C4-P-10Three-dimensional ultrastructural analysis of secretory granules in histological paraffin sections of endocrine tumors using low-vacuum SEM

Microscopy ◽  
2015 ◽  
Vol 64 (suppl 1) ◽  
pp. i138.2-i138
Author(s):  
Sumire Inaga ◽  
Masako Kato ◽  
Masako Nishimura ◽  
Kaori Ichikawa ◽  
Toshio Kameie ◽  
...  
Keyword(s):  
Secretory Granules ◽  
Ultrastructural Analysis ◽  
Endocrine Tumors ◽  
Paraffin Sections ◽  
Low Vacuum Sem

The Demonstration of Hemoprotein Crystals in Secretory Lumina of Dimethyl-benzanthracene-Induced Mammary Tumors

1981 ◽  
Vol 39 ◽  
pp. 592-593
Author(s):  
J. S. Hanker ◽  
M. S. Silverman ◽  
A. M. deCamargo ◽  
B. L. Giammara ◽  
E. M. Bossen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Reproductive Tract ◽  
Tumor Tissue ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Mammary Tumors ◽  
Female Rats ◽  
Paraffin Sections ◽  
Usual Manner ◽  
Cryostat Sections

A number of hormone-dependent reproductive tract tissues synthesize a peroxidase and secrete it into their lumina. An estrogen-induced mammary gland peroxidase, probably lactoperoxidase, has been reported in the acinar cells of prelactating and lactating rats and has been found to be a marker of hormone-dependent 7,12-dimethylbenzanthracene (DMBA)-induced rat mammary tumors. Study of the enzyme in tumor acinar cells showed it in cisternae of the nuclear envelope, granular ER and apical secretory granules. Its presence in lumina of the acini has not been described. It was therefore of interest to determine whether lactoperoxidase could be demonstrated in their secretory lumina.Mammary tumors were induced in female rats by DMBA in the usual manner. Paraffin sections of tumor tissue were stained with H & E or the Leder stain.Fixed touch preparations, cryostat sections, and blocks of tumors for electron microscopy were treated for peroxidative activity with 3,3'-diaminobenzidine (DAB) or p-phenylenediamine/pyrocatechol (PPD/PC, available from Polysciences).

scholarly journals Detection of gastrin mRNA in human antral mucosa and digestive endocrine tumors by in situ hybridization: a correlative study with immunocytochemistry and electron microscopy.

1992 ◽  
Vol 40 (9) ◽  
pp. 1363-1372 ◽  
Author(s):  
F M Walker ◽  
T Lehy ◽  
D G Bernuau ◽  
I Sobhani ◽  
D Bayle ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Secretory Granules ◽  
Cdna Probe ◽  
High Serum ◽  
Endocrine Tumors ◽  
Tumor Type ◽  
Antral Mucosa ◽  
Electron Microscopic ◽  
Gastrin Cells

In gastrinomas, as well as in other endocrine tumors whose hormone overproduction is responsible for clinical syndromes, antibodies against the bioactive form(s) of hormones can fail to detect immunoreactivity. Moreover, tumor secretory granule morphology may fail to allow tumor type identification. The use of anti-pre-pro-gastrin antibodies has been proposed as an alternative to identify gastrinomas. The aim of the present study was to demonstrate that in situ detection of gastrin mRNA may represent another possibility. A 35S-labeled cDNA probe encoding the human gastrin pre-pro-hormone was used to localize gastrin gene transcripts in antral mucosa and digestive endocrine tumors from patients with a Zollinger-Ellison syndrome characterized by high serum gastrin levels. In situ hybridization was combined with light and electron microscopic immunostaining of the bioactive gastrin 17/34 form and morphological study of secretory granules. Gastrin mRNAs were detected in antral gastrin cells and in a variable proportion of tumor cells in all endocrine tumor studied. Transcript expression correlated well with immunohistochemical staining and granule ultrastructure for most of the tumors, and provided crucial evidence for identifying as gastrinomas two tumors with weak immunoreactivity and poorly granulated cells. Our data show that in situ hybridization is a sensitive method for gastrin mRNA detection and represents a valuable tool for the identification of gastrinomas.

scholarly journals Distinct Molecular Events during Secretory Granule Biogenesis Revealed by Sensitivities to Brefeldin A

1997 ◽  
Vol 8 (11) ◽  
pp. 2171-2185 ◽  
Author(s):  
Carlos J. Fernandez ◽  
Michael Haugwitz ◽  
Benjamin Eaton ◽  
Hsiao-Ping H. Moore
Keyword(s):  
Time Window ◽  
Secretory Granules ◽  
Brefeldin A ◽  
Peptide Hormone ◽  
Subcellular Fractionation ◽  
Proteolytic Processing ◽  
Secretory Process ◽  
Endocrine Tumors ◽  
Proteolytic Activation ◽  
Molecular Events

The biogenesis of peptide hormone secretory granules involves a series of sorting, modification, and trafficking steps that initiate in the trans-Golgi andtrans-Golgi network (TGN). To investigate their temporal order and interrelationships, we have developed a pulse–chase protocol that follows the synthesis and packaging of a sulfated hormone, pro-opiomelanocortin (POMC). In AtT-20 cells, sulfate is incorporated into POMC predominantly on N-linked endoglycosidase H-resistant oligosaccharides. Subcellular fractionation and pharmacological studies confirm that this sulfation occurs at thetrans-Golgi/TGN. Subsequent to sulfation, POMC undergoes a number of molecular events before final storage in dense-core granules. The first step involves the transfer of POMC from the sulfation compartment to a processing compartment (immature secretory granules, ISGs): Inhibiting export of pulse-labeled POMC by brefeldin A (BFA) or a 20°C block prevents its proteolytic conversion to mature adrenocorticotropic hormone. Proteolytic cleavage products were found in vesicular fractions corresponding to ISGs, suggesting that the processing machinery is not appreciably activated until POMC exits the sulfation compartment. A large portion of the labeled hormone is secreted from ISGs as incompletely processed intermediates. This unregulated secretory process occurs only during a limited time window: Granules that have matured for 2 to 3 h exhibit very little unregulated release, as evidenced by the efficient storage of the 15-kDa N-terminal fragment that is generated by a relatively late cleavage event within the maturing granule. The second step of granule biogenesis thus involves two maturation events: proteolytic activation of POMC in ISGs and a transition of the organelle from a state of high unregulated release to one that favors intracellular storage. By using BFA, we show that the two processes occurring in ISGs may be uncoupled: although the unregulated secretion from ISGs is impaired by BFA, proteolytic processing of POMC within this organelle proceeds unaffected. The finding that BFA impairs constitutive secretion from both the TGN and ISGs also suggests that these secretory processes may be related in mechanism. Finally, our data indicate that the unusually high levels of unregulated secretion often associated with endocrine tumors may result, at least in part, from inefficient storage of secretory products at the level of ISGs.

Ultrastructural Analysis of Secretory Granules of Myocardial Capillary Endothelium in Cardiosurgical Stress

2005 ◽  
Vol 140 (2) ◽  
pp. 257-261 ◽  
Author(s):  
G. M. Kazanskaya ◽  
A. M. Volkov ◽  
L. M. Nepomnyashchikh ◽  
Ya. V. Malinovskaya ◽  
A. M. Chernyavskii ◽  
...  
Keyword(s):  
Secretory Granules ◽  
Ultrastructural Analysis ◽  
Capillary Endothelium

scholarly journals Immunohistochemical Localization of Chromogranin A in Endocrine Tissues and Endocrine Tumors of Dogs

1998 ◽  
Vol 35 (4) ◽  
pp. 312-315 ◽  
Author(s):  
J. C. Doss ◽  
A. Grone ◽  
C. C. Capen ◽  
T. J. Rosol
Keyword(s):  
Chromogranin A ◽  
Chromaffin Cells ◽  
Endocrine Cells ◽  
Secretory Granules ◽  
Hormone Secretion ◽  
Immunohistochemical Localization ◽  
Endocrine Tumors ◽  
Parathyroid Adenomas ◽  
Immunohistochemical Identification ◽  
Endocrine Tissues

Chromogranin A is present in the secretory granules of endocrine cells and functions in hormone packaging, secretory granule stabilization, and regulation of hormone secretion. Immunohistochemical identification of chromogranin A can facilitate diagnosis of endocrine neoplasia. Normal and neoplastic canine tissues were stained immunohistochemically for chromogranin A. Staining of normal endocrine tissues demonstrated chromogranin A in chromaffin cells of the adrenal medulla, C cells of the thyroid gland, and pancreatic islets. The parathyroid chief cells and anterior pituitary stained lightly positive for chromogranin A. Pheochromocytomas (7/7), chemodectomas (5/7), islet cell carcinomas (2/6), pituitary adenomas (4/6), parathyroid adenomas (3/7), and a C-cell carcinoma (1/1) stained positive for chromogranin A. The data indicate that chromogranin A is widely distributed in canine endocrine tissues, and immunohistochemical staining of chromogranin A can be used to confirm the presence of secretory granules in endocrine tumors.

Pituitary Follicular Cells: Their Origin, Possible Function and Fate

1974 ◽  
Vol 32 ◽  
pp. 34-35
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
G. Penz ◽  
C. Ezrin
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Follicular Cells ◽  
Human Pituitary ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Junctional Complexes

Follicular structures, in the rat pituitary, composed of cells joined by junctional complexes and possessing few organelles and few, if any, secretory granules, were first described by Farquhar in 1957. Cells of the same description have since been observed in several species including man. The importance of these cells, however, remains obscure. While studying human pituitary glands, we have observed wide variations in the fine structure of follicular cells which may lead to a better understanding of their morphogenesis and significance.

Tissue section lifting for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 86-87
Author(s):  
Adrian F. van Dellen
Keyword(s):  
Infectious Disease ◽  
Electron Microscopy ◽  
Tissue Culture ◽  
Organ System ◽  
Surrounding Tissue ◽  
Paraffin Sections ◽  
Surface Areas ◽  
Specific Determination ◽  
High Degree ◽  
Accuracy And Repeatability

The morphologic pathologist may require information on the ultrastructure of a non-specific lesion seen under the light microscope before he can make a specific determination. Such lesions, when caused by infectious disease agents, may be sparsely distributed in any organ system. Tissue culture systems, too, may only have widely dispersed foci suitable for ultrastructural study. In these situations, when only a few, small foci in large tissue areas are useful for electron microscopy, it is advantageous to employ a methodology which rapidly selects a single tissue focus that is expected to yield beneficial ultrastructural data from amongst the surrounding tissue. This is in essence what "LIFTING" accomplishes. We have developed LIFTING to a high degree of accuracy and repeatability utilizing the Microlift (Fig 1), and have successfully applied it to tissue culture monolayers, histologic paraffin sections, and tissue blocks with large surface areas that had been initially fixed for either light or electron microscopy.

Ultrastructural Aspects of Golgi Complex Function in Parathyroid Cells of Winter Frogs

1973 ◽  
Vol 31 ◽  
pp. 680-681
Author(s):  
William J. Dougherty
Keyword(s):  
Golgi Complex ◽  
Secretory Granules ◽  
Complex Function ◽  
Secretory Activity ◽  
Secretory Proteins ◽  
Perivascular Spaces ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
Ca Ions ◽  
Regulation Of Secretion

The regulation of secretion in exocrine and endocrine cells has long been of interest. Electron microscopic and other studies have demonstrated that secretory proteins synthesized on ribosomes are transported by the rough ER to the Golgi complex where they are concentrated into secretory granules. During active secretion, secretory granules fuse with the cell membrane, liberating and discharging their contents into the perivascular spaces. When secretory activity is suppressed in anterior pituitary cells, undischarged secretory granules may be degraded by lysosomes. In the parathyroid gland, evidence indicates that the level of blood Ca ions regulates both the production and release of parathormone. Thus, when serum Ca is low, synthesis and release of parathormone are both stimulated; when serum Ca is elevated, these processes are inhibited.

Contributions to the mechanisms of mitosis and roles of cytoplasmic microtubules from ultrastructural analyses of fungi

1978 ◽  
Vol 36 (2) ◽  
pp. 266-267
Author(s):  
I. Brent Heath
Keyword(s):  
Nuclear Envelope ◽  
Direct Application ◽  
Ultrastructural Analysis ◽  
General Interest ◽  
Research Results ◽  
Organelle Motility ◽  
Cytoplasmic Microtubules

Detailed ultrastructural analysis of fungal mitotic systems and cytoplasmic microtubules might be expected to contribute to a number of areas of general interest in addition to the direct application to the organisms of study. These areas include possibly fundamental general mechanisms of mitosis; evolution of mitosis; phylogeny of organisms; mechanisms of organelle motility and positioning; characterization of cellular aspects of microtubule properties and polymerization control features. This communication is intended to outline our current research results relating to selected parts of the above questions.Mitosis in the oomycetes Saprolegnia and Thraustotheca has been described previously. These papers described simple kinetochores and showed that the kineto- chores could probably be used as markers for the poorly defined chromosomes. Kineto- chore counts from serially sectioned prophase mitotic nuclei show that kinetochore replication precedes centriole replication to yield a single hemispherical array containing approximately the 4 n number of kinetochore microtubules diverging from the centriole associated "pocket" region of the nuclear envelope (Fig. 1).

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