Number Of Gold Particles Research Articles

Ultrastructural localization of relaxin in the corpus luteum of the nonpregnant, pseudopregnant, and pregnant pig.

Relaxin was localized in luteal cells of ovaries from nonpregnant, pseudopregnant, and pregnant pigs using porcine relaxin antiserum and peroxidase-antiperoxidase light microscopy immunohistochemistry. The number of immunoreactive cells seemed to increase from Days 17 to 106 of gestation. Luteal cells from pseudopregnant (Day 110) and nonpregnant (Day 14 of the estrous cycle) pigs were also positive for relaxin. However, less than 3% of the luteal cells in the nonpregnant animals were immunoreactive. Electron microscopy immunocytochemistry using porcine relaxin antiserum and goat antirabbit immunoglobulin G-colloidal gold demonstrated that relaxin was packaged in the small membrane-bound granules in luteal cells of pregnant as well as pseudopregnant and nonpregnant pigs. The intensity of labeling (number of gold particles) of the granules increased with pregnancy. There was a 10-fold increase in labeling of granules with the 10-nm versus 25-nm diameter gold. The goat antirabbit labeled with the smaller 10-nm gold particles was necessary to demonstrate the apparent low levels of relaxin in the luteal cells of the nonpregnant pigs. These data further indicate that pregnancy is not required for relaxin synthesis. However, physiologic significance of relaxin in corpora lutea of nonpregnant pigs has not been determined.

Localisation of C-terminal gastrin immunoreactivity in gastrinoma cells. An immunoelectron microscopy study on conventionally processed tissue.

Localisation of C-terminal gastrin immunoreactivity has been studied, using the immunogold staining procedure, on ultrathin sections of 6 human gastrinomas conventionally processed for electron microscopy. The specific labelling, whose density depended on the mean diameter of the gold marker, was restricted to endocrine secretory granules. However, in poorly differentiated cells from malignant tumours, a number of granules remained unreactive. The labelling pattern depended also on the functional state of each cell. The immunoreactive granules showed various morphological features. A moderate number of gold particles was demonstrated over the floccular content of the infrequent diagnostic G-type granules. Non-diagnostic round granules of varying size and electron density were prevalent in most cells; their usually strong immunostaining allowed immediate recognition of cell specificity. Dense granules which were large in size and angular in shape and present in one case, were also intensely labelled. In the same tumour, unequal labelling occurred over polymorphous, often elongated granules, of varying size. Granules of different types, including intermediate forms, could be found in the same cell, indicating a spectrum of granule maturation towards well-defined types of the fetal or adult normal tissues. The present methodology would help to identify gastrin-producing cells in prospective or retrospective electron microscopy studies of multi-hormonal endocrine tumours.

Immunolabeling of adenohypophysial cells with protein A-colloidal gold--antibody complex for electron microscopy: use of the freeze-substitution technique in tissue preparation.

The value of the freeze-substitution (FS) method for preparing tissues for electron microscopic immunohistochemistry was studied by comparing anterior pituitary cells prepared by this method and by a conventional method. Ultrathin sections of tissues embedded in Epon were subjected to immunostaining. The antigens adrenocorticotropin (ACTH) and prolactin (PRL) in a single ultrathin section were demonstrated by a simple double-labeling technique using a protein A-colloidal gold-antibody (pAG-Ab) complex. The preservation of cellular ultrastructure was superior in preparations obtained by FS. Gold-labeling was seen over secretory granules, and in ACTH cells also over the cytoplasmic matrix. The labeling was more intense in preparations obtained by FS, judging from the numbers of gold particles. In the double-labeling procedure, in which the pA-small colloidal gold-anti-PRL complex and pA-large colloidal gold-anti-ACTH complex were applied sequentially to sections, no cross-labeling with small and large gold particles was observed. It is concluded that if the antisera are sufficiently specific, the use of FS and the pAG-Ab complex is very effective in peptide immunohistochemistry. However, in the double-labeling procedure it is essential that the Fc-binding sites of pAG are saturated by the use of excess amounts of antibodies.

Surface localization of wheat germ agglutinin and concanavalin a binding sites on normal human blood cells: An ultrastructural histochemical study

In order to determine the extent and variations in surface concavanalin A (CON A) and wheat germ agglutinin (WGA) labeling of different varieties of normal blood cells, gluraraldehyde-fixed human blood cells were exposed to CON A-gold labeled horseradish peroxidase (CON A-HRP-G) and WGA-gold labeled ovomucoid (WGA-OVO-G) histochemical methods. The resultant particulate reaction product permitted assessment of binding and number of gold particles per micrometer of cell surface. Particle counts and data were subjected to statistical analysis. Six subjects (three female and three male) were used and compared in this study. In spite of moderate variations in surface labeling of the various types of leukocytes, erythrocytes and platelets within a given subject, determinations of mean labeling values for similar cell varieties proved quite similar between subjects with the given lectin. WGA and CON A had substantially different labeling densities on the various hemic cells. WGA surface labeling of all types of hemic cells, with the exception of platelets, showed far more labeling than was found with CON A. WGA mean labeling of the grouped subjects was significantly higher for each variety of leukocyte than for either erythrocytes or platelets although this distinction was not always evident in an individual subject. With CON A, mean labeling density for each of hemic cell types showed significant differences between each of the hemic cell varieties. Erythrocytes had only minimal CON A binding while monocyte and platelet populations represented the most reactive of the hemic cells. No difference was noted between corresponding cell varieties in the female vs. male subjects.

Specific pancreatic beta-cell surface antigens recognized by a xenogenic antiserum.

An antiserum (R4) from a rabbit immunized with suspensions of C57BL/61 ob/ob mouse islet cells contains antibodies which in a 125I-protein A radioligand assay can be demonstrated to bind to single cell suspensions of normal Naval Medical Research Institute (NMRI) mouse islet cells. The binding of 125I-protein A to islet cells was about four times that of normal rabbit serum (NRS) after incubation at a 1/600 dilution of R4 antiserum quantitatively absorbed to mouse spleen lymphocytes (R4A antiserum) and hepatocytes. Subsequent absorption of the R4A antiserum to islet cells significantly reduced the binding of 125I-protein A to islet cells incubated with the doubly absorbed serum. Immunoprecipitation of radiolabeled islet cell lysates followed by SDS polyacrylamide gel electrophoresis and autoradiography suggested that the R4A antiserum recognized a Mr 40,000 glycoprotein. This glycoprotein was not detected in spleen lymphocytes. Electron microscope detection of gold-protein A complexes suggested that the binding of islet cell surface antibodies was cell specific. islet cell suspensions incubated with R4A antiserum and gold-protein A showed that 86 +/- 3 gold particles were bound per 100 beta-cells (mean +/- SE for six experiments). In contrast, the number of gold particles per 100 endocrine non-beta-cells was 8 +/- 1 which was similar to the number achieved with NRS (3 +/- 1) on all endocrine islet cells. Our observations suggest that the pancreatic islet cells, in particular the beta-cells, express a specific antigen.

Differential expression of surface monosialoganglioside GM1 in various hemic cell lines of normal human bone marrow. A quantitative immunocytochemical study using the cholera toxin-gold-labeled anti-cholera toxin procedure.

The cholera toxin-colloidal gold-labeled IgG-F(ab')2 anti-cholera toxin ultrastructural immunocytochemical procedure has been used for the localization of GM1 monosialogangliosides on the surface of human bone marrow cells. The number of gold particles per micron of cell surface was counted and the data subjected to statistical analysis. Cholera toxin (CT) binding characteristics assessed in several subjects showed consistent labeling patterns for the various types of marrow cells, although minor quantitative differences were noted in surface labeling densities between subjects. Surface labeling was nonuniformly distributed along the cell membrane of the marrow cells and label clusters or domains were commonly noted. Data analysis indicated that CT labeling was related to cell type, to cell lineage, and to the stage of maturation. Mature neutrophils were the most reactive of the marrow cells and the CT labeling of this cell series increased stepwise from the promyelocyte stage to the segmented neutrophil. A similar pattern occurred during eosinophil maturation and the maturation of the monocyte. A different labeling pattern was found during the differentiation of the erythrocytic cell series with low labeling of proerythroblasts increasing modestly to the early normoblast stage and then decreasing during the final phase of maturation. Exposure to neuraminidase prior to the immunocytochemical sequence induced a major increase in surface CT labeling of the various types of marrow cells, as was particularly evident for the platelet, promyelocyte, myelocyte, monocyte, promonocyte, and erythrocyte cell groups. The data indicated that the number of cryptic GM1 and/or higher gangliosides exposed by neuraminidase in the cell membrane varied during cell differentiation and was directly related to specific cell types. Exogenous GM1 also was demonstrated to be incorporated into the surface of the bone marrow cells in a differential manner and the extent of incorporation was found to be related to specific cell types and to their stage of maturation.

ChemInform Abstract: NUCLEATION IN PHOTOSENSITIVE GOLD RUBY GLASS

AbstractDie Anzahl der Au‐Partikel in einem Au‐Rubinglas wird als Funktion der Bestrahlungsdauer, der Keimbildungs‐ und Bestrahlungstemp. und der Ce‐Konzentration berechnet.

Nucleation in Photosensitive Gold Ruby Glass

The numbers of gold particles in a gold ruby glass were calculated as a function of irradiation time, nucleation and irradiation temperature, and cerium concentration. Photonucleation in Ce‐containing glasses and nucleation by X rays in glasses without cerium were similar, suggesting that cerium was not directly involved in nucleating the gold particles. The results were consistent with nucleation by trapped photoelectrons. Temperature of irradiation and cerium concentration influenced production and recombination of the trapped electrons. A decreased number of nuclei as the nucleation temperature increased probably resulted from recombination of the trapped electrons.

Distribution of wheat germ agglutinin binding sites on normal human and guinea pig bone marrow cells: an ultrastructural histochemical study.

The wheat germ agglutinin-gold labeled ovomucoid (WGA-Ovo-G) method has been employed in the ultrastructural localization of WGA surface receptor sites on gluteraldehyde-fixed normal human and guinea pig bone marrow cells. The number of gold particles per micron of cell surface were counted and data subjected to statistical analysis. WGA labeling of the bone marrow cells was found to be quite heavy and evenly distributed along the cell surface. Only macrophages, in both species, and a number of lymphocytes in the guinea pig exhibited limited WGA labeling. Comparison of morphologically similar cell types in human and guinea pig marrow indicated that WGA receptor sites were more abundant on the guinea pig hemic cells. WGA surface labeling was found to be not only related to cell type and to animal species but, in some instances, varied with the stage of maturation of a given cell line; viz., neutrophilic cell series in both man and guinea pig and erythrocytic cell series in the guinea pig.

Membrane differentiation of developing hemic cells of the bone marrow demonstrated by changes in concanavalin A surface labeling.

The concanavalin A-gold labeled horseradish peroxidase (Con A-HRP-G) method has been employed in the ultrastructural localization of Con A surface receptor sites on glutaraldehyde-fixed normal human and guinea pig bone marrow cells. The number of gold particles per micron of cell surface was counted and data subjected to statistical analysis. All cells of the bone marrow exhibited Con A binding; however, the extent of surface labeling was dependent both on cell type and stage of differentiation. Distinctive modifications in mean surface density correlated with specific periods during the maturation of the erythrocytic, neutrophilic, eosinophilic and monocytic cell series. In several instances, the differentiative changes in surface Con A labeling proved to be species dependent. These observations are discussed in relationship to methodology and to potential changes in number and/or spatial arrangement of Con A receptor sites, primarily attributable to mannosyl and/or glucosyl residues associated with membrane glycoproteins and/or glycolipids of developing neutrophilic and erythrocytic cells.