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Transmission Microscopy (transmission + microscopy)
Selected AbstractsElectron microscopic detection of statherin in secretory granules of human major salivary glandsJOURNAL OF ANATOMY, Issue 5 2008M. Isola Abstract In order to increase current knowledge regarding statherin secretion into the oral cavity, ultrastructural localization of this peptide was investigated in human salivary glands by using a post-embedding immunogold staining technique. Statherin reactivity was found inside the granules of serous cells of parotid and submandibular glands. In parotid granules immunostaining was preferentially present in the less electron-dense region, whereas in submandibular serous granules the reactivity was uniform and the dense core always stained. By contrast, none or weak reactivity was observed in serous cells of major sublingual glands. These findings reveal for the first time the subcellular localization of statherin by electron transmission microscopy and confirm that of the three major types of salivary glands, the parotid and submandibular glands are the greatest source of salivary statherin. Moreover, they suggest that more than one packaging mechanism may be involved in the storage of statherin within serous granules of salivary glands. [source] Structure of the quaternary alloy Zn0.6Mn0.4In2S4 from synchrotron powder diffraction and electron transmission microscopyJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2006Asiloé J. Mora The aim of the present work was to determine the structure of the quaternary alloy Zn0.6Mn0.4In2S4 and to locate the Mn2+. This was accomplished by means of powder synchrotron X-ray diffraction, high-resolution microscopy and convergent-beam electron diffraction (CBED). The powder X-ray diffraction pattern was indexed in a rhombohedral cell, with cell constants a = 3.875,(2), c = 37.208,(4),Ĺ, and possible space groups Rm or R3m. Rietveld refinements using different cationic arrangements in these space groups were performed. A model in space group R3m, in which the tetrahedral and octahedral sites were occupied by different proportions of Zn, Mn and In atoms, gave the best result. The Rietveld refinement of this model led to figures of merit Rwp = 9.8%, Rp = 9.1% and ,2 = 11.1. Selected-area electron diffraction patterns and high-resolution transmission electron micrographs along [001] reveal the rhombohedral configuration. CBED patterns perpendicular to [001], showing the distinctive 3m symmetry, confirmed space group R3m and the breaking of the centrosymmetry of the parent compound, ZnIn2S4. [source] Ultrastructural characterization of the new NG97ht human-derived glioma cell line using two different electron microscopy technical proceduresMICROSCOPY RESEARCH AND TECHNIQUE, Issue 4 2009Camila Maria Longo Machado Abstract On the basis of transmission electron microscopy observations in tumor cell lines, oncologists have made innumerous diagnostic and therapeutical progresses. Following this path, the UNICAMP immunopathologies laboratory established the NG97 cell line derived from a human astrocytoma grade III, which when injected to the athymic nude mouse flank developed a grade IV astrocytoma. In this study, we focused on ultrastructural characterization of the NG97 cells after being recovered from xenotransplant (NG97ht). These cells in culture were assayed by two different electron microscopy procedures to characterize ultrastructures related to grade IV astrocytomas and to observe their structures through cell subcultivation. Additionally, comparative morphological descriptions of different cell passages in these technical procedures could be a useful tool for improving electron microscopy cell lineage protocols. Results from many cell passage observations showed ultrastructural similarities, which suggest malignant and glioblastoma phenotypes. In the first procedure, NG97ht cells were harvested and then incorporated into agarose before subjecting them to electron microscopy protocols, whereas in the second one, monolayer cells grew first on cover slides. Comparison among protocols revealed that organelles, cytoplasmatic extensions, spatial conformation of filopodia, and cell attachment to substrate were more preserved in the second procedure. Furthermore, in this latter procedure, a unique ellipsoidal structure was observed, which was already described when dealing with gliosarcoma cell line elsewhere. Therefore, these analyses demonstrated a morphological characterization of a new NG97ht cell line using electron transmission microscopy. Moreover, it has been shown that the second procedure provides more detailed information compared with the first. Microsc. Res. Tech, 2009. © 2008 Wiley-Liss, Inc. [source] The expression pattern of MUC1 glycoforms and other biomarkers of endometrial receptivity in fertile and infertile women,MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2005A.W. Horne Abstract Changes in the surface epithelium of the endometrium, characterized in part by alterations in cell-surface molecules, sex steroid receptors and the appearance of pinopodes, coincide with the window of endometrial receptivity in the menstrual cycle. This study was performed to evaluate the usefulness of hematoxylin and eosin staining, scanning and transmission microscopy, and MUC1 glycoform, sex steroid receptor, and interleukin receptor (type 1) expression as biomarkers of endometrial receptivity using carefully characterized clinical fertile and infertile groups of women. Using a combination of immunohistochemistry and scanning electron microscopy (SEM) called scanning immunoelectron microscopy (SIM), we confirmed that MUC1 mucin was not associated with the endometrial pinopodes, which have been linked with embryo adhesion. We also showed that failure of embryo implantation was associated with an abnormal endometrial expression of MUC1 mucin, and retention of nuclear progesterone receptor (PR) particularly in epithelial cells. Hematoxylin and eosin staining, transmission electron microscopy (TEM), SEM in isolation and immunohistochemistry for interleukin receptor were not shown to be useful markers. Progesterone-dependent regulation of MUC1 appears to be an important factor in determining endometrial receptivity. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Filling of carbon nanotubes for bio-applicationsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2007S. Costa Abstract Carbon nanotubes (CNT) provide a smart carrier system on the nanometer scale. The system can be used as a template for ferromagnetic fillers. Such a molecular hybrid is a promising potential candidate for the controlled heating of tumour tissue at the cellular level. This is a key reason why it is important to optimize the synthesis route of metal filled carbon nanotubes with regards bulk scale synthesis and purity. In the current study we present multiwalled carbon nanotubes filled with ,-iron phase (Fe-MWCNT). The influence of acid treatment on the stability of the filling and the sample purity is also presented. High resolution transmission microscopy, its Energy dispersive X-Ray spectroscopy (EDX) and electron energy-loss spectroscopy (EELS) modes have been applied for the analysis of the morphology and chemical composition of the samples. The phase of iron nanowires encapsulated into the carbon nanotubes was determined with selected area electron diffraction (SAED) on a local scale. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis and structure of BN-doped multi-walled and single-walled carbon nanotubesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006S. Enouz Abstract We report on the direct synthesis of different kinds of BN,C multi-walled and single-walled nanotubes exhibiting a segregation between BN and C domains. Multi-walled BN,C nanotubes (MW-BN/C-NTs) were synthesized using the aerosol method whereas single-walled BN,C nanotubes (SW-BN/C-NTs) have been for the first time produced using a continuous CO2 -laser vaporization process [S. Enouz et al., to be published]. Degrees of purity, homogeneity and yield have been estimated from a systematic inspection of the samples by scanning electron microscopy. Structure of these tubes and spatial distribution of C, B and N as well as their chemical environments have been inspected at the nanometer scale by combining high resolution transmission microscopy and nano-electron energy loss spectroscopy. These analyses provide clear evidence of new kinds of arrangements of C, B and N within the graphene layer, which are due to the segregation properties of h-BN and graphite. Thus, combining BN and C elements into nanotubular systems can open the way to a broad range of new nanodevices. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Pollen studies in subtribe Centaureinae (Asteraceae): the Jacea group analysed with electron microscopyBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2000JOAN MARÍN VILLODRE Although it has been recognized for many years that the genus Centaurea L. is an artificial assemblage of taxa, its partition into more natural affiliations has been impossible due to its incredible complexity. One of the most reliable characteristics for establishing the phylogeny within this group is the type of pollen. Most of the classification difficulties centre in the Jacea group, which has a characteristic Jacea pollen type. Recent molecular studies indicate that this assemblage is probably polyphyletic. Specifically, previous DNA sequence analyses indicate that Centaurea pulchella and the genera Oligochaeta and Zoegea represent different lineages. This finding prompted an investigation of their pollen types, using scanning electron microscopy, and for some species, transmission microscopy. For a rigorous comparison, the study also included a wide representation of other species across the entire Jacea group. Results showed that both Oligochaeta and Zoegea, but not C. pulchella, can be clearly distinguished from the Jacea group on the basis of pollen morphology. The genus Oligochaeta has a peculiar pollen type that may represent a simplified form of the Serratula pollen type, and the genus Zoegea has Serratula pollen type. [source] | ||||||||||