scholarly journals OBSERVATIONS ON THE FINE STRUCTURE OF LUTEIN CELLS

1962 ◽  
Vol 12 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Allen C. Enders
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Steroid Hormones ◽  
Osmium Tetroxide ◽  
Secretory Activity ◽  
Corpora Lutea ◽  
Pericapillary Space ◽  
Lutein Cell

Corpora lutea from the period of delayed implantation and from early postimplantation stages of the armadillo, mink, and rat were fixed in buffered osmium tetroxide-sucrose or potassium permanganate. After rapid dehydration, the portions of the corpora lutea were embedded in either methacrylate or epoxy resin. Examination of the lutein cells by electron microscopy revealed the presence, in the better preserved material, of an extensive development of tubular agranular endoplasmic reticulum. Although the membranes of the endoplasmic reticulum are the most striking feature of the lutein cells of both stages of the three animals examined, very numerous large mitochondria with cristae that exhibit a variety of forms tending toward villiform, and protrusions and foldings of the lutein cell margins on the pericapillary space are also characteristic of these cells. Certain minor differences in the lutein cells of the species examined are also noted. No indications of conversion of mitochondria into lipid, of accumulation of lipid in the Golgi area, or of the protrusion of lutein cells into spaces between the endothelial cells, as suggested by other authors, were noted in these preparations. Some of the difficulties inherent in the visualization of the secretory activity of cells producing steroid hormones are briefly discussed.

FINE STRUCTURE IN DETACHED, SENESCING WHEAT LEAVES

1965 ◽  
Vol 43 (6) ◽  
pp. 747-755 ◽  
Author(s):  
Michael Shaw ◽  
M. S. Manocha
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Osmium Tetroxide ◽  
Mesophyll Cells ◽  
Laboratory Bench ◽  
Detached Leaves ◽  
Petri Dishes ◽  
Wheat Leaves ◽  
Cytoplasmic Ribosomes

Detached leaves of Little Club wheat were allowed to senesce on water or on kinetin (10 mg/l.) in petri dishes on the laboratory bench. Samples taken at intervals of 24 to 48 hours for 8 to 10 days were fixed in permanganate or osmium tetroxide, embedded, usually in araldite or epon, and examined by electron microscopy. Abnormalities were noted in the endoplasmic reticulum (ER) of the mesophyll cells 2 days after the leaves were detached; ER and cytoplasmic ribosomes were not present after 4 or 5 days. Swelling of the mitochondria and degeneration of the cristae, collapse of the chloroplast grana, and abnormalities in nuclear structure were noted after 3 days. Vacuolar contraction occurred in some cells after 4 days but the plasma membrane usually remained unbroken until the seventh or eighth day, by which time the mitochondria were no longer recognizable and most of the chloroplasts and nuclei had also disintegrated.Kinetin induced an increase in the amount of ER and ribosomes and markedly delayed the degeneration of cellular fine structure.

THE ULTRASTRUCTURE OF THE HUMAN GRANULOSAL LUTEIN CELL OF THE FIRST TRIMESTER OF GESTATION

1968 ◽  
Vol 58 (3) ◽  
pp. 481-496 ◽  
Author(s):  
Poul Hjortkjær Pedersen ◽  
Jørgen Falck Larsen
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
First Trimester ◽  
Corpora Lutea ◽  
Steroid Synthesis ◽  
Intracellular Location ◽  
Human Pregnancy ◽  
Subendothelial Space ◽  
Lutein Cell ◽  
Early Human

ABSTRACT The ultrastructure of granulosal lutein cells of 13 corpora lutea in early human pregnancy was studied. The predominant cytoplasmic element was the smooth endoplasmic reticulum. No convincing signs of degeneration of the lutein cells could be demonstrated within the first 14 weeks of pregnancy, as the mitochondria as well as the rough and smooth endoplasmic reticulum were well preserved. However, lysosomes may be slightly more numerous in older specimens and the subendothelial space increases with the age of gestation. A particular type of multilaminated structure one to five micron in diameter was observed, particularly in the earliest specimens. The possible intracellular location of steroid synthesis is discussed.

scholarly journals The fine structure produced in cells by primary fixatives 2. Potassium dichromate

1965 ◽  
Vol s3-106 (73) ◽  
pp. 15-21
Author(s):  
JOHN R. BAKER
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Membrane ◽  
Osmium Tetroxide ◽  
Potassium Dichromate ◽  
Potassium Dichromate Solution ◽  
Zymogen Granules ◽  
Mouse Pancreas

The exocrine cells of the mouse pancreas were fixed in potassium dichromate solution, embedded in araldite or other suitable medium, and examined by electron microscopy. Almost every part of these cells is seriously distorted or destroyed by this fixative. The ergastoplasm is generally unrecognizable, the mitochondria and zymogen granules are seldom visible, and no sign of the plasma membrane, microvilli, or Golgi apparatus is seen. The contents of the nucleus are profoundly rearranged. It is seen to contain a large, dark, irregularly shaped, finely granular object; the evidence suggests that this consists of coagulated histone. The sole constituent of the cell that is well fixed is the inner nuclear membrane. The destructive properties of potassium dichromate are much mitigated when it is mixed in suitable proportions with osmium tetroxide or formaldehyde.

The Fine Structure of the Respiratory Tree in Cucumaria

1964 ◽  
Vol s3-105 (69) ◽  
pp. 7-11
Author(s):  
WILLIAM L. DOYLE ◽  
G. FRANCES McNIELL
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Muscle ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Secretory Activity ◽  
Muscle Fibres ◽  
Coelomic Epithelium ◽  
Free Surfaces ◽  
Respiratory Tree ◽  
Synchronous Contraction

The delicate tubules of the respiratory tree consist of 4 layers: a lining epithelium, a thick mucoid layer containing collagenous filaments, a smooth muscle net, and a coelomic epithelium. The free surfaces of both epithelia have well developed plasmodesms. Amoebocytes are present in all layers and the spherules of one type are considered to be precursors of the mucoid substance; another amoebocyte may be a fibroblast. Perpendicularly oriented smooth muscle fibres, as well as those parallel to each other, are linked by desmosomes ensuring synchronous contraction. Secretory activity is evident in distended cisternae of the endoplasmic reticulum of certain epithelial cells and in the vacuoles of the lining epithelium.

Temperature Effects on Formation and Fine Structure of Brassica napus Leaf Waxes

1976 ◽  
Vol 24 (3) ◽  
pp. 309 ◽  
Author(s):  
DJ Armstrong ◽  
MI Whitecross
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Brassica Napus ◽  
Growth Temperature ◽  
Temperature Effects ◽  
Structural Changes ◽  
Leaf Waxes ◽  
Surface Waxes ◽  
Biochemical Level

Incorporation of 1-14C-palmitic acid, a precursor of leaf waxes, into leaf strips of Brassica napus was examined by thin section autoradiography and electron microscopy. Label was found to be associated with mitochrondria, Golgi vesicles and endoplasmic reticulum of epidermal cells, and also with the outer epidermal wall across which cuticular lipids are expected to migrate. Variations in growth temperatures produced structural changes in surface waxes as previously reported but no specific correlation could be found between changes in surface fine structure and variations in subcellular morphology. It is concluded that variations in wax fine structure, as influenced by growth temperature, resulted from effects at the biochemical level.

scholarly journals THE FINE STRUCTURE OF DIFFERENTIATING SIEVE TUBE ELEMENTS

1965 ◽  
Vol 25 (1) ◽  
pp. 79-95 ◽  
Author(s):  
G. Benjamin Bouck ◽  
James Cronshaw
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Fibrous Material ◽  
Sieve Tube ◽  
Longitudinal Direction ◽  
Sieve Plate ◽  
Wall Surface ◽  
Developmental Sequences ◽  
Tubular Form

The developmental sequences leading to the formation of mature sieve tube elements were studied in pea plants by electron microscopy. From this study it has been found that the peripheral layer of cytoplasm in the mature element is composed of flattened cisternae which are apparently derived from a tubular form of endoplasmic reticulum (ER) and possibly the nuclear envelope. These flattened cisternae, designated in this report as sieve tube reticula, are attached perpendicularly to the wall surface and are oriented in a predominantly longitudinal direction. Cisternae of the sieve tube reticulum are frequently associated with the slime in mature elements, and tubular ER may be associated with slimelike material in the developing sieve tube element. During differentiation mitochondria become reduced in size and chloroplasts either fail to develop stroma and grana lamellae or lose them early in development. In agreement with other workers it is found that the sieve plate pores appear to be plugged with a finely fibrous material, presumably "slime." Nacreous wall formation is well established before reorganization of cytoplasmic components. Microtubules are prevalent during these early stages, but are lost as the element matures.

scholarly journals Crystals of Protein Nature in the Cytoplasm of Lymphatic Cells in a Case of Lymphoreticular Malignancy

Blood ◽  
1962 ◽  
Vol 20 (4) ◽  
pp. 492-500 ◽  
Author(s):  
J. C. H. DE MAN ◽  
W. B. H. MEINERS ◽  
W. Beens
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Lymphocytic Leukemia ◽  
Water Soluble ◽  
Protein Nature

Abstract The occurrence of crystals in the cytoplasm of lymphatic cells in a case of lymphoreticular malignancy—probably lymphocytic leukemia—is reported. Histochemistry revealed the protein nature of these crystals. It appeared that the protein was water-soluble, with no admixture of polysaccharides. Electron microscopy of the crystals showed a fine structure of regularly arranged thin lines with a spacing of 100 Å. The crystals were surrounded by membranes of the endoplasmic reticulum.

scholarly journals FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE

1965 ◽  
Vol 26 (2) ◽  
pp. 523-537 ◽  
Author(s):  
G. Benjamin Bouck
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Envelope ◽  
Brown Algae ◽  
Algal Cell ◽  
Plant Cells ◽  
Membrane Systems ◽  
Two Envelopes

The structural interrelationships among several membrane systems in the cells of brown algae have been examined by electron microscopy. In the brown algae the chloroplasts are surrounded by two envelopes, the outer of which in some cases is continuous with the nuclear envelope. The pyrenoid, when present, protrudes from the chloroplast, is also surrounded by the two chloroplast envelopes, and, in addition, is capped by a third dilated envelope or "pyrenoid sac." The regular apposition of the membranes around the pyrenoid contrasts with their looser appearance over the remainder of the chloroplast. The Golgi apparatus is closely associated with the nuclear envelope in all brown algae examined, but in the Fucales this association may extend to portions of the cytoplasmic endoplasmic reticulum as well. Evidence is presented for the derivation of vesicles, characteristic of those found in the formative region of the Golgi apparatus, from portions of the underlying nuclear envelope. The possibility that a structural channeling system for carbohydrate reserves and secretory precursors may be present in brown algae is considered. Other features of the brown algal cell, such as crystal-containing bodies, the variety of darkly staining vacuoles, centrioles, and mitochondria, are examined briefly, and compared with similar structures in other plant cells.

Ultrastructure of the Intestinal Absorptive Cells of Fed and Fasted Tadpoles

1970 ◽  
Vol 28 ◽  
pp. 86-87
Author(s):  
Robert Giaquinta ◽  
M. A. Hayat
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Fine Structure ◽  
Osmium Tetroxide ◽  
Rana Pipiens ◽  
Ultrastructural Changes ◽  
Amphibian Metamorphosis ◽  
Absorptive Cells ◽  
Food Absorption ◽  
Tissue Specimens

The ultrastructural changes that occur in the intestinal absorptive cells during amphibian metamorphosis have been reported (Bonneville, 1963). These changes accompany a change in diet (from an herbivorous to a carnivorous state) during metamorphosis. Little information is available, however, on the ultrastructural changes in the absorptive cells of amphibians in relation to the state of feeding. This report describes the differences in the fine structure of these cells in the tadpole stage of Rana pipiens during periods of food absorption and fasting.Rana pipiens at tadpole stages were fed an herbivorous diet, and after a period of 48 hr, the animal was dissected and segments of the small intestine were collected for electron microscopy. A second group of tadpoles was fasted for 7 days, and segments of the small intestine were collected. The tissue specimens were immersed in phosphate-buffered glutaraldehyde (3%) for 1 hr at 4C and postfixed with phosphate-buffered osmium tetroxide (2%) for 1 hr at 4C.

scholarly journals THE ACTION OF EXCESS OF VITAMIN A ALCOHOL ON THE FINE STRUCTURE OF RAT DERMAL FIBROBLASTS

1966 ◽  
Vol 30 (3) ◽  
pp. 465-475 ◽  
Author(s):  
Mary R. Daniel ◽  
J. T. Dingle ◽  
Audrey M. Glauert ◽  
J. A. Lucy
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Vitamin A ◽  
Respiratory Activity ◽  
Dermal Fibroblasts ◽  
Rapid Decline ◽  
Primary Action ◽  
Membranous Material

Rat dermal fibroblasts were grown as monolayers, and changes in the fine structure of the cells that occurred during 12 hr incubation in a medium containing protein and excess of retinol (vitamin A alcohol) were studied by electron microscopy. There is little change during the first 6 hr, although some of the nuclei have highly convoluted membranes. During the subsequent 3 hr, there is some disorganization of the mitochondrial cristae; the cisternae of the rough-surfaced endoplasmic reticulum diminish in number; and the amount of smooth membranous material and free ribosomes increases. There is a rapid decline in the respiratory activity of the cells after 6 hr exposure to the vitamin. It is concluded that the primary action of excess of retinol is to cause alterations in the membranes of the cells and that these alterations affect the functions of the mitochondria and endoplasmic reticulum.

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