon and pancreatic polypeptide (PP). Some D cells were observed to contain secretory granules with both the appearance and immunoreactivity of A cell secretory granules.     

Preliminary observations on the co-existence of regulatory peptides in cells of the baboon endocrine pancreas

Immunocytochemical procedures at ultrastructural and light microscopy level revealed, in the Chacma baboon endocrine pancreas, cells which were immunoreactive for glucagon and pancreatic polypeptide (PP). Some D cells were observed to contain secretory granules with both the appearance and immunoreactivity of A cell secretory granules.     

Beobachtungen über das Auftreten von Keratohyalingranula im Zellkern

Summary Electron microscopic studies on the oesophageal epithelium of the rat revealed for the first time intranuclear granules of keratohyalin. The results strongly suggest that these granules were extruded from the nucleus and were enlarged in the cytoplasm by ribonucleoprotein (RNP) particles aggregating to the keratohyalin.     

Reinterpretation of the ultrastructure of cartilage matrix

Summary The epiphyseal cartilage from new-born mouse was treated with collagenase in two ways: either before fixation or after glutaraldehyde fixation. The electron dense granules of the matrix were not seen in the micrographs of cartilage treated with collagenase before fixation. It is concluded that collagen plays a definite role in the formation of the granules at the time of tissue fixation and that the granules are fixation artifacts.Commonwealth Academic Staff Fellow. Permanent address: Department of Zoology, University of Poona, Poona 411007, India.     

Pigment granules in choroidal melanophores of the albino goldfish

Summary Pigment granules in choroidal melanophores of the albino goldfish contained fine particulate materials which were in various degrees aggregated in clumps. Tyrosinase was considered to be present in an inhibited state in these pigment granules.Supported by the Ministry of Education of Japan Research grant No. 234046.     

Elektronenmikroskopische Untersuchungen an den heterophilen Granulozyten des Haushuhns

Summary Ultra-thin sections of heterophil granulocytes of clinically healthy, laying hybrid-hens were examined by electron microscope. Within the cytoplasm of these cells, round, oval or fusiform granules (rods) of different electron density were found. Osmiophilic and electron light areas (cores) were seen, either together within the same granular body, or separately in different granules.     

Evaluation of the ability of intact platelets to accumulate acridine organge

Summary A new approach to the evaluation of the uptake of fluorescent, probes by intact, cells is described. Acridine organe (AO) was used because it can be selectively accumulated by serotonin-containing granules of platelets. Analysis of the fluorescence signal allows the estimation of the relative volume of the granules and the equilibrium coefficients for AO transport across the cytoplasm and granule membranes. The following results were obtained for human and rabbit platelets: the relative volumes of the granules were 14±1% and 29±2%, the ratios of intragranular-extracellular probe concentration were 2260±382 and 30,000±5500, and the cytoplasm-extracellular medium concentration ratios were 375±60 and 225±60, respectively.     

Identification of hemolytic granules isolated from human myocardial cells

Human myocardial cells from fresh autopsy material contained granules which possessed hemolytic activity against guinea pig and rabbit erythrocytes. The hemolytic granules, which had a density of 1.02 and a diameter of 200-300 nm, were recovered as a microsome fraction from subcellular homogenates of human myocardial cells by differential centrifugation in 300 mM sucrose containing 0.1 mM PMSF and 10 mM EDTA. The membrane lesions caused by the granules were ring-like structures with an internal diameter of about 10-17 nm, analogous to that caused by perforin- and complement-induced lysis. However, the requirement for divalent cation differed from that for perforin-induced lysis, since the microsome-mediated lysis occurred in the presence of EDTA.     

Plurihormonality in the secretory granules of the normal human pituitary. An immunoelectron microscopic study

Normal human autopsy anterior pituitary tissue from 5 cases was embedded in LR White resin and immunolabelled using silver-enhanced 5-nm protein A gold probes. Follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), adrenocorticotrophic hormone (ACTH), growth hormone (GH) and prolactin (PRL) were immunolocalised to the level of secretory granule. A two-sided double-labelling method was used to cross-react two hormones at a time with respect to their corresponding antibodies. All possible combinations of the six pituitary hormones were tested. Plurihormonal granules were found that contained LH + FSH, LH + TSH, and FSH + TSH. Each hormone was also found in monohormonal granules. Granule diameter was significantly larger in the pluri as opposed to monohormonal granules.     

Plurihormonality in the secretory granules of the normal human pituitary. An immunoelectron microscopic study

Summary Normal human autopsy anterior pituitary tissue from 5 cases was embedded in LR White resin and immunolabelled using silver-enhanced 5-nm protein A gold probes. Follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), adrenocorticotrophic hormone (ACTH), growth hormone (GH) and prolactin (PRL) were immunolocalised to the level of secretory granule.A two-sided double-labelling method was used to cross-react two hormones at a time with respect to their corresponding antibodies. All possible combinations of the six pituitary hormones were tested. Plurihormonal granules were found that contained LH+FSH, LH+TSH, and FSH+TSH. Each hormone was also found in monohormonal granules. Granule diameter was significantly larger in the pluri as opposed to monohormonal granules.     

Identification of hemolytic granules isolated from human myocardial cells

Summary Human myocardial cells from fresh autopsy material contained granules which possessed hemolytic activity against guinea pig and rabbit erythrocytes. The hemolytic granules, which had a density of 1.02 and a diameter of 200–300 nm, were recovered as a microsome fraction from subcellular homogenates of human myocardial cells by differential centrifugation in 300 mM sucrose containing 0.1 mM PMSF and 10 mM EDTA. The membrane lesions caused by the granules were ring-like structures with an internal diameter of about 10–17 nm, analogous to that caused by perforin- and complement-induced lysis. However, the requirement for divalent cation differed from that for perforin-induced lysis, since the microsome-mediated lysis occurred in the presence of EDTA.     

Preparing the lethal hit: interplay between exo- and endocytic pathways in cytotoxic T lymphocytes

Cytotoxic T lymphocytes patrol our body in search for infected cells which they kill through the release of cytotoxic substances contained in cytotoxic granules. The fusion of cytotoxic granules occurs at a specially formed contact site, the immunological synapse, and is tightly controlled to ensure specificity. In this review, we discuss the contribution of two intracellular compartments, endosomes and cytotoxic granules, to the formation, function and disassembly of the immunological synapse. We highlight a recently proposed sequential process of fusion events at the IS upon target cell recognition. First, recycling endosomes fuse with the plasma membrane to deliver cargo required for the docking of cytotoxic granules. Second, cytotoxic granules arrive and fuse upon docking in a SNARE-dependent manner. Following fusion, membrane components of the cytotoxic granule are retrieved through endocytosis to ensure the fast, efficient serial killing of target cells that is characteristic of cytotoxic T lymphocytes.     

Modifications ultrastructurelles provoquées par quelques médicaments sur les terminaisons nerveuses adrénergiques et sur la médullaire surrénale

Summary It has been shown that reserpine and guanethidine deplete granules containing catecholamine in sympathetic nerve endings of both the pineal gland and the vas deferens. This effect is blocked by iproniazid. Bretylium is not able to deplete these granules but it modifies their aspect. It has also been observed that granules of the adrenal medulla are depleted less easily than those of sympathetic nerve endings.     

Platelet heterogeneity and dense tubular system changes on activation

Platelets impregnated with heavy metals appeared as 3 distinct morphological types: 'reticular' cells with a polygonal dense tubular network and stained granules, dark metallophilic cells, and pale metallophobic cells with microvesicles and non-staining granules. On stimulation, type 1 cells decreased while type 3 cells increased, suggesting that with activation dense tubules break up into microvesicles and granules become metallophobic. In the type 2 cells a different functional mechanism may exist.     

Quantitative ultrastructural features of maturing mononuclear phagocytes in rat peritoneal fluids.

Ultrastructural features of the in vivo transformation of macrophage congeners in resident and adjuvant-induced peritoneal populations are evaluated by sterological methods. Maturation involves an increase in cell size by the differential hypertrophy of subcellular compartments, notably remaining cytoplasm, nucleus and lysosome-like granules. Larger cells have more and larger granules, more mitochondria and a greater plasmalemmal surface. In contrast, adjuvant activation tends to produce fewer granules and a nett loss of surface membrane.     

Evaluation of the ability of intact platelets to accumulate acridine orange

A new approach to the evaluation of the uptake of fluorescent probes by intact cells is described. Acridine orange (AO) was used because it can be selectively accumulated by serotonin-containing granules of platelets. Analysis of the fluorescence signal allows the estimation of the relative volume of the granules and the equilibrium coefficients for AO transport across the cytoplasm and granule membranes. The following results were obtained for human and rabbit platelets: the relative volumes of the granules were 14 +/- 1% and 29 +/- 2%, the ratios of intragranular-extracellular probe concentration were 2260 +/- 382 and 30,000 +/- 5550, and the cytoplasm-extracellular medium concentration ratios were 375 +/- 60 and 225 +/- 60, respectively.