PubMed HealthSearch

SEARCH · PubMed Health

Results for “Cytoplasmic Granules”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

[Ultrastructural analysis of reactive changes in the exo- and endocrine epithelium of embryonal pancreas in organ cultures].

The purpose of the work was to study reactive changes of endocrine and exocrine epithelii of the rat embryonic pancreas in organic culturation. The culturation was carried out at 34 degrees C and in the nutritional mixture of the following composition: medium 199--70%, cattle serum--20%, chicken embryo extract--10%, glucose--400 mg/100 ml, vitamin "C"--7 mg/100 ml, benzilpenicillin--50 U/ml. Three series of experiments were carried out with cultivation of the pancreatic gland of 18, 19 and 20-day-old embryos for 4--28 days. The electronograms obtained demonstrate a certain difference in reactivity, cytophysiology and differentiation of exocrine and endocrine epithelium under the conditions of organic cultivation. During the process, endocrine epithelium undergoes primary differentiation, secondary cytodifferentiation and, further, degenerative changes and necrosis develop. B-cells of the insular apparatus grow and function better than the exogenous epithelium. On the 28th day of cultivation, the embryonic pancreas of 19-day-old embryo demonstrates certain signs of synthesis and B-granule formation. In B-cells cytoplasm, granules of different stages of secrete formation are revealed.

Animals

Fluorescence microscopy of viable mast cells stained with different concentrations of acridine orange.

Freshly harvested rat peritoneal mast cells were stained with different concentrations of acridine orange, a metachromatic fluorochrome known to form complexes with chromatin and muscopolysaccharides. Fluorescence metachromasia was observed in cytoplasmic granules in cell populations with intracelluar dye contents as low as 5 X 10(-16) mole per cell, one-half decade lower than required to produce metachromatic staining of the nucleus. Cytoplasmic granules did not stain uniformly throughout the cell; some granules exhibited red fluorescence and others green. As the amount of acridine orange uptake per cell was increased, cytoplasmic fluorescence became uniformly red and nuclear fluorescence gradually changed from green to yellow.

Acridine Orange

Morphologic and functional characteristics of bone marrow macrophages from imferon-treated mice.

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 basophilic inclusions. These macrophages are actively phagocytic and pinocytic; histochemical studies show that these cells are rich in acid phosphatase, nonspecific esterase, and PAS diastase-resistant activity. Iron storage macrophages do not incorporate the 3H-thymidine. The electron microscopic appearance of this macrophage shows that the cell has ferritin free in the cytoplasm and several types of cytoplasmic granules: those with large quantities of electron-dense ferritin and/or hemosiderin (type A), elongated granules (type B) with moderately electron dense homogeneous matrix and some ferritin at the periphery, and granules with heterogeneous content (type C). The above findings demonstrate that the iron storage cell is a mature macrophage which contains hydrolases, ferritin, and a unique population of cytoplasmic granules which are lysosomal in nature. There is some evidence to suggest that the unusual lysosome (type B granule) occurs after macrophages have ingested erythrocytes.

Acid Phosphatase

Enzyme release and morphological changes in leukocytes induced by mechanical trauma.

Polymorphonuclear (PMN) leukocytes exposed to mechanical trauma in vitro will release enzymes both from azurophilic and specific granules at shear stress levels of between 75 and 150 dyn/cm2 for 10 min. In addition, at these shear stresses the leukocyte count in whole blood decreased only slightly and the number of ruptured leukocytes on Wright-stained blood films increased significantly. At higher shear stresses, enzyme release and leukocyte damage increased monotonically. Transmission electron microscopy evaluation of sheared PMNs revealed that remaining intact cells had minor morphological changes at stresses of 150 dyn/cm2. They were characterized by clublike cytoplasmic potrusions, spherical shape, and a circumferential distribution of cytoplasmic granules. At higher shear stresses (600 dyn/cm2) cell destruction was marked. Intact PMNs contained fewer cytoplasmic granules, a large number of vacuoles, and condensed nuclear chromatin. These studies show that PMN morphology and function are at least as sensitive to mechanical trauma as similar platelet alterations seen in other studies.

Alkaline Phosphatase

On the occurrence of argyrophil cells in salivary glands.

Salivary glands (parotid, submandibular and sublingual glands) of nine mammalian species were investigated with respect to presence and localization of argyrophil and argentaffin cells. With the exception of the parotid gland of the rat, no positive staining was observed within the examined glands. In the rat parotid distinctly argyrophil cells could be demonstrated in the intercalated ducts. Histochemical studies of the cells, ultrastructural analysis of their cytoplasmic granules as well as their reactions to certain drugs indicate that these cells are of exocrine rather than of endocrine nature. After a subcutaneous injection of pilocarpine, the intensity of the argyrophil staining was markedly reduced. No specific catecholamine fluorescence could be detected within the cells, not even after pretreatment of the animals with high doses of L-DOPA. The membrane-bounded cytoplasmic granules of the intercalated duct cells furthermore displayed a strong positive staining reaction after treatment of ultrathin Vestopal sections with the periodic acid-chromic acid-silver technique of Rambourg et al. (1969).

Animals

Granule release by polymorphonuclear leukocytes treated with the ionophore A23187.

Polymorphonuclear leukocytes (PMN's) incubate three to eight minutes at 37 degrees C in medium containing 1 X 10(-6) M of the ionophore antibiotic A23187 released their cytoplasmic granules into the extracellular medium. Transmission electron microscopy of treated cells showed microfilament bundles extending between adjacent granules within the cytoplasm and between granules and the plasma membrane. Tiny dense projections (beads) 8-12 nm in diameter were observed along segments of the cytoplasmic surface of the plasma membrane with a periodicity of 20-30 nm. These beads were observed on the plasma membrane only in the vicinity of intra- or extracytoplasmic granules. The structural relationships of the beads with the plasma membrane microfilaments suggest they play a role in the process of ionophore-induced granule release from polymorphonuclear leukocytes.

Animals

ACTH-secreting carcinoma of the breast.

We report a case of ACTH-secreting carcinoma of the breast. Membrane-bound secretory granules were seen within the cancer cells electron microscopically. Cytoplasmic granules reacting immunochemically to anti-ACTH antisera were seen on light microscopy. Breast cancers have been shown to secrete calcitonin, parathyroid hormone, human chorionic gonadotropin, and norepinephrine in addition to ACTH. This suggests either the presence of neuroendocrine cells in the breast as a source of such neoplasms, as in the lung, or genomic derepression during neoplastic transformation.

Adrenocortical Hyperfunction

The fine structure of macrophage granules in experimental granulomas in rodents.

Macrophages in granulomas in four rodent species contain cytoplasmic granules with an ordered substructure similar to those previously described in human granuloma macrophages. These appearances, as well as other ultrastructural features of the cells, are compatible with the view that those macrophages have a secretory function.

Animals

Molecular organization of rat prolactin granules. I. In vitro stability of intact and "membraneless" granules.

Studies carried out on a number of secretory cell systems suggest that the specific cytoplasmic granules in which the secretion products are stored before their release are complex organelles which can possess a distinct molecular organization. For instance, it has been reported that in some granules the segregated secretion products are organized into crystalline structures (1-3) or large intermolecular aggregates (4-8). It is likely that all phenomena of this type are favorable to the economy of the cell, in the sense that they reduce the energy required for storage of the secretion products. The prolactin (LTH) granules of the rat pituitary possess a number of morphological features which strongly suggest that the molecules(s) of their content might be arranged in a relatively stable structure. Thus, these granules are remarkably polymorphic in shape, and their membrane is usually separated from their content by a clear space. Furthermore, identifiable LTH granules devoid of their membrane are often seen in the pericapillary space, suggesting that upon discharge by exocytosis they are dissolved only slowly (9). However, no studies specifically concerned with the mechanisms of LTH storage have been reported so far. In order to obtain some information on this question, we have studied the behavior of isolated granule fractions incubated in vitro under a variety of carefully controlled experimental conditions.

Animals

Localization of chymotrypsin-like cationic protein, collagenase and elastase in azurophil granules of human neutrophilic polymorphonuclear leukocytes.

The subcellular localization of granulocyte collagenase, elastase and chymotrypsin-like cationic protein was determined using velocity centrifugation of cytoplasmic granules of human polymorphonuclear leukocytes. The proteases were assayed by immunochemical and enzymatic methods. Measurements of lactoferrin and myeloperoxidase distinguish exactly between constituents of specific and azurophil granules. Collagenase, elastase and chymotrypsin-like cationic proteins showed an almost identical sharp and unimodal distribution. They co-sedimented with myeloperoxidase demonstrating that these enzymes are localized exclusively in the azurophil granules.

Adult

The appearance of transition forms between monocytes and Kupffer cells in the liver of rats treated with glucan. A cytochemical and ultrastructural study.

A massive accumulation of mononuclear phagocytes in the rat liver was found after the injection of glucan, a beta-1,3-polyglucose. Portal vessels and central veins contained large numbers of rounded and elongated cells which were adherent to the endothelium. By scanning electron microscopy most of these cells exhibited prominent lemellopodia, raised ridge-like profiles and blebs, the typical features of mononuclear phagocytes. Peroxidase cytochemistry revealed that whereas most cells in portal vessels were monocytes with peroxidase positive and negative granules, the majority of cells in central veins were macrophages exhibiting peroxidase activity in nuclear envelope (NE) and endoplasmic reticulum (ER). In sinusoids monocytes and macrophages were seen side by side. The major finding of the present study was that some cells, adherent to the endothelium or portal vessels or to the lining of sinusoids, exhibited a peroxidase pattern intermediate between monocytes and Kupffer cells, i.e. strong peroxidase activity in cytoplasmic granules, as well as a weak to moderately positive peroxidase reaction in NE and ER. These intermediate cells also contained peroxidase-negative granules with halo, which are usually seen in monocytes. Furthermore, examination of serial ultrathin sections of typical Kupffer cells revealed numerous peroxidase-positive granules and peroxidase-negative granules with halo in their cytoplasm. Finally, dividing Kupffer cells with positive peroxidase reaction in ER were found. These in vivo observations provide ultrastructural and cytochemical evidence in support of the concept of derivation of Kupffer cells from monocytes, demonstrating in addition that Kupffer cells are capable of self-replication in situ.

Animals

Ultrastructure of the gut neurotensin cell.

In mammals, neurotensin cells occur scattered in the epithelium of the jejunum-ileum. In chicken, neurotensin cells are abundant in the region of the gizzard-duodenal junction (antrum) where they occur intermingled with numerous somatostatin and gastrin cells. The neurotensin cells in chicken, dog and man were identified at the electron microscopic level by immunocytochemistry, using the consecutive semithin/ultrathin section technique. They contain numerous electron dense cytoplasmic granules, pre-dominantly in the basal portion of the cell. It was shown that these granules are the storage site for neurotensin. The neurotensin granules are round, highly electron dense and of about the same size in the different species examined (mean diameter 260--290 nm). In dog and man the granules have a tightly applied surrounding membrane while in the chicken a relatively electron lucent zone separates the electron dense core from the granule membrane. The ultrastructure of the neurotensin granules in chicken is somewhat reminiscent of that of the gastrin granules. The mean diameter of the gastrin granules in chicken antrum is 230 nm; for the somatostatin granules the mean diameter is 305 nm.

Animals

The localization of catalase in the pulmonary alveolar macrophage.

A combined biochemical and cytochemical study of catalase was performed on alveolar macrophages lavaged from the lungs of adult male rats. Biochemically, catalase activity was present in both a high-speed granule fraction and in the supernatant. The granule-associated activity exhibited latency. Two methods of cell breakage, sonication and homogenization, yielded similar levels and distributions of catalase activity. Catalase activity in whole cells was identified cytochemically by the alkaline diaminobenzidine method and was localized within membrane-lined cytoplasmic granules similar in size to microperoxisomes and associated with cisternae of smooth endoplasmic reticulum. Localization of the reaction product was inhibited by 0.04 M aminotriazole, by cyanide, and by boiling prior to incubation. The cytochemical reaction continued in the absence of exogenous peroxide, but could be prevented by addition of catalase or pyruvate to the peroxide-free medium. Enzyme activity was also localized within a portion of the membrane-bound granules present in the cell fractions used for the biochemical assays.

Amitrole

Ultrastructural studies of the gray platelet syndrome.

The gray platelet syndrome (GPS) is a rare inherited disorder in which peripheral blood platelets are relatively large, vacuolated, and almost devoid of cytoplasmic granulation. In the present study we have evaluated the ultrastructure and cytochemistry of platelets from 2 patients with the GPS to determine precisely which organelles are missing from their cells. The findings indicate that gray platelets contain normal numbers of mitochondria, dense bodies, peroxisomes, and lysosomes but specifically lack alpha-granules. Preliminary studies of megakaryocytes from 1 of the 2 patients suggest that the defect in granule formation may lie at the level of the Golgi zone.

Adult

Basophilic leucocytes: structure, function and role in disease.

We have attempted to review the current state of our knowledge concerning the human basophilic leucocyte, drawing on experimental data derived from animals when necessary. Long neglected, a great deal has been learned about these cells in recent years, about their morphology, their biochemical constitutents and their ability to synthesize certain of these constitutents, their interactions with homocytotropic antibodies, their release of mediators in anaphylaxis, their response to chemotatic stimuli, their participation and progressive degranulation in cell-mediated hypersensitivity reactions, and their capacity for ingesting and releasing certain exogenous tracers. Despite this vast accumulation of new information, much more must be learned before we can confidently describe the role of basophils, or of the closely related mast cells, in health or disease. It seems most unlikely that either cell exists for the purpose of destroying the organism in anaphylactic shock. Nonetheless, it is highly probably that basophil/mast cell function is closely related to the potent chemicals stored within their cytoplasmic granules. One likely possibility holds that small amounts of these chemicals are required for homeostasis (e.g., for regulation of the tone of the microvasculature) and that these cells function by releasing such substances continuously, as they are needed, in small aliquots rather than by explosive discharge. This hypothesis requires that basophils be capable of releasing their contents in piecemeal fashion. Such gradual release apparently occurs in delayed-type hypersensitivity reactions, but the mechanisms responsible for this form of degranulation have not yet been identified. This hypothesis also requires that physiological, rather than pharmacological, roles be found for histamine, heparin and possibly for other components of the basophils/mast cell granules. Progress in this direction has been extremely slow.

Animals

[Lysosome-like alpha-granules of thrombocytes: detection by acridine orange treatment, properties and transformations during the course of blood coagulation reactions].

Using the ability of lysosome-like alpha-granules of thrombocytes to accumulate flurochrome acridine orange, their transformation kinetics was studied in the course of cell viscous metamorphosis utilizing the fluorometric technique. It turned out that during the thrombin induced cellular viscous metamorphosis lysosomes released their contents: the process is stimulated by the presence of extracellular Ca2+. Competitive relations were revealed between the accumulation within cytoplasmic granules of thrombocytes of acridine orange and serotonin, and that of histamine and novocaine. The process of fluorochrome accumulation was found to be temperature dependent and to be inhibited by monoiodacetate.

Acridines

Hairy cells and macrophages: a comparative study.

Leighton tube cultures of peripheral blood leukocytes and splenic cell suspensions of 11 patients with hairy cell leukemia (leukemic reticuloendotheliosis) were utilized to compare characteristics of hairy cells and macrophages. Light and electron microscopy, both transmission and scanning, as well as cytochemical studies demonstrated several striking similarities to macrophages. They included phagocytosis of red cells, platelets, cellular debris, and latex particles, adherence to glass with development of long pseudopodia and cytoplasmic granules, alpha-naphthyl butyrate esterase activity and diffuse and granular periodic acid-Schiff positivity.

Animals

Catecholamine-storing cells in the cyclostome heart.

The lamprey heart contains characteristic catecholamine-storing cells in both the atrium and the ventricle. Sufficient circumstantial evidence is available indicating that catecholamines together with protein carbohydrate complexes are contained in these cells within the membrane bound cytoplasmic granules. If the "recepto-secretory function" and "neuroectodermal origin" of these cells are proved, then they may be classified as typical paraneurons.

Animals