Complementary replica of freeze-fractured human lymphocyte nuclei

Complementary replicas of freeze-fractured human lymphocyte nuclei were obtained, and were studied with the electron microscope. Complementarity was evident in cross-fractured nuclear pore complexes and in particle-free membrane areas. Explanations for the observed structural peculiarities are considered.     

Elektronenmikroskopische Untersuchungen an den heterophilen Granulozyten des Haushuhns

Summary Ultra-thin sections of heterophil granulocytes of clinically healthy, laying hybrid-hens were examined by electron microscope. Within the cytoplasm of these cells, round, oval or fusiform granules (rods) of different electron density were found. Osmiophilic and electron light areas (cores) were seen, either together within the same granular body, or separately in different granules.     

Developmental control of the orientation of cuticular structures inDrosophila

Summary A scanning electron microscope study of bristle mutations inDrosophila melanogaster has shown that the cell hairs (trichomes) can be altered in predictable ways. The trichomes appear to act as markers of a diffusion gradient dttermining the orientation of cuticular structures in the thorax.We are grateful to W.F. Chissoe and M.R. Whitmore for theil help with the electron microscopy.This work was supported by DHEW-NIGMS grant GM2480901.     

A light and electron microscope study of spherical structures in the test cells of an ascidianCiona intestinalis L.

Summary Spherical structures in the test cells that surround the embryos of the ascidianCiona intestinalis L. (Tunicata, phylum Chordata) were studied by both light and electron microscope. Our data support the view that these structures are microorganism-like cells living in symbiosis with the test cells. Their possible role is discussed.Acknowledgment. The authors are indebted to the Institute of Comparative Anatomy of Palermo for the use of the Zeiss EM 9 Electron Microscope. Particular thanks to Mr Salvatore Bucculeri for his technical assistance.     

Comparative studies on the covalent binding of the carcinogen benzo(a)pyrene to DNA in various model systems

Summary The covalent binding of tritiated benzo(a) pyrene (BP) to DNA has been determined in rat liver in vivo, in rat liver perfused in situ, after incubation of BP with liver single cells, with liver homogenate, with liver microsomes and DNA, with fibroblasts from a rat granuloma pouch, and with 2 cell lines. Liver single cells were found to be a valuable compromise between the most sensitive system (microsomal incubation of BP with DNA) and the biologically most relevant system (in vivo).Presented in part at the 10th Annual Meeting of the Union of Swiss Societies of Experimental Biology, Experientia34, 925 (1978), abstract.Acknowledgment. We thank Dr G. Kistler, Institute of Anatomy, University of Zurich, for generously supplying the SIRC and VERO cell lines, and Mr P. Manser for the preparation of the granuloma pouch fibroblasts.     

Genetic and histological aspects of stomach lesions induced by systemic injection of phenylbutazone in the rat

Summary Roman high-avoidance (RHA/Verh) rats, food-deprived (F-D) for 5 days, had higher stomach lesion scores than did F-D Roman low-avoidance (RLA/Verh) rats. F-D RLA/Verh rats which were injected i.p. with phenylbutazone (PBZ) 24 h before examination, however, had higher scores than did PBZ-treated, F-D RHA/-Verh rats. Histologically, extensive edema and cellular infiltration (including numerous erythrocytes) were seen below lesions, in the submucosa, denoting vascular damage. An attenuating influence of food on the ulcerogenic effects of PBZ, which were much more severe in F-D than in fed rats was also indicated.The authors thank K. Bättig and J. R. Martin for their assistance during the planning stages, B. Hauser, A. Waldvogel and P. Wild of the Veterinary Medical Faculty of Zurich University for preparing the histological sections and for the photography, and P. Elsinger for technical help.     

Impact of thickness of GaN buffer layer on properties of AlN/GaN distributed Bragg reflectors grown by metalorganic chemical vapor deposition

We studied the impact of the thickness of GaN buffer layer on the properties of distributed Bragg reflector (DBR) grown by metalorganic chemical vapor deposition (MOCVD). The samples were characterized by using metallographic microscope, transmission electron microscope (TEM), atomic force microscopy (AFM), X-ray diffractometer (XRD) and spectrophoto- meter. The results show that the thickness of the GaN buffer layer can significantly affect the properties of the DBR structure and there is an optimal thickn...     

Presence of giant mitochondria during cerebellar ontogenesis in reptiles

Summary Giant mitochondria were observed in the perikarya and dendrites of Purkinje cells in the developing cerebellar cortex of the lizardGallotia galloti at sevral stages previous to hatching. Such mitochondria are absent from the adult cerebellum.4 December 1986The authors would like to thank Prof. L. Puelles (Murcia University) for his critical assistance and the Edafology Department of La Laguna University for facilities offered, specially for the use of the electron microscope. This work has been pertially suported by a CAICYT research grant No. 909-2.     

Electron-microscopic mapping of the hinge region of myosin

Summary The trypsin-sensitive sites in the labile hinge region of the myosin molecule are located with heightened accuracy (±2 nm) by electron microscopy as lying at 70, 85, 95, and 103 nm from the C-terminus of the rod section of the molecule.I thank Dr.Michael Young for valuable advice and encouragement, Drs.Jerome Gross andRomaine R. Bruns for use of their electron microscope, and Mrs.Muriel H. Blanchard for excellent technical assistance. This work was supported by the American Heart Association, The John A. Hartford Foundation, Inc., and the National Institutes of Health.     

Dermatologically active sesquiterpene lactones in trichomes ofParthenium hysterophorus L. (Compositae)

Summary Scanning electron microscopy of the leaf surface, phyllaries and achene-complex ofParthenium hysterophorus L. showed the presence of 4 types of glandular and non-glandular trichomes. Chemical analysis established the presence of sesquiterpene lactones in the trichomes that cause eczematous dermatitis.Acknowledgments. We thank Dr.Garry Cole, University of Texas, for the use of the AMR-1000 Scanning electron microscope andJudy Stevenson for technical assistance. The work at the University of Texas was supported by the National Science Foundation (Grant No. BMS 71-01088) and the Robert A. Welch Foundation (Grant No. F-130).     

The electron microscopy of fluorescent dextrans (FITC-dextrans) in thin sections of tissue

Summary Fluorescein-coupled dextrans (FITC-Ds) were detected in sections in the electron microscope using 4 different contrasting methods when tissue was postfixed in osmium tetroxide. Endogeneous glycogen was also stained by the methods used, but FITC-D particles appeared smaller and more irregular, and in other locations. In dextranase treated specimens glycogen was still visible, while FITC-D was not.Acknowledgments. The author is grateful to Susan Max-Jacobsen, Kjeld Stub and Sonja Fich for excellent technical assistance. The author was supported by a research fellowship from the Danish Medical Research Council (12–1688).     

The localization of [3H]-desipramine in central nerve terminals studied with electron microscope autoradiography and subcellular fractionation

Summary The cellular and subcellular distribution of [³H]-desipramine (DMI) in rat brain was studied by electron microscope (EM) autoradiography and by subcellular fractionation. A considerable proportion of label was found to be bound to the membranes of presynaptic nerve terminals, as well as to sites inside those terminals.Acknowledgment. The authors are most grateful to Mr and Mrs Gudelsky for their generous support.     

Mouse sex vesicle. C-band and pairing at the light and electron microscope

Summary C banded mouse pachytene chromosomes were studied with the light and electron microscopes by the whole mount technique. The X and Y chromosomes show pairing by the long, by the short or by both long and short arms. Assuming Lyon's hypothesis, the latter suggests that the Y segment transferred to the X is intercalar. With the light microscope, a negative image of the synaptonemal complex is evidenced.This work was supported by grants of the Brazilian Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundo Especial de Despesas do Instituto Butantan (FEDIB).We acknowledge Dr. N. Leon for his editorial suggestions.     

Elektronenmikroskopische Untersuchungen an Bianconekalken des Südtessins

Summary The Biancone limestone (Uppermost Jurassic-? Barremian) from southern Ticino, and the small organisms (Nannoconi incertae sedis) of which it mainly consists, have been examined in the electron microscope.The applied technique of preparing the limestone for investigation is described.Furthermore, a few remarks are made concerning the stratigraphic value of Nannoconus.

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Die Arbeit wurde unterstützt durch den Schweizerischen Nationalfonds.     

Sodium and calcium action potentials in human anterior pituitary cells

Summary Human anterior pituitary cells derived from a somatotropin-secreting adenoma were capable of generating action potentials with Ca²⁺ and tetrodotoxin-sensitive Na⁺ components. A major fraction of the action current was carried by Na ions.We wish to thank Dr O. Sand for correcting the English and Miss Michiko Takano for technical assistance. We also acknowledge the collaboration of Dr S. Miyazaki in the electron microscope.     

Characterization of polyphenol-containing dense cells

Summary Dense cells ofRubus chamaemorus L. (cloudberry) root meristems have been characterized by histochemical staining reactions at light and electron microscope levels. Presence of polyphenolic compounds in the cellular matrix contribute to the density of the dense cells.This research was supported by an operating grant from Agriculture Canada.     

Association of intermediate filaments with other cell organelles in carcinoid tumor of the colon

Summary Carcinoid tumor of the colon was studied in electron microscope. In cytoplasm, prominent intermediate-sized filaments were seen frequently attaching to nucleus and mitochondria. Direct contacts of intermediate filaments with secretory granules were not observed.Acknowledgments. The skilful technical assistance of Ms Tuire Koro is gratefully acknowledged. — This study was supported by grants from the Finnish Medical Research Council, Finnish Culture Foundation and J.K. Paasikivi Foundation for Cancer Research.     

Changes of profiles of neutrophil granulocytes induced with the administration of L-DOPA and prednisolone

Summary Morphological changes of granulocytes following combined treatment with L-DOPA and prednisolone were elucidated at the electron microscopic level. Neutrophil granulcytes exhibited marked changes in their surface as evidenced by scanning electron microscope It is suggested that neutrophil granulocytes are sensitive to some biogenic amines.     

Changes of profiles of neutrophil granulocytes induced with the administration of L-DOPA and prednisolone

Morphological changes of granulocytes following combined treatment with L-DOPA and prednisolone were elucidated at the electron microscopic level. Neutrophil granulocytes exhibited marked changes in their surface as evidenced by scanning electron microscope. It is suggested that neutrophil granulocytes are sensitive to some biogenic amines.