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At least 415 records · Page 23Linked to original sources
PubMed2005

Neuropeptide Y expression, localization and cellular transducing effects in HUVEC.

BACKGROUND INFORMATION: NPY (neuropeptide Y) may have an effect on the properties of vascular endothelial cells such as pro-angiogenic effects and potentiation of noradrenaline-induced vasoconstriction. In HUVEC (human umbilical-vein endothelial cells), immunoreactive neuropeptide Y has been detected, but NPY synthesis, storage and secretion have not been studied. The aim of the present study was to establish NPY expression, storage and cellular transducing effects in HUVEC. RESULTS: HUVEC contain 0.19 fmol of NPY/microg of protein and 0.46 fmol of pro-NPY/microg of protein, as measured by ELISA. RT (reverse transcriptase)-PCR confirmed the expression of NPY in HUVEC. Immunofluorescence revealed the presence of NPY in small punctate structures, with a fluorescence pattern different from that observed for von Willebrand factor, indicating distinct storage compartments. Double labelling for NPY and Rab3A demonstrated similar granular patterns, with at least partial co-localization. Electron microscopy showed NPY immunoreactivity in vesicle-like cytoplasmic structures, of a fine fibrillar texture, as well as in mitochondria and in the nucleus. A similar general distribution pattern was also obtained for Rab3A. Y1 and Y2 receptors were expressed in HUVEC as assessed by RT-PCR, and they were functional since NPY induced a 42 nM intracellular calcium increase within 100 s, representing 22% of the histamine-induced response. In contrast with histamine, NPY did not induce acute von Willebrand factor secretion. CONCLUSIONS: HUVEC produce, store and respond to NPY, suggesting an autocrine regulatory role for NPY in the endothelium.

Calcium↗
PubMed2004

Autoantibodies to protein transport and messenger RNA processing pathways: endosomes, lysosomes, Golgi complex, proteasomes, assemblyosomes, exosomes, and GW bodies.

Over 50 years ago the lupus erythematosus (LE) cell phenomenon was described and this was quickly followed by the introduction of the LE cell test and indirect immunofluorescence (IIF) to detect antinuclear antibodies (ANA) in clinical laboratories. Recently, attention has turned to the identification of the autoantigens that bind to cytoplasmic organelles such as the Golgi complex, endosomes and other "cytoplasmic somes". Three endosome autoantigens include early endosome antigen 1 (EEA1, 160 kDa), cytoplasmic linker protein-170 (CLIP-170, 170 kDa), and lysobisphosphatidic acid (LBPA). Antibodies to EEA1 were seen in a variety of conditions but approximately 40% of the patients had a neurological disease. Despite the prominence of lysosomes in cells and tissues, reports of autoantibodies are limited to the lysosomal antigen h-LAMP-2 and the cytoplasmic antineutrophil antibodies (cANCA). Autoantigens in the Golgi complex include giantin/macrogolgin, golgin-245, golgin 160, golgin-97, golgin 95/gm130, and golgin-67. More recently, there has been an interest in autoantibodies that bind components of the "SMN complex" or the "assemblyosome". Arginine/glycine (RG)-rich domains in components of the SMN complex interact with Sm, like-Sm (LSm), fibrillarin, RNA helicase A (Gu), and coilin proteins, all of which are antigen targets in a variety of diseases. More recently, components of a novel cytoplasmic structure named GW bodies (GWBs) have been identified as targets of human autoantibodies. Components of GWBs include GW182, a unique mRNA-binding protein, like Sm proteins (LSms), and decapping (hDcp1) and exonuclease (Xrn) enzymes. Current evidence suggests that GWBs are involved in the cytoplasmic processing of mRNAs. Autoantibodies to the "cytoplasmic somes" are relatively uncommon and serological tests to detect most of them are not widely available.

Animals↗
PubMedDate not supplied

[Ultrastructure of the hematoencephalic barrier in subarachnoid hemorrhage and effect of phenobarbital].

Electron and light microscopies were used to study capillary and astrocytic structural changes by modelling subarachnoid hemorrhage (SAH) and by using oral phenobarbital. The ultrastructural changes determining hydropic disorders and brain edema were found to achieve its maximum on day 3 after SAH. They were manifested by the lamination of the basement membrane, edema of cytoplasm and processes of astrocytes, their cytoplasmic structural depletion. Day 7 was marked by the recovery of impaired structures that became normal by day 14. Phenobarbital could accelerate elimination of hydropic changes. The recovery observed on day 7 was similar to that on day 14 without phenobarbital.

Animals↗
PubMed2002

The use of ionized iodine for cancer prevention and eradication.

Using an ionized iodine compound, it may be possible to transmit a weak effect of the digestive enzymes from the duodenal lumen to the cytoplasmic structures beyond the cell membrane in general organic tissues. Povidone-iodine is easily obtainable at present, and may be the most suitable ionized material for the transmission of the enzymatic effects to body tissues. Consequently, to remove certain cellular byproducts accumulated abnormally in cancerous cytoplasm, and to achieve cancer prevention and eradication, a method of using povidone-iodine, as a conceptual model, should be devised and developed in the future.

Animals↗
PubMed1999

Immunocytochemical mapping of the hemoglobin biosynthesis site in amphibian erythroid cells.

During the past 25 years, several studies have attempted to determine the site of integration of the heme and the four globin chains in vertebrate erythroid cells that is important in the formation of the hemoglobin molecule. Mitochondrion-like organelles or hemosomes were pointed out as responsible for this task. We performed several experiments to investigate this hypothesis. The intracellular distribution of hemoglobin in amphibian erythroid cells was detected by post-embedding immuno-electron microscopy, using a polyclonal anti-human hemoglobin-proteinA-gold complex. Hemoglobin mapping showed an intense labeling in the cell cytoplasm, but none in cytoplasmic structures such as endoplasmic reticulum, mitochondria, mitochondrion-like organelles, Golgi complex, ribosomes or ferruginous inclusions. The mitochondrial fraction obtained according to the protocol described for some authors, showed by ultrastructural examination that this fraction has a heterogeneous content, also composed by microvesicles rich in cytoplasmic hemoglobin, an artifact generated by mechanical action during cell fractionation. Thus, when this fraction is lysed and its content submitted to electrophoresis, hemoglobin bands would be found inevitably, causing false-positive results, erroneously attributed to hemoglobin content of mitochondrion-like organelles. Our data do not confirm the hypothesis that the final hemoglobin biosynthesis occurs inside mitochondrion-like organelles. They suggest that the hemoglobin molecule be assembled in the erythrocyte cytoplasm outside of mitochondria or hemosomes.

Animals↗
PubMed1997

Ultrastructure of a well-preserved lymphocyte from a mummified human.

A well-preserved lymphocyte was found during the electron microscopic examination of the cerebral material recovered from a naturally preserved male mummy from northern Chile dating back over 500 years. The cytoplasmic structures were easily recognizable. This study represents one of the best ultrastructural analyses of mummified human peripheral blood elements.

Adult↗
PubMed1985

Ultrastructural analysis of the initiation and development of cytasters in sea-urchin eggs.

Two approaches were used to study the origin and overall development of cytasters in relation to the emergence and maturation of new centrioles in sea-urchin eggs. A continuous hypertonic treatment was used to gather information on cytoplasmic areas of potential cytaster formation and the subsequent development of these cytastral areas. A two-step parthenogenetic stimulation procedure was used to analyse various cytastral changes during and after mitosis. Potential cytastral areas are associated with extensive Golgi complexes and astral formation occurs only about newly induced centrioles. The construction of a single aster involves a large redistribution of local cytoplasmic structures, concentrating some components, excluding others and orienting more and more microtubules in an increasingly focussed arrangement. These events are correlated with an extensive accumulation of astral endoplasmic reticulum, an increase in the size of the astral area, and a gradual acquisition of a more typical radial configuration. The astral shape becomes more pronounced during mitosis, after which the cytasters regress, but retain the mature centrioles. The data reveal that cytaster formation is initiated after the activation and appearance of centriolar precursor bodies, and that both centrioles and associated cytasters are complementary structures, which develop in unison. The results suggest that developing centrioles, from the moment of their emergence, control and direct the events of cytastral formation.

Animals↗
PubMed2006

The three-dimensional structure of complex I from Yarrowia lipolytica: a highly dynamic enzyme.

The structure of complex I from Yarrowia lipolytica was determined by three-dimensional electron microscopy. A random conical data set was collected from deep stain embedded particles. More than 14000 image pairs were analyzed. Through extensive classification combined with three-dimensional reconstruction, it was possible for the first time to show a much more detailed substructure of the complex. The peripheral arm is subdivided in at least six domains. The membrane arm shows two major protrusions on its matrix facing side and exhibits a channel like feature on the side facing the cytoplasm. Structures resembling a tether connecting the subunits near the catalytic center with the protrusions of the membrane arm provide a second connection between matrix and membrane domain.

Cell Membrane↗
PubMed1976

On the fungitoxicity of some new thiocyanatopyrazole derivatives: electron microscopical study in Trichophyton mentagrophytes.

Four thiocyanatopyrazole derivatives were synthesized and their fungistatic activity was demonstrated in vitro against a number of dermatophytic fungi. In Trichophyton mentagrophytes, the most active compound induced as unusual increase of the plasma membrane with production of intra and extracytoplasmic complexes, a deterioration of nuclear and mitochondrial membranes and a formation of autophagic-like vacuoles. Plasmolysis, accompanied by an almost complete disorganization of cytoplasmic structures, seemed to be the final event. A possible mechanism of action of the compounds were discussed.

Antifungal Agents↗
PubMed1997

[The endocrine apparatus of the epithelium of the gastric mucosa in the steppe turtle (Testudo horsfieldi)].

Endocrinocytes of stomach mucosal epithelium were studied using light and electron microscopy in steppe turtle (Testudo horsfieldi). Endocrine apparatus of stomach in turtle was shown to retain the pattern characteristic for other representatives of vertebrates. Difference is observed in endocrinocytes localization. The latter are accumulated predominantly in upper and middle regions of glandulae, sometimes being encountered also in surface epithelium. 8 cell types were identified according to size and structure: EC, G, D, D1, A-like, X, ECL and P. Relating to glandular lumen, endocrinocytes are divided into elements of closed (D, D1, A-like, ECL, X, and P) and open types (EC, G). In the latter apico-basal differentiation is expressed in cytoplasmic structure. Endocrinocytes are unevenly distributed throughout the stomach regions. Greatest number is concentrated in pyloric part, EC-cells being the predominant type. EC, ECL-cells and less A-like and D-cells are mostly encountered in fundal part, EC, G and single D and P cells--in pyloric part and, agranular and exo-endocrine cells--in both stomach parts.

Animals↗
PubMed1991

Spatial and dynamic changes in intracellular Ca2+ measured by confocal laser-scanning microscopy in bullfrog sympathetic ganglion cells.

Confocal laser scanning microscopy (CLSM) was used to record spatial and dynamic changes in the intracellular Ca2+ [(Ca2+]i) of bullfrog sympathetic ganglion cells in excised tissue or in culture. A CLSM utilizing Ar ion laser (488 nm) and recording fluo-3 fluorescence yielded the sliced image of ganglion cells, while conventional epifluorescence microscopy provided the cell image of a convex structure. A high K+ (50 mM) solution, caffeine (3-10 mM) and electrical stimulation (10-20 Hz, 0.5-10 s) caused a homogeneous increase in fluo-3 fluorescence with or without regional differences, possibly due to intracellular organelles and other constituents. Scanning a single horizontal line across the cytoplasm with He-Cd laser (325 nm) and recording indo-1 fluorescence demonstrated that the rate of rise in [Ca2+]i following action potentials depends on the distance from the cell membrane and on the cytoplasmic constituents, showing an inward spread of 'Ca(2+)-wave' at variable speeds of 17-219 microns/s. These results suggest that heterogeneity of the cytoplasmic structures and constituents affects dynamic and spatial changes of [Ca2+]i in response to stimuli in neurones. Such heterogenic changes in [Ca2+]i would better be studied by CLSM.

Aniline Compounds↗
PubMed1992

Properties of chicken cardiac dystrophin.

We investigated the presence of dystrophin by immunoblot and immunofluorescence analyses, negative staining, rotatory shadowing and immunogold electron microscopy in chicken cardiac muscle. Saponin was found to be better than Triton X-100 for providing a new 'dystrophin-enriched' solution for use in biochemical studies of the molecule. By Western blot analysis, only a 400-kDa band was revealed with polyclonal antibodies directed against a central region (residues 1178-1723) of the dystrophin molecule and no cross-reactions with other proteins or degraded products were observed. Specific cleavage of the dystrophin molecule showed that the central rod-shaped domain corresponded to a resistant 'core'. This structure might rigidify the protein. By immunofluorescence, dystrophin was localized at the periphery of cardiac ventricular cells. The molecule was examined by electron microscopy and found to have variable lengths (140-160 nm for the monomeric from and about 260 +/- 10 nm or more for oligomeric forms). These oligomeric structures are considered to be associated molecules which are only partially overlapped lengthwise. The precise distribution of dystrophin within the cardiac muscle was determined by visualisation of gold particles in immuno-electron microscopy. Gold particles were found on the sarcolemma with no evidence of any association with cytoplasmic structures. The present data provide further details on the cardiac dystrophin molecule and suggest that its capacity of self-association may elasticize the dystrophin dimer.

Animals↗
PubMed1987

Phase-contrast microscopy of the primate retina.

The study of hematoxylin and eosin stained thick sections (15 microns) of the primate retina with the phase-contrast microscope provided a means for the selective demonstration of many cellular structures that could not be resolved with the same degree of detail which was possible when bright-field microscopy was used, or when phase-contrast microscopy was employed to examine unstained material. The H & E-stain greatly enhanced the phase-contrast image, so that cytoplasmic structure, fiber trajectories, and gross synaptic detail of the retina could be demonstrated to better advantage.

Animals↗
PubMed1994

A murine monoclonal antibody (RV3-27) raised against isolated human placental endogenous retroviral particles and reactive with syncytiotrophoblast.

Particles with the characteristic shape of enveloped retroviral particles and maximal specific reverse transcriptase (RTase) activity at buoyant density of 1.15-1.17 g/ml have been isolated from human first-trimester chorionic villous tissue. Murine monoclonal antibodies (mAbs) to these isolated particles were generated. One IgM mAb (RV3-27) showed granular staining of cytoplasmic structures within syncytiotrophoblast by immunohistochemistry. Immunoelectron microscopic studies have demonstrated focal localisation to small submembranous regions of syncytiotrophoblast, as well as reaction with detergent-disrupted isolated placental retroviral-like particles. The RV3-27 mAb did not stain other human tissues in this focal manner, although increased generalised cytoplasmic staining was not uncommon; also, this mAb did not react strongly with the surface or cytoplasm of a variety of human cell lines (including choriocarcinoma cells). Immunoblotting and HPLC analyses have indicated the reactive placental antigen to be a 17-25 kDa protein. It is suggested that the RV3-27 mAb may be reactive with a syncytiotrophoblast antigen encoded by an endogenous retroviral sequence.

Animals↗
PubMed2000

Light scattering from cells: the contribution of the nucleus and the effects of proliferative status.

As part of our ongoing efforts to understand the fundamental nature of light scattering from cells and tissues, we present data on elastic light scattering from isolated mammalian tumor cells and nuclei. The contribution of scattering from internal structures and in particular from the nuclei was compared to scattering from whole cells. Roughly 55% of the elastic light scattering at high-angles (> 40 degrees) comes from intracellular structures. An upper limit of 40% on the fractional contribution of nuclei to scattering from cells in tissue was determined. Using cell suspensions isolated from monolayer cultures at different stages of growth, we have also found that scattering at angles greater than about 110 degrees was correlated with the DNA content of the cells. Based on model calculations and the relative size difference of nuclei from cells in different stages of growth, we argue that this difference in scattering results from changes in the internal structures of the nucleus. This interpretation is consistent with our estimate of 0.2 micron as the mean size of the scattering centers in cells. Additionally, we find that while scattering from the nucleus accounts for a majority of internal scattering, a significant portion must result from scattering off of cytoplasmic structures such as mitochondria.

Animals↗
PubMed1976

[Cellular ultrastructure of developing conglomerates of fresh water sponges].

The fine structure of cells of the conglomerates formed after dissociation of tissues of fresh-water sponges has been studied. In the development of the conglomerates of Ephydatia fluviatilis an important role is played by amoebocytes and choanocytes. In amoebocytes the shape of the nucleus, the mitochondria structure, the Golgi complex and endoplasmic reticulum have been found to change. In choanocytes, in addition to changes of organoids, the structure of the collar and flagella are subjected to desorganization. They have great plasticity and are able to re-differentiate in pinacocytes according to their position in the conglomerates. The transformation of amoebocytes and choanocytes into pinacocytes is accompanied by a successive modification of the nucleus and the cytoplasmic structures. In redifferentiation of amoebocytes the amount of Golgi apparatus zones decreased, the content of vacuoles of different size and the amount of elements of the agranular endoplasmic reticulum increased, and the defined nucleus disappeared.

Animals↗
PubMed2004

Digital chemospectrophotographic identification of intracellular hyperlipidemia in diabetic endometrial epithelial cells: structural and metabolic basis of organoatrophy.

OBJECTIVE: Digital chemospectrophotographic (DCSP) microscopic analysis and evaluation methodology applicable for enhanced cytopathological analysis of diabetes-induced, cytohyperlipidemia-associated cellular involution in endometrial epithelial and stromal tissues that promotes reproductive dysfunction and organoatrophy. METHODS: Combined light microscopy (LM), transmission electron microscopy (TEM) and described DCSP evaluation of endometrial samples collected from control (+/?) and genetically diabetic (db/db) C57BL/KsJ, hyperglycemic-hyperinsulinemic (type II) mice, designed to enhance the intracellular localization of chemically specified triglyceride and free fatty acid depositions, on progressive reproductive tract atrophy and cellular involution indices. RESULTS: Compared to both the LM and TEM analysis of cytopathological changes associated with diabetes-induced endometrial involution and reproductive dysfunction, the application of DCSP provided enhanced pathovisual analysis of chemical-specific metabolic alterations and cytoplasmic structural changes which accompany cytohyperlipidemia-induced endometrial epithelial cell apoptosis and reproductive tract atrophy. CONCLUSIONS: DCSP analysis provides an enhanced analytical method for the evaluation of cytoplasmic changes associated with the expression of genomic-, endocrine- or metabolic-based disease states by providing intercytoplasmic specific chemical or metabolic substrate alterations to be identified from conventional pathocellular preparations without requiring the use of exogenous ligand binding or fluorescent methodologies, allowing for a more complete metabolic and cellular evaluation of cytoplasmic indices associated with organoatrophy.

Animals↗
PubMed1978

Negative staining of whole cells: transmission electron microscopy of peripheral organelles in rat venous endothelial cells.

The study of whole negatively stained cells has revealed details of cellular organelles in rat venous endothelial cells. In particular, details of surface membrane organelles and small tubular structures were demonstrated. The surface membrane organelles which appeared "vesicular-like" were found to be connected with small tubular attachments. These findings were correlated with those described by other techniques. It is significant that this simple technique appears to permit the demonstration of fine details of three-dimensional cytoplasmic structures.

Animals↗